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  • 1.
    Adamopoulos, Stergios
    et al.
    Technological Educational Institute of Thessaly, Greece.
    Hosseinpourpia, Reza
    Georg-August-University Göttingen, Germany.
    Mai, Carsten
    Georg-August-University Göttingen, Germany.
    Tensile strength of handsheets prepared with macerated fibres from solid wood modified with cross-linking agents2015In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 69, no 8, p. 959-966Article in journal (Refereed)
    Abstract [en]

    This study was conducted to explain the tensile strength loss of wood due to the modification with 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU) and glutaraldehyde (GA). Modified and control wood blocks were macerated to deliberate fibres, and handsheets were produced thereof. The nitrogen content of the fibres indicated that maceration removed the major proportions of DMDHEU. The stability of GA in wood during maceration was not assessed. Tensile strength determined at zero span (z-strength) and finite span (f-strength) was equal for the handsheets from DMDHEU-modified fibres and the control handsheets. The microscopic appearance of the tested finite-span paper strips from DMDHEU-modified fibres mainly indicated interfibre failure and did not differ from the fibre fracture mode of the control handsheets. In contrast, the z-strength of the handsheets from GA-modified fibres was lower than that of controls and decreased with increasing content of GA in the initial modified wood. The f-strength behaviour of the handsheets from GA-modified fibres was the opposite: it was higher than that of controls and increased with increasing GA content. The microscopic appearance of the rapture zones of the finite-span testing mainly indicated intrafibre failure for the GA-modified fibres. It was concluded that cross-linking is likely to be the major reason for tensile strength loss of GA- and DMDHEU-modified wood. In terms of DMDHEU-modified wood, the incrustation of the cell wall by the resin and the reduction in pliability could play an additional role.

  • 2.
    Ahmed, Sheikh Ali
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Michigan Technological University, USA.
    Adamopoulos, Stergios
    Swedish University of Agricultural Sciences, Sweden.
    Micro-Fibrillated Cellulose in Lignin–Phenol–Formaldehyde Adhesives for Plywood Production2023In: Forests, ISSN 1999-4907, E-ISSN 1999-4907, Vol. 14, no 11, article id 2249Article in journal (Refereed)
    Abstract [en]

    Petrochemical-based phenol–formaldehyde (PF) adhesives are widely used in plywood production. To substitute phenol in the synthesis of PF adhesives, lignin can be added due to its structural similarity to phenol. Moreover, micro-fibrillated cellulose (MFC) can further enhance the bond performance, mechanical properties, and toughness of adhesive systems. Thus, the aim of this study was to evaluate the adhesion performance of lignin–PF (LPF) adhesives reinforced with MFC. In LPF formulations, three levels of MFC (0, 15, and 30 wt% based on the total solid content of adhesives) were added to the homogenous adhesive mixture. Three-layer plywood panels from birch (Betula pendula Roth.) veneers were assembled after hot pressing at 130 °C under two pressing durations, e.g., 60 and 75 s/mm. Tensile shear strength was measured at dry (20 °C and 65% RH) and wet conditions (water soaked at room temperature for 24 h). The results indicated that the addition of lignin reduced the strength of LPF adhesives in both dry and wet conditions compared to the control PF adhesive. However, MFC reinforcement enhanced the shear strength properties of the plywood. Furthermore, a longer pressing time of 75 s/mm slightly increased the shear strength.

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  • 3.
    Ahmed, Sheikh Ali
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials. Linnaeus University, The University Administration.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials. Linnaeus University, Linnaeus Knowledge Environments, Green Sustainable Development.
    Brischke, Christian
    University of Goettingen, Germany.
    Adamopoulos, Stergios
    Swedish University of Agricultural Sciences, Sweden.
    Anatomical, Physical, Chemical, and Biological Durability Properties of Two Rattan Species of Different Diameter Classes2022In: Forests, ISSN 1999-4907, E-ISSN 1999-4907, Vol. 13, no 1, article id 132Article in journal (Refereed)
    Abstract [en]

    Rattan cane is an important forest product with economic value. Its anatomical, physical, and biological properties vary with the cane height. This makes it difficult to select the appropriate cane diameter for harvesting. Understanding the material properties of rattan cane with different diameter sizes is important to enhance its utilization and performance for different end uses. Thus, the present study was performed on two rattan species, Calamus zollingeri and Calamus ornatus, at two different cane heights (bottom/mature and top/juvenile). Calamus zollingeri was studied at diameter classes of 20 mm and 30 mm, while Calamus ornatus was analyzed at a diameter class of 15 mm. The anatomical properties, basic density, volumetric swelling, dynamic moisture sorption, and biological durability of rattan samples were studied. The results showed that C. zollingeri with a 20 mm diameter exhibited the highest basic density, hydrophobicity, dimensional stability, and durability against mold and white-rot (Trametes versicolor) fungi. As confirmed by anatomical studies, this could be due to the higher vascular bundle frequency and longer thick-walled fibers that led to a denser structure than in the other categories. In addition, the lignin content might have a positive effect on the mass loss of different rattan canes caused by white-rot decay.

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  • 4.
    Altgen, Michael
    et al.
    Aalto Univ, Finland.
    Willems, Wim
    FirmoLin Technol BV, Netherlands.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Rautkari, Lauri
    Aalto Univ, Finland.
    Hydroxyl accessibility and dimensional changes of Scots pine sapwood affected by alterations in the cell wall ultrastructure during heattreatment2018In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 152, p. 244-252Article in journal (Refereed)
    Abstract [en]

    There is a complex link between the water sorption behavior and the presence of accessible hydroxyl groups in the wood cell wall, which can be altered by heat-treatment (HT). This study analyses the effect of changes in the cell wall ultrastructure caused by two HT techniques on the hydroxyl accessibility, water vapor sorption and dimensional changes of Scots pine (Pinus sylvestris L.) sapwood. HT of wood in pressurized hot water at 120-170 °C was applied to cause the preferential bond cleavage, whereas HT of wood in oven-dry state in superheated steam at 180-240 °C was performed to create additional covalent cross-links within the cell wall matrix. Removal of cell wall polymers by HT and water leaching reduced the oven-dry dimensions of wood and enhanced the cellulose aggregation during drying. Cellulose aggregation restricted the cell wall shrinkage in circumferential direction, resulting in inhomogeneous shrinkage of the cell wall with only little changes in lumen volume by HT. Cellulose aggregation also reduced the water-saturated dimensions, but a decrease in swelling was only achieved when additional cross-links were formed by HT in dry state. Additional cross-links in the cell wall matrix also resulted in an additional reduction in water sorption at 25 °C and 93% RH. However, this was not caused by a further reduction in the hydroxyl accessibility. Instead, cross-linking was shown to reduce the amount of accessible OH groups that are simultaneously active in sorption, which was explained based on the concept of sorption of water dimers at hydroxyl group pairs at high RH levels.

  • 5.
    Anuar Bahari, Shahril
    et al.
    Universiti Teknologi MARA (UiTM), Malaysia.
    Nazarudin Zakaria, Mohd
    Universiti Teknologi MARA (UiTM), Malaysia.
    Osman, Syaiful
    Universiti Teknologi MARA (UiTM), Malaysia.
    Abu, Falah
    Universiti Teknologi MARA (UiTM), Malaysia.
    Jani Saad, Mohamad
    Malaysian Agricultural Research and Development Institute (MARDI), Malaysia.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials. Linnaeus University, Linnaeus Knowledge Environments, Green Sustainable Development.
    Strength Performance and Microstructure Characteristic of Naturally-Bonded Fiberboard Composite from Malaysian Bamboo (Bambusa vulgaris)2022In: Journal of Renewable Materials, ISSN 2164-6325, E-ISSN 2164-6341, Vol. 10, no 10, p. 2581-2591Article in journal (Refereed)
    Abstract [en]

    This study investigated the mechanical properties and microstructural characteristics of fiberboard composite produced by naturally-bonded Malaysian bamboo fiber (Bambusa vulgaris). The components that obtained through soda pulping of bamboo culms such as fiber and black liquor, were used for the preparation of high-density fibreboard composite at two target densities of 850 and 950 kg/m3. The bamboo fiberboard composite (BFC) were then produced at 200°C and two pressing parameters of 125 and 175 s/mm. The mechanical properties, e.g., flexural strength and internal bonding (IB) of BFC samples were evaluated according to BS EN 310: 1993 and BS EN 319: 1993, respectively. It was found that the mechanical performance of the composite with 850 kg/m3 density was significantly higher than 950 kg/m3 ones, especially for the samples with 125 s/mm pressing parameter. Microstructure characteristic of the BFC samples illustrated that the fiber linkages were cracked in the composites with higher density, e.g., the composite with the density of 950 kg/m3 and also black liquor were slightly degraded at longer pressing time, which led to the reduction in mechanical properties, especially in IB strength.

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  • 6. Balea, A
    et al.
    Blanco, A
    Fuente, H
    Concepción, M
    Negro, C
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Hosseinpourpia, Reza
    Mai, C
    Tubek-Lindblom, A
    Hansen, P
    Morphology, properties and recyclability of modified fibres and papers with different chemicals at laboratory and pilot plant trials2015In: 46th Congresso Annuale Aticelca, May 28-29, Sestri Levante-Genova, Italy, Aticelca , 2015, p. 23-31Conference paper (Refereed)
    Abstract [en]

    Fibre+ (2012-2015) is a European project aiming to develop potential treatments for recovered fibre modification capable of improving the recyclability and the properties of recycled papers. This study reports on the results on fibre morphology, paper properties and recyclability of fibres and papers modified with different chemicals and approaches from both laboratory and pilot plant trials. Sixteen modification chemical agents were studied in a set of laboratory trials. The raw material used was 100% recycled paper grade from old corrugated board containers (OCC). The laboratory analysis to evaluate the effectiveness of fibre modifications treatments included FBRM for pre-screening of chemicals, preparation of laboratory control and modified handsheets to a target grammage of 80 g/m2, and measurement of the fibre morphology, recyclability and mechanical and physical properties of the modified handsheets. Based on the results of laboratory testing, Fibre+ modifications pilot plant trials were carried out at a FEX paper machine. Furthermore the effect of the better dispersion of the cPAM using an ECOWIRL was studied. The overall laboratory and pilot plant results were promising for further implementation of the Fibre+ modifications at industrial scale and projection of improvements of fibre and paper properties on the performance of packaging products thereof

  • 7. Bari, Ehsan
    et al.
    Ghorbanian Far, Mohammad
    Moradi, N
    Morrell, Jefry J
    Daniel, Geoffrey
    Mohebby, Behbod
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Humar, M
    Failure characteristics of thermally modified poplar wood subjected to mechanical tests2023In: IRG documents database and compendium, International Research Group of Wood Protection , 2023, article id 23-40983Conference paper (Refereed)
    Abstract [en]

    Poplar (Populus spp.) are among the fastest growing timber species and have been widely planted for use in plywood, composites, pallets, furniture components and paper production. However, the low density of the wood limits many structural applications and the wood has little resistance to biodegradation. Thermal modification represents one approach to improving durability by changing the moisture behavior of the wood, but it can also have adverse effects on structural performance. Understanding the potential effects of thermal treatment on poplar properties can help define the most appropriate applications for these materials. Poplar timbers from Iran were subjected to 30 or 60 min of thermal treatment at temperatures ranging from 110 to 220 °C. Samples were then evaluated for mass loss during treatment, changes in flexural properties, e.g., modulus of elasticity (MOE) and modulus of rupture (MOR), the degree of polymerization, and water absorption characteristics. MOR of controls subjected to 100 °C were similar to those exposed to 160 °C, while MOE was more variable with a slight upward trend for samples exposed to a given heating regime for only 30 min. The increases in MOE may be related to changes in cellulose crystallinity. Mass losses increased with increasing temperature exposure while moisture absorption decreased as expected with longer thermal exposure. The degree of polymerization remained similar for samples exposed up to 170 °C and then increased at higher temperatures. The increases may reflect the complete destruction of shorter chain polymers, leaving only the heat-resistant longer chain polymers. The results suggest that poplar can be thermally modified within limited parameters to improve some performance attributes without adversely affecting its structural capacity.

  • 8.
    Cristina, Simón
    et al.
    Technical University of Madrid, Spain.
    Francisco, García Fernández
    Technical University of Madrid, Spain.
    Luis, García Esteban
    Technical University of Madrid, Spain.
    Paloma, de Palacios
    Technical University of Madrid, Spain.
    Hosseinpourpia, Reza
    University of Göttingen, Germany.
    Carsten, Mai
    University of Göttingen, Germany.
    Comparison of the saturated salt and dynamic vapor sorption methods in obtaining the sorption properties of Pinus pinea L.2017In: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 75, no 6, p. 919-926Article in journal (Refereed)
    Abstract [en]

    Several methods are available for obtaining the sorption isotherms of wood. Among these, the saturated salt and dynamic vapor sorption methods are the most frequently used  ones. For the first time, the hygroscopic response of wood obtained using these two methods is compared. This is done by determining the 35 and 50°C adsorption isotherms of juvenile and mature wood of Pinus pinea L. The hygroscopic behavior of the two types of wood is different, as the mature wood has a higher moisture content than the juvenile wood in the isotherms studied. Comparison of the static saturated salt method and dynamic vapor sorption shows few significant differences between the equilibrium moisture content obtained by each method during the adsorption process, both in a point by point comparison and in the comparison of quadratic polynomial forms of the Guggenheim Anderson-de Boer model. Moreover, in both methods the point of relative humidity from which multilayer sorption predominates over monolayer sorption is similar.

  • 9.
    Danesh, Mohammad Amin
    et al.
    Islamic Azad University, Iran.
    Ziaei Tabari, Hassan
    Islamic Azad University, Iran.
    Hosseinpourpia, Reza
    Georg-August University, Germany.
    Nazarnezhad, Noradin
    Sari Agricultural Science and Natural Resources University, Iran.
    Shams, Morteza
    Islamic Azad University, Iran.
    Investigation of the morphological and thermal properties of waste newsprint/recycled polypropylene/nanoclay composite2012In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 7, no 1, p. 936-945Article in journal (Refereed)
    Abstract [en]

    The main objective of this research was to study the potential of waste polypropylene and waste newsprint fiber for making wood-plastic nanocomposites. We used 30 wt.% waste newsprint fiber and 10 wt.% compatilizer in this study. Nanoclay was used at two levels: 2.5 and 5% by wt. Materials were mixed with either recycled or virgin polypropylene. The effects of nanoclay (NC) on the mechanical and thermal properties were also studied. The improvements in tensile properties of the blended composites with the addition of NC were further supported by Scanning Electron Microscope (SEM) micrographs and X-Ray Diffraction (XRD) data. Thermal degradation behavior of the composites showed that the degradation temperatures shifted to higher values after addition of nanoclay. The XRD data showed that the relative intercalation of composites with 2.5% nanoclay was higher than 5% nanoclay. The experimental results demonstrated that the waste materials could be used as appropriate alternative raw materials for making low cost wood-plastic composites (WPCs).

  • 10.
    Esteban, Luis García
    et al.
    Ciudad Universitaria, Spain.
    Simón, Cristina
    Ciudad Universitaria, Spain.
    Fernández, Francisco García
    Ciudad Universitaria, Spain.
    Palacios, Paloma de
    Ciudad Universitaria, Spain.
    Martín-Sampedro, Raquel
    Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Spain.
    Eugenio, María Eugenia
    Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Spain.
    Hosseinpourpia, Reza
    Georg August University, Germany.
    Juvenile and mature wood of Abies pinsapoBoissie: sorption and thermodynamic properties2015In: Wood Science and Technology, ISSN 0043-7719, E-ISSN 1432-5225, Vol. 49, no 4, p. 725-738Article in journal (Refereed)
    Abstract [en]

    For industrial processes, it is important to study the hygroscopicity and thermodynamic properties of juvenile and mature wood. Samples of Abies pinsapo Boiss. collected in the natural areas of the species in Spain were used to study these properties in both types of wood. The equilibrium moisture contents were obtained, and the 15, 35 and 50 °C isotherms were plotted following the Guggenheim–Anderson–Boer–Dent model. The thermodynamic parameters were calculated using the integration method of the Clausius–Clapeyron equation. Chemical analyses, infrared spectra and X-ray diffractograms were applied to assess chemical modifications and possible changes in the cell wall structure. The chemical composition of the mature wood shows a decrease in the lignin and hemicelluloses content and an increase in the extracts and α-cellulose. The sorption isotherms for the three temperatures studied are higher in the mature wood than in the juvenile wood. Causes of this include the higher content of α-cellulose, the higher crystallinity index and the shorter crystallite length in the mature wood. No difference was found between the juvenile and mature wood in relation to the point of inflexion where the multilayer starts to predominate over the monolayer (approximately 30 %). In terms of the thermodynamic properties, the heat involved is greater in desorption than in adsorption, and more heat is involved in the mature wood than in the juvenile wood.

  • 11.
    García-Iruela, Alberto
    et al.
    Universidad Politécnica de Madrid, Spain.
    García Esteban, Luis
    Universidad Politécnica de Madrid, Spain.
    Garcia Fernández, Francisco
    Universidad Politécnica de Madrid, Spain.
    De Palacios, Paloma
    Universidad Politécnica de Madrid, Spain.
    Rodriguez-Navarro, Alejandro B
    Universidad de Granada, Spain.
    Gil Sánchez, Luis
    Universidad Politécnica de Madrid, Spain.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Effect of Degradation on Wood Hygroscopicity: The Case of a 400-Year-Old Coffin2020In: Forests, ISSN 1999-4907, E-ISSN 1999-4907, Vol. 11, no 7, p. 1-15, article id 712Article in journal (Refereed)
    Abstract [en]

    The hygroscopicity and thermodynamic properties of Pinus sylvestris L. wood from a coffin allegedly holding the remains of famous Spanish author Miguel de Cervantes Saavedra (1547–1616) were studied using the 15 °C and 35 °C isotherms fitted to the Guggenheim–Anderson–de Boer model and comparing them with the isotherms of recently felled wood of the same species. In addition, using infrared spectroscopy (FTIR-ATR) and X-ray diffractograms, the functional groups were determined and the crystallinity and organization of the cell wall components were analyzed. The absence of the 1740 cm−1 group indicates hemicellulose degradation in the archaeological wood, and the X-ray diffractograms show a considerable decrease in cellulose crystallinity and disorganization of the cellulose crystallites. The greater availability of active –OH groups means that the archaeological wood isotherms are above the juvenile and mature wood isotherms, and therefore the thermodynamic balance in the sorption of the archaeological wood is greater.

  • 12.
    Ghavidel, Amir
    et al.
    University of Iasi, Romania.
    Bak, Miklós
    University of Sopron, Hungary.
    Hofmann, Tamás
    University of Sopron, Hungary.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials. Linnaeus University, Linnaeus Knowledge Environments, Green Sustainable Development.
    Vasilache, Viorica
    University of Iasi, Romania.
    Sandu, Ion
    Academy of Romanian Scientists (AOSR), Romania;Romanian Inventors Forum, Romania.
    Comparison of chemical compositions in wood and bark of Persian silk tree (Albizia julibrissin Durazz)2022In: Wood Material Science & Engineering, ISSN 1748-0272, E-ISSN 1748-0280, Vol. 17, no 6, p. 759-770Article in journal (Refereed)
    Abstract [en]

    This research was conducted to identify and compare the chemical compositions in Persian silk tree(Albizia julibrissin Durazz.) from different parts of wood and bark, using Fourier Transform Infrared(FTIR) Spectroscopy, gas and liquid chromatography coupled to mass spectrometry (GC-MS, LCMS),and elemental analysis. FTIR analysis showed significant differences in the chemical structureof bark and wood at peaks that belong to the cellulose and hemicelluloses. According to theresults, the C-O-C asymmetric stretch vibration in cellulose and hemicelluloses peak of Persian silktree was lower in the bark and ѵC=O in quinone or p-quinone peak was higher in the bark. Theresults of GC-MS showed 12 chemical constituents in the bark and 43 in the wood, respectively.Among these, hexadecanoic acid and inositol were in common. According to the LC-MS analyses,bark samples were rich in lignan compositions and triterpenoid saponins, whereas wood was poorin these compositions. Altogether 61 compositions have been tentatively identified and describedfrom bark and wood tissues; many of them were identified for the first time. Energy-dispersive Xray(EDX) spectrometry illustrated that the bark contained iron and aluminium, sodium,phosphorus, sulphur and chlorine, while these elements did not exist in wood.

  • 13.
    Ghavidel, Amir
    et al.
    Alexandru Ioan Cuza University, Romania.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Chemical composition of recent and naturally-aged european spruce (Picea abies) and silver fir (Abies alba) woods2020In: Proceedings of the 16th Annual Meeting of the Northern European Network for Wood Science and Engineering – WSE2020 / [ed] Marketta Sipi;Juha Rikala, University of Helsinki, Finland , 2020, p. 29-31Conference paper (Refereed)
  • 14.
    Ghavidel, Amir
    et al.
    Alexandru Ioan Cuza University of Iasi, Romania.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Gelbrich, Jana
    Leibniz-IWT-Institute for Materials Testing, Germany.
    Bak, Miklós
    University of Sopron, Hungary.
    Sandu, Ion
    Alexandru Ioan Cuza University of Iasi, Romania;Academy of Romanian Scientists (AOSR), Romania;Romanian Inventors Forum, Romania.
    Microstructural and Chemical Characteristics of Archaeological White Elm (Ulmus laevis P.) and Poplar (Populus spp.)2021In: Applied Sciences: APPS, E-ISSN 1454-5101, Vol. 11, no 21, article id 10271Article in journal (Refereed)
    Abstract [en]

    The degradation states of archaeological white elm, with an age estimation of ~350 years, and poplar, with an age approximation of ~1000–1200 years, were studied by means of different chemical and microscopy analyses. Recently cut samples from the respective species were used for comparison reasons. The chemical composition analysis of the archaeological samples showed significantly low holocellulose values, while the lignin, extractive, and ash contents were considerably high, as compared with the recently cut samples. The Fourier-transform infrared (FTIR) spectroscopy also confirmed the changes in the chemical structure of the archaeological elm and poplar samples. The light and scanning electron microscopies illustrated that the erosion bacteria were the main degrading agent in both archaeological elm and poplar, although the hyphae of rot fungi were detected inside the vessel elements of the archaeological poplar sample.

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  • 15.
    Ghavidel, Amir
    et al.
    University of Iasi, Romania.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Militz, Holger
    University of Göttingen, Germany.
    Vasilache, Viorica
    University of Iasi, Romania.
    Sandu, Ion
    Academy of Romanian Scientists (AOSR), Romania;Romanian Inventors Forum, Romania.
    Characterization of Archaeological European White Elm (Ulmus laevis P.) and Black Poplar(Populus nigra L.)2020In: Forests, ISSN 1999-4907, E-ISSN 1999-4907, Vol. 11, no 12, p. 1-13, article id 1329Article in journal (Refereed)
    Abstract [en]

    The present study aims at characterization of freshly-cut and archaeological European white elm and poplar. The archaeological elm sample was buried at a depth of 8–10 m inside of soil with age approximation of ~1800–2000 years old, and the archaeological poplar sample was apart of a boat in a freshwater lake or river with age estimation of ~1000–1200 years. Alteration in the chemical structure of the elm and poplar samples due to the ageing process were confirmed by X-ray photoelectron spectroscopy (XPS). Both archaeological wood (AW) samples illustrated considerably lower cellulose crystallinity than the fresh samples as determined by X-ray diffraction. The sorption behavior of AW and fresh wood (FW) samples were evaluated by means of dynamic vapor sorption (DVS) analysis. Results exhibited a higher equilibrium moisture content (EMC) and sorption hysteresis values in archaeological elm and poplar as compared with the fresh samples. Higher hydrophilicity of the AW samples than the FW ones is attributed to their higher amorphous structure. The extensive degradation of AW samples were also confirmed by scanning electron microscopy (SEM) micrographs.

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  • 16.
    Ghavidel, Amir
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Jorbandian, Amin
    University of Tehran, Iran.
    Bak, Miklós
    University of Sopron, Hungary.
    Gelbrich, Jana
    Leibniz-IWT, Germany.
    Morrell, Jeffrey J.
    University of the Sunshine Coast, Australia.
    Sandu, Ion
    Academy of Romanian Scientists (AOSR), Romania;Romanian Inventors Forum, Romania.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials. Linnaeus University, Linnaeus Knowledge Environments, Green Sustainable Development. Michigan Technological University , USA.
    Degradation assessment of archaeological oak (Quercus spp.) buried under oxygen-limited condition2023In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 77, no 3, p. 198-207Article in journal (Refereed)
    Abstract [en]

    The biological deterioration of archaeological wood under oxygen-limited conditions varies due to the limited activities of microorganisms. It is essential to expand the knowledge of the degradation types and the status of archaeological monuments for selecting the proper consolidates. The physical, chemical, and anatomical properties of approximately 600–650 year old archaeological oak collected from an archaeological site in Iasi-Romania were analysed to assess the quality and to identify the degradation types. The results were compared with similar tests on recently-cut oak. X-ray photoelectron spectroscopy (XPS) revealed the presence of more lignin-related peaks in the archaeological oak, which likely reflected the degradation of the wood carbohydrates as evidenced by the decreased oxygen-to-carbon ratio Cox/Cnon-ox. The differences in cellulose crystallinity were not significant suggesting that any cellulose degradation occurred in the amorphous regions. This was also reflected in the dynamic water vapor sorption analysis where the differences in sorption isotherms and hysteresis of archaeological and recently-cut oaks were marginal. Microscopic analysis of the oak cells illustrated bacterial degradation patterns, while the field emission scanning electron microscopy (FESEM) showed the presence of erosion bacteria in the archaeological oak collected from the site with low oxygen conditions.

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  • 17.
    Gholamiyan, Hadi
    et al.
    University of Tehran, Iran.
    Ashouri, Javad
    Shahid Rajaee Teacher Training University, Iran.
    Ahmadi, Peyman
    University of Tehran, Iran.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials. Linnaeus University, Linnaeus Knowledge Environments, Green Sustainable Development. Michigan Technological University, USA.
    Surface Wettability and Coating Performance of Plasma-Treated Wood-Based Composite Panels2022In: Coatings, ISSN 2079-6412, Vol. 12, no 12, article id 1894Article in journal (Refereed)
    Abstract [en]

    The effect of dielectric barrier discharge (DBD) plasma treatment was studied on the surface characteristics and coating performance of transparent epoxy resin on the surface of particleboard (PB) and medium-density fiberboard (MDF). The plasma treatment was performed at three plasma energies (10, 15, and 20 kW) and three distances from the nozzle (10, 20, and 30 mm). Analyzing the samples by Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) indicated the changes of their chemical structure by means of the plasma treatment. The contact angle study showed a significant increase in surface wettability after plasma treatment with a pronounced effect observed by treatment parameters. The surface roughness was also significantly increased by the plasma treatment. The strength of the coating adhesion to the surface of the PB and MDF composite panels was also significantly improved by the plasma treatment, while no obvious trend was observed by treatment parameters. The highest adhesion strength of 2.03 MPa and 3.63 MPa were obtained by the PB and MDF samples, respectively, treated at a 10 mm nozzle distance and 15 kW plasma energy. The scratch resistance of the epoxy coatings showed a similar trend as the adhesion strength illustrating an inferior isolated surface of the coating after the plasma treatment.

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  • 18.
    Gholamiyan, Hadi
    et al.
    University of Tehran, Iran.
    Gholampoor, Behnam
    University of Tehran, Iran.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials. Linnaeus University, Linnaeus Knowledge Environments, Green Sustainable Development.
    Application of Waterborne Acrylic and Solvent-Borne Polyester Coatings on Plasma-Treated Fir (Abies alba M.) Wood2022In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 15, no 1, article id 370Article in journal (Refereed)
    Abstract [en]

    This research investigates the effect of plasma treatment with air, nitrogen (N2), and carbon dioxide (CO2) gases on the performance of waterborne (acrylic) and solvent-borne (polyester) coated fir (Abies alba M.) wood samples. The properties of the plasma-coated samples were analyzed before and after exposure to accelerated weathering and compared with those of untreated and solely treated ones. According to pull-off testing, the coating adhesion of the wood samples was considerably improved by plasma treatment, and obvious differences were observed between different plasma gases. The effect was more pronounced after the weathering test. Similar results were obtained for the abrasion resistance of the samples. The water contact angle measurement illustrated more hydrophilic character in the solely plasma-treated wood in comparison with the untreated wood. The application of coatings, however, strongly improved its hydrophobic character. The performances of waterborne and solvent-borne coatings on plasma-treated wood were comparable, although slightly better values were obtained by the waterborne system. Our results exhibit the positive effect of plasma treatment on coating performances and the increased weather resistance of the waterborne and solvent-borne coating systems on plasma-treated wood.

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  • 19.
    Hemmilä, Venla
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Ahmed, Sheikh Ali
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Ammonium Lignosulfonate Adhesives for Particleboards with pMDI and Furfuryl Alcohol as Crosslinkers2019In: Polymers, E-ISSN 2073-4360, Vol. 11, no 10, p. 1-17, article id 1633Article in journal (Refereed)
    Abstract [en]

    Tightening formaldehyde emission limits and the need for more sustainable materials have boosted research towards alternatives to urea-formaldehyde adhesives for wood-based panels. Lignin residues from biorefineries consist of a growing raw material source but lack reactivity. Two crosslinkers were tested for ammonium lignosulfonate (ALS)—bio-based furfuryl alcohol (FOH) and synthetic polymeric 4,4′-diphenylmethane diisocyanate (pMDI). The addition of mimosa tannin to ALS before crosslinking was also evaluated. The derived ALS adhesives were used for gluing 2-layered veneer samples and particleboards. Differential Scanning Calorimetry showed a reduction of curing temperature and heat for the samples with crosslinkers. Light microscopy showed that the FOH crosslinked samples had thicker bondlines and higher penetration, which occurred mainly through vessels. Tensile shear strength values of 2-layered veneer samples glued with crosslinked ALS adhesives were at the same level as the melamine reinforced urea-formaldehyde (UmF) reference. For particleboards, the FOH crosslinked samples showed a significant decrease in mechanical properties (internal bond (IB), modulus of elasticity (MOE), modulus of rupture (MOR)) and thickness swelling. For pMDI crosslinked samples, these properties increased compared to the UmF. Although the FOH crosslinked ALS samples can be classified as non-added-formaldehyde adhesives, their emissions were higher than what can be expected to be sourced from the particles. 

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  • 20.
    Hemmilä, Venla
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Eceiza, Arantxa
    University of the Basque Country UPV/EHU, Spain.
    Characterization of Wood-based Industrial Biorefinery Lignosulfonates and Supercritical Water Hydrolysis Lignin2020In: Waste and Biomass Valorization, ISSN 1877-2641, E-ISSN 1877-265X, Vol. 11, no 11, p. 5835-5845Article in journal (Refereed)
    Abstract [en]

    Understanding the properties of any particular biorefinery or pulping residue lignin is crucial when choosing the right lignin for the right end use. In this paper, three different residual lignin types [supercritical water hydrolysis lignin (SCWH), ammonium lignosulfonate (A-LS), and sodium lignosulfonate (S-LS)] were evaluated for their chemical structure, thermal properties and water vapor adsorption behavior. SCWH lignin was found to have a high amount of phenolic hydroxyl groups and the highest amount of beta-O-4 linkages. Combined with a low ash content, it shows potential to be used for conversion into aromatic or platform chemicals. A-LS and S-LS had more aliphatic hydroxyl groups, aliphatic double bonds and C=O structures. All lignins had available C-3/C-5 positions, which can increase reactivity towards adhesive precursors. The glass transition temperature (T-g) data indicated that the SCWH and S-LS lignin types can be suitable for production of carbon fibers. Lignosulfonates exhibited considerable higher water vapor adsorption as compared to the SCWH lignin. In conclusion, this study demonstrated that the SCWH differed greatly from the lignosulfonates in purity, chemical structure, thermal stability and water sorption behavior. SCWH lignin showed great potential as raw material for aromatic compounds, carbon fibers, adhesives or polymers. Lignosulfonates are less suited for conversion into chemicals or carbon fibers, but due to the high amount of aliphatic hydroxyl groups, they can potentially be modified or used as adhesives, dispersants, or reinforcement material in polymers. For most value-adding applications, energy-intensive purification of the lignosulfonates would be required. [GRAPHICS] .

  • 21.
    Hosseini, Payam
    et al.
    Sharif University of Technology, Iran ; Alaodoleh Semnani Institute of Higher Education, Iran.
    Hosseinpourpia, Reza
    Georg-August University, Germany.
    Pajum, Arash
    University of Tehran, Iran.
    Khodavirdi, Mohammad Mahdi
    University of Tehran, Iran.
    Izadi, Hamed
    Sharif University of Technology, Iran.
    Vaezi, Ali
    Politecnico di Milano, Italy.
    Effect of nano-particles and aminosilane interaction on the performances of cement-based composites: An experimental study2014In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 66, p. 113-124Article in journal (Refereed)
    Abstract [en]

    The aim of the present study was to experimentally investigate the interaction between a low replacement ratio of different nano-particles (SiO2, Al2O3, clay, and CaCO3) and aminosilane in the matrices of cement paste and mortar. Results showed that the optimum content of aminosilane for improving the 28-day compressive strength of cement mortar was 0.75% (by weight of the total binder). The utilization of nano-SiO2 and nano-clay particles improved the strengths of the cement mortar containing hybrid systems of nano-particles/aminosilane at early (7 days) and middle curing ages (28 and 91 days). The 28-day compressive strength enhancement of cement mortar with hybrid systems of nano-SiO2/aminosilane and nano-clay/aminosilane was about 19% and 20%, respectively. Additionally, the application of aminosilane with nano-CaCO3 and nano-Al2O3 particles showed lower efficacy on mechanical performance of the cement-based composites in comparison with nano-clay and nano-SiO2. Despite the fact that the utilization of aminosilane with and without different nano-particles enhanced the flowability of the cement paste and mortar, it reduced the electrical resistivity of the cement mortar. In this regard, the minimum electrical resistivity was achieved for specimens with only aminosilane. This reduction was about 19.5% for samples containing 0.75% aminosilane for a curing time of 28 days.

  • 22.
    Hosseinpourpia, Reza
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Eceiza, Arantxa
    University of the Basque Country UPV/EHU, Spain.
    Thermal stability and water vapor sorption of wheat starch modified with isocyanate functional groups2019In: 7th International Conference on Biobased and Biodegradable Polymers (BIOPOL), 17-19th June 2019, Stockholm, Sweden, KTH , 2019Conference paper (Refereed)
    Abstract [en]

    Wheat starch polymer was modified through the unequal reactivity of isocyanate groups in isophorone diisocyanate (IPDI) monomer. Fourier transform infrared spectroscopy (FTIR) and 13C nuclear magnetic resonance (13C NMR) confirmed the presence of both urethane and isocyanate functionalities in the modified polymer. Thermal stability and water vapor sorption properties of the modified polymer were evaluated by means of thermogravimetric analysis (TGA) and auto-dynamic vapor sorption (AVS) method, respectively. The results indicated that the modified starch polymer showed a better thermal stability (e.g. higher temperature at maximum weight loss) compared to the unmodified one. Water vapor sorption of starch polymer was considerably reduced after modification with IPDI monomer.

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  • 23.
    Hosseinpourpia, Reza
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. University of Göttingen, Germany.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Holstein, Nonna
    University of Göttingen, Germany.
    Mai, Carsten
    University of Göttingen, Germany.
    Dynamic vapour sorption and water-related properties of thermally modified Scots pine (Pinus sylvestris L.) wood pre-treated with proton acid2017In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 138, p. 161-168Article in journal (Refereed)
    Abstract [en]

    This study investigates the effect of proton acid pre-treatment and subsequent thermal modification at relatively low temperatures (up to 180 °C) on wood with respect to dimensional stability and water vapour sorption properties. The effects are compared to those of solely thermally-modified wood at higher temperatures (up to 250 °C). Scots pine sapwood (P. sylvestris L.) was impregnated with a proton acid or demineralised water, and subsequently, thermally modified to various mass losses (ML). Acid pre-treatment and thermal modification improved the dimensional stability and reduced the equilibrium moisture content (EMC) until certain ML. Excess surface work (ESW) obtained from vapour sorption studies indicated that, at comparable ML, the acid pre-treatment reduced the available sorption sites as compared to sole thermal treatment. Samples pre-treated with acid also showed stronger decreasing courses of EMC- and ESW-ratios than sole thermally modified ones. This was attributed to degradation of amorphous wood polymers and a stiffer matrix due to cross-linking of the cell wall polymers as a consequence of acid pre-treatment. Electron spin resonance (ESR) analysis indicated that acid pre-treatment did not enhance the concentration of phenoxy radicals, whereas thermally modified wood showed a considerably higher concentration of phenoxy radicals, suggesting that high radical density cannot be used as an indicator for high matrix stiffness.

  • 24.
    Hosseinpourpia, Reza
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Mai, C
    Georg-August-University Gottingen, Germany.
    Analysis of the vapour sorption behaviour of wood modified with thermosetting resins with Hailwood-Horrobin and Excess Surface Work models2018In: 29th International Conference on Wood Science and Technology, ICWST 2018: Implementation of Wood Science in Woodworking Sector - Proceedings / [ed] Spanic N.,Zupcic I., University of Zagreb , 2018, p. 87-92Conference paper (Refereed)
    Abstract [en]

    Wood modification is a well-known technology to enhance the dimensional stability of wood and the resistance to abiotic and biotic degradation. Impregnation modification of wood with thermosetting resins, such as melamine formaldehyde (MF) or phenol formaldehyde (PF), alters the material properties of wood through formation of a three-dimensional network within the cell wall. This work investigates the vapour sorption behaviour of Scots pine (Pinus sylvestris L.) micro-veneers modified with MF and PF resins by means of Hailwood-Horrobin (H-H) and excess surface work (ESW) models. The analysed sorption data indicated that the available sorption sites were increased in the modified samples compared to the unmodified controls due to an increase of the monolayer sorption. However, modification resulted in a considerable reduction of the multilayer sorption. This could be attributed to the formation of a rigid, three-dimensional corset within the cell wall formed by auto-polymerization reactions of resin monomers and oligomers, which is known to reduce the cell wall swell-ability upon water absorption.

  • 25.
    Hosseinpourpia, Reza
    et al.
    Georg-August-University Göttingen, Germany.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Mai, Carsten
    Georg-August-University Göttingen, Germany.
    Dynamic vapour sorption of wood and holocellulose modified with thermosetting resins2016In: Wood Science and Technology, ISSN 0043-7719, E-ISSN 1432-5225, Vol. 50, no 1, p. 165-178Article in journal (Refereed)
    Abstract [en]

    Micro-veneers of wood and holocellulose (HC) were modified with the thermosetting resins phenol formaldehyde and melamine formaldehyde. The dynamic water vapour sorption of the modified and untreated veneers was studied in a dynamic vapour sorption apparatus to assess the effects of resin modification. The adsorption of wood and HC as well as the desorption of wood was little affected by the modification in the low relative humidity (RH) range but decreased in the RH range above 60–70 %. The desorption isotherm of HC, however, was increased in the RH range of 15–80 % due to modification. Resin modification gradually decreased the EMC ratio of wood and HC and also influenced the moisture increment, equilibrium time and sorption rate in RH range above 50–60 % RH for wood and above 70–80 % RH for HC. HC exhibited a clearly lower hysteresis than wood. Modification of wood slightly reduced hysteresis compared to untreated wood, but modification of HC clearly increased hysteresis about to the same extent as that of wood. This indicates that the stiffening effect of lignin and thermosetting resins reduces the flexibility of the HC matrix, which results in increased hysteresis.

  • 26.
    Hosseinpourpia, Reza
    et al.
    Georg-August-University Göttingen, Germany.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Mai, Carsten
    Georg-August-University Göttingen, Germany.
    Dynamic water vapour sorption properties and dimensional stability of thermally and acid-treated Scots pine (Pinus sylvestris L.)2015In: 69th Forest Products Society (FPS) International Convention, June 10-12, Atlanta, GA, Forest Products Society , 2015Conference paper (Refereed)
    Abstract [en]

    In order to accelerate the thermal modification process, Scots pine sapwood samples were subjected to two types of treatments. One group of samples was impregnated with water and exposed to 220oC and the second group was initially treated with low concentration of acids (1 mol l-1 AlCl3 and a mixture of 0.5 mol l-1 H2SO4 and 1 mol l-1 AlCl3), and then heated at different temperatures (180 and 120oC) to achieve comparable mass loss (ML) levels. The water vapour sorption isotherms of the thermally and acid-treated wood samples were determined using a dynamic vapour sorption (DVS) apparatus. Increasing the temperature in both thermally and acid-treated samples resulted in ML attributable to hemicelluloses degradation. As a result thereof, dimensional stability and reduction in the hygroscopicity of wood were observed. Acid-treated samples heated at lower temperature exhibited similar water sorption behaviour as water-treated samples subjected to considerably higher temperature. The sorption data were analysed using the Hailwood-Horrobin (H-H) and excess surface work (ESW) models. The data indicated that the monolayer and polylayer sorption were reduced by the acid and thermal treatments, but acid treatment reduced the monolyer sorption stronger than the thermal. The effect of thermal and acid treatments on the flexibility of the cell wall matrix could not be fully distinguished.

  • 27.
    Hosseinpourpia, Reza
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Mai, Carsten
    Effect of lignin and hemicelluloses removal on dynamic water vapour sorption behavior of wood2017In: IUFRO Division 5 Conference, 12-14 June, 2017 - Vancouver, British Columbia: Final program, proceedings and abstracts, IUFRO Division 5 Conference , 2017Conference paper (Refereed)
    Abstract [en]

    Water-related properties of wood are strongly depended on the sorption behavior of its hygroscopic polymers such as cellulose, hemicelluloses and lignin. To assess the sorption performance of wood matrix in the absence of hemicelluloses and lignin, micro-veneers of Scots pine (Pinus sylvestris L.) were hydrolyzed with sulphuric acid and delignified with sodium chlorite and acetic acid, respectively. The dynamic water vapour sorption of the hydrolyzed, delignified and untreated veneers was studied in a dynamic vapour sorption (DVS) apparatus. The moisture adsorption of hydrolyzed veneers was decreased in the relative humidity (RH) range above 60-70 %. Delignified veneers, however, showed obviously higher moisture adsorption at RH above 70%, as compared to untreated controls. Hydrolyzed and untreated veneers exhibited a comparable hysteresis, while delignified veneers showed a considerably lower hysteresis in comparison to them. This explains that, despite the fact that the hydrophilic hemicelluloses influence the moisture sorption of wood, the expand-ability of the cell wall matrix is mainly controlled by lignin.

  • 28.
    Hosseinpourpia, Reza
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Georg-August-University, Germany.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Mai, Carsten
    Georg-August-University, Germany.
    Effects of acid pre-treatments on the swelling and vapor sorption of thermally modified Scots pine (Pinus sylvestris L.) wood2018In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 13, no 1, p. 331-345Article in journal (Refereed)
    Abstract [en]

    Scots pine sapwood samples were pre-treated with a Lewis acid (AlCl3) and a combination of Lewis and protonic acids (AlCl3 and H2SO4), and were subsequently exposed to respective temperatures of 180 °C and 120 °C for establishing a comparable mass loss with those impregnated with demineralized water and solely thermally modified at 220 °C. Water impregnated samples dried at 120 °C also served as controls. The swelling behavior of all wood samples was examined with respect to maximum swelling in water, anti-swelling efficiency (ASE), shrinkage, and dynamic water vapor sorption at relative humidity ranges of 0% to 95%. The thermal modification at 220 °C diminished swelling and moisture adsorption, and also reduced moisture increment and decrement compared with the unmodified control. However, it was less obvious than both acid pre-treated samples. Excess surface work and Hailwood-Horrobin results calculated from water vapor sorption studies demonstrated that, at comparable mass loss, the available sorption sites were reduced to a greater extent by Lewis acid and combination of Lewis and protonic acids pre-treatment than the sole thermal treatment. This was attributed to more pronounced degradation of polysaccharides, mainly hemicelluloses and amorphous parts of cellulose, and to cross-linking of cell wall polymers due to the acid pre-treatments.

  • 29.
    Hosseinpourpia, Reza
    et al.
    Georg August University Göttingen, Germany.
    Adamopoulos, Stergios
    Technological Educational Institute of Thessaly, Greece.
    Mai, Carsten
    Georg August University Göttingen, Germany.
    Tensile strength of handsheets from recovered fibers treated with N-methylol melamine and 1,3-dimethylol-4,5-dihydroxyethyleneurea2015In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 132, no 3, article id 41290Article in journal (Refereed)
    Abstract [en]

    The main objective of this study was to assess the effect of two amino resins, N-methylol melamine (NMM) and 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU), on the intrafiber and interfiber strengths and water absorption of two types of waste paper categories, office paper (OP), and old corrugated containers (OCCs). The tensile strength of individual fibers measured at zero span was reduced by increases in the resin concentrations. The dry tensile strengths of the recovered handsheets measured at a finite span were enhanced with increases in the weight percentage gain of the resins. The increasing of the resin concentration also significantly improved the intrabonding of the OP and OCCs in moist measuring conditions. The water absorption of the handsheets considerably decreased at the higher concentration of the thermosetting resins, especially with NMM. The results are promising for the use of NMM- and DMDHEU-treated recovered fibers as an alternative fiber resource for the production of laminated paper and also for the use of DMDHEU as a new N-methylol compound for laminated paper.

  • 30.
    Hosseinpourpia, Reza
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Georg-August-University Göttingen, Germany.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Mai, Carsten
    Georg-August-University Göttingen, Germany.
    Hemmilä, Venla
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Effect of Bio-Based Additives on Physico-Mechanical Properties of Medium Density Fibreboards2017In: 28th ICWST, International Conference on Wood Science and Technology: Implementation of Wood Science in Woodworking Sector, Proceedings. Zagreb, 7th - 8th of December 2017 / [ed] Ivica Zupcic, Vjekoslav Zivkovic, Josip Miklecic, Zagreb: University of Zagreb, Faculty of Forestry , 2017, p. 153-158Conference paper (Refereed)
    Abstract [en]

    Dimensional stability of wood-based panels is generally improved with application of suitable additives. Most of these additives, such as paraffin wax, are petroleum-based and with relatively high cost, and therefore, it is desirable to develop low-cost and effective substitutes from renewable resources. This work studied the potential of using a renewable water-repellent additive, such as tall oil fatty acid, for lab-scale manufacturing of medium density fibreboards (MDF). Tall oil fatty acid (TOFA) was used at 1 and 3% w/w of urea formaldehyde (UF) resin. MDF panels with similar concentrations of paraffin wax (wax) and panels without adding a water-repellent agent were served as controls. It was assessed the dimensional stability of the panels in terms of thickness swelling and water uptake after 4 and 24h immersion in water, and their mechanical performance in terms of modulus of elasticity, modulus of rupture and internal bonding. Results showed no obvious differences in the strength behaviour of the panels by addition of water-repellent agents. Dimensional stability, however, considerably improved by addition of TOFA, but it was still inferior when compared to that provided by wax.   

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  • 31.
    Hosseinpourpia, Reza
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Mai, Carsten
    Georg-August-University Göttingen, Germany.
    Taghiyari, Hamid Reza
    Shahid Rajaee Teacher Training University, Iran.
    Properties of medium-density fibreboards bonded with dextrin-based wood adhesive2019In: Wood research, ISSN 1336-4561, Vol. 64, no 2, p. 185-194Article in journal (Refereed)
    Abstract [en]

    This study focuses on manufacturing of medium density fibreboard (MDF) panels bonded with dextrin-based wood adhesive and crosslinked in situ with various weight ratios of synthetic (e.g., polymeric-methane diphenyl-diisocyanate, pMDI) or bio-based (e.g., glyoxal) crosslinkers. The physical and mechanical properties of the panels were evaluated and compared with those from panels without crosslinker (control). Modulus of rupture (MOR) and internal bond (IB) strength of the MDF panels were considerably increased by increasing the crosslinkers’ content. While, slight improvements were observed in modulus of elasticity (MOE) of the panels as a function of crosslinker type and content. Addition of crosslinkers clearly reduced the thickness swelling (TS) and water absorption (WA) of the panels, whereas, the panels with pMDI showed superior performances than the control and glyoxal added ones within 4 h and 24 h immersion in water. The results indicate the potential of dextrin as wood panel adhesive along with the use of appropriate crosslinkers.

  • 32.
    Hosseinpourpia, Reza
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Parsland, Charlotte
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Utilization of different tall oils for improving the water resistance of cellulosic fibers2019In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 136, no 13, article id 47303Article in journal (Refereed)
    Abstract [en]

    This study was conducted to assess the effect of the pulping by-products crude tall oil (CTO), distilled tall oil (DTO), andtall oil fatty acid (TOFA) on dynamic water vapor sorption behavior, interfiber strength, and thermal stability of cellulosic paper-sheets.The results were compared against those obtained in cellulose papers treated with the conventional petroleum-derived hydrophobicagent hydrowax and in untreated ones. The tall oil treatments caused strong reduction in equilibrium moisture content of the paper-sheets during adsorption and desorption runs. The same trend was noticed for the hydrowax-treated papers, however, it was lesspronounced than the CTO-treated and DTO-treated samples in the relative humidity range of 75–95%. The sorption hysteresis was con-siderably decreased after the treatments. The ultimate dry-tensile strengths of the paper-sheets were significantly reduced by TOFA andhydrowax treatments, while CTO and DTO showed comparable strength as that of untreated control. The ultimate wet-strengths of thepaper-sheets were improved after the treatments. The thermal stability of the specimens was improved by the tall oil treatments, and thehydrowax-treated samples illustrated lower degradation temperature than the untreated control. The results are promising for the use oftall oils as alternative hydrophobic agents of cellulosicfiber-based products, such as wood panels and paper packaging.

  • 33.
    Hosseinpourpia, Reza
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Adamopoulos, Stergios
    Swedish University of Agricultural Sciences, Sweden.
    Santamaria Echart, Arantzazu
    Instituto Politecnico de Braganca, Portugal.
    Eceiza, Arantxa
    University of the Basque Country UPV/EHU, Spain.
    Polyurethane films prepared with isophorone diisocyanate functionalized wheat starch2021In: European Polymer Journal, ISSN 0014-3057, E-ISSN 1873-1945, Vol. 161, article id 110826Article in journal (Refereed)
    Abstract [en]

    This study reports the fabrication and performance of sustainable polyurethane (PU) films based on wheat starch (native NS, modified MS), bio-polyols (1,3-propanediol PD, glycerol Gly), and polymeric diphenylmethane diisocyanate (pMDI). NS was successfully modified with isophorone diisocyanate, confirmed by Fourier transform infrared spectroscopy (FTIR) and 13C nuclear magnetic resonance (13C NMR). Various PU films were prepared using NS, PD or Gly, MS and pMDI. For comparison, reference films were also synthesized without MS. PU films were analyzed from the viewpoint of their chemical, thermomechanical and flexural properties, and microstructural morphology. FTIR spectra demonstrated the total consumption of NCO groups, while the scanning electron microscopy micrographs of the films revealed that MS addition promoted the interactions between the compounds, enhancing in consequence their mechanical and thermomechanical performance. The study supported the suitability of functionalized carbohydrates to substitute petrochemical compounds in the synthesis of more environmentally-friendly PUs.

  • 34.
    Hosseinpourpia, Reza
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Walther, Thomas
    IKEA Industry AB, Sweden.
    Naydenov, Valeri
    SunPine AB, Sweden.
    Hydrophobic Formulations Based on Tall Oil Distillation Products for High-Density Fiberboards2020In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 13, no 18, p. 1-13, article id 4025Article in journal (Refereed)
    Abstract [en]

    This study investigates the effect of renewable formulations based on tall oil bio-refinery products on the water vapor sorption and interfiber strength of cellulosic fibers as well as on the properties of high-density fiberboard (HDF) panels. The results obtained for HDF prepared using renewable formulations were compared to the results for HDF obtained using conventional synthetic paraffin wax (hydrowax), which is the hydrophobic agent currently utilized by the industry. Four tall oil distillation products (TODPs) with different levels of fatty and rosin acids were used for preparing the hydrophobic formulations with furfuryl alcohol as an organic solvent. According to determinations with an automated vapor sorption apparatus, the formulations had a similar effect with hydrowax on the sorption behavior of natural fibers. Unlike to hydrowax treatment, the ultimate tensile strength of cellulosic paper-sheets treated with the formulations remained unchanged or significantly increased. At the standard addition load of 1% (wt/wt dry fibers) of the formulations, HDF panels showed comparable and only in one case, e.g., TODP3-based formulation, slightly higher thickness swelling (24 h) than those with hydrowax. The best performing formulation (TODP2-based) in terms of tensile strength of paper sheets did not significantly change the mechanical properties of HDF panels in both standard climate and high humid conditions. Promising results at the standard and humid climate conditions were obtained for HDF panels manufactured with higher TODP2-based formulation amounts (3-5%) and reduced melamine-urea-formaldehyde resin content (10-12% instead of 14%, wt dry resin/wt dry fibers).

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  • 35.
    Hosseinpourpia, Reza
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials. Linnaeus University, Linnaeus Knowledge Environments, Green Sustainable Development.
    Eceiza, Arantxa
    University of the Basque Country UPV/EHU, Spain.
    Adamopoulos, Stergios
    Polyurethane Wood Adhesives Prepared from Modified Polysaccharides2022In: Polymers, E-ISSN 2073-4360, Vol. 14, no 3, article id 539Article in journal (Refereed)
    Abstract [en]

    This study investigated the performance of polyurethane adhesives prepared with various combinations of wheat starch that had been modified by isophorone diisocyanate (MS), two polyol types (1,3-propanediol (PD) and glycerol (Gly)), native wheat starch (NS), and 4,4′-diphenylmethane diisocyanate (pMDI) at a NCO:OH weight ratio of 1:1. Two more adhesives were also synthesized with NS, PD, or Gly and pMDI blends and served as controls. The thermal behavior of the adhesives before and after the curing process, as well as their rheological performance and lap shear strength, were analyzed. Differential scanning calorimetry (DSC) showed a reduction in curing temperature and heat by adding MS. The thermal stability of the cured adhesives was slightly increased by MS addition. The viscosity of the adhesives that contained MS substantially increased at a linear ascendant ramp of shear, while the controls exhibited relatively low viscosity during the whole shear rate spectrum from 0.1 to 100 s−1. The tensile shear strength of wood veneers was also significantly increased by the incorporation of MS under both dry and wet measuring conditions. The maximum dry shear strength was obtained for the adhesive with Gly polyol and a higher content of MS and was comparable to the control adhesive with pMDI.

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  • 36.
    Hosseinpourpia, Reza
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Echart, Arantzazu Santamaria
    University of the Basque Country UPV/EHU, Spain.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Gabilondo, Nagore
    University of the Basque Country UPV/EHU, Spain.
    Eceiza, Arantxa
    University of the Basque Country UPV/EHU, Spain.
    Modification of Pea Starch and Dextrin Polymers with Isocyanate Functional Groups2018In: Polymers, E-ISSN 2073-4360, Vol. 10, no 9, article id 939Article in journal (Refereed)
    Abstract [en]

    Pea starch and dextrin polymers were modified through the unequal reactivity of isocyanate groups in isophorone diisocyanate (IPDI) monomer. The presence of both urethane and isocyanate functionalities in starch and dextrin after modification were confirmed by Fourier transform infrared spectroscopy (FTIR) and 13C nuclear magnetic resonance (13C NMR). The degree of substitution (DS) was calculated using elemental analysis data and showed higher DS values in modified dextrin than modified starch. The onsets of thermal degradation and temperatures at maximum mass losses were improved after modification of both starch and dextrin polymers compared to unmodified ones. Glass transition temperatures (Tg) of modified starch and dextrin were lower than unmodified control ones, and this was more pronounced in modified dextrin at a high molar ratio. Dynamic water vapor sorption of starch and dextrin polymers indicated a slight reduction in moisture sorption of modified starch, but considerably lower moisture sorption in modified dextrin as compared to that of unmodified ones.

  • 37.
    Hosseinpourpia, Reza
    et al.
    Islamic Azad University, Iran ; Georg-August University, Germany.
    Hosseini, Payam
    Sharif University of Technology, Iran.
    Mofidian, Seyedehrashin
    Mazandaran University of Science and Technology, Iran.
    Hosseinpourpia, Rezvan
    Islamic Azad University, Iran.
    Varshoee, Ali
    Islamic Azad University, Iran.
    Influence of Nanosilica on Properties of Green Cementitious Composites Filled with Waste Sulfite Pulp Fiber and Aminosilane2014In: Arabian Journal for Science and Engineering, ISSN 2193-567X, Vol. 39, no 4, p. 2631-2640Article in journal (Refereed)
    Abstract [en]

    Developments in the field of green cement-based products are characterized as an important approach to sustainable development and are being devoted much attention by the construction industry. Numerous types of materials are utilized; however, based on other published studies, the use of waste material as a filler normally deteriorates the performance of cementitious products. Appropriate additives thus need to be employed to improve the performances and properties of green products. As a consequence, the aim of this study has been to investigate the properties of a novel green cement-based composite—a hybrid system composed of cement, waste natural fiber, silica nano-particles, and aminosilane. Experiments were performed to assess the physical properties (density and flowability), mechanical properties (compressive strength and bending performance), and microstructural properties (as determined by scanning electron microscopy) of the cement sheets. The results demonstrated an improvement in the mechanical and microstructural properties of green cement-based composites by using this hybrid system.

  • 38.
    Hosseinpourpia, Reza
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Göttingen university, Germany.
    Mai, Carsten
    Dynamic water vapour sorption properties of wood cell wall polymer constituents2015In: COST FP1303 (Performance of bio-based building materials) / [ed] Dennis Jones, Christian Brischke, Jaan Kers, Triinu Poltimäe and Joachim Schmid, SP Technical Research Institute of Sweden , 2015, p. 42-44Conference paper (Refereed)
    Abstract [en]

    Lignin, cellulose and hemicelluloses have main roles on swelling and shrinkage of wood products. Interaction of these components with moisture has an important effect on market-friendly when the wood is subjected to the outside utilizations. In the heterogeneous structure of wood, sorption and desorption are occurred in different stages and it calls hysteresis. Hysteresis is a characteristic result from a moisture/temperature/time-dependent, slow, non-equilibrium, swelling-related conformational change, which is facilitated by increasing free volume and mobility in a polymer that is being plasticized during sorption that usually progresses through the stage of water clustering (Reina et al. 2001). Cell wall polymers of wood have a different behavior in the face of moisture in terms of sorption, desorption and hysteresis (Engelund et al. 2013).

    In order to better comprehension of the effect of cell wall material such as lignin, cellulose and hemicelluloses, Scots pine micro-veneers were subjected to hydrolysis with sulphuric acid or delignification with acidic sodium chlorite, as previously described (Klüppel and Mai 2012). Then the hemicelluloses were isolated from the delignified veneers according to the chloride method. The commercial lignin was also used after dialysis tubing. The water adsorption and desorption mechanism of delignified and hydrolysed veneers as well as cell wall polymers such as cellulose, hemicelluloses and lignin were determined using a dynamic vapour sorption (DVS) apparatus.

    The hydrolysed veneers were resulted in obviously lower moisture content in adsorption and desorption processes with increasing the relative humidity (RH) (Fig. 1a). While, delignified veneers showed slightly higher moisture content compared to control with increasing the ambient moisture until 70% RH and then considerably higher until 95% RH. Control specimens shown higher hysteresis than hydrolysed veneers and also higher hysteresis than delignified veneers after hygroscopic range (Fig. 1b). Moisture content of cell wall constituents in various relative humidity exhibited the higher moisture sorption and desorption of cellulose than lignin, however, hemicelluloses illustrated the significantly higher moisture content than other two cell wall polymers which might be attributed to the softening of hemicelluloses in higher relative humidity (Fig. 2a,b,c). Lignin showed higher hysteresis than cellulose in different relative humidity. Hemicellulose demonstrated the relatively low hysteresis until 50% RH, and with increasing the ambient pressure from 60% RH the hemicelluloses exhibited the extremely higher hysteresis than other cell wall polymers.

  • 39.
    Hosseinpourpia, Reza
    et al.
    Georg-August-University Göttingen.
    Mai, Carsten
    Georg-August-University Göttingen.
    Mode of action of brown rot decay resistance in phenol-formaldehyde-modified wood: resistance to Fenton’s reagent2016In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 70, no 3, p. 253-259Article in journal (Refereed)
    Abstract [en]

    The mode of action of phenol-formaldehyde (PF)-modified wood has been investigated with respect to its resistance to brown rot decay. The Fenton reaction is assumed to play a key role in the initial brown rot decay. Pine microveneers were modified to various weight percent gains (WPG) with low molecular weight PF and exposed to a solution containing Fenton’s reagent. The mass loss (ML) and tensile strength loss (TSL) as well as the decomposition of hydrogen peroxide within the incubation time decreased with the increasing WPG of the veneers. Incubation of untreated and PF-modified veneers in acetate buffer containing ferric ions without H2O2 revealed that the modification strongly reduces the uptake of iron by the wood cell wall. Further studies indicated that lignin promotes the decay of wood by Fenton’s reagent. The reason for the enhanced resistance of modified wood to the Fenton reaction is attributable to the impeded diffusion of iron ions into the cell wall rather than to the blocking of free phenolic sites of lignin, which accelerate redox cycling of iron.

  • 40.
    Hosseinpourpia, Reza
    et al.
    Georg-August-University Göttingen.
    Mai, Carsten
    Georg-August-University Göttingen.
    Mode of action of brown rot decay resistance of acetylated wood: resistance to Fenton’s reagent2016In: Wood Science and Technology, ISSN 0043-7719, E-ISSN 1432-5225, Vol. 50, no 2, p. 413-426Article in journal (Refereed)
    Abstract [en]

    Acetylation is known to enhance the resistance of wood to brown rot fungi. As initial decay by some brown rot fungi is assumed to be caused by the Fenton reaction, pine micro-veneers acetylated to various weight percent gains (WPG) were exposed in a solution containing iron ions and hydrogen peroxide, i.e., Fenton’s reagent. Mass loss and tensile strength loss as well as the decomposition of hydrogen peroxide within the incubation time decreased with increasing WPG of the veneers. Incubation of untreated and acetylated veneers in acetate buffer containing ferric ions without H2O2 revealed that the modification strongly reduced the uptake of Fe ions by the wood cell wall. FT-IR analysis indicated oxidation of the unmodified control veneers but did not show predominant decay of specific cell wall components. Spectra of acetylated veneers did not reveal any significant changes induced by Fenton’s reagent. It was concluded that one possible reason for the enhanced resistance of acetylated wood to the Fenton reaction could be the reduced or almost completely prevented uptake of Fe ions by the wood cell wall.

  • 41.
    Hosseinpourpia, Reza
    et al.
    Georg-August-University Göttingen, Germany.
    Mai, Carsten
    Georg-August-University Göttingen, Germany.
    Mode of action of brown rot decay resistance of thermally modified wood: resistance to Fenton’s reagent2016In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 70, no 7, p. 691-697Article in journal (Refereed)
    Abstract [en]

    The resistance of heat treated (HT) wood to brown rot fungi has been investigated, while the role of the Fenton reaction (FR) in the initial phase of degradation was in focus. Micro-veneers made of Scots pine, were HT with various intensities and their mass losses (MLHT) were determined before soaking with a solution of Fenton’s reagent containing Fe ions and hydrogen peroxide. The mass loss of the veneers treated that way (MLFT), their tensile strength loss (TSLFT) and the H2O2 decomposition were observed. The MLFT, TSLFT, and H2O2 loss decreased with increasing MLHT of the veneers. Soaking of the veneers in acetate buffer containing only Fe without H2O2 revealed that the heat treatment (HT) strongly reduces the Fe uptake by the cell walls. FTIR spectroscopy indicated oxidation of the unmodified control veneers but did not reveal predominant decay of cell wall components; the HT veneers were not changed at all due to FR. It was concluded that the reason for the enhanced resistance of HT wood to FR is attributable to hindered diffusion of Fe ions into the wood cell wall.

  • 42.
    Hosseinpourpia, Reza
    et al.
    Islamic Azad University, Iran.
    Varshoee, Ali
    Islamic Azad University, Iran.
    Soltani, Mojtaba
    Islamic Azad University, Iran.
    Hosseini, Payam
    Sharif University of Technology, Iran.
    Effects of sulfite waste fibers incorporating silica nano-particles on mechanical and microstructural properties of cementitious composite2010In: 2nd International Conference on Composites: Characterization, Fabrication and Application, 2010, p. 431-436Conference paper (Refereed)
    Abstract [en]

    Natural fibers are one of the most appropriate alternatives for designation and production of structural panels due to low final production cost. However a principal point is the strength loss caused by usage of these fibers in the matrix of cement based composites. Hence, a simple and cheap method should be applied to develop the properties of these fibers. Therefore, in this study by application of sulfite waste (along with waste management in the wood and paper industries) and usage of low-dosage silica nanoparticles (in order to enhance the interfacial transition zone of the cement-fiber paste), production of cement based sheets reinforced with natural fibers and silica nano-particles are investigated. Alongside, flexural strength and microstructure of sheets are examined by calculating the Modulus of Rupture (MOR) and Modulus of Elasticity (MOE), and applying the Scanning Electron Microscopy (SEM), respectively. Results show that mechanical performance and microstructure of cement based composites containing waste natural fibers and silica nano-particles can be improved.

  • 43.
    Hosseinpourpia, Reza
    et al.
    Islamic Azad University, Iran ; Georg-August University, Germany.
    Varshoee, Ali
    Islamic Azad University, Iran.
    Soltani, Mojtaba
    Islamic Azad University, Iran.
    Hosseini, Payam
    Sharif University of Technology, Iran.
    Ziaei Tabari, Hassan
    Islamic Azad University, Iran.
    Production of waste bio-fiber cement-based composites reinforced with nano-SiO2 particles as a substitute for asbestos cement composites2012In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 31, p. 105-111Article in journal (Refereed)
    Abstract [en]

    The environmental impact of asbestos fibers on human health and their consequent safety-related problems indicate that there is a significant need to replace this material in all asbestos-containing products. Many different types of fibers have been introduced to replace asbestos fibers.

    In this study, the performance of silica nano-particles combined with waste paper pulp fibers (sulfite fibers) has been investigated. Different mechanical (compressive and flexural strengths and bending performance), durability (water absorption), physical (bulk density and flowability), and microstructural (scanning electron microscopy) tests were conducted to examine the properties of manufactured green composites.

    The results reveal that the mechanical properties of cement-based composites containing a ternary system of “natural waste fiber–silica nano-particle cement” have been enhanced. Adding silica nano-particles allows the development of green cement-based composites and movement toward sustainable development in the concrete industry.

  • 44.
    Jiang, Wen
    et al.
    University of Eastern Finland, Finland.
    Adamopoulos, Stergios
    Swedish University of Agricultural Sciences, Sweden.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Michigan Technological University, USA.
    Walther, Thomas
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. IKEA Industry, Sweden.
    Medved, Sergej
    University of Ljubljana, Slovenia.
    Properties and Emissions of Three-Layer Particleboards Manufactured with Mixtures of Wood Chips and Partially Liquefied Bark2023In: Materials, E-ISSN 1996-1944, Vol. 16, no 5, article id 1855Article in journal (Refereed)
    Abstract [en]

    Partial liquefaction of residual biomass shows good potential for developing new materials suitable for making bio-based composites. Three-layer particleboards were produced by replacing virgin wood particles with partially liquefied bark (PLB) in the core or surface layers. PLB was prepared by the acid-catalyzed liquefaction of industrial bark residues in polyhydric alcohol. The chemical and microscopic structure of bark and residues after liquefaction were evaluated by means of Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM), while the particleboards were tested for their mechanical and water-related properties, as well as their emission profiles. Through a partial liquefaction process, some FTIR absorption peaks of the bark residues were lower than those of raw bark, indicating hydrolysis of chemical compounds. The surface morphology of bark did not change considerably after partial liquefaction. Particleboards with PLB in the core layers showed overall lower densities and mechanical properties (modulus of elasticity, modulus of rupture, and internal bond strength), and were less water-resistant as compared to the ones with PLB used in the surface layers. Formaldehyde emissions from the particleboards were 0.284–0.382 mg/m2·h, and thus, below the E1 class limit required by European Standard EN 13986:2004. The major emissions of volatile organic compounds (VOCs) were carboxylic acids as oxidization and degradation products from hemicelluloses and lignin. The application of PLB in three-layer particleboards is more challenging than in single-layer boards as PLB has different effects on the core and surface layers.

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  • 45.
    Jiang, Wen
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Žigon, Jure
    University of Ljubljana, Slovenia.
    Petrič, Marko
    University of Ljubljana, Slovenia.
    Šernek, Milan
    University of Ljubljana, Slovenia.
    Medved, Sergej
    University of Ljubljana, Slovenia.
    Utilization of Partially Liquefied Bark for Production of Particleboards2020In: Applied Sciences, E-ISSN 2076-3417, Vol. 10, no 15, p. 1-14, article id 5253Article in journal (Refereed)
    Abstract [en]

    Bark as a sawmilling residue can be used for producing value-added chemicals and materials. This study investigated the use of partially liquefied bark (PLB) for producing particleboard with or without synthetic adhesives. Maritime pine (Pinus pinaster Ait.) bark was partially liquefied in the presence of ethylene glycol and sulfuric acid. Four types of particleboard panels were prepared with a PLB content of 4.7%, 9.1%, 20%, and 33.3%, respectively. Another five types of particleboard panels were manufactured by using similar amounts of PLB and 10 wt.% of melamine–urea–formaldehyde (MUF) adhesives. Characterization of bark and solid residues of PLB was performed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and automated vapor sorption (AVS). Mechanical and physical properties of the particleboard were tested according to the European standards EN 310 for determining modulus of elasticity and bending strength, EN 317 for determining thickness swelling after immersion in water, and EN 319 for determining internal bond strength. The results showed that the increase in PLB content improved the mechanical strength for the non-MUF boards, and the MUF-bonded boards with up to 20% of PLB met the requirements for interior uses in dry conditions according to EN 312. The non-MUF boards containing 33.3% of PLB and the MUF-bonded boards showed comparable thickness swelling and water absorption levels compared to the reference board.

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  • 46.
    Jiang, Wen
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Biziks, Vladimirs
    Georg-August University Göettingen, Germany.
    Ahmed, Sheikh Ali
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Militz, Holger
    Georg-August University Göettingen, Germany.
    Adamopoulos, Stergios
    Swedish University of Agricultural Sciences, Sweden.
    Preparation of Polyurethane Adhesives from Crude and Purified Liquefied Wood Sawdust2021In: Polymers, E-ISSN 2073-4360, Vol. 13, article id 3267Article in journal (Refereed)
    Abstract [en]

    Polyurethane (PU) adhesives were prepared with bio-polyols obtained via acid-catalyzedpolyhydric alcohol liquefaction of wood sawdust and polymeric diphenylmethane diisocyanate(pMDI). Two polyols, i.e., crude and purified liquefied wood (CLW and PLW), were obtained fromthe liquefaction process with a high yield of 99.7%. PU adhesives, namely CLWPU and PLWPU,were then prepared by reaction of CLW or PLW with pMDI at various isocyanate to hydroxyl group(NCO:OH) molar ratios of 0.5:1, 1:1, 1.5:1, and 2:1. The chemical structure and thermal behavior of thebio-polyols and the cured PU adhesives were analyzed by Fourier transform infrared spectroscopy(FTIR) and thermogravimetric analysis (TGA). Performance of the adhesives was evaluated by singlelap joint shear tests according to EN 302-1:2003, and by adhesive penetration. The highest shearstrength was found at the NCO:OH molar ratio of 1.5:1 as 4.82 ± 1.01 N/mm2 and 4.80 ± 0.49 N/mm2 for CLWPU and PLWPU, respectively. The chemical structure and thermal properties of the cured CLWPU and PLWPU adhesives were considerably influenced by the NCO:OH molar ratio. 

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  • 47.
    Kovacikova, Janka
    et al.
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Kroon, Martin
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Ahmed, Sheikh Ali
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Swedish University of Agricultural Sciences, Sweden.
    Mechanical properties of fiberboard composite bonded with polymer matrixcomputed by mean-field homogenization methods2021In: 25th International Congress of Theoretical and Applied Mechanics, August 22-27, 2021: Book of Abstracts / [ed] Alberto Corigliano, Milano, Italy, 2021, p. 1984-1985Conference paper (Other academic)
    Abstract [en]

    Nowadays, the design of composite materials considering sustainability and the environmental impact of the production is conspicuous. Therefore, in this work, we focus on investigating the mechanical behaviour and structure of a new green wood-based fibrous composite material bonded with a novel polymer matrix. The constitutive prediction models employing the material and structure design approaches simultaneously are proposed here to describe the material's microstructure. The goal is speeding up trials and reducing experiments expenses by replacing tests with computer simulations. Additionally, the relationship between material behaviour and structure is established and will be later used to generate Representative Volume Elements (RVEs) for finite element analysis (FEA).

  • 48.
    Kumar, Anuj
    et al.
    Natural Resources Institute Finland (Luke), Finland.
    Ryparová, Pavla
    Czech Technical University in Prague, Czech Republic.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Prošek, Zdeněk
    Czech Technical University in Prague, Czech Republic.
    Žigone, Jure
    Czech Technical University in Prague, Czech Republic.
    Petrič, Marko
    University of Ljubljana, Slovenia.
    Hydrophobicity and resistance against microorganisms of heat and chemically crosslinked poly(vinyl alcohol) nanofibrous membranes2019In: Chemical Engineering Journal, ISSN 1385-8947, E-ISSN 1873-3212, Vol. 360, p. 788-796Article in journal (Refereed)
    Abstract [en]

    Poly(vinyl alcohol) (PVA) is a water-soluble, semi-ionic and biocompatible polymer with excellent chemical and thermal stability. The chemical crosslinking of PVA membrane improve its stability towards humidity and water. In the present work, PVA nanofibrous membranes were fabricated using roller electrospinning techniques. The prepared membranes were crosslinked by heat treatment, glutaraldehyde dipping, and glutaraldehyde vapour. Furthermore, octadecyltrichlorosilane (OTS) treatment was used for hydrophobization of the crosslinked membranes. The prepared crosslinked membranes were analysed by scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). The hydrophobization of PVA nanofibrous membranes were analysed by employing optical goniometer and auto-dynamic vapour sorption (AVS) techniques. Further, the PVA membranes were tested against algae and mould growth at in-vitro laboratory conditions. The SEM and FTIR results revealed significant differences in the morphology of the PVA nanofibrous membranes and in chemical bond formation due to crosslinking treatments. Water contact angle and AVS data confirmed a hydrophobization of PVA membranes by the treatments.

  • 49.
    Neitzel, Nicolas
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Eder, Michaela
    Max Planck Institute of Colloids and Interfaces, Germany.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Michigan Technological University, USA.
    Walther, Thomas
    IKEA Industry AB, Sweden.
    Adamopoulos, Stergios
    Swedish University of Agricultural Sciences, Sweden.
    Chemical composition, particle geometry, and micro-mechanical strength of barley husks, oat husks, and wheat bran as alternative raw materials for particleboards2023In: Materials Today Communications, ISSN 2352-4928, Vol. 36, article id 106602Article in journal (Refereed)
    Abstract [en]

    Particleboards are used worldwide in various industry segments, like construction and furniture production. Nevertheless, increase in wood prices and logistical challenges urge the particleboard industry to find alternative raw materials. By-products and residues from the agricultural and food industries could offer possibilities for material sourcing at a local level. This study aimed to investigate the chemical composition, particle geometry, anatomical structure, and microtensile characteristics of such material, specifically barley husks (BH), oat husks (OH), and wheat bran (WB). Barley and oat husks were found to have comparable hemicelluloses and lignin contents to industrial wood chips but contained more ash. Wheat bran was rich in extractives and showed high buffering capacity. Light microscopy and microcomputed tomography revealed details of leaf structure for BH and OH as well as the multi-layer structure of WB. The ultimate microtensile strength of BH, various OH samples, and WB were respectively 2.77 GPa, 0.84-2.42 GPa, and 1.45 GPa. The results indicated that the studied materials could have potential uses as furnish materials in non-load bearing particleboards, where thermal or acoustic insulation properties are desirable.

  • 50.
    Neitzel, Nicolas
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Michigan Technological University, USA.
    Adamopoulos, Stergios
    Swedish University of Agricultural Sciences, Sweden.
    A dialdehyde starch-based adhesive for medium-density fiberboards2023In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 18, no 1, p. 2155-2171Article in journal (Refereed)
    Abstract [en]

    Bio-based adhesives have gained considerable attention in the last years as more sustainable and healthier alternatives to the formaldehyde-based adhesives used today in wood-based panel manufacturing. In this study, dialdehyde starch (DAS) with various aldehyde contents was prepared by using sodium metaperiodate as an oxidizing agent. Characterizations were performed by employing Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and thermal stability analysis. Different adhesive compositions were used for making medium-density fiberboard (MDF) panels. They were based on DAS (12 wt% based on fiber), emulsifiable diphenylmethane diisocyanate (eMDI, 2-4 wt% based on DAS), and microfibrillated cellulose (MFC, 0.5-1.0 wt% based on DAS). Fibers and the adhesive components were mixed with a combination of dry mixing and wet spraying. The physical and mechanical properties of MDF panels bonded with different DAS-based adhesives were compared with those of melamine urea-formaldehyde (MUF) adhesive and sole eMDI. The results showed that the MDF panels made with DAS-MFC-eMDI of 99.52% bio-based content showed comparable properties to standard panels with a commercial MUF adhesive. It was implied that DAS in the presence of small amount of eMDI can create strong bonds with wood fibers, while an additional positive effect on bonding was due to the contact surface enlargement of MFC.

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