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Adamopoulos, StergiosORCID iD iconorcid.org/0000-0002-6909-2025
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Publications (10 of 123) Show all publications
Hosseinpourpia, R., Adamopoulos, S. & Parsland, C. (2019). Utilization of different tall oils for improving the water resistance of cellulosic fibers. Journal of Applied Polymer Science, 136(13), Article ID 47303.
Open this publication in new window or tab >>Utilization of different tall oils for improving the water resistance of cellulosic fibers
2019 (English)In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 136, no 13, article id 47303Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2019
National Category
Wood Science Composite Science and Engineering Paper, Pulp and Fiber Technology Bio Materials Polymer Chemistry
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-78872 (URN)10.1002/app.47303 (DOI)000454418300034 ()
Funder
VINNOVA, 2015‐04825The Kamprad Family Foundation, 20160052
Available from: 2018-11-19 Created: 2018-11-19 Last updated: 2019-01-22Bibliographically approved
Adamopoulos, S., Ahmed, S. A. & Lankveld, C. (2018). Acoustic properties of acetylated wood under different humid conditions and its relevance for musical instruments. In: Jos Creemers, Thomas Houben, Bôke Tjeerdsma, Holger Militz and Brigitte Junge (Ed.), Proceedings of the 9th European Conference on Wood Modification 2018, Arnhem, The Netherlands: . Paper presented at 9th European Conference on Wood Modification (ECWM9), September 17-18, Arnhem, The Netherlands (pp. 61-61). The Netherlands: Practicum
Open this publication in new window or tab >>Acoustic properties of acetylated wood under different humid conditions and its relevance for musical instruments
2018 (English)In: Proceedings of the 9th European Conference on Wood Modification 2018, Arnhem, The Netherlands / [ed] Jos Creemers, Thomas Houben, Bôke Tjeerdsma, Holger Militz and Brigitte Junge, The Netherlands: Practicum , 2018, p. 61-61Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

In musical instrument making, less expensive wood species and materials with good characteristics and acoustical properties can provide potentials to find alternatives to the traditional exotic wood species used today. Modified wood could be such a choice if shows similar sound characteristics to wood coming from endangered and expensive tropical species with problematic commercial availability. In musical instruments, the overall functionality depends on the contribution of wood to different material performance indexes like sound radiation coefficient (R), characteristic impedance (z) and acoustic conversion efficiency (ACE). In this study, the performance indexes were measured for acetylated beech, maple and radiata pine and compared with these obtained for the reference wood materials maple, mahogany, alder and ash. A non-destructive free-free flexural vibration test method was used at constant temperature (20oC) but in different humid conditions- dry (35% RH), standard (65% RH) and wet (85% RH). Dimensional changes in the different humid conditions were also taken in account. Acetylated wood showed lower EMC with higher dimensional stability at each humidity level as compared with the reference wood materials. These properties are considered important factors for making quality musical instruments. Based on the acoustical properties, acetylated wood materials, especially radiata pine, showed good potential for use for musical instruments where specific characteristics of sound are required. However, the other types of acetylated wood can also be used for specific musical instruments.

Place, publisher, year, edition, pages
The Netherlands: Practicum, 2018
Keywords
Acoustic conversion efficiency, damping, equilibrium moisture content, free-free flexural vibration, volumetric shrinkage
National Category
Wood Science Chemical Engineering Polymer Technologies
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-77908 (URN)
Conference
9th European Conference on Wood Modification (ECWM9), September 17-18, Arnhem, The Netherlands
Available from: 2018-09-20 Created: 2018-09-20 Last updated: 2018-10-22Bibliographically approved
Ahmed, S. A. & Adamopoulos, S. (2018). Acoustic properties of modified wood under different humid conditions and their relevance for musical instruments. Applied Acoustics, 140, 92-99
Open this publication in new window or tab >>Acoustic properties of modified wood under different humid conditions and their relevance for musical instruments
2018 (English)In: Applied Acoustics, ISSN 0003-682x, Vol. 140, p. 92-99Article in journal (Refereed) Published
Abstract [en]

In musical instrument making, there is a strong need to find alternatives to the traditional endangered and expensive tropical wood species used today. The present study examined whether different commercial and experimental modified wood materials have the necessary acoustic qualities under different humid conditions (dry, standard and wet) to contribute to the use of raw materials for wooden musical instruments. The materials were thermally-modified wood (ash, aspen and birch), acetylated wood (beech, maple and radiata pine), melamine- and phenol formaldehyde-treated beech and furfurylated Scots pine (Kebony Scots pine). Investigations involved physical (density ρ, Equilibrium moisture content EMC, volumetric shrinkage) and dynamic elastic testing by a free-free flexural vibration method to determine various acoustic characteristics: specific dynamic modulus (MOEdyn/ρ), damping coefficient (tanδ), speed of sound (c), specific acoustic impedance (z), sound radiation coefficient (R) and acoustic conversion efficiency (ACE). The modified materials and especially acetylated wood showed low EMC values and high dimensional stability at each humidity level, which are considered important factors for making quality musical instruments. Based on the obtained value ranges of all acoustical properties, the different modified wood materials could find uses in musical instruments where specific characteristics of sound are required. Furthermore, most of the modified materials showed an excellent acoustic performance in the three humid conditions based on a high ACE and low tanδ. Furfurylated Scots pine and phenol formaldehyde-treated beech showed an inferior acoustic quality with the lowest ACE and the highest tanδ, which is a less favourable combination for most of the musical instruments.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Wood modification; Dimensional stability; Free-free flexural vibration; Dynamic elastic modulus; Damping; Sound velocity; Sound radiation; Acoustic impedance; Acoustic conversion efficiency
National Category
Wood Science
Research subject
Physics, Waves and Signals
Identifiers
urn:nbn:se:lnu:diva-74511 (URN)10.1016/j.apacoust.2018.05.017 (DOI)000440121900010 ()
Available from: 2018-05-24 Created: 2018-05-24 Last updated: 2018-08-28Bibliographically approved
Hosseinpourpia, R., Adamopoulos, S. & Mai, C. (2018). Effects of acid pre-treatments on the swelling and vapor sorption of thermally modified Scots pine (Pinus sylvestris L.) wood. BioResources, 13(1), 331-345
Open this publication in new window or tab >>Effects of acid pre-treatments on the swelling and vapor sorption of thermally modified Scots pine (Pinus sylvestris L.) wood
2018 (English)In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 13, no 1, p. 331-345Article in journal (Refereed) Published
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.

National Category
Wood Science Polymer Chemistry
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-68862 (URN)10.15376/biores.13.1.331-345 (DOI)000427790000027 ()
Available from: 2017-11-20 Created: 2017-11-20 Last updated: 2018-04-06Bibliographically approved
Hemmilä, V., Zabka, M. & Adamopoulos, S. (2018). Evaluation of dynamic microchamber as a quick factory formaldehyde emission control method for industrial particleboards. Advances in Materials Science and Engineering, Article ID 4582383.
Open this publication in new window or tab >>Evaluation of dynamic microchamber as a quick factory formaldehyde emission control method for industrial particleboards
2018 (English)In: Advances in Materials Science and Engineering, ISSN 1687-8434, E-ISSN 1687-8442, article id 4582383Article in journal (Refereed) Published
Abstract [en]

The most common formaldehyde control method for wood panels in Europe, the perforator method, measures formaldehyde content, while most of the legal requirements in the world are based on emissions. Chamber methods typically used for emission measurements require too much time to reach steady state for factory quality control. The aim of this study was therefore to investigate whether emission values of particleboards measured one day after production would be usable for quality control purposes. The correlation between 1-day and 7-day emission values was determined using a dynamic microchamber (DMC). Three industrial board types that differed in density and emission levels were used for the evaluation. The online emission measuring equipment Aero-laser AL4021 connected to the 1 m3 chamber was used to gain further information on the emission reduction behaviour of the different board types. Only the two particleboard types with higher densities showed good correlation between the 1-day and 7-day emissions. The overall results suggested that 1-day emission values can be used for factory quality control purposes; however, if the initial 1-day values are above the permitted level, extensive evaluation for each individual board type needs to be performed

Place, publisher, year, edition, pages
Hindawi Publishing Corporation, 2018
National Category
Wood Science Other Chemical Engineering
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-75901 (URN)10.1155/2018/4582383 (DOI)000436291600001 ()
Available from: 2018-06-14 Created: 2018-06-14 Last updated: 2018-07-13Bibliographically approved
van Blokland, J., Adamopoulos, S., Olsson, A., Oscarsson, J. & Källander, B. (2018). Evaluation of non-destructive test methods to predict bending properties of thermally modified timber. In: 2018 World Conference on Timber Engineering (WCTE),August 20-23, 2018, Seoul, Republic of Korea: . Paper presented at 2018 World Conference on Timber Engineering (WCTE),August 20-23, 2018, Seoul, Republic of Korea (pp. 8). National Institute of Forest Science (NIFoS)
Open this publication in new window or tab >>Evaluation of non-destructive test methods to predict bending properties of thermally modified timber
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2018 (English)In: 2018 World Conference on Timber Engineering (WCTE),August 20-23, 2018, Seoul, Republic of Korea, National Institute of Forest Science (NIFoS) , 2018, p. 8-Conference paper, Published paper (Refereed)
Abstract [en]

Thermally modified wood is available through a number of manufacturers in Europe on today’s market for interior and exterior building products. Thermal modification of wood allows for improvement of dimensional stability and durability, but a considerable decrease in strength properties occurs. Despite this loss in strength, thermally modified wood shows potential to be further exploited in structures exposed to loading. For such applications, accurate prediction of its static bending behaviour is essential. This paper studies the applicability of two different non-destructive test (NDT) techniques in estimating the bending properties of thermally modified timber (TMT). The study was done on 100 Norway spruce logs. One hundred (100) boards (i.e. one from each log) were thermally modified and the mirrored 100 boards were used as controls. After modification, resonance-based and time-of-flight measurements of axial wave velocity were carried out. Subsequently, all 200 boards were bent to failure following European standard EN408. This study shows that although TMT has a lower bending strength than unmodified timber, predictions of bending strength and stiffness using the NDT techniques are possible and with sufficient accuracy. The resonance-based method gave better predictions of the bending properties of TMT in respect to time-of-flight method.

Place, publisher, year, edition, pages
National Institute of Forest Science (NIFoS), 2018
Keywords
ThermoWood®, resonance method, time-of-flight method, four-point bending, Norway spruce
National Category
Wood Science Building Technologies
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-77976 (URN)
Conference
2018 World Conference on Timber Engineering (WCTE),August 20-23, 2018, Seoul, Republic of Korea
Note

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Available from: 2018-09-24 Created: 2018-09-24 Last updated: 2018-10-22Bibliographically approved
Adamopoulos, S. (2018). Group of Forest Products. In: : . Paper presented at Symposium "Perspectives in Renewables", 4-5 June 2018, BOKU Vienna, Tulln, Austria.
Open this publication in new window or tab >>Group of Forest Products
2018 (English)Conference paper, Poster (with or without abstract) (Other academic)
National Category
Wood Science Other Chemical Engineering
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-76992 (URN)
Conference
Symposium "Perspectives in Renewables", 4-5 June 2018, BOKU Vienna, Tulln, Austria
Available from: 2018-07-25 Created: 2018-07-25 Last updated: 2018-07-25Bibliographically approved
Jiang, W., Kumar, A. & Adamopoulos, S. (2018). Liquefaction of lignocellulosic materials and its applications in wood adhesives — A review. Industrial crops and products (Print), 124, 325-342
Open this publication in new window or tab >>Liquefaction of lignocellulosic materials and its applications in wood adhesives — A review
2018 (English)In: Industrial crops and products (Print), ISSN 0926-6690, E-ISSN 1872-633X, Vol. 124, p. 325-342Article in journal (Refereed) Published
Abstract [en]

Liquefaction, a useful method of turning whole biomass into liquids, provides advantages for energy andpolymers and finds applications in many sectors. This paper reviews the different liquefaction technologies andrecent advances in the development of sustainable wood adhesives. Current liquefaction technologies includehydrothermal liquefaction (HTL) and moderate acid-catalyzed liquefaction (MACL). HTL produces bio-oils asprimary products, and solid residues and gases as by-products. MACL depends on the solvent types used, whichare grouped to polyhydric alcohols and phenols. Bio-polyols from alcohol liquefaction, phenolated biomass fromphenol liquefaction and phenolic compounds rich-HTL bio-oils have been used in the production of liquefiedbiomass-based adhesives, which have shown competitive properties but face challenges for industrial uses. Yet, abetter understanding of reaction pathways and optimization of the liquefaction processes is needed.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Biomass liquefaction, Bio-oils, Phenolic compounds, Polyols, Wood adhesives
National Category
Polymer Technologies Biochemicals Composite Science and Engineering Wood Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology; Natural Science, Chemistry
Identifiers
urn:nbn:se:lnu:diva-77108 (URN)10.1016/j.indcrop.2018.07.053 (DOI)000447569100039 ()
Available from: 2018-08-13 Created: 2018-08-13 Last updated: 2018-11-08Bibliographically approved
Hosseinpourpia, R., Echart, A. S., Adamopoulos, S., Gabilondo, N. & Eceiza, A. (2018). Modification of Pea Starch and Dextrin Polymers with Isocyanate Functional Groups. Polymers, 10(9), Article ID 939.
Open this publication in new window or tab >>Modification of Pea Starch and Dextrin Polymers with Isocyanate Functional Groups
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2018 (English)In: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 10, no 9, article id 939Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
MDPI, 2018
National Category
Polymer Chemistry Food Science Wood Science
Research subject
Natural Science, Food Science; Chemistry, Organic Chemistry
Identifiers
urn:nbn:se:lnu:diva-77435 (URN)10.3390/polym10090939 (DOI)000449988800008 ()
Funder
VINNOVA, 2015-04825
Available from: 2018-08-28 Created: 2018-08-28 Last updated: 2018-11-29Bibliographically approved
Kumar, A., Ryparovà, P., Kasal, B., Adamopoulos, S. & Hajek, P. (2018). Resistance of bamboo scrimber against white-rot and brown-rot fungi. Wood Material Science & Engineering
Open this publication in new window or tab >>Resistance of bamboo scrimber against white-rot and brown-rot fungi
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2018 (English)In: Wood Material Science & Engineering, ISSN 1748-0272, E-ISSN 1748-0280Article in journal (Refereed) Epub ahead of print
Abstract [en]

Bamboo scrimber is one of the most emerging structural materials for future building applications andit possesses properties comparable to other natural wood-based engineered materials such as glulam,laminated veneer lumber and cross-laminated timber. The goal of this work was to study the decayresistance of bamboo scrimber against white-rot (Trametes versicolor) and brown-rot fungi (Serpulalacrymans). Bamboo scrimber samples were incubated in petri dishes with the wood-decaying fungiand the weight loss after 12 weeks was measured. The surface morphology of fungal-degradedbamboo scrimber was evaluated using optical microscopy. Based on the percentage weight loss,bamboo scrimber could be classified as highly resistant against bio-deterioration by white andbrown-rot fungi.

National Category
Wood Science
Research subject
Technology (byts ev till Engineering), Forestry and Wood Technology
Identifiers
urn:nbn:se:lnu:diva-74431 (URN)10.1080/17480272.2018.1475420 (DOI)
Available from: 2018-05-21 Created: 2018-05-21 Last updated: 2019-01-18
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ORCID iD: ORCID iD iconorcid.org/0000-0002-6909-2025

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