Your search resulted in 23 documents.
The distribution of introduced acetyl groups and a linseed oil model substance in wood examined by microautoradiography and ESEM
2000 - IRG/WP 00-40169
Microautoradiography, a photographic method that shows the localization of substances labelled with radioactive isotope, and Environmental Scanning Electron Microscopy (ESEM) were combined to enhance sensitivity, resolution and reliability for examination of the distribution of introduced substances in wood. The preparation of microautoradiographs is less complicated when investigated with ESEM an...
Improvements of stability and durability of beechwood (Fagus sylvatica) by means of treatment with acetic anhydride
1991 - IRG/WP 3645
In the present investigations, beechwood (Fagus sylvatica) was treated with non-catalysed acetic anhydrid at 120°C and some physical- and biological parameters of the treated wood were compared with those of non-treated wood. The radial and tangential shrinkage and swelling, respectively, and the absorption capacity of the acetylated wood against moisture is considerably lower. The durability aga...
A survey of factors affecting decay resistance of wood modified with acetic anhydride
2012 - IRG/WP 12-40594
From the range of information published, acetylation appears well suited to provide adequate protection against biological attack for materials derived from typically non-durable wood species. Acetylated wood is now commercially available both in Europe and in the USA. But still there are a lot of unanswered questions related to fungal decay mechanisms in acetylated wood. The paper summarize exist...
G Alfredsen, P O Flæte, H Militz
Elucidation of reactive sites of wood modified with acetic anhydride: Insights from density functional theory calculations
2020 - IRG/WP 20-40892
Density functional theory (DFT) was employed to investigate the interaction of cellulose and lignin with acetic anhydride for explaining the wood modification process. Atoms in molecules (AIM) and reduced density gradient (RDG) along with non-covalent interaction (NCI) plots were used to analyse the intermolecular bonding characteristics. Cellulose was modelled with a cellobiose unit (dimer of glu...
V Ponnuchamy, A Sandak, J Sandak, R Herrera Diaz
The decay resistance of chemically modified aspen composites to the white rot fungus Coriolus versicolor (L.) Quelet
1998 - IRG/WP 98-40122
Chemical modification of Aspen wood (Populus tremula L.) in the form of solid wood, veneers and sawdust was undertaken by a two step procedure consisting of esterification with maleic anhydride (MA) and subsequent oligoesterification with MA and glycidyl methacrylate (GMA) or allyl glycidyl ether (AGE). Modified wood was thermoplastic and was thermally formed by hot-pressing to produce veneer or s...
M C Timar, A J Pitman, M D Mihai
Durability of pine modified by 9 different methods
2004 - IRG/WP 04-40288
The decay resistance was studied for pine modified by nine methods of wood modification: 1) Acetylation, 2) Treatment with methylated melamine resin (MMF), 3) Acetylation followed by post-treatment with MMF-resin, 4) Thermal modification, 5) Furfurylation, 6) Maleoylation (using water solution of MG or ethanol solution of maleic anhydride), 7) Succinylation, 8) NMA-modification and 9) modification...
M Westin, A O Rapp, T Nilsson
Efficacy of anhydrides as wood protection chemicals - II. Performance against soft rot fungi
1998 - IRG/WP 98-30174
Pine sapwood modified with various anhydrides and with butyl isocyanate was tested for its resistance to soft rot decay. Small stakes were exposed for 20 months in unsterile soil in a fungal cellar test. Wood modified with butyl isocyanate performed better than any of the anhydrides tested, with a threshold level of protection (less than 3% weight loss) at 12% weight percent gain (WPG). Stakes ac...
S C Forster, M D C Hale, G R Williams
The biological effectiveness of wood modified with heptadecenylsuccinic anhydride against two brown rot fungi: Coniophora puteana and Gloeophyllum trabeum
1992 - IRG/WP 92-3705
A modified soil block test was carried out using wood samples reacted with heptadecenylsuccinic anhydride (ASA). This modification gave good resistance to decay brought about by the brown rot fungi Coniophora puteana and Gloeophyllum trabeum during the twelve week exposure period. Results indicated that there was a good correlation between increased loading of modifying reagent and an increase in ...
C Codd, W B Banks, J A Cornfield, G R Williams
Experiments on the degradation of tributyltin oxide: A progress report
1984 - IRG/WP 3287
A variety of experiments designed to assess the chemical and physical factors affecting the degradation of tributyltin oxide in treated timber are described. Simple procedures in which temperature and oxygen availability were increased in the presence of wood and water suggest that the wood itself was of prime importance. Attempts to decrease degradation with antioxidants were unsuccessful but led...
R J Orsler, G E Holland
Dimensional stability and decay resistance of wood upon modification with some new type chemical reactants
1994 - IRG/WP 94-40028
Solid wood of home grown species can be upgraded by chemical modification with environmentally acceptable chemicals. The best kwown example of modification reaction is acetylation with acetic anhydride. A continued search for reactive chemicals other than acetic anhydride is ongoing, aiming at the improvement of technical properties of wood. This contribution deals with the results of a screening ...
P Goethals, M Stevens
The kinetics of anhydride modification reactions of wood. Experimental results and theoretical modelling
1998 - IRG/WP 98-40125
Although the chemical modification of wood remains a fertile area for research, there has been little work performed on the kinetics of the modification process. The reaction kinetics of a series of linear chain and cyclic anhydrides has been studied and activation energies of the reaction determined. The reaction kinetic profiles are determined by the relative rates of reaction of the reagent wit...
C A S Hill, J G Hillier
Production, function and neutralization of oxalic acid produced by the dry rot fungus and other brown rot fungi
1987 - IRG/WP 1330
The formation of oxalic acid by the wood-destroying fungi causing brown rot, is found to be the key which by hydrolysing the hemicellulose brings the cellulose in the tracheid wall in contact with the cellulase enzymes and yeld watersoluble sugars leaving only a lignin skeleton. To control the pH in the substrate the excess oxalic acid is precipitated to water insoluble calcium oxalate by the dry ...
Decay resistance of propionylated Iranian beech against the white rot fungus Tramets versicolor
2008 - IRG/WP 08-30449
In this study, the decay resistance of propionylated beech was investigated against the white rot fungus Trametes versicolor. Iranian beech (Fagus orientalis) was modified with propionic anhydride at different temperatures, concentrations and times without using any catalyst. Different weight percentage gains (WPGs) were obtained under different conditions. The decay resistance of the esterifed wo...
M R M Farahani, S M Hosseini
Wood preservation by a mixed anhydride treatment: Using simple models of polymeric wood compounds
2008 - IRG/WP 08-30457
Treatment of wood by a mixed aceto/oleic (or other fatty acid residue) anhydride promoted as a safe and environment friendly wood preservation system has been examined quantitatively by liquid phase 13C NMR and solid phase MAS-DEC (proton decoupling) 13C NMR through all its different stages to determine which reactions occur with simple model compounds of the polymeric constituents of wood. The p...
F Lyon, M-F Thevenon, A Pizzi, G Tondi, A Despres, J Gril, S Rigolet
Effects of acetic acid and nitric acid pre-treatment on copper content of spruce wood treated with CBA-A and CCA
2008 - IRG/WP 08-40406
This work investigates the effects of nitric acid and acetic acid on compression strength values and copper retention contents of refractory spruce wood (Picea oriental L.) treated with the waterborne preservative Copper azole, (CBA-A, Tanalith-E 3492) and copper / chrom / arsenic (CCA). Before the CBA-A and CCA treatment, the samples were immersed in 500 ml of nitric and acetic acid solutions for...
S Yildiz, E Dizman, Ü C Yildiz
Surface moulds and staining fungi on acetylated wood – effect of increasing acetyl content
2013 - IRG/WP 13-10797
Wood used in outside applications is susceptible to weathering and photo degradation, which often leads to surface discoloration, loss of brightness and surface deterioration. Research has shown that acetylated wood is more resistant against brown rot, white rot and soft rot, and more dimensionally stable than untreated wood. However, acetylated wood seems still to be disfigured by surface moulds ...
L Ross Gobakken, S Bardage, C J Long II
Short-term protection of palm wood against moulds and decay fungi by environment-friendly organic acids
2015 - IRG/WP 15-10843
Felled palm trunks are susceptible to fungi as long as their moisture content is above fibre saturation. During this period, it has to be protected against moulds and decay fungi. The study tested environmental-friendly organic acids for their protecting efficiency. Small samples of Date palm (Phoenix dactylifera) and Oil palm (Elaeis guineensis) wood were treated with weak organic acids and subse...
M Bahmani, O Schmidt
Prevention of fungal damage of oil and date palm wood by organic acids
2017 - IRG/WP 17-10877
Felled palm trunks are susceptible to fungi as long as their moisture content is above fibre saturation. During this period, palm wood has to be protected against mould and rot fungi. Environmental-friendly organic acids are suitable. Small samples of oil palm (Elaeis guineensis) and date palm (Phoenix dactylifera) wood were treated with 1 to 10% solutions of acetic acid and propionic acid, respec...
M Bahmani, O Schmidt
Copolymers of tannin extracts as wood protection agents
2017 - IRG/WP 17-30709
Wouldn´t be a dream to preserve wood with the substances which the nature already synthesizes for protecting itself? The idea we would like to pursue is simple: Increase the concentration of these substances, the tannins, trying to fix them properly in wood. It appears easy but it is not. Sensibility against leaching, fungal decay and weathering were observed. In this paper new flavonoid co-polym...
G Tondi, L Sommerauer, A Oberle, A Petutschnigg, M-F Thevenon
Accessibility of hydroxyl groups in anhydride modified wood as measured by deuterium exchange
2017 - IRG/WP 17-40784
Acetylated wood shows improved properties largely due to the reduced amount of water in the acetylated cell wall. However, the exact mechanism by which water is excluded in acetylated wood remains unclear. Acetylation reduces hydroxyl content by substitution of hydroxyl groups in wood polymers but may also hinder access to unmodified hydroxyls by physical bulking. This work assesses hydroxyl acces...
G Beck, S Strohbusch, E Larnøy, H Militz, C Hill
Development of beech wood thermo-chemical modification treatments based on different vinylic derivatives of glycerol and polyglycerol
2019 - IRG/WP 19-40855
In this study, a combination between chemical and thermal wood modification has been investigated. Seven types of a low concentration of 10% aqueous additive solution of vinylicglycerol [glycerol-maleic anhydride (Gly-MA), glycidyl methacrylate (GM), and Glycerol methacrylate-maleic anhydride (GM/MA(2eq))], vinylicpolyglycerol [polyglycerol-maleic anhydride (PG-MA), polyglycerol methacrylate (PGM...
M Mubarok, S Dumarcay, H Militz, K Candelier, M-F Thevenon, P Gerardin
Investigations into the use of Maleic Anhydride/Sodium Hypophosphite as a Wood Modification Process
2020 - IRG/WP 20-40891
The formation of crosslinked bonds between wood constituents is believed to be an effective way to stabilize wood against wet conditions. The possibility to use maleic anhydride (MA) combined with sodium hypophosphite (SHP) as crosslinking agents was studied, using Scots pine sapwood and a model compound. The modified wood showed weight gain and bulking effect after treatment and subsequent Soxhle...
I Kim, D Jones, O Karlsson, D Sandberg, O N Antzutkin, F Ullah Shah
Mechanical and biological durability properties against soft-rot and subterranean termite in the field (grave-yard test) of beech wood impregnated with different derivatives of glycerol or polyglycerol and maleic anhydride followed by thermal modification in an opened or in a closed system
2021 - IRG/WP 21-40917
This paper presents mechanical and biological durability properties in soil beg test (soft-rot test) and field test (grave-yard test) against subterranean termite of the wood modified with an aqueous vinylic derivative of glycerol/polyglycerol or maleic anhydride cured in an opened or in a closed system. Wood modification was performed through impregnation of European beech (Fagus sylvatica) with ...
M Mubarok, H Militz, S Dumarcay, I W Darmawan, Y S Hadi, P Gerardin