Your search resulted in 2977 documents. Displaying 25 entries per page.
Effect of acetylation on decay resistance of wood against brown-rot, white-rot and soft-rot fungi
1989 - IRG/WP 3540
Effect of acetylation on decay resistance of wood was investigated using wood blocks of Cryptomeria japonica, Pinus densiflora, Albizia falcata and Fagus crenata. Blocks were treated with uncatalyzed acetic anhydride for different lengths of time and exposed to Tyromyces palustris, Serpula lacrymans, Coriolus versicolor and unsterilized soil. The action of OH-radical on acetylated wood was also ex...
M Takahashi, Y Imamura, M Tanahashi
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
Novel wood modification processes for window and cladding products
2004 - IRG/WP 04-40285
Because of the low natural durability and low dimensional stability of European wood species, the usage of wood for window frames has decreased dramatically during the last decade. In a joint project of several German research institutes and the window industry, following wood modification systems were compared.
heat treatment (3 different materials from 2 companies)
acetylation (pine sapwood an...
A Krause, C Hof, H Militz
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...
M Rosenqvist
Worldwide in-ground stake test of acetylated composite boards
1997 - IRG/WP 97-40088
Acetylated wood composite stakes are being tested in ground contact (graveyard test) in seven fields around the world. Three types of acetylated wood composites were prepared: spruce fiberboard in Sweden, aspen fiberboard in Madison and rubber wood particle board in Indonesia. Two levels of acetylation were used, a high level of ~20% acetyl content and a low level of 10% acetyl content. Control bo...
R M Rowell, B S Dawson, Y S Hadi, D D Nicholas, T Nilsson, D V Plackett, R Simonson, M Westin
Acetylated solid wood. Laboratory durability test (part 2) and field trials
1995 - IRG/WP 95-40048
Degradation of acetylated beech, pine and poplar by soft rot fungi was related to strength loss in a laboratory test. No strength loss was noticed for poplar acetylated to a weight percent gain (WPG) of more than 11.2% and beech with a WPG of 12.8%. Several field trials were set up to determine the durability of acetylated products in practice. They included a field test to determine the durabilit...
E P J Beckers, H Militz, M Stevens
Soft rot decay in acetylated wood. Chemical and anatomical changes in decayed wood
2002 - IRG/WP 02-40231
Acetylated Beech (Fagus sylvatica) and Scots Pine (Pinus sylvestris) wood were studied in soil beds under laboratory conditions for longer periods. High mass losses and dynamic MOE losses were measured in non-acetylated wood and at lower weight percent gains (WPG). Rapid losses of lignin, holocellulose and ?-cellulose occurred in non-acetylated beech wood and no losses were detected at the highest...
B Mohebby, H Militz
Termite and fungal resistance of in situ polymerized tributyltin acrylate and acetylated Indonesian and USA wood
2000 - IRG/WP 00-30219
Wood [Indonesian pine (IP), Indonesian Jabon (IJ) and USA southern yellow pine (USP)] was either in situ polymerized with tributyltin acrylate (TBTA) or acetylated and then exposed to termite and fungal degradation both in laboratory tests and field exposure. The TBTA woods had an average weight percent gain (WPG) of 11% for IP, 12% for IJ, and 10% for USP. The acetylated woods had a WPG of 15-27%...
R E Ibach, Y S Hadi, D Nandika, S Yusuf, Y Indrayani
Resistance of acetylated wood to basidiomycetes, soft rot and blue stain
1994 - IRG/WP 94-40021
Poplar (Populus spp.), beech (Fagus sylvatica) and pine sapwood (Pinus sylvestris) samples were acetylated in a semi-industrial acetylation plant and tested for durability according to European standards. Resistance to Gloeophyllum trabeum, Coniophora puteana and Coriolus versicolor could be reached at a weight percent gain (WPG) of 12%. Susceptibility of acetylated pine to Poria placenta was high...
E P J Beckers, H Militz, M Stevens
Resistance of acetylated wood to biological degradation. Evaluation of field test
1997 - IRG/WP 97-30139
Acetylated wood samples were tested in ground contact (stake test) at two test fields, one in Simlångsdalen, Sweden, and one in Viikki, Finland, according to European standard EN 252. The test samples were inspected annually and their condition was compared with that of untreated controls and of samples treated with two reference CCA preservatives. The use of untreated controls and preservative t...
P Larsson Brelid, R Simonson, Ö Bergman
Chitosan for wood protection - state of the art
2005 - IRG/WP 05-30378
The aim of this paper was to give a state of the art description of chitosan as a wood protecting agent. Chitosan is a metal free natural compound derived from crustacean shells and is under evaluation as an environmentally benign wood protecting agent. Information from journals states that chitosan may act both fungistatically and at higher concentrations, as fungitoxic, but the mode of action is...
M Eikenes, G Alfredsen, E Larnøy, H Militz, B Kreber, C Chittenden
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
Biological degradation resistance of wood acetylated with thioacetic acid
1983 - IRG/WP 3223
Chemically, modification of wood is being considered as an alternative to conventional preservation by toxic chemicals. Acetylated wood has been reported to be quite resistant to most biodegrading organisms at weight percent gains (WPG) around 15-19. The conventional acetylation techniques with acethic anhyrdride result in generation of acetic acid. However, acetylation with thioacetic acid overco...
S Kumar, S C Agarwal
Durability of some alternatives to preservative treated wood
2004 - IRG/WP 04-30353
The environmental discussion in Sweden has lead to an increasing use of naturally durable domestic wood species and wood treated according to alternative methods for use above ground. A number of these alternatives have been tested according to field- and laboratory tests and compared to wood treated with preservatives for above ground use. Seven untreated wood species, four alternative wood treat...
M-L Edlund
Effect of fungal degradation on the chemical composition of acetylated beech wood
2003 - IRG/WP 03-40267
This study investigated the impact of fungal attack on the chemical composition of acetylated wood. Beech wood acetylated to different degrees was exposed to decay by the white-rot fungus Trametes versicolor under solid-state fermentation conditions. Laboratory soil-bed assays were also conducted to study the degradation of acetylated wood by soft rot fungi and other soil-inhabiting microorganisms...
H Militz, Dong-won Son, L Gómez-Hernández, R Sierra-Alvarez
Wood plastic composites from modified wood; Part 1 - Conceptual idea, mechanical and physical properties
2006 - IRG/WP 06-40338
Wood plastic composites, WPCs, are rapidly taking shares from preservative treated wood on the decking market. However, the long term performance of the WPC products in this application is uncertain. Therefore, in an attempt to increase the long term performance and durability, the substitution of the unmodified wood component with modified wood has been studied in the work presented in this paper...
P Larsson Brelid, B K Segerholm, M Westin, M E P Wålinder
Further discussion of biological durability assessments of acetylated wood from several European institutes
2006 - IRG/WP 06-40340
In the last decade, interest in the development of wood modification systems has increased in Europe. Alongside several industrial initiatives for heat treatments, there have also been scaling up and pilot plant projects for chemical wood modification. Between 2000-03, the European Commission funded the "Thematic Network on Wood Modification". This paper features a re-evaluation of work undertaken...
D Jones, W Homan, F Bongers
Wood plastic composites from modified wood. Part 2 - Durability in laboratory decay tests
2006 - IRG/WP 06-40353
The decay resistance of wood plastic composites, WPCs, was tested according to modified versions of AWPA E10 (soil-block test) and ENV 807 (tests in three un-sterile soils, terrestrial microcosms, TMCs). The WPC materials were conically extruded profiles with 30% polypropylene content. The 70% wood content was untreated Scots pine sapwood, acetylated pine and heat treated Norway spruce, respective...
M Westin, P Larsson Brelid, M L Edlund, G Alfredsen
Durability of some alternatives to preservative-treated wood. Progress report 2: Results from field tests after 5 years’exposure
2007 - IRG/WP 07-30442
A number of alternatives to preservative-treated wood have been tested according to EN 252 (stake test) and a specially designed ground-proximity field test, the latter in Sweden as well as in Hawaii, USA. Seven untreated wood species and four alternative wood treatments labelled as environmentally friendly (acetylation, linseed oil, heat treatment, vinyl polymer) were included in the study. Four ...
M-L Edlund, J Jermer
A step towards a better understanding of fungal colonization of modified wood - QRT-PCR studies
2008 - IRG/WP 08-10653
The area of wood protection is in a period of change. New wood protection systems have been developed while their mode of action remains insufficiently understood. The development of molecular methods provides potential tools to investigate the interaction between modified wood and decay fungi. One small step to tackle some of the unsolved questions about the mode of action of modified wood is tak...
G Alfredsen, A Pilgård, A Hietala
Chemical modification of Scots Pine Sawdust by mixed anhydrides
2008 - IRG/WP 08-40439
By making react mixtures containing acetic-fatty anhydrides on Scots pine sawdust (SPS) without any solvent or catalyst; we synthesized mixed acetic-fatty esters of SPS. Such mixtures were synthesized by reaction between a carboxylic acid and acetic anhydride. These mixtures were obtained after reaction of acetic anhydride and a fatty acid that yields at equilibrium a mixture of five compounds: ac...
J Peydecastaing, E Borredon, S El Kasmi
Termite resistance of some modified wood species
2009 - IRG/WP 09-40449
During the last few decades, researchers worldwide have investigated and developed new treatment techniques to improve intrinsic wood properties. Some of these techniques were introduced to the market recently and are gaining in importance.. Various wood properties of these new materials have been studied intensively. These include physical-mechanical properties (dimensional stability, moisture ...
H Militz, B C Peters, C J Fitzgerald
Investigation of chemical changes in acetylated beech wood during weathering
2009 - IRG/WP 09-40460
In this study Beech wood (Fagus orientalis) acetylated and has been subjected to a variety of artificial weathering conditions (water only, light only, water and light together)in difference times (0,50,150 and 300 h), then wood surface analyzed using Fourier Transform Infrared spectroscopy (FTIR).Results shown that weathering process affected the functional groups on the wood surface. Light and w...
M Akhtari, M Arefkhani
Study of Microscopy Properties of Modified Wood During Weathering Process
2010 - IRG/WP 10-40517
In this study spruce (Picea excelsa) and Beech (Fagus orientalis) wood acetylated and has been subjected of artificial weathering in difference times (0, 50,150&300 h), then wood surface analyzed using Scanning Electron Microscopy (SEM). The SEM results shown that the surface of wood exposed to weathering undergoes distinct physical changes and the surface degradation appears to be directly propor...
M Akhtari
Biological degradation of acetylated wood after 18 years in ground contact and 10 years in marine water
2010 - IRG/WP 10-40522
This paper addresses the resistance to biological degradation of acetylated wood.
Firstly, it presents results from an EN 252 test after 18 years’ exposure. The test is still running in Nordic NWPC test fields, Simlångsdalen in Sweden and Viikki in Finland. Results from this test were presented after 5 years’ exposure ( IRG/WP 97-30139), and showed that the resistance of acetylated wood wit...
P Larsson Brelid, M Westin