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Wood furfurylation process and properties of furfurylated wood
2004 - IRG/WP 04-40289
The first processes for “furfurylation” of wood (wood modification with furfuryl alcohol) were developed several decades ago. Furfuryl alcohol is a renewable chemical since it is derived from furfural, which is produced from hydrolysed biomass waste. Over the last decade modernised processes for furfurylation of wood have been developed. These new processes are based on new catalytic systems and process additives. Two main processes for production of furfurylated wood have been developed for WPT (Wood Polymer Technology ASA) by the authors – Kebony 100 for high modification levels of hardwoods and VisorWood for lower modification levels of pine. Commercial production according to the Kebony process has been running since August 2000, mainly for flooring. A small Kebony production plant is now in operation in Lithuania. A larger Kebony/VisorWood production plant started up in September 2003 in Porsgrunn, Norway. Several new plants operating according to the VisorWood process, each with an annual capacity of 10 000 m³ or more, are under construction. The properties of furfurylated wood depend on the retention of grafted/polymerised furfuryl alcohol (PFA) in the wood. At high modification levels (high retention of PFA) the enhancement of a wide variety of properties are achieved: an exceptional hardness increase, exceptional resistance to microbial decay and insect attack, high resistance to chemical degradation, increase in MOR & MOE, and high dimensional stability. At lower modification levels many property enhancements also occur, however to slightly lower extent. Notable are resistance to microbial decay and insect attack, increase in MOR & MOE, and relatively high dimensional stability.
M Westin, S Lande, M Schneider

Prediction of Weight Percent Gain (WPG) of furfurylated wood by FT-NIR spectroscopy
2004 - IRG/WP 04-20295
Wood modification based on furfuryl alcohol improves several important wood properties, such as the resistance to fungal decay and insect attack, hardness, dimensional stability, bending strength and stiffness. The improvements of wood properties depend on the weight percent gain (WPG) due to furfurylation. Fourier transform near infrared (FT-NIR) spectroscopy was used to calibrate PLS-regression models for prediction of WPG due to furfurylation in birch wood. Spectra were obtained in cross-sections of solid wood. A PLS-regression model based on wood samples with WPG ranging from 16.7 to 35.1%, performed well when validated on a separate test set. The coefficient of determination between laboratory measured WPG and predicted WPG was high (R2 = 0.87). The prediction error given by the root mean square error of prediction was low (RMSEP = 1.23). The results showed that the technique should be considered a prospective tool for quality assessment of furfurylated wood.
M Eikenes, P O Flæte, E Ystrøm Haartveit, S Lande

Furfurylated wood - An alternative to Preservative-treated wood
2006 - IRG/WP 06-40349
Chemically modified wood is currently being marketed as a non-toxic alternative to traditional preservative treated wood (wood impregnated with biocides). Over the last decade the authors have developed modernised processes for wood modified by furfurylation. These new systems do not add metals or halogens to the product, which is important for an environmentally acceptable product. This presentation deals with the environmental aspects and durability of furfurylated wood. Results from several decay tests; emission analysis studies and eco-toxicity tests are presented. . The results show that furfurylated wood is highly decay resistant. There was no significant eco-toxicity of water leached from furfurylated wood and burning furfurylated wood does not release any more volatile organic compounds or poly-aromatic hydrocarbons than normal levels for wood combustion. Durability enhancement by furfurylating wood has not proven to be harmful to the environment. Test results have shown it to have performance similar to traditionally preserved wood. Furfurylated wood has some improved mechanical and physical properties such as increased modulus of elasticity (MOE) and increased anti shrink efficiency (ASE).
S Lande, M H Schneider, M Westin, J Phillips

Furfurylated wood – withdrawal load for fasteners
2007 - IRG/WP 07-40381
The withdrawal load for hot dip galvanized nails and chromated decking screws in furfurylated Baltic redwood (Pinus sylvestris) with a Weight Percent Gain (WPG) of approximately 40 % was measured according to DIN 1052. The average withdrawal loads were 60-100 % higher for the nails and approximately 20 % higher for the screws in the furfurylated wood compared to untreated wood. The results indicate that the withdrawal load is considerably higher for furfurylated wood (with approximately 40 % WPG) than for untreated wood. The main explanation for this is the higher density of furfurylated wood compared to untreated wood.
J Jermer, A Clang

Feasibility study on three furfurylated non-durable tropical wood species evaluated for resistance to brown, white and soft rot fungi
2008 - IRG/WP 08-40395
Furfurylation can protect non-durable wood species against biological degradation, but the method used today cannot fully protect the heartwood of Scots pine due to insufficient penetration. In order to test alternative wood substrates for furfurylation, three Malaysian grown wood species (Kelempayan, Rubberwood and Sena) were furfurylated and subjected to soil block decay testing. Their performance was compared to furfurylated Scots pine and furfurylated Beech modified using the same process. In addition, treatment characteristics were evaluated. One of the species tested, Kelempayan, seems to be a promising substrate for furfurylation. Kelempayan is easy to impregnate in both sap- and heartwood, and a 50% higher weight gain was reached using equivalent amounts of impregnation solution compared to Scots pine. Sena, Rubberwood and Beech returned weight gains 40-60% lower than Scots pine. Decay protection was largely comparable at equivalent weight percent gains for all wood species tested, although differences appeared. Generally, a weight gain of approximately 25% by furfurylation seems to offer good protection in the chosen soil block test.
T Mark Venås, A H H Wong

Ecotoxicity of furfurylated wood – Effect of leachate on aquatic bacteria
2008 - IRG/WP 08-50250
Environmental concern regarding the use of toxic preservatives such as CCA (chromated copper arsenate) has been put forward. In the EU, USA and Japan, CCA is now phased out for residential use and for use in water contact. Several ecotoxicological studies of wood treated with conventional preservatives were carried out in the late 1990s. In these studies it was concluded that the main impact is to water and thereby to aquatic organisms. Today, alternatives to conventional preservation, marketed as “environmentally friendly” or “non-toxic” are emerging on the market. Examples of such alternatives are modified wood, e.g. thermally modified, furfurylated and acetylated wood. So far, not enough ecotoxicological studies have been done on these new methods. In the presented study the Microtox assay with the marine bacterium Vibrio fischeri are used as a screening method. Vibrio fischeri were exposed to water leachates from furfurylated wood using two different leaching procedures. The results from the OECD 2 standard test show that Kebony 2 (one of the commercially used furfurylation processes) treated Scots pine have a lower toxicity than all the other samples at all points and that it is the lowest at every point for Radiata pine as well. The explanation might be that there is an immobilization of slightly toxic wood extractives by incorporation in the furan polymer. The lower toxicity for Kebony 2 than for Kebony 1 might be a result of the intermediate vacuum drying step for Kebony 2 that leads to a more efficient curing/polymerisation and less hydrophobic oligomers of a type that may be slightly toxic.
A Pilgård, M Westin

Postia placenta gene expression of oxidative and carbohydrate metabolism related genes during growth in furfurylated wood
2009 - IRG/WP 09-10701
A range of studies the last decade have shown that modified wood can provide excellent protection against a range of wood deteriorating organisms, including decay fungi. However, we still lack information about why the modified wood is protected from microbial attack. Several hypotheses have been put forward e.g. inhibition of action of specific enzymes, but they still need testing. An understanding of the mechanisms utilized by decay fungi when exposed to modified wood is important for further optimisation of new modified wood products. In this study gene expression of the brown rot fungus Postia placenta has been monitored after 2, 4 and 8 weeks of colonization in furfurylated Scots pine and control samples. Preliminary results are given. The main finding was that genes related to oxidative metabolic activity was higher in furfurylated wood compared to untreated Scots pine, and that carbohydrate metabolism related expression was lower in furfurylated wood compared to untreated control.
G Alfredsen, C G Fossdal

Durability and fungal colonisation patterns in wood samples after six years in soil contact evaluated with qPCR, microscopy, TGA, chitin- and ergosterol assays
2009 - IRG/WP 09-20402
There is a need to establish new objective and sensitive methods for early detection and quantification of decay fungi in wood materials. Molecular methods have proven to be a useful tool within wood protection issues, however, this field is still poorly explored and so far relatively few have used these methods within the field of wood deterioration. Among the techniques used in the indirect quantification of fungi in decayed wood and building material are chitin and ergosterol assays. DNA-based methods are rarely used for identification in connection with quantification. Access to knowledge about fungal colonisation patterns in different wood substrates would allow further improvement of new products. The aim of this study was to investigate the colonisation pattern of decay fungi in wood samples after six years in soil exposure, in an EN252 test. We analysed stakes of furfurylated wood (Scots pine) with two different treatment levels, while a copper organic preservative impregnated Scots pine and Scots pine heartwood served as reference material. Samples were taken from below ground and soil surface parts of the EN252 stakes. To quantify fungi involved in wood degradation a specific and quantitative real-time PCR (qPCR) method using universal internal transcribed spacer (ITS) primers, specific for Basidiomycetes, was used. To further verify this method, the ergosterol and chitin assays were performed, together with thermogravimetric (TGA) and light microscopic analyses. The highest amount of fungal DNA, ergosterol and chitin was found in the sample rated as 4. As expected, a lower amount of DNA was found in the samples rated as 3 and 2 and even lower in those rated as 1 and 0. This difference could not be detected with the ergosterol and chitin assays which may indicate that the qPCR method is more sensitive. The results from the TGA showed that the below ground sample rated as 4 had the lowest cellulose content and the light microscopic observations showed a large variation in decay between and within the individual stakes.
A Pilgård, G Alfredsen, I Børja, C Björdal

Material properties of furfurylated wood for window production
2009 - IRG/WP 09-40480
Wood modification with furfuryl alcohol is an extensively investigated process and already produced commercially. Furfurylated wood is in the focus of a European project on its use for the production of high performance windows. Different wood species were treated with furfuryl alcohol and tested on water uptake, dimensional changes, leaching in water, resistance to fungal degradation, and ecotoxicity. The results show a reduced water uptake and a reduced swelling of the furfurylated wood samples. A high resistance against fungal attack of the treated wood samples can be shown. A low amount of furfuryl alcohol was leached out and the water samples of two different leaching tests showed in general low toxicity. Southern yellow pine showed good results in all of the tests and has potential for the production of window frames according to the tests performed.
A Treu, A Pilgård, S Puttmann, A Krause

Postia placenta gene expression during growth in furfurylated wood
2010 - IRG/WP 10-10734
Modified wood can provide protection against a range of wood deteriorating organisms. But we still lack information about why the modified wood is protected from microbial attack. Several hypotheses have been put forward for the mode of action against wood decaying fungi, including inhibition of action of specific enzymes, but they still need further testing. In this study gene expression of the brown rot fungus Postia placenta FPRL 280 has been monitored after 2, 4 and 8 weeks of colonization in furfurylated Scots pine (Pinus sylvestris L.) and in untreated control samples. Preliminary results are given. The main finding was that genes related to oxidative metabolic activity generally was higher in furfurylated wood compared to untreated Scots pine. Carbohydrate metabolism related expression varied. For one endo-glucanase and two β -glucosidases the expression was lower in furfurylated wood compared to untreated control, while for one glucoamylase and one glucan 1,3b glucosidase the expression was higher in furfurylated wood. The four cytochrome P450 tested, involved in breakdown of toxic compounds, gave inconsistent results between furfurylated and untreated control samples. Phenylalanine ammonia lyase and cytosolic oxaloacetase gave higher expression in control than in furfurylated samples.
G Alfredsen, C G Fossdal

Durability of Furfurylated Wood – Results from Laboratory and Field Tests in the Ecobinders project
2012 - IRG/WP 12-40602
Within the EU project Ecobinders, laboratory tests were performed with furfurylated wood produced in semi-industrial scale in the factory of Kebony ASA. Field trials in Horizontal double layer decks and in-ground of transmission poles were also started. Four wood species, Southern yellow pine (SYP), maple, beech and aspen were treated to two treatment levels by using two impregnating liquids with different furfuryl alcohol content. Full length Scots pine poles were only treated with the higher furfuryl alcohol concentration treating liquid. SYP and beech samples were tested according to EN113 and maple and aspen samples according to the corresponding American test, AWPA E10. All wood species except Scots pine, at two treatment levels were installed in a HDL deck and the poles in ground with a creosoted pole as reference. The laboratory tests with three test fungi showed very consistent results. The low FA-content treating liquid (FA40) resulted in durability class 2-3 and the higher FA-content treating liquid (FA70) resulted in Durability class 1. After these tests Kebony ASA decided to switch from FA40 treating liquid to FA70 treating liquid in all of their production and is still using this mix in the production. The field trials were started in 2006 and after 5 years all 6 furfurylated poles (WPG=40 in the sapwood zone) were sound, which is, however, also the case for the creosoted pole reference. In the HDL test all furfurylated test stakes are more or less sound, whereas the controls are moderately to severely decayed.
M Westin

Relevance of natural pre-weathering for laboratory decay tests with native, modified, and preservative-treated wood
2013 - IRG/WP 13-20522
The on-going development of new wood protection systems is hampered by the long term field tests currently in use. New accelerated test methods and novel methods for faster and more accurate evaluation of wood protection methods are requested. For both field decay tests and accelerated laboratory decay tests, limitations are imposed. This study is part of the research program ‘WoodBuild’, which aims at developing a comprehensive test methodology for determination of wood durability. Field tests under various exposure conditions are regarded as well as laboratory tests. An overall objective is to find methods having the potential to reflect real life situations for all use classes. Therefore this particular study aimed at investigating the differences in mass loss with a mini-block test (Bravery 1979) following ageing with either leaching (EN 84) or natural weathering. The aim of this paper is not focussing on the durability (and definitely not on the efficacy) of any treatment but to highlight the differences in durability between naturally weathered samples and laboratory leached samples. The present study indicates that natural weathering and laboratory ageing procedures influence various wood species and various wood treatments differently with regard to durability. For preservative treated wood, none out of six treatments had a significantly higher mass loss for P. placenta when the samples were pre-weathered compared to pre-leached. For T. versicolor, 3 out of 6 treatments showed higher mass loss after natural pre-weathering. For the modified woods, 2 out of 7 treatments had a significantly higher mass loss for P. placenta when the samples were pre-weathered compared to pre-leached. When exposed to T. versicolor, 4 out of 7 treatments had a higher mass loss for P. placenta when the samples were pre-weathered. The mass loss for T. versicolor for the softwoods and hardwoods did not seem at all to be affected by the pre-treatments. Although, when exposed to P. placenta, 3 out of 9 softwoods and 1 out of 5 hardwoods had a significantly higher mass loss when the samples were pre-weathered compared to pre-leached. The present study indicates that the impact of natural weathering on mass loss seems not only to be treatment dependent but also wood species and test fungus dependent. The effects of natural weathering might be explained by the losses of active substances from treated wood but also the biological influence of microorganisms is a contributing factor. Taken this into account, it seems very important to consider the effect of any pre-treatment on both, the test materials and the untreated and per definition non-durable reference species.
A Pilgård, C Brischke, L Meyer

Possible targets of wood modification in brown rot degradation
2014 - IRG/WP 14-40676
Wood modification protects wood from fungal degradation in a non-toxic manner. However, the mechanisms behind the decay resistance in modified wood are currently unknown. The aim of this study was to discuss the i) colonisation, ii) nutrient recognition, iii) transcription, iv) depolymerisation and v) hydrolysis steps in the brown rot degradation progress and explore whether they are inhibited by wood modification, based on new and previously published data from our group. In previous studies, it has been shown that fungi were able to colonise modified wood, to recognise it as a source of nutrients and express genes associated with cellulose degradation while growing on modified wood. In this study, Fenton derived hydroxyl radicals (∙OH) and brown rot cellulases were able to degrade modified wood. We conclude that the five degradation steps discussed in this paper are unlikely targets for wood modification and that wood modification rather inhibits a step that in a schematic overview of the brown rot degradation process is downstream from transcription but upstream of depolymerisation and hydrolysis.
R Ringman, A Pilgård, G Alfredsen, B Goodell, K Richter

High-frequency monitoring of mass loss due to brown rot degradation of modified wood
2016 - IRG/WP 16-10862
Fungi growing in liquid culture undergoes three separate phases in which they i) adapt to the new environment, ii) grow unrestrictedly and exponentially, and iii) are inhibited to increase in number/mass due to lack of nutrients etc. Filamentous fungi have been shown to exhibit similar growth phases in a solid food substrate and have been modelled to grow in this way also in solid wood. In modified wood with high treatment levels, fungi cause no or little mass loss but the reason for this has not been fully explained. To be able to predict the service-life of modified wood, understanding the growth pattern of wood degrading fungi in these materials may be important. The aim of this study was to find out whether brown rot fungi undergoes the same growth phases in solid wood as in liquid culture and study the growth pattern of brown rot fungi in modified wood. This was done through high-frequent monitoring of mass loss over 300 days of exposure of acetylated and furfurylated wood to Postia placenta. Mass loss results of the untreated wood indicated clearly that the fungi in this material go through phases similar to phases seen in liquid cultures. However, the results for the modified wood materials were less clear. Little mass loss and a degradation rate 100 times lower than in the untreated wood during exponential growth may suggest that the fungi in the modified wood samples were still adapting to the new environment. On the other hand, the fact that mass was lost at all suggests that degradation did occur and that the fungi were growing exponentially.
R Ringman, A Pilgård, K Richter

The impact of catalyst on the properties of furfurylated beech wood
2016 - IRG/WP 16-40748
European beech (Fagus sylvatica L.) is a major tree species of European forest that is underexploited because of its low dimensional stability and durability. Similarly to what has been developed with radiata pine, furfurylation might be the answer to optimize the utilization of local beech wood. Beech wood furfurylation process was studied using five different catalysts: maleic anhydride, maleic acid, citric acid, itaconic acid and tartaric acid. Optimization of the furfurylation process was investigated for different catalyst and furfuryl alcohol (FA) contents, and different duration of polymerization. The following properties were studied: weight percent gain (WPG), leachability, anti-swelling efficiency (ASE), wettability, modulus of elasticity (MOE), modulus of rupture (MOR), Brinell hardness (BH), and decay durability. Tartaric acid, never investigated up to now, was retained as catalyst to optimize the furfurylation process conditions due to its efficacy compared to other catalysts. Wood modification with FA and tartaric acid as catalyst led samples with high WPG even after leaching, improved ASE and lower wettability with water. Increasing the polymerization duration increased the fixation of FA in treated wood. Most of all, treatment gave a significant improvement in mechanical properties and resistance to wood decaying fungi.
P S Sejati, A Imbert, C Gérardin, S Dumarçay, E Fredon, E Masson, D Nandika, T Priadi, P Gérardin

Marine Borer Resistance of Acetylated and Furfurylated Wood – Results from up to 16 years of Field Exposure
2016 - IRG/WP 16-40756
Furfurylated and acetylated Scots pine sapwood has been tested since 1999 in a marine field with high marine borer activity. In 2004, two test groups with acetylated southern yellow pine (product later known as Perennial Wood™) were put out and over the whole test period differently furfurylated wood (later marketed as Kebony®) test groups have been started. Furthermore, some combinations of modification methods have also been included, e.g. acetylation followed by treatment with MMF resin or furfurylation. The testing, according to European Standard EN 275, was done in a bay on the Swedish west coast. The marine borer (mainly Teredo navalis) activity at the test site is very high, always resulting in failure of control specimens within a year. Furfurylated wood at a treatment level, resulting in weight percent gain (WPG) figures corresponding to those for current production of Kebony pine and Kebony beech, led to excellent resistance to teredo attack, i.e. no attack or very slight attack after 16 years exposure. Specimens cut from factory-produced Kebony Beech decking boards from 2006 are only slightly attacked after 9 years of exposure whereas factory-produced Kebony pine failed after 8 years of exposure. Specimens of acetylated Scots pine (WPG=21) is severely attacked after 16 years, and acetylated SYP (Perennial Wood™) specimen at the higher acetylation level are either completely sound or only slightly attacked after 11 years of exposure whereas specimens at the lower acetylation level all failed in three years. Furfurylation as post treatment after acetylation resulted in poorer performance than each of the treatments by themselves. However, post treatment with melamine resin after acetylation seems to provide excellent resistance to borer attack.
M Westin, P Larsson Brelid, T Nilsson, A O Rapp, J P Dickerson, S Lande, S Cragg

Corrosion of fasteners in furfurylated wood – final report after 9 years exposure outdoors
2017 - IRG/WP 17-40810
The corrosion of some common fastener materials – mild steel, stainless steel, zinc-coated steel, brass and Sanbond Z (nickel, zinc and chromate) coated steel – has been evaluated after nine years exposure outdoors in untreated Scots pine and furfurylated beech and southern yellow pine (SYP). The furfurylation was carried out according to a process that resulted in approximately 40 % WPG (Weight Percent Gain). The results show that the corrosion of fasteners in furfurylated wood according to the particular specification is considerably more severe than in untreated wood and very similar to the corrosion caused by thermally modified wood. Mild steel and zinc coated steel has been most susceptible. Stainless steel has not been attacked at all and is therefore strongly recommended for furfurylated wood in outdoor applications.
J Jermer, B-L Andersson, J Schalnat

Thermodynamic properties of furfurylated wood during moisture adsorption process
2018 - IRG/WP 18-40828
Furfurylation of wood seems a promising wood modification method considering the wide raw material source of furfuryl alcohol (FA) and overall performance of FA modified wood. However, the modification mechanism of furfurylation is still not clear and needs further investigation. In this study, poplar (Populus cathayana Rehd.) samples with the size of 1(R) mm × Ф4 mm, were impregnated with aqueous solutions of 10, 25, and 50% FA and then carried out the dynamic water vapor sorption experiment. From the isotherms, the moisture adsorption thermodynamic properties of FA modified wood were calculated. The results showed that: (1) the moisture sorption isotherms of FA treated wood are similar in shape to that of untreated control group, but showed significant reduction in moisture content; (2) the differential heat of sorption (QL) of FA treated wood was lower than that of control group, which can be analysed by the changed contributions of monolayer, multilayer, and capillary condensed water; (3) moisture adsorption, differential heat constant of absorption (C), absorption of monolayer (W1) and internal surface of absorption (S) decrease with increasing FA concentration.
J Wang, J Cao, T Yang, E Ma, W Wang

Danish wood preservatives approval system with special focus on assessment of the environmental risks associated with industrial wood preservatives
2001 - IRG/WP 01-50166-01
The following is a description of the procedure used by the Danish Environmental Protection Agency to assess the environmental risks associated with preservatives used in the pressure impregnation of wood. The risk assessment covers issues considered to be of significance for the environment and which are adequately documented so as to allow an assessment. Such issues are persistence and mobility in soils, bioaccumulation and the impact on aquatic and terrestrial organisms. Unless required in special circumstances, the assessment does not apply to birds and mammals as the normal use of preservative treated wood is not expected to involve any noteworthy exposure of these groups. Approval of wood preservatives will be based on a general assessment of the environmental risk associated with the normal use of wood treated with the preservative in a realistic worst case situation. The assessment may address other aspects such as disposal and total life cycle.
J Larsen

Data sheet on wood-boring insects. Apate monachus Fabricius. 2. Position systématique, nomenclature, identification et distribution - Espèces végétales attaquée
1981 - IRG/WP 1105
R L A Damoiseau

Confocal laser scanning microscopy of a novel decay in preservative treated radiata pine in wet acidic soils
1997 - IRG/WP 97-10215
Light microscopy of radiata pine (Pinus radiata D. Don) field test stakes (20x20x500mm3) exposed in wet acidic (pH 3-4) soil for 12 - 24 months showed predominance of an unusual type of decay characte-rised by tunnelling attack of wood cell walls. After two years decay was moderate to severe in wood treated to ground contact CCA specifications and also equivalent retentions of creosote, and a number of new generation preservatives. Relative to other New Zealand temperate test sites and also an Australian tropical site, the New Zealand acidic soil test site was very aggressive. Correlative scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were used to elucidate the micromorphology of this attack. Tunnels of diameter 0.2-5 µm were present throughout all layers of the cell wall, and their orientation was not related to cellulose microfibril orientation. They also showed no preference for particular cell wall layers, indicating a lignin degrading capability. CLSM images showed that living, connecting fungal hyphae were present in the cell lumina and tunnels. This type of attack was predominant in wood that was highly saturated with water whereas wood that was less moist was predominantly attacked by classical white rot. Ongoing isolation and incubation studies in conjunction with further microscopy should enable identification of the fungal species involved.
R N Wakeling, Ying Xiao, A P Singh

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 examined using Fenton's reagent. The enhancement of decay resistance by acetylation was revealed clearly for all cases of exposures but varying with fungal and wood species used. For a brown-rot fungus Tyromyces palustris, the weight loss reached almost nil in all woods at 20 WPG (weight percent gain) of acetylation, after the striking decrease from 10 to 15 WPG. For a white-rot fungus Coriolus versicolor, it was counted until 12-15 WPG in the perishable hardwoods used, but not in a softwood Cryptomeria japonica, even at 6 WPG. In cases of another brown-rotter Serpula lacrymans and soil burial, effect of acetylation was intermediate between Tyromyces palustris and Coriolus versicolor. Anti-degradation mechanism by acetylation was discussed, from these weight loss - weight gain relationships, and the IR-and 13C-NMR spectral analyses of fungus-exposed wood.
M Takahashi, Y Imamura, M Tanahashi

The IRG..Chanelling information and ideas into the mainstream of wood preservation technology
1985 - IRG/WP 5241
IRG Secretariat

Wood preservation in Poland
2004 - IRG/WP 04-30362
Dynamic growth of market demand for wooden elements and articles, generated in Poland increase of interest in industrial preservation. Today, Poland is a substantial producer and exporter of wood made products. Majority of exported wood - approximately 70% - is scotch pine (Pinus silvestris L.), which, due to its natural durability, requires preservation.
A Kundzewicz

Wood preservatives: Field tests out of ground contact. Brief survey of principles and methodology
1976 - IRG/WP 269
This paper contains the following spots: 1.: The general need for field tests. 2.: Interests and limits of field tests in ground contact. 3.: Various methods in use for out-of-ground contact field tests. 4.: Fungal cellar tests are they an alternative to above-ground decay exposure tests? 5.: Conclusions.
M Fougerousse

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