Your search resulted in 232 documents. Displaying 25 entries per page.
Efficacy of linear chain carboxylic acid anhydrides as wood protection chemicals
2002 - IRG/WP 02-30295
This paper presents an assessment of the effectiveness of linear chain carboxylic acid anhydrides namely, acetic, propionic, butyric, valeric and hexanoic anhydride, in improving the decay resistance of Corsican pine (Pinus nigra Schneid) sapwood. Wood-anhydride bond formation was verified by the increase in sample weight and volume. A brown rot fungus
[Coniophora puteana (Schum.:Fr)] was selec...
A N Papadopoulos, M D C Hale, C A S Hill
Treatment of wood with formaldehyde. Acid catalysis of the reaction between formaldehyde and wood
1980 - IRG/WP 3146
Formaldehyde reacts with the free OH-groups in wood forming cross-linking bonds. The reaction can be brought about without any catalyst but in that case the activation energy is very high and high temperatures and long reaction times are needed. Normally, the reaction is catalysed by different acids. Acid catalysts, however, tend to degrade the cellulose and the wood matrix causing reduction in th...
T Vihavainen, K Piispanen, P Mansikkamäki
Summaries of two Russian papers received from Professor Dr. D.A. Belenkov and V.A. Seletskaya of the Ural Forest Engineering Institute, Sibirsky Trakt, 37, Sverdlovsk, USSR, on the toxicity to Coniophora cerebella of salts of hydrofluoric acid and some fluoroborates
1977 - IRG/WP 298
1) Evaluation of the toxicity of some salts of hydrofluoric acid against the house cellar fungus (Coniophora cerebella Schroet)
Data are presented on the method of probability evaluation of the toxicity of the fluorides of sodium, ammonium, potassium, zinc and iron. On the retention of fluorine in wood all salts, except iron, possess practically equal toxicity at the standard level of the probability of the protection of the wood - 0.95 . There is good agreement between the analytically and graphically determined dose level. Evidence is given for dose variabitility, probabilities of wood protection at 0.5 and 0.95, the curve of efficacy - activity and the construction of the empirical probit graph.
2) Investigation of the toxicity of some borofluorides towards the house cellar fungus
Probability evaluation of the toxicity of borofluorides against the cellar fungus, and probit analysis evidence show that toxicity decreases in the sequence sodium borofluoride, copper borofluoride, tributyltin borofluoride. The effectiveness of protection method is able to evaluate the amount of fluorine and boron required in the wood.
C Grant
Copper naphthenate: An analysis of the materials found in the worldwide marketplace using a new analytical technique
2000 - IRG/WP 00-30224
Naphthenic acid has been recovered from products of petroleum refining for well over 100 years. The metal soaps, specifically copper and zinc naphthenate, have been evaluated and used as commercial wood preservatives for in excess of 60 years. Most of the early data supporting the continued use of copper naphthenate as a wood preservative was based on materials manufactured from naturally occurrin...
J A Brient, R E Moyer, M H Freeman, H Jiang
Microscopical analysis of formaldehyde-acid modified wood
1981 - IRG/WP 3182
Cross-linking of wood with gaseous formaldehyde improves its hygroscopic and dimensional behaviour, and its resistance against micro-organisms. However, formaldehyde cross-linking reactions take place only in the presence of an acid catalyst, which results in losses in mechanical By optimization of a formaldehyde-sulfur dioxide vapour phase process the reaction conditions were established to limit...
M Stevens, N Parameswaran
Incorporation of phenyl boronic acid treatment with vapor phase formalization
1997 - IRG/WP 97-40083
Phenylboronic acid (PBA) treatment was incorporated with vapor phase formalization (VPF) in order to increase dimensional stability and boron fixation as well as enhancement of biological resistance. Five and ten hours VPF were applied after PBA treatment as 0.34, 0.50, 1.00 and 2.00% concs. aqueous solutions. Anti swelling efficiency (ASE) attended to 71% in specimens impregnated with 0.50% PBA s...
M K Yalinkilic, S Yusuf, T Yoshimura, W-Y Su, K Tsunoda, M Takahashi
Reaction of osmium tetroxide with a diphenolic compound as a model substance for demethylated lignin
1986 - IRG/WP 1303
By using caffeic acid as a model substance for diphenolic moieties of demethylated lignin it was found that electron dense particles called by the authors "osmiophilic particles" in former papers are reaction products of OsO4 with the model substance. By these products it is possible to indicate the enzymatic demethylation of lignin taking place during wood decay. The appearance of the electron de...
K Messner, E Srebotnik
Evaluation of the corrosivity of the treated wood - Laboratory vs field test methodologies
2000 - IRG/WP 00-20211
The corrosivity of treated wood to fasteners has been evaluated using laboratory test procedures, including AWPA Standard E12-94. The standard method was modified in order to allow detailed study of commercial metal fasteners in terms of sample types, installation configuration and exposure conditions. Parallel field tests were also performed. The experimental results generated from these tests su...
L Jin, A F Preston
Fungicidal efficacy of some dimethyldithiocarbamates, dymethylaminopropionitrile and some salts of S-substituted thioglycolic acid
1998 - IRG/WP 98-30180
Screening for fungicidal activity against Trametes versicolor and Coniophora puteana of the following compounds was performed: sodium N,N-dimethyldithiocarbamate, dimethylalkylammonium (C12-C14) N,N-dimethyldithiocarbamate, benzyldimethylalkylammonium (C12-C14) N,N-dimethyldithiocarbamate, N,N-dimethylaminopropionitrile and ammonium, copper and zinc salts of N,N-dimethyldithiocarbamoylacetic acid....
M Petric, F Pohleven, M Humar, U Kolman
Electrodialytic remediation of CCA-treated wood in larger scale
2005 - IRG/WP 05-50224-20
A pilot plant for the electrodialytic remediation of CCA-treated waste wood has been developed and tested at the Technical University of Denmark. Results from two experiments with different amount of wood chips are presented here. Prior to the electrodialytic remediation the wood was soaked in oxalic acid and phosphoric acid. The main purpose of soaking is to remove the most available fraction fir...
I V Christensen, L M Ottosen, A J Pedersen
Identification of phanerosporic acid in birch degraded by Phanerochaete chrysosporium
2003 - IRG/WP 03-10496
Extracts of Phanerochaete chrysosporium cultures grown on birch or on a malt extract-peptone-glucose agar medium were analysed by HPLC. A major component from the two sources appears to be identical by HPLC and UV-visible spectrometry. The product isolated from agar-grown cultures was purified to apparent homogeneity and structure analysis by NMR indicates that the metabolite is the beta-resorc...
M D Mozuch, P J Kersten
Biochemical relationships between biodegradation of cellulose and formation of oxalic acid in brown-rot wood decay
1991 - IRG/WP 1472
Non-enzymic hydrolysis of cellulose with low concentrations of oxalic acid was examined. The incubation of pine wood pulp with 1% oxalic acid (pH 1.3) at 35°C for 4 weeks reduced the original viscosity to 60%. Reducing sugars were liberated from various cellulosic samples by the oxalic acid treatment. However, crystallinities of cellulose in those samples did not change before and after the treat...
M Shimada, Y Akamatsu, A Ohta, M Takahashi
Fungal remediation of CCA-treated wood
2004 - IRG/WP 04-50210
This study evaluates oxalic acid accumulation and bioremediation chromated copper arsenate (CCA) treated wood by three brown-rot fungi, Fomitopsis palustris, Coniophora puteana, and Laetiporus sulphureus and ten mold and staining fungi, Aspergillus niger, Aureobasidium pullulans, Gliocladium virens, Penicillium funiculosum, Rhizopus javanicus, Ceratocystis pilifera, C. peceae, Alternaria alternata...
S N Kartal, Y Imamura
Oxalic acid quantification, oxaloacetase assay and ESI localization of P, C, and Fe from the brown rot fungus Postia placenta
1994 - IRG/WP 94-10063
The mechanism by which brown-rot fungi initiate depolymerization of holocellulose in wood remains unknown. Recently, oxalic acid (OA) has received considerable attention in cellulose breakdown by brown-rot fungi. The OA could serve as a proton donor for hydrolytic or an electron donor for oxidative (Fenton's reaction-H2O2/Fe2+) cleavages of cellulose. The acid may originate via oxaloaceta...
C R Jordan, W V Dashek, T L Highley
Production of exraxellular hydrogen peroxide and oxalic acid by brown-rot fungus Poria placenta
1995 - IRG/WP 95-10112
Hydrogen peroxide and oxalic acid have been suggested to be essential in the degradation of wood carbohydrates by brown-rot fungi. Hydrogen peroxide has been suggested to be one of the diffusible low molecular weight agents produced by brown-rot fungi for the degradation of wood carbohydrates by generating highly active radicals. The production of hydrogen peroxide and oxalic acid by Poria placent...
A-C Ritschkoff, M Rättö, J Buchert, L Viikari
Composting of waste building up in sawmill dipping basins
1990 - IRG/WP 3570
We have studied composting of waste building up in dipping basins at sawmills although this waste can also be disposed of by incineration. Controlled composting within the sawmill area seems to be a feasible method. Another possibility is to accomplish composting directly at the local dumping site. Waste containing antistain chemicals is generally classed as hazardous. It cannot therefore be place...
I A Linderborg, U Ek
The use of propionic acid to prevent Pinus patula biodeterioration during outside chip storage in Zululand
1989 - IRG/WP 3531
Pinus patula SCHIEDE ET DEPPE IN SCHLD. ET CHAM. is susceptible to biodeterioration during outside chip storage (OCS), reducing pulp quality and tear and burst indices of resulting paper. Accelerated laboratory trials showed that chips treated with 2% (w/v) propionic acid and stored for 17 weeks, produced pulp of quality indistinguishable from fresh untreated chips. Pulp tests during field trials ...
S Ismail, E J Smith, A A W Baecker
Adsorption of ACQ and CuMEA Wood Preservatives in Red pine
2005 - IRG/WP 05-30374
The rates of stabilization or fixation of ACQ subcomponents (CuO, DDAC and MEA) in red pine (Pinus resinosa) were compared for different solution concentrations (0.75%, 1.5%, 2.25% and 3% ACQ-D) and post treatment conditioning temperatures. Preservative solutions were impregnated into red pine sapwood by a full-cell treatment. Copper and MEA adsorptions from copper monoethanolamine solutions witho...
C Tascioglu, P A Cooper, Y T Ung
A note on the distribution of copper-chrome-boric (CCB) along the culm length of freshly felled bamboo treated by modified Boucherie process
2005 - IRG/WP 05-40317
Preservative treatment of green and dry bamboo poses severe problems. A number of bamboo/ wood preservatives (Chemical formulations) for the destroying organism like fungi, borers and termites etc. In this paper we reported preliminary results of treatment of fresh green round bamboo attached with baranches by modified Boucheri process. Sample full length of an Indian species of bamboo Dendrocalam...
R Lal, C N Vani
An example of media response to perceived environmental problems with CCA-treated wood
1990 - IRG/WP 3564
A recent study suggested that CCA-treated wood exposed to acidic precipitation could lose significant amounts of copper chromium and arsenic resulting in loss of efficacy and possible environmental contamination. The study received wide newspaper and radio coverage in Canada, thereby heightening public concern about CCA use. Subsequent studies in our laboratory confirmed that the high losses were ...
P A Cooper
Evaluating the potential of amine chemicals for use as wood protecting agents. Part 1: Investigation of cation components of quaternary ammonium compounds
1994 - IRG/WP 94-30049
Quaternary ammonium compounds (quats) have shown a great potential as more environmentally acceptable wood preservatives. In order to identify chemicals possessing the wood protecting potential, an evaluation was carried out of a range of commercially available 'quats', using a modified soil block test. Ponderosa pine sapwood blocks were treated with selected 'quat&a...
Hang Tang, J N R Ruddick
Hemicellulosic induction of oxalic acid in Postia placenta
1994 - IRG/WP 94-10060
Most studies suggest that enzymes produced by brown-rot fungi are too large to penetrate sound wood structures, even after decay begins. Thus, nonenzymatic agents have been proposed to initiate brown-rot decay. We have reported that the brown-rot fungus Postia placenta MAD-698 initiates a 2-fold decrease in wood pH within 7 days of colonization which is mediated by production of oxalic acid. Strai...
F Green III, M Larsen, T L Highley
Comparison of methods for monitoring CCA fixation
1994 - IRG/WP 94-40023
The CCA fixation status in the outer 12.5 mm of pole sections of southern pine (Pinus sp.), red pine (Pinus resinosa) and lodgepole pine (Pinus contorta var. latifolia) were followed during fixation at 21°C under non-drying conditions by the following procedures: - Qualitative CrVI indication by the chromotropic acid spot test. - Quantitative CrVI in the expressate by the diphenylcarbazide method...
P A Cooper, Y T Ung, G Zanjani
Effect of humic acid on leaching of CCA from treated wood
2000 - IRG/WP 00-50151
Laboratory studies indicate that relatively high concentrations (1.000 - 10.000 ppm) of humic acids can increase the leaching of chromium and copper from CCA-C treated wood, and that copper is most affected. They also show that leaching with natural water samples can result in higher leaching of all components than leaching with distilled water. Evaluation of CCA component retentions and mass bala...
P A Cooper, D Jeremic, J L Taylor, Y T Ung
The long road to understanding brown-rot decay. A view from the ditch
1995 - IRG/WP 95-10101
Interest in understanding how brown-rot fungi decay wood has received increasing interest in recent years because of a need to identify novel targets that can be inhibited for the next generation of antifungal wood preservatives. Brown-rot fungi are unique in that they can degrade holocellulose (cellulose and hemicellulose) in wood without first removing the lignin. Furthermore, they degrade holoc...
F Green III, T L Highley