Your search resulted in 3003 documents. Displaying 25 entries per page.
The effect of certain wood extractives on the growth of marine micro-organisms
1977 - IRG/WP 438
S E J Furtado, E B G Jones, J D Bultman
Evaluation of chlorpyrifos as an insecticidal component of a wood preservative
1984 - IRG/WP 3301
After two years of laboratory and field testing, chlorpyrifos is showing excellent potential as an insecticidal treatment to wood. In laboratory termite tests, retentions as low as 1-2 parts-per-million or approximately 0.0008 kg/m³ (0.00005 lbs/ft³) are effective against the Coptotermes formosanus. Laboratory leaching tests have shown no significant effect on the concentration of the retained chlorpyrifos. Pressure treatments and dip treatments, as an aqueous emulsion or oil solution, have resulted in good penetration of effective concentrations. Combinations of chlorpyrifos and various fungicides are being evaluated.
K Rose, J Kozuma, P Sparrow
FIPRONIL - une nouvelle molécule insecticide Rhône Poulenc pou le PCO et la protection du bois [FIPRONIL - A new insecticide from Rhône Poulenc for PCO and wood preservation]
1995 - IRG/WP 95-50040-16
We will explain here after the advantages and key points of the new insecticide "FIPRONIL" from Rhône Poulenc Agrochemicals. We will have a look from the physical and chemical properties to the possible uses in PCO and wood preservation, including toxicology, efficacy and the main beneficial impacts on the environment. FIPRONIL, a new solution against undesirable and damageable insects, from cockroaches and termites up to woodworms, highly active with very low dose rates.
M G E J Van Maanen
Tebuconazole - A new triazole fungicide for wood preservation
1990 - IRG/WP 3629
The main cause of economic damage to timber and millwork worldwide are Basidiomycetes (brown and white rot). After testing a wide range of triazole derivatives for their effectiveness against decay fungi, Tebuconazole, a triazole compound, was selected. The physico-chemical, toxicological and ecotoxicological data of this substance are described. Tebuconazole is unleachable, light-stable, heat-stable and suitable for use in both solvent-borne and water-borne formulations. Tests carried out by official institutes show that Tebuconazole is resistant to both leaching and evaporation. Toxic values measured in accordance with EN 113 and EN 73 (e.g. Gloeophyllum trabeum: 0.03-0.08 kg/m³ a.i.) reveals the great potential of Tebuconazole to protect treated wood against decay fungi.
R Gründlinger, O Exner
IPBC - A new fungicide for wood protection
1984 - IRG/WP 3295
3-iodo-2-propynyl butyl carbamate (IPBC) is presented as a potential low toxic alternative to pentachlorophenol and the sodium chlorophenoxides. Data on its effect against basidiomycetes is shown. Tests according to both the European standard method, EN-113, and American, ASTM D-413, have shown its potential. The chemical gives protection against both the wood destroying fungi, blue stain, mould and algae. It is possible to have it formulated in both water-based and organic solvent-based products. Treatment of wood out of ground contact (vac-vac products, pretreatment products, primers, stains, etc.) and sapstain control are some of the most potential end use areas within wood protection. Besides wood protection, the IPBC is used as a fungicide in paint, adhesives, caulks and sealants, cement, leather, paper, cutting oil, ink and in different roofing materials.
Influence of the decay of spruce chips by the selected fungi on their chemical structure and the pulp properties
2004 - IRG/WP 04-10510
The paper focuses on changes in the weight and in the molecular structure of spruce chips submitted to long-term storing as well as to medium- and long-term model rotting degradation caused by some chosen fungi identified at storing processes on the pile. For the model decay of chips under laboratory conditions during 3 or 6 weeks the white-rot fungi: Phanerochaete chrysosporium, Heterobasidion annosum, Onnia circinata or Climacocystis borealis, and the brown-rot fungus Fomitopsis pinicola, have been used. Mass losses and changes in chemical composition of chips depended on the fungus used and time of decay. The highest weight losses were caused by the fungi H.annosum and F.pinicola, the most of cellulose was removed due to F.pinicola, the most of lignin due to H.annosum, at which the amounts of removed lipophilic extractives depended selectively on the fungus and time of degradation. The further aim of this work was to evaluate biodegradation processes in wood for the pulp production. Pulps prepared from the model rotted chips and also from the long-term stored chips had changed properties, obviously reduced Kappa number, content of rejects, tear length and tear index.
R Solár, L Reinprecht, A Geffert, F Kacík
Biological screening assays of wood samples treated with creosote plus chemical additives exposed to Limnoria tripunctata
1980 - IRG/WP 408
Laboratory methods for exposure of treated wood coupons to Limnoria tripunctata are described. Chemical additions to creosote were screened using this method. Three pesticides, Endrin, Kepone, and Malathion proved particularly effective. The addition of varying percentages of naphthalene to creosote using several treatment methods are currently being assayed. Results to date show that the coupons treated by the empty cell method have better performance than those prepared by the toluene dilution method. The naphthalene coupons treated by the full cell method show no attack after six months' exposure.
B R Richards, D A Webb
Results of chemical analyses in the field of wood preservation in the Bundesanstalt für Materialprüfung
1973 - IRG/WP 321
The results of qualitative and quantitative chemical analyses of wood preservatives are often the basis for evaluating the various works in the field of wood preservation. In the past 10 to 15 years a number of such works was carried out in the Bundesanstalt fur Materialprüfung, Berlin-Dahlem, dealing with the identification and effectiveness of wood preservatives and with methods of wood preservation. Fundamental realisations were made which will be summarised below. It seems advisable to differentiate between inorganic and organic chemical wood preservatives and methods of analyses. These are two distinct fields which differ also with regard to the analytical techniques applied.
H J Petrowitz
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 solid wood samples with smooth glossy surfaces, while plastic-like wafers were obtained by hotpressing modified sawdust. Chemical modification alone was shown to enhance the biological resistance of Aspen to decay by Coriolus versicolor. In addition, hot-pressing enhanced decay resistance of both unmodified wood and esterified wood veneer samples, although no improvement was found by hot pressing oligoesterified wood. The most effective treatment for the improvement of decay resistance was chemical modification of the sawdust in conjunction with hot-pressing. A microscopic examination of chemically modified and control samples following exposure to the fungus showed more extensive colonisation and decay in untreated, unpressed samples.
M C Timar, A J Pitman, M D Mihai
Protocol for evaluation and approving new wood preservative
1985 - IRG/WP 2159
M E Hedley, J A Butcher
Di-sodium fluorophosphate, a new fluorine containing, water-borne wood preservative
1986 - IRG/WP 3373
The physical, chemical properties of Di-sodiumfluorophosphate (Na2PO3F) are compared with those of a trade-mark SF-salt. The opposition of biological activity and toxicological data showed that Di-sodiumfluorophosphate may be a suitable alternative to SF-salts ( based on MgSiF6).
D Seepe, W Metzner
Discussion of diiodomethyl p-tolyl sulfone (Amical® 48) as a fungicide for wood preservatio
1987 - IRG/WP 3425
The effectiveness of diiodomethyl-p-tolyl sulfone (Amical® 48) as a fungicide for preservation of wood is supported by a discussion of results from the literature and current research programs.
J M Stamm, K J Littel, F M H Casati, M B Friedman
Chemical compounds from Eperua falcata and Eperua grandiflora heartwood and their biological activities against wood destroying fungus (Coriolus versicolor)
2005 - IRG/WP 05-30373
The chemistry analysis of the compounds present in dichloromethane and ethanolic fraction as well as bioassays enables to understand the durability differences of Eperua falcata and Eperua grandiflora. The principal distinction between these two species is the acidic subfraction of diterpenoic extract, which is antifungic in Eperua falcata when tested in in-vitro conditions. This study also enables to show that ethanolic fraction plays an important role in the mechanism of natural durability. It also reports the first isolation of cativic acid in Eperua falcata wood.
N Amusant, C Moretti, B Richard, E Prost, J M Nuzillard, M-F Thévenon
European standardization for wood preservation
1989 - IRG/WP 2335
Contribution to study of the degradation caused in Pinus spp. poles used in field test
1989 - IRG/WP 1417
The study of the degradation produced by soil natural microflora on wood in contact with it in the field, has been going on for several years now. Our contribution to this aim in the present work has dealt with the possible relationship of the microorganisms in the soil. The microscopic visualization of wood colonization by the microorganisms, and the chemical analysis of the degraded wood compared with the undergraded.
M T De Troya, A Garcia, M J Pozuelo, A M Navarrete, A Cabanas
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 acetylated to 15% WPG did not give complete protection against soft rot. Stakes modified with alkenyl succinic anhydride showed increasing resistance to soft rot with WPG up to about 10% WPG, above which no further improvements were evident. Succinic anhydride and phthalic anhydride treated stakes showed little or no noticeable protection.
S C Forster, M D C Hale, G R Williams
Electron microscopic detection and chemical analysis of three-lamellar structures in wood-destroying fungi
1984 - IRG/WP 1240
In the course of transmission electron microscopical investigations of pine wood decay by various brown- and white-rot fungi extracellular three-lamellar structures (TLS) formed by the fungi were found in specimens stained with ruthenium red. These structures occured in the lumen of the wood cell surrounding the hypha at the outermost layer of the fungal cell wall. In the course of the investigations these structures were also detected in fungi cultivated with glucose on a rotary shaker, where they showed forms similar to tubuli and vesicles. The three-lamellar structures formed by the white-rot fungus Sporotrichum pulverulentum, which were contained in the outermost cell wall layer, were isolated by disintegration of the fungal pellet and subsequent digestion of the fungal cell wall by snail enzyme. It was found that these structures are resistant to the enzymatic digestion and are composed of 80 to 90% carbohydrates, mainly consisting of glucose monomeres, 5 to 10% proteins, containing 5 fractions with molecular weights between 30000 and 200000, and finally 5 to 10% lipids which do not contain any phospholipid.
R Foisner, K Messner, H Stachelberger, M Röhr
United States Federal Committee on Wood Protection
1971 - IRG/WP 43
A C Jewett
About the water and biological resistance of some new chemically modified wood composites
1997 - IRG/WP 97-40077
As well known, wood represents a valuable natural composite material with a very large utilisation as solid wood or in wood based composite materials. Its qualities but also its defects as the dimensional instability, the susceptibility to biological attack, the anisotropy, are due to its complex structure. Research has demonstrated that the chemical modification of wood, meaning the involving of its main chemical components through their reactive alcoholic hydroxyl groups in chemical reactions with different chemical reagents, can be a new way to ameliorate the wood or wood composites but also to obtain new wood based materials. The chemical thermoplasticization of wood, studied theoretically and experimentally by the Japanese researchers as Matsuda, Mori, Morita, Nakano, Shiraishi, Ueda seems to be a very interesting possibility. The paper presents the results of our experiments concerning the chemical thermoplasticization of wood through oligoesterification and the obtaining and characterisation of some products based on this type of chemically modified wood. In fact the main goals of this stage of the researches were: - the obtaining and characterisation of the thermoplastic wood; - the study of the thermoformation possibilities for the thermally flowable material obtained as sawdust; - the evaluation of the possibilities to carry out this chemical modification process as a surface treatment for solid wood; - the evaluation of the water and biological resistance for the obtained products.
M C Timar, M D Mihai, G Baciu
Termiticidal chemicals derived from tropical tree resins
1991 - IRG/WP 1477
To test the hypothesis that defensive chemicals protect tropical primary forest trees against biological attack, a bioassay and fractionation program was conducted in Indonesia. Fresh dipterocarp resins were fed in no-choice tests to Neotermes dalbergiae termites on 4.5 cm filter papers, or tested for inhibition of fungal growth. Fractionation of biologically active resins via flash column chromatography, followed by subsequent bioassay and analytical chemical studies, revealed that several sesquiterpene compounds inhibited fungal growth and killed 50% of test termites in 3-7 days. Toxic fractions contained caryophyllene, caryophyllene oxide, alloaromadendrene, and other compounds. From the relatively non-toxic a-gurjunene, novel termiticidal compounds were synthesized, indicating the potential for manufacture of insecticides from natural products.
A Messer, K McCormick, D Richardson, Sunjaya, H Hagedorn, J Meinwald
Fungal degradation of wood treated with metal-based preservatives. Part 2: Redox states of chromium
1996 - IRG/WP 96-10164
Concerns have arisen about the leaching of heavy metals from wood treated with metal-based preservatives, such as chromated copper arsenate (CCA). Of particular concern is the toxic redox state of chromium and arsenic in aging and decayed CCA-treated wood. Generally, hexavalent chromium is more toxic than trivalent chromium and trivalent arsenic is more toxic than pentavalent arsenic. The desired outcome from treating wood with CCA is total change of Cr(VI) to Cr(III) and As(III) to As(V). As part of an on-going study to determine the fate of copper, chromium and arsenic during aging and decay of CCA-treated wood, we detected Cr(III) and Cr(VI) in situ in CCA-treated southern yellow pine lumber. The redox states of Cr were determined using synchrotron X-ray fluorescence spectroscopy (SXRF). An SXRF microprobe was used to to detect Cr redox states by measuring X-ray absorption near-edge structure (XANES). The ratio of Cr(III) to Cr(VI) was determined (1) on the surface and interior of lumber two years after CCA treatment and (2) in lumber during decay by a CCA-tolerant fungus, Meruliporia incrassata TFFH-294. The XANES spectrum for Cr(VI) has a strong pre-edge feature that is not present in the spectrum for Cr(III). Only the Cr(III) XANES spectrum was detected on the surface and in the interior of the wood, indicating total reduction of Cr(VI). The XANES spectrum for Cr(III) was detected in wood after 12 week decay by Meruliporia incrassata TFFH-294, indicating that the fungus does not oxidize Cr(III) to Cr(VI) during the decay process. We are currently using XANES spectroscopy to detect and map in situ redox states of As in CCA-treated wood.
B Illman, S Bajt, T L Highley
The permanence of permethrin in wood preservation
1984 - IRG/WP 3288
The permanence of the synthetic pyrethroid permethrin in treated wood has been assessed for double vacuum and immersion treated Scots pine sapwood and whitewood using a 0.5% m/m solution of the insecticide in a hydrocarbon solvent. It is concluded that for all but the outermost 0.5 mm of the treated battens the distribution of the permethrin is relatively permanent. The outermost 0.5 mm appears vulnerable to degradation rather than volatile loss, and this varies with timber species and the loading in that zone. Linking this information with published bioassay work allows speculation as to the strength of treating solutions needed for adequate long-term protection
R J Orsler, M W S Stone
Biological degradation resistance of pine wood treated with dimethylol compounds
1989 - IRG/WP 3528
The study reports the increase of dimensional stability and biological degradation resistance of pine wood (Pinus sylvestris L) after impregnation with dimethyloldibydroxyethyleneurea. Decay resistance was determined according to BS 838:961. Nearly complete protection against Coniophora puteana, (Schum.ex Fr. Karst) weight loss of 2-3% was shown when modification, expressed as weight gain, exceeded 15%. Resistance to biological attack of modified wood is speculated to be due to modification of the wood components and cross linking with dimethyloldihydroxyethyleneurea.
C L Videlov
Electronic noses for detection of rot in wood
1996 - IRG/WP 96-20098
In an ongoing project an electronic nose is being studied and developed for detection of volatile organic compounds (VOC) emitted from wood colonised and decayed by fungi. The electronic nose consists of an array of gas sensors with different selectivity patterns for different groups of volatile organic compounds (VOC). The use of pattern recognition routines implemented by artificial neural networks (ANN) is used to evaluate data from the sensor array. The responses from the sensor array have been correlated to weight loss of and contents of chitin in the decayed wood samples. The results obtained so far indicate that the electronic nose qualitatively can detect significant differences between sound and decayed sapwood of Scots pine (Pinus sylvestris). Preliminary results also indicate that the electronic nose can detect differences between decay types like brown rot (Lentinus lepideus) and soft rot (Phialophora A). Results from a study aiming at investigating the abilities of the electronic nose to quantitatively detect different stages of decay is now being analysed statistically. The influence on the responses from the sensor array due to variation in relative humidity, moisture content of the decayed wood samples and temperature have also been studied.
An experimental method to simulate incipient decay of wood by basidiomycete fungi
2000 - IRG/WP 00-20200
At very early stages of decay of wood by basidiomycete fungi, strength loss can be measured from wood before any measurable weight loss. Therefore, strength loss is a more efficient measure of incipient decay than weight loss. However, common standard decay tests (e.g. EN 113 or ASTM D2017) use weight loss as the measure of decay. A method was developed that allowed progressive removal of samples so that all stages of colonisation and decay could be monitored by strength testing, weight loss determination and chemical analysis. Our results indicated that substantial and rapid decay (90% strength loss and 40% weight loss after 12 weeks) of southern pine by brown rot fungi was possible using the method. Our results also demonstrate a direct relationship between strength loss and weight loss and suggest a quantitative relationship between strength loss and chemical composition (hemicellulose sugars) during incipient decay of southern pine by basidiomycete fungi.
S F Curling, J E Winandy, C A Clausen