Your search resulted in 136 documents. Displaying 25 entries per page.
Resistance of phenol formaldehyde impregnated beech (Fagus sylvativa L.) LVL against biodegradation in soil contact
2023 - IRG/WP 23-40965
Alternatives to preservative impregnation are emphasized in Germany and other European countries. Even though these treatments significantly improve wood's resistance to decay, they often do not have a beneficial impact on the dimensional stability. One alternative product, which may be used in ground contact for items like poles and railway sleepers, could be beech (Fagus sylvatica L.) laminated ...
M Slabohm, C Brischke, S Bicke, H Militz
Wood and filter paper degradation, phenol oxidase and one-electron oxidation activities by the white rot fungus Ceriporiopsis subvermispora
2003 - IRG/WP 03-10486
The activities of one-electron oxidation and phenol oxidase during incubation of cultures of the white-rot basidiomycete Ceriporiopsis subvermispora containing either glucose or wood were periodically measured. Further, the degradation activities against wood and filter paper were examined during the course of cultivation. Weight losses of Japanese beech wood and Japanese cedar wood after 12 wee...
H Tanaka, S Itakura, A Enoki
Thermotolerant mould growth in dehumidifier kilns in New Zealand
1996 - IRG/WP 96-10169
Growth of Aspergillus fumigatus and Paecilomyces variottii is common on wood dried in dehumidifier kilns that operate within a temperature range of 35-55°C. Aspergillus fumigatus causes an unacceptable blue / grey discolouration of the woods surface and prolonged exposure to spores during handling of mouldy wood can cause health problems amongst timber workers. A survey of dehumidifier kiln opera...
R N Wakeling, J G Van der Waals
The effect of low molecular weight chelators on iron chelation and free radical generation as studied by ESR measurement
2000 - IRG/WP 00-10367
The focus of this work was to improve our current knowledge of the non-enzymatic mechanisms involved in brown-rot decay. Electron Spin Resonance (ESR), also known as Electron Paramagnetic Resonance (EPR), is an attractive technique for the identification and study of chemical species containing unpaired electrons (such as radicals and certain transition metal species). ESR spin-trapping techniques...
Yuhui Qian, B Goodell
A novel defaunation method of the protozoa to investigate cellulose metabolism in Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae)
1994 - IRG/WP 94-10050
The largest protozoa in the hindgut of workers of Formosan subterranean termite, Coptotermes formosanus Shiraki, was selectively eliminated by forced-feeding on low-molecular weight cellulose (LC) with a mean DP of 17. Although one week's feeding on LC caused perfect disappearance of Pseudotrichonympha grassii Koidzumi, the selective defaunation method itself had no detrimental effect on ...
T Yoshimura, K Tsunoda, M Takahashi
Durability of surface preserved wood particle boards submitted to atmospherical influence
1995 - IRG/WP 95-40039
The worldwide problem of the continuously growing deficit of high quality natural wood material has caused the attempts of many research workers to find effective composites such as wood particle boards (WPBs) for replacing the massive wood for constructive purposes, depending on where the boards are exploited - in the open or under a shed, they are submitted to various climatic factors such as he...
L Valcheva
Curing conditions for a low formaldehyde etherificated melamine resin
1998 - IRG/WP 98-40108
Waterbased methanol etherificated melamine formaldehyde resins have the potential to increase the resistance of impregnated wood against wood destroying fungi. Previous studies indicated that the resin with the lowest formaldehyde content tested showed the best results regarding fungal resistance, dimensional stability and formaldehyde emissions after curing. In the present paper the influence of ...
D Lukowsky, R-D Peek, A O Rapp
The role of oxygen and oxygen radicals in one-electron oxidation reactions mediated by low-molecular weight chelators isolated from Gloeophyllum trabeum.markup
1994 - IRG/WP 94-10086
The KTBA assay for determination of one-electron oxidation activity was used to assay reactions of low-molecular weight chelators isolated from the brown rot fungus Gloeophyllum trabeum. The assay, performed either under air or nitrogen showed that molecular oxygen was an important factor in chelator-mediated oxidation reactions. A reduction in oxidative activity was observed when superoxide dismu...
Jun Lu, B Goodell, Jiang Liu, A Enoki, J Jellison, H Tanaka, F Fekete
The involvement of extracellular substances for the generation of hydroxyl radical during wood degradation by white-rot fungi
1997 - IRG/WP 97-10218
The activities of one-electron oxidation, hydroxyl radical generation, and phenol oxidase during the incubation of cultures of four white-rot fungi containing either glucose or wood were periodically measured. Further, their degradation activities against wood were examined during the course of cultivation. The generation of hydroxyl radical was correlated to the activity of wood degradation and i...
H Tanaka, S Itakura, A Enoki
Stability of bifenthrin in a commercial phenol-formaldehyde plywood glue
2003 - IRG/WP 03-30311
Liquid phenol formaldehyde (PF) glue mixes used for plywood manufacture are strongly alkaline. At this pH insecticidal additives may not be stable for long periods. In order to establish practical working life of the synthetic pyrethroid insecticide, bifenthrin, in liquid PF glues the concentration of bifenthrin in the glue mix was measured under laboratory conditions over a 24 hour period. Glu...
M J Kennedy, P A Collins, R D Vella
Degradation of wood veneers by Fenton’s reagents: effects of low molecular weight phenolic compounds on hydrogen peroxide decay and tensile strength loss
2009 - IRG/WP 09-20400
Pine wood (Pinus sylvestris) veneers strips were incubated in acetate buffer containing hydrogen peroxide and iron to mimic mechanisms of brown rot decay and assess the degradation of cellulose through analysis of the tensile properties of the decayed wood. The tensile properties of thin wood strips treated with Fenton system reagents or precursors were determined and correlated to weight loss as ...
Yanjun Xie, R Well, Zefang Xiao, B Goodell, J Jellison, H Militz, C Mai
Leaching performance, decay and termite resistance of wood treated with boron compounds incorporated with phenol-formaldehyde resin
2009 - IRG/WP 09-30503
A resol-type phenol-formaldehyde (PF) resin was synthesized and designed to penetrate wood incorporated with boron compounds in order to immobilize boron in wood. The leaching performance, decay and termite resistance of treated wood was investigated. Three kinds of boron compounds, that is, boric acid (BA), borax (BX) and disodium octaborate tetrahydrate (DOT), were selected to mix with PF and tw...
Liping Yu, Jinzhen Cao
Properties of strand board bonded with ammonium pentaborate (APB) modified phenol formaldehyde resin
2009 - IRG/WP 09-40455
Ammonium pentaborate (APB) is combined with phenol formaldehyde (PF) resin in this study to develop a high-performance wood-based composite. The effect of APB and its combination with polyethylene glycol (PEG) on the physical, mechanical properties as well as formaldehyde emission of strand board were tested and compared with disodium octaborate tetrahydrateand (DOT) and zinc borate (ZB). The resu...
Wei Gao, Jinzhen Cao
Fungal Attack on Lignin and Cellulose: Elucidation of Brown- and White-Rot Mechanisms Comparing Biomimetic and In-Vivo Degradation Patterns
2010 - IRG/WP 10-10714
This paper examines research and hypotheses that have been developed over several years on wood degradation mechanisms. This information is combined with new data and analyses to explain why wood decay patterns caused by brown-rot fungi and specific types of white-rot fungi are different. New data, including work with both biomimetic studies on low molecular weight compounds, degradative enzymes, ...
V Arantes, B Goodell, A M F Milagres, Yuhui Qian, T Filley, J Jellison, S Kelley
Fungal decay resistance and mechanical properties of plywood panels made from maritime pine (Pinus pinaster) and bonded with cornstarch-quebracho tannin-phenol formaldehyde adhesive
2010 - IRG/WP 10-40490
The aim of this work is to demonstrate the performances of cornstarch-quebracho tannin-based resins designed as adhesive in the plywood production. In this way, the cornstarch and quebracho tannin was introduced in the classic adhesive formulation in order to supply a part of phenol-formaldehyde (PF). In order to evaluate the mechanical performances of optimal cornstarch-quebracho tannin-PF, plywo...
F Charrier, A Moubarik, A Allal, A Pizzi, B Charrier
Effect of P/F ratio, PF concentration and treating method on boron leaching from wood treated with PF modified boron compounds
2011 - IRG/WP 11-30559
In order to immobilize boron in wood, three kinds of resol-type phenol-formaldehyde (PF) resin with different P/F ratios were synthesized in laboratory and incorporated with three types of boron compounds to treat wood. The used boron compounds included boric acid (BA), borax (BX) and disodium octaborate tetrahydrate (DOT). The leaching test of boron from wood blocks was performed according to the...
Liping Yu, Jinzhen Cao
Smart hydrogels from low molecular weight amphiphilic compounds: toward a solution to decrease leachability and increase efficacy of boron preservatives?
2012 - IRG/WP 12-30589
A new catanionic system associating amphiphilic carnosine (AlaHisC8) and lauric acid forms supramolecular hydrogel at very low concentration. This gel was investigated and we have checked the validity of the concept of hydrogels utilization to reduce boron leachability and to develop new wood protection treatments. Impregnation with 5% aqueous borax solution (w/w) and 0.3% gelator agent (...
F Obounou Akong, P Gérardin, C Gérardin-Charbonnier
Hydrogels: a solution to reduce boron leachability without reduction of its biodisponibility to wood decaying fungi?
2012 - IRG/WP 12-30602
Products used today for wood protection must fulfill to more and more environmental constraints, such as being of low toxicity in answer to the Biocidal Product Directory, but also to involve waterborne treatments to limit rejection of volatile organic compounds in the atmosphere. Boron preservatives have been described as valuable alternatives for wood protection for non-ground contact applicatio...
F Obounou Akong, P Gérardin, M-F Thévenon, S Parant, C Gérardin-Charbonnier
Termite resistance of wood impregnated with phenol-formaldehyde (PF) modified boron compounds
2012 - IRG/WP 12-30604
In order to investigate the effect of phenol-formaldehyde (PF) modified boron compounds on termite resistance of two main plantation-grown wood species, namely, Masson pine (Pinus massoniana Lamb.) and Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.), laboratory termite tests and field tests were carried out according to AWPA standard E1-97 and AWPC protocols/2007. Different concentrations of b...
Jinzhen CAO, Liping YU, Xuexiang HE
State of progress of utilisation of supramolecular gels for formulations of water-soluble wood preservation salts
2013 - IRG/WP 13-30630
This article is a compilation of the work done so far concerning the utilization of supramolecular hydrogels, built on low-molecular-weight amphiphilic molecules and containing boron salts conferring fungicidal properties. Mixing boron with thermoreversible hydrogels allows the formation of a supra molecular network incorporating boron and important amount of water upon gelification of the solutio...
F Obounou Akong, P Gérardin, M-F Thévenon, C Gérardin-Charbonnier
Curing kinetics of nano cupric oxide (CuO) modified PF resin as wood adhesive: Effect of surfactant
2013 - IRG/WP 13-40620
The effect of nano cupric oxide (CuO) in combination with surfactants on the curing kinetics of phenol formaldehyde (PF) resin, as well as the bonding strength of plywood prepared using the modified resin were investigated in this study using dynamic and isothermal differential scanning calorimetry (DSC). The result showed that the incorporation of nano CuO along with alkane surfactant made in the...
Wei Gao, Guanben Du
Dynamic mechanical analysis (DMA) of nano cupric oxide (CuO) modified aqueous phenol formaldehyde (PF) resin
2014 - IRG/WP 14-40654
Phenol formaldehyde (PF) resins, modified by nano CuO incorporating alkane surfactant and polyvinyl alcohol (PVA) 17-99, were analyzed by dynamic mechanical analysis (DMA). The mechanical properties of its bonded plywood including tensile strength, modulus of rupture (MOR), modulus of elasticity (MOE) and shear strength under five test conditions were evaluated. Results indicated that the incorpor...
Wei Gao, Guanben Du
Penetration of phenol formaldehyde (PF) resin into beech wood studied by light microscopy
2015 - IRG/WP 15-20558
In this study, we examined the distribution and penetration depth of phenol-formaldehyde (PF) resin into wood specimens by light microscopy (LM). Two PF resins from different producers, of concentrations 9, 18 and 27 wt % in water, were vacuum impregnated into European beech wood (Fagus sylvatica) blocks of 15x25x50 mm³. The presence of chemical agent in the wood was carried out by way of their i...
V Biziks, S Bicke, H Militz
Decay resistance of beech wood and plywood treated with different type of phenol-formaldehyde (PF) resins
2016 - IRG/WP 16-40717
In this study treatment of beech and poplar wood veneers with (PF) resin industrial scale and screening tests of nine different phenol-formaldehyde (PF) resins were made. Specifically, the effect of different phenol-formaldehyde (PF) resin types on the resistance of beech wood against brown- and white-rot fungi was evaluated. Criteria for selection of optimal (PF) resin were based on minimum WPG ...
V Biziks, S Bicke, H Militz
Lignin-Based Adhesive for Engineered Wood Products
2016 - IRG/WP 16-50319
Lignin as a naturally occurring polyphenolic compound has an excellent potential to replace petroleum-based phenol in formulation of phenol-formaldehyde adhesive that are used in manufacturing of engineered wood products. However, there are three major obstacles in application of polymeric lignin as phenol replacement: 1) low reactivity toward phenol, 2) high molecular weight, and 3) high polydisp...
I Kalami, M Arefmanesh, E Master, M Nejad