Your search resulted in 13 documents.
Identification of terminal structures in cellulose degraded by the brown-rot fungus Postia placenta
1989 - IRG/WP 1389
To gain insight into the biochemical mechanism employed by brown-rot fungi to depolymerize cellulose, we identified the end-groups of chemically pure cellulose that had been depolymerized by the brown-rot fungus, Postia placenta. The depolymerized cellulose was acid hydrolyzed and the anion fractions isolated by ion chromatography. Sugar acids were identified by gas chromatographic and mass spectr...
T K Kirk, T L Highley, R E Ibach, M D Mozuch
Low polymer levels containing bioactive monomer polymerized in situ provide resistance to Gloeophyllum trabeum
1995 - IRG/WP 95-30066
Wood preservation based on in situ polymerization of potentially bioactive monomers has been studied. Tributyltin oxide acrylate (TBTOA) and pentachlorophenol acrylate (PCPA) were synthesized. Wood samples were treated at 2, 5, 10, 15 and 20% by weight solutions with varying amounts of crosslinker (trimethylolpropane trimethacrylate, TMPTM) and polymerized in situ in wood samples (2.54 x 2.54 x 0....
R E Ibach, R M Rowell
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
The Effect on Biological and Moisture Resistance of Epichlorohydrin Chemically Modified Wood
2002 - IRG/WP 02-40224
Southern pine solid wood and fiber were chemically modified with epichlorohydrin to help in understanding the role of moisture in the mechanism of biological effectiveness of chemically modified wood. The solid wood had weight gains from 11% to 34%, while the fiber had weight gains from 9% to 75%. After modification, part of the specimens were water leached
for 2 weeks or extracted for 2 hours ...
R E Ibach, B-G Lee
Properties of cellulose degraded by the brown rot fungus, Postia placenta
1988 - IRG/WP 1350
To gain further understanding of the nature of the cellulose depolymerizing agent or agents of brown-rot fungi, brown-rotted cellulose was chemically and physically characterized. Various culture conditions, such as low nitrogen and elevated oxygen levels, did not induce degradation of cellulose by Postia placenta in liquid cultures. Therefore, brown-rotted cellulose for analysis was prepared by a...
T L Highley, R E Ibach, T K Kirk
Moisture and Fungal Durability of Wood-Plastic Composites Made With Chemically Modified and Treated Wood Flour
2013 - IRG/WP 13-40648
Evaluating the fungal durability of wood-plastic composites (WPCs) is complicated by the influence of slow moisture sorption. Recently, the American Wood Protection Association (AWPA) Standard Method E10, Testing Wood Preservatives by Laboratory Soil-Block Cultures, was modified to incorporate not only solid wood, but also wood-based composites and WPCs. To simulate long term WPC performance, cond...
B K Segerholm, R E Ibach
Decay resistance of wood-plastic composites reinforced with extracted or delignified wood flour
2014 - IRG/WP 14-40655
The moisture and decay resistance of wood-plastic composites (WPCs) reinforced with extracted or delignified wood flour (WF) was investigated. Three different extractions were preformed: toluene/ethanol (TE), acetone/water (AW), and hot water (HW). Delignification (DL) was performed using a sodium chlorite/acetic acid solution. All WPCs specimens were made with 50% by weight HDPE and WF, first com...
R E Ibach, Yao Chen, N M Stark, M A Tshabalala, Yongming Fan, Jianmin Gao
Modern Instrumental Methods to Investigate the Mechanism of Biological Decay in Wood Plastic Composites
2014 - IRG/WP 14-40674
Various instrumental techniques were used to study the fungal decay process in wood plastic composite (WPC) boards. Commercial boards exposed near Hilo, Hawaii (HI) for eight years in both sun and shadow locations were inspected and tested periodically. After eight years of exposure, both boards were evaluated using magnetic resonance imaging (MRI), while a selected area of the board exposed in sh...
G Sun, R Ibach, M Gnatowski, J Glaeser, M Leung, J Haight
The use of new, aqueous chemical wood modifications to improve the durability of wood-plastic composites
2017 - IRG/WP 17-40787
The wood flour used in wood-plastic composites (WPCs) can biologically deteriorate and thus the overall mechanical performance of WPCs decrease when exposed to moisture and fungal decay. Protecting the wood flour by chemical modification can improve the durability of the wood in a nontoxic way so it is not harmful to the environment. WPCs were made with modified wood flour and then evaluated for m...
R E Ibach, C M Clemons, G C Chen
Termite resistance of wood-plastic composites made with acetylated wood flour, coupling agent or zinc borate
2018 - IRG/WP 18-10917
There is little published scientific literature on the laboratory or field testing of wood-plastic composites (WPC) against termite attack. Therefore, the objective of this research was to investigate termite resistance (both laboratory and field) of 5 different extruded WPC blends of 50% western pine wood flour (WF) and high-density polyethylene (HDPE), and untreated pine solid wood. The study in...
R E Ibach, Y S Hadi, C M Clemons, S Yusuf
Effects of teak, Tectona grandis Linn, heartwood extractives against Heterotermes indicola (Isoptera; Rhinotermitidae)
2018 - IRG/WP 18-10910
Heartwood extractives from Tectona grandis were investigated for antitermitic activities against Heterotermes indicola in laboratory experiments. Extractives were removed from wood shavings by soxhlet extraction using an ethanol: toluene (2:1) solvent system. Termite feeding and mortality followed a concentration dependent response. The highest termite mortality occurred at an extractive concentra...
B Hassan, S Ahmed, M Mankowski, G Kirker, R E Ibach, M Misbah ul Haq
Using X-ray scattering to elucidate the mechanisms behind the moisture and fungal decay resistance of epoxybutene modified wood
2019 - IRG/WP 19-40854
Chemical modification of the hydroxyl groups of wood can improve the properties of wood by providing moisture and biological resistance, as well as dimensional stability. Southern pine solid wood was chemically modified to various weight percentage gains (WPG) with epoxybutene (EpB, 8%-38% WPG). After modification, specimens were extracted with a toluene: ethanol (2:1) solution for 2 hours or wate...
R E Ibach, N Plaza
Long-term field exposure of wood-plastic composites processed on a commercial-size extruder
2020 - IRG/WP 20-40894
Wood-plastic composites (WPC) contain wood fiber (or flour), thermoplastics and additives and are exposed to UV light, moisture, and biological deterioration in outdoor installations. Accelerated laboratory tests can help to predict the durability of WPCs, but long term evaluations are needed to validate these results. Field exposed above-ground WPC deck boards (30.5 x 139.7 x 609.6 mm) and in-gro...
R E Ibach, C M Clemmons, N M Stark