Abstract
Chemical modification was carried out on disodium octoborate tetrahydrate (DOT)-treated wood using allyl glycidyl ether (AGE) in combination with methyl methacrylate (MMA) to limit boron leaching. Co-polymerization of the monomers in DOT-treated sugi (Cryptomeria japonica D. Don) wood was completed by catalyst heat treatment. Besides boron leachability, the dimensional stability and decay, and termite resistance of chemically modified wood were also determined. Dimensional stability in terms of anti-swelling efficiency and water absorption was found to improve in chemically modified wood specimens. Co-polymerization of AGE with MMA in DOT-treated wood resulted in less boron leaching compared with DOT-only-treated wood. Chemically modified wood containing boron proved to be more resistant to the brown-rot fungus Fomitopsis palustris (Berkeley et Curtis) Murrill (FFPRI 0507) and the white-rot fungus Trametes versicolor (L. ex Fr.) Quel. (FFPRI 1030) in laboratory decay resistance tests after severe leaching for 10 days. Termite resistance tests also showed that wood specimens treated with DOT and MMA plus AGE monomers were effective against subterranean termites Coptotermes formosanus Shiraki even after severe leaching cycles.