Biological degradation resistance of wood acetylated with thioacetic acid
S Kumar, S C Agarwal
Chemically, modification of wood is being considered as an alternative to conventional preservation by toxic chemicals. Acetylated wood has been reported to be quite resistant to most biodegrading organisms at weight percent gains (WPG) around 15-19. The conventional acetylation techniques with acethic anhyrdride result in generation of acetic acid. However, acetylation with thioacetic acid overcomes this problem. Since different reagents may be reacting with hydroxyls located on different wood components, preliminary investigations on the resistance of wood acetylated with thioacetic acid were carried out. Tests against a brown rot fungus (Poria monticola) were carried out using soil block method with chir, a softwood. The wood exhibited good resistance to this fungus at WPG around 18. Resistance tests against a substerranean termite species Microcerotermes beesoni using forced feading method showed fairly good resistance at WPG around 13. Tests against softrot attack in a running cooling tower, however, did not show any resiastance upto a WPG of 14.