Indian Journal of Chemical Technology, Vol.7, No.6, 312-317, 2000
Treatment of wood with thermosetting resins: Effect on dimensional stability, strength and termite resistance
The effect of thermosetting resins viz. phenol formaldehyde (PF) and melamine formaldehyde (MF) on dimensional stability, strength property and termite (Odontotermis spp) resistant capacity of a soft wood, bombax ceiba were assessed. The wood was treated with 30% resin concentration in 110 degreesC at 75 psi air pressure and then dimensional stability in terms of anti-shrink efficiency (ASE) of 70.59% and 68.23% were achieved at 32.1 and 33.0 levels of weight percent gain (WPG) for PF and MF resins respectively. Maximum bulking co-efficient (BC) of 15.39% and 13.28%, and moisture excluding efficiency (MEE) of 45.31% and 41.39% were achieved for PF and MF treated samples at the above two WPG levels. Three cycles of repeated wetting and drying did not cause any further change in BC and ASE. The treatment also increased modulus of rupture (MOR) by 21.6% and 19.48% and modulus of elasticity (MOE) by 12.86% and 11.10% over the untreated samples without any remarkable change in specific gravity. Furthermore, the treated wood showed resistance to termite.