Chemical modification of wood with thermosetting resin: effect on dimensional stability and strength property

The effects on dimensional stability and strength property of a soft-wood ( Anthocephalus cadamba Mig.) treated with thermosetting resins; phenol forma ldehyde (PF), melamine formaldehyde (MF) and urea formaldehyde (UF), were s tudied. Dimensional stability efficiencies of 70.59%, 68.23% and 48.5% were obtained at about 33-35 levels of weight percent gain (WPG) for PF, MF and UF resins, respectively, when wood samples were treated with 30% resin con centration at 90-100 degrees C and 75 psi air pressure. These levels of WPG of polymers caused 9-15% bulking coefficient (BC) and 31-47% moisture excl uding efficiency (MEE) of treated wood. Repeated wetting and drying did not change the value of BC and anti-shrink efficiency (ASE) of treated samples . The treatment also increased the modulus of rupture (MOR) and modulus of elasticity (MOE) by 12-20% and 5-12%, respectively, at 33-35 WPG. Furthermo re, the treated wood samples showed resistance to termite (Odontotermis spp .) attack. (C) 2000 Elsevier Science Ltd. All rights reserved.