Abstract
Japanese cedar wood was acetylated, impregnated with polystyrene (PS) and then compressed in the radial direction. The dynamic Young's modulus (E'), bending strength and dimensional stability of that wood-PS composite were measured to investigate the effects of inter-cellular adhesion with the introduced PS resin. The acetylation and the following PS impregnation had little influence on the E' of the wood, but after hot-pressing at 180°C, the wood was effectively densified and its E' in the tangential direction was significantly enhanced. Such an enhancement was not recognized when the PS-impregnated wood was compressed at room temperature. The improved mechanical properties due to the hot-pressing was explained by the adhesion of the wood cell walls with the PS resin. That inter-cellular adhesion was also effective to fix the compressive deformation of wood: the reversible and irreversible swelling due to alternate dry-wet cycles were considerably reduced when the acetylated wood-PS composite was hot-pressed.
