Effect of different coupling agents on the thermal, mechanical and biological behavior of vinyl acetate-wood polymer composite

Abstract

Abstract Poplar wood (Populus deltoides Bartr.) was modified by a combined two-step treatment with different chemicals to improve its properties. Maleic anhydride (MAN), 3-(trimethoxysilyl) propyl methacrylate (TMPS) and glycidyl methacrylate (GMA) were first employed to modify wood cell wall resulting in WMAN, WTMPS and WGMA. Then, in a second step, the vinyl acetate (VA) monomer was let to polymerize within the cell lumina resulting in WPCMAN/VA, WPCTMPS/VA and WPCGMA/VA (WPCs). Field emission scanning electron microscopy (FESEM) observations confirmed the bulking of modified cell walls. The thermal stability, mechanical properties and decay resistance of WPCs were remarkably improved compared to unmodified wood in the order WPCGMA/VA >  WPCTMPS/VA > WPCMAN/VA. WPCMAN/VA displayed a significant decay resistance increment, despite lower retention and reactivity than the WPCTMPS/VA, which is probably due to a better penetration into the cell wall and the higher degree of chemical modification of the wood components.