Wood-Polymer Composites

Abstract

This paper is an update of several earlier review articles on wood polymer composites (WPC). Notable polymer types that have been used to make WPC are phenol-formaldehyde (PF), various vinyls, and furfuryl alcohol. Phenol-formaldehyde and similar chemicals typically enter wood cell walls, whereas the vinyls usually fill cell lumens. Combination treatments that modify both lumens and walls are possible. Diffusion and mass flow are two possible methods of introducing the chemical into the wood. Curing can be accomplished using a catalyst and heat or penetrating radiation. Type of treating chemical and final density are major determinants of WPC properties. Physical and mechanical properties of WPC have been extensively studied. Major WPC improvements over untreated wood are in hardness, finishability, and dimensional stability. There is much yet to be learned about chemical formulations, treating and curing, and their relationships to property enhancements, WPC recyclability, and chemicals from renewable sources for making WPC.