1 - Raw materials for wood-polymer composites

Abstract

Publisher Summary This chapter highlights that to understand Wood-Plastic Composites (WPCs) adequately, one must first understand the two main constituents. Though both are polymer-based, they are very different in origin, structure, and performance. Polymers are high molecular weight materials whose performance is largely determined by its molecular architecture. In WPCs, a polymer matrix forms the continuous phase surrounding the wood component. Those matrix polymers are typically low-cost commodity polymers that flow easily when heated, allowing for considerable processing flexibility when wood is combined with them. The polymers tend to shrink and swell with temperature but absorb little moisture and can be effective barriers to moisture intrusion in a well-designed composite. The chapter explores the basic structure and properties of polymers and wood individually to lay a foundation for a greater understanding of the composites made from them. Basic concepts and properties are briefly summarized in the chapter with emphasis on materials common to current commercial technology.