Morphology-property relationships in wood-fibre-based polyurethanes

Abstract

Many of the advances in material performance over the last decade can be attributed to developments in multicomponent polymer systems and, specifically, to multiphase materials such as incompatible polymer blends and fibre-reinforced composites. In these types of material, performance properties are not often dominated by the interphase that defines the transition region from one pure phase to another. Although typically a minor component, the interphase effectively determines the mechanism and efficiency of stress transfer between the components that make up the material system. With the potential for chemical reaction across the interface, complications exist when viewing the material as an incompatible polymer blend or a reinforced polymer composite. One example of this type of composite is polyurethanes incorporating a lignocellulosic fibre. This class of natural fibre is characterized by a hydroxy-rich surface that may react with the isocyanate group of the urethane formulation. Wood-fibre polyurethanes that incorporate synthetic polyols are of interest because of the versatility that is afforded by urethane chemistry and the possibility of alternative market developments for wood composites. At the same time, research on this material may provide additional insight into the complexities of the fibre-polymer interfacial structure. In this report, preliminary results on the phase morphology of wood-fibre-urethane composites are presented. In addition, the effect of fibre and polyol characteristics on interfacial quality is discussed.

Citation

Rials, Timothy G.; Wolcott, Michael P. 1998. Morphology-property relationships in wood-fibre-based polyurethanes. Journal of Materials Science Letters. 17: 317-319.