Effect of the Coupling Agent on the Properties of PNC-based Wood/Plastic Composites

Shu-Kai Yeh¹, Adam Al-Mulla², and Rakesh K. Gupta¹

^1. Department of Chemical Engineering, West Virginia University, P.O. Box 6102, Morgantown, WV 26506, USA

^2. Department of Chemical Engineering, Kuwait University,
Safat 13060, Kuwait

ABSTRACT

The increase in modulus of polypropylene (PP) upon addition of montmorillonite makes PP-based polymer nanocomposites (PNCs) ideal matrix materials for wood/plastic composites (WPCs) for decking, railing, roofing and siding applications, among others. In this work, the influence of maleated PP (that is used both as a coupling agent for WPCs and as a compatibilizer for the PNC) on increasing the modulus of extruded and injection molded PP-based WPCs is investigated. Also examined are the effects of the sequence of compounding steps and the use of different processing conditions. The improvement in mechanical properties is explained with the help of available theories and is also related to the composite morphology with the help of scanning and transmission electron micrographs.