Effects of Formulation Design on Thermal Properties of Wood/Thermoplastic Composites

In this study, thermal properties of wood/HDPE composites were measured by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The composites comprised of different wood (45%, 55%, and 65%) and maleic anhydride grafted polypropylene (MAPP) contents (0%, 1.5%, and 3%), and particle size (20, 40, and 80 mesh) were produced by extrusion method. TGA measurements showed that wood content is the most important factor affecting the thermal stability, initial mass loss, and ash content of the composites. Any increase in wood content led to increase in ash content and less thermally stable composites. MAPP and particle size were found to have less impact on thermal stability. By retarding the formation of charcoal MAPP influenced thermal stability of composites adversely in composites consisting of bigger particle. Composites made of 65% wood content with 20 mesh size and 0% MAPP were more thermally stable than composites made of 65% wood content with 80 mesh size and 3% MAPP, in the temperature range of 270-500 degrees C. Melting point measurements by DSC showed that melting point had no relationship with wood and MAPP contents, and particle size.