Thermal and Tensile Properties of Treated and Untreared Red Balau (Shorea Dipterocarpaceae)/LDPE Composites

Abstract

In Wood Plastic Composites (WPC), incompatibility between the polar wood and the non polar matrix constitutes a problem which can result in poor interfacial adhesion, leading to poor mechanical properties. This paper is aimed at alleviating this problem by modifying wood with heat treatment. Heat treated Red balau saw dust was compounded with Low Density Polyethylene (LDPE) at different filler loadings. Thermal and tensile properties of the resultant composites were investigated as a function of filler loadings and treatment temperature. Tensile moduli increased compared to the neat LDPE matrix when heat treated wood was used as filler, relative to the untreated wood. Differential scanning calorimetric investigations revealed a decreasing trend in the degree of crystallinity (Xc) of the matrix with heat treated wood. On the other hand, untreated wood showed an increase in Xc with increasing wood content. Wood treated at 200oC showed a rapid decrease in the degree of crystallinity. Melting temperatures were not significantly altered. Thermogravimetric analysis revealed an increase in degradation peak temperature (Tp) of the composites relative to the neat matrix. Reduction in the degree of crystallinity and increase in thermal stability offer advantages in WPC processing.