Effect of Compatibilizer on Mechanical, Morphological, and Thermal Properties of Chemimechanical Pulp-reinforced PP Composites

Abstract

Mechanical, morphological, and thermal properties of injection molded, chemimechanical pulp (CMP)-reinforced polypropylene (PP) composites were investigated as a function of different concentrations of maleic anhydride-grafted PP. It was found that tensile strength and failure strain and the notched impact strength increased progressively with increasing compatibilizer content, whereas the addition of any concentration of compatibilizer did not alter the tensile modulus. Scanning electron microscopy — micrographs of tensile fracture surfaces of composites with 2% compatibilizer indicated very little fiber pullout and many fractured fibers. The thermal stability of pure PP was found to be higher than that of CMP-reinforced PP composites. With addition of compatibilizer, the thermal stability of the composites was slightly increased. The activation energy was determined to describe the energy consumption of the initiation of the thermal degradation process. The activation energy of the composites was found to depend on the dispersion and interfacial adhesion of CMP and PP matrix.