Effect of Heat Treatment on the Tensile Strength of Glass Fibre Reinforced Polypropylene

Abstract

Improvement of the interfacial adhesion by heat treatment of glass fibre reinforced polypropylene composite was studied. Polypropylene blended with glass fibres was injection-molded. The molded parts were heat treated at various temperatures for various times. Characterization of the mechanical properties of the resulting samples was performed including measurement of the critical fibre length, and differential scanning calorimetry. The results show that the critical fibre length increases while the tensile strength decreases with increasing testing temperature. At 25 and 80°C, heat treatment can improve the tensile strength. At or above 120°C, certain treatment conditions cause the tensile strength to drop significantly.