Fabrication and characterization of short glass fiber reinforced polypropylene hybrid composite foams

Abstract

To improve the comprehensive performances of polypropylene/ethylene-α-octene copolymer foams, short glass fiber was introduced to prepare polypropylene hybrid composite foams. Then, the effects of short glass fiber on the foaming qualities, interfacial morphologies, mechanical properties and energy absorption behavior of polypropylene hybrid composite foams were investigated. Results showed that the foaming qualities of the hybrid composite foams were improved greatly. The minimum average cell diameter and maximum cell density were achieved with adding 30% short glass fiber. From the analysis of interfacial structures, the interfacial interactions were mainly occurred in the polypropylene/short glass fiber and polypropylene/ethylene-α-octene copolymer pairs rather than short glass fiber/ethylene-α-octene copolymer pair. With increasing content of short glass fiber, the mechanical properties (excluding elastic modulus) of polypropylene hybrid composite foams were increased first and then declined. Within the study range, the energy absorption capability of polypropylene hybrid composite foams could be doubled with 30% short glass fiber added. The energy-absorption ratio was improved only with relative higher short glass fiber content, of which, however, the improvement was not as remarkable as that shown in the energy absorption capability.