Characterization of short glass fiber reinforced polypropylene foam composites with the effect of compatibilizers: A comparison

Abstract

To improve the performance of short glass fiber reinforced polypropylene (SGF/PP) foam composites, the maleic anhydride (MAH) grafted PP (PP-g-MAH) and MAH grafted ethylene-α-octene copolymer (EOC-g-MAH) were introduced as the interfacial compatibilizers. Then, the effects of compatibilizers on the cellular structures, interfacial morphologies, and mechanical properties of SGF/PP foam composites were investigated and compared in detail. Results showed that the foaming qualities of composites were remarkably improved in the presence of either PP-g-MAH or EOC-g-MAH. The best samples were achieved with minimum average cell diameters and maximum cell densities, when the content of either PP-g-MAH or EOC-g-MAH was added up to 8%. Increased compatibilizers promoted the wettability of PP to SGF, and PP-g-MAH showed the more obvious influence on enhancing SGF–polymer interfacial bonding that that of EOC-g-MAH. Mechanical tests claimed that mechanical properties, except for compression strength, were all strengthened with growing compatibilizers. It was emphasized that EOC-g-MAH had much advantage of improving the impact toughness, whereas the PP-g-MAH was more beneficial of increasing the flexural and compression strength of SGF/PP foam composites.