High performance glass fiber reinforced polypropylene realized by reactive extrusion technology

High performance polypropylene/glass fiber (PP/GF) composites were prepared by introducing different percentage of maleic anhydride-g-polypropylene (MPP) and epoxy resin (EP) in the matrix. The coupling effect of MPP and EP on the mechanical properties of the hybrid composites were highlighted and the complicated reinforcing mechanism were discussed in detail. Even though the addition of MPP could apparently improve the performance of composites, as the EP coupled especially at higher MPP and EP content, both the tensile and impact strength get further enhancement. For the sample with 10 wt% MPP and 10 wt% EP (10MPP/10EP), the tensile and impact strength show significant enhancement by 136% and 171%, respectively, compared to the control PP/GF composite. It is demonstrated that the good compatibility among each constituent as well as the reaction between EP and MPP, which could efficiently facilitate the network formation, contribute to the high performance of the composites. The finer EP particles caused by the enhanced compatibility as nucleating agent could promote the crystallization, but the crystallinity of the composites does not change so much. A schematic mechanism of the interfacial structure on both molecular and microscopic levels is depicted, where the reaction between MPP and EP are considered as a dominated factor to influence the above-mentioned network formation. This local network structure causes the composites as an integrate showing excellent mechanical performance.