Effect of ethylene-propylene copolymers on the phase morphologies and properties of ultrahigh molecular weight polyethylene: Dissipative particle dynamics simulations and experimental studies

This work aims to experimentally and theoretically study the effects of ethylene-propylene copolymers as compatibilizer on the phase morphologies, interfacial properties, theological behaviors and mechanical properties of ultrahigh molecular weight polyethylene/homopolymerized polypropylene (UHMWPE/HPP) blends. The results indicate that the addition of ethylene-propylene block copolymer EPS3OR or random copolymer DP3000 ranging within 1-3 parts per hundred parts (phr) of UHMWPE/HPP blends can remarkably reduce the sizes of the UHMWPE particles and significantly improve the mechanical property such as tensile strength and elongation at break. Moreover, the ternary blends still show two-phase morphologies, and the favorable melt flowability of the UHMWPE/HPP blends can be basically maintained. Besides, dissipative particle dynamics simulations on the ternary UHMWPE/HPP/ethylene-propylene copolymer blends indicate that with fixed mole number of the block copolymer, longer block chains have higher efficiency on reducing the interfacial tension than the shorter ones. But for the block copolymers with fixed volume fraction, interfacial tensions firstly decrease and then increase with increasing the chain length of block copolymer. (C) 2011 Elsevier B.V. All rights reserved.