Effect of poly(ethylene methyl acrylate) copolymer on thermal, morphological, and mechanical properties of polypropylene copolymer blown films

摘要

Blends of polypropylene copolymer (PP-cp) and poly(ethylene methyl acrylate) [poly(EMA)] copolymer blends were processed by blown film extrusion. The orientation and crystallinity of PP-cp matrix in the blend did not change significantly with the addition of EMA. The low machine direction and transverse direction tear strengths, which are observed for neat polypropylene blown films more than doubled at 6 wt % or higher content of EMA. The increase in tear properties was mainly attributed to a fine dispersion of EMA in the matrix with an average particle size of 100-500 nm and the formation of elongated domains. The dispersed nonrounded EMA domains, resulting from the blown-film process, enhance better energy dissipation mechanism with the formation of an extended plastic zone in the blend films as compared with that in pure PP-cp films. (c) 2007 Wiley Periodicals, Inc.