Preparation and characterization of melt‐stretched polypropylene–polypropylene‐ g ‐poly(α‐methyl styrene‐ co ‐glycidyl methacrylate‐ co ‐γ‐methacryloxypropyl trimethoxy silane)–silicon dioxide compound microporous membranes

Polypropylene (PP)–silicon dioxide (SiO 2 ) compound microporous membranes were fabricated by a melt‐stretching method. Although the permeability, porosity, and hydrophilicity values of the microporous membranes were found to be highest at an SiO 2 content of 2 wt %, the heat resistance of the membranes was relatively low. To improve the heat resistance of the microporous membranes, a macromolecular coupling agent, PP‐ g ‐poly(α‐methyl styrene‐ co ‐glycidyl methacrylate‐ co ‐γ‐methacryloxypropyl trimethoxy silane) (PAGK), was introduced into the membrane. In the PP–PP‐ g ‐PAGK–SiO 2 composite systems, the content of SiO 2 was controlled at 2 wt %, and the proportion of PP‐ g ‐PAGK was varied. With increasing PP‐ g ‐PAGK content to 0.6%, the Gurley value decreased from 250 to 239 s, and the porosity increased from 50.8 to 51.6%. The hydrophilicity of the microporous membranes increased with the incorporation of PP‐ g ‐PAGK, and their water vapor transmission rate reached a maximum of 3360 g m −2 /24 h at a PP‐ g ‐PAGK content of 0.6%. The heat resistance of the PP–PP‐ g ‐PAGK–SiO 2 compound microporous membranes was slightly higher than that of the pure PP microporous membrane. Additionally, the cycle performance of a cell assembled with the PP–PP‐ g ‐PAGK–SiO 2 membrane was better than that constructed with the pure PP membrane. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47937.