Polypropylene (PP)-silicon dioxide (SiO2) 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 SiO2 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(alpha-methyl styrene-co-glycidyl methacrylate-co-gamma-methacryloxypropyl trimethoxy silane) (PAGK), was introduced into the membrane. In the PP-PP-g-PAGK-SiO2 composite systems, the content of SiO2 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-SiO2 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-SiO2 membrane was better than that constructed with the pure PP membrane. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47937.
