Grafting polypropylene and treatment of calcium carbonate to improve structure and properties of polypropylene composites

In this paper, calcium carbonate was chemically treated with two kinds of dicarboxylic acids before compounding with polypropylene in the presence of dicumyl peroxide (DCP). It was observed that the mixture of dicarboxylic acids could improve the crystallization and impact strength properties of calcium carbonate/polypropylene composite. With further addition of DCP, more PP-g-MA was produced in the blend, resulting in PP composites with larger β-phase content and improved mechanical properties. In the experiments, the maximum Kβ value of 52.0 % was obtained. The elongation at break of composite increased from 252 % for PP composite with untreated calcium carbonate to 444 % for PP composite with chemically treated calcium carbonate.