Grafted Polyolefin-Coated Synthetic Mica-Filled Polypropylene-co-ethylene Composites: A Study on the Interfacial Morphology and Properties

Abstract

Purified maleic anhydride grafted isotactic polypropylene (iPP-MA) and maleic anhydride grafted polyolefin elastomer (POE-MA) were used to coat synthetic mica, which was added to block polypropylene-co-ethylene (cPP) to prepare composites with 10 wt% mica content. The effect of the kinds of grafted polyolefin, their contents and composition ratios on the interfacial morphology, mechanical properties, crystallization behavior, and essential work of fracture parameters for the composites were studied. The results showed that the coating of synthetic mica with grafted polyolefin could effectively lower the surface polarity of the mica and improve the interfacial adhesion between mica and cPP. The sedimentation volume of mica reached a minimum, and the interface adhesion of the composites was comparatively good when the grafted polyolefin was 3 wt% of the weight of the mica. When the content of grafted polyolefin was fixed at 3–5 wt% of the weight of the mica, the sedimentation volume of mica decreased and the interface adhesion of the composites improved with increasing POE-MA content. The coating with grafted polyolefin and the composition change of the grafted polyolefin had little effect on the mechanical properties and crystallization behavior of the mica-filled composites. However, the coating with grafted polyolefin increased the special essential work of fracture (we ) of the composites significantly, whereas the special non-essential work of fracture (βwp ) showed a slight decrease. When the total grafted polyolefin was fixed, the we decreased and the βwp increased a little as the POE-MA content was increased.