Effects of calcium carbonate and compounding sequence on the phase morphology and properties of maleic anhydride‐grafted polypropylene compatibilized polyamide 6/polypropylene blend

Abstract

Effects of calcium carbonate (CaCO 3 ) and compounding sequence on the phase morphology of maleic anhydride-grafted polypropylene (MAPP) compatibilized polyamide 6 (PA6)/polypropylene (PP) blend were investigated. The morphology in the subskin and core regions of injection molded specimen was observed using scanning electron microscopy, which shows great changes due to the incorporation of CaCO 3 . With the addition of CaCO 3 (25 phr), oriented ''ginger-like'' network (directly mixing) or loose elongated network (mixing PA6, PP, and MAPP with premixed PA6/CaCO 3 masterbatch) of PP phase is formed in the core region, instead of spherical dispersed PP domains for unfilled blend. The distribution of CaCO 3 in PA6 and PP phases was determined by selectively dissolving PA6 phase and thermogravimetric analysis of PP phase. A possible mechanism is proposed based on the morphology evolution process to interpret the morphological differences. The mechanical properties and heat distortion temperature of the materials were tested and correlated with the morphology formed.

Effects of anhydrites before and after modification as well as their contents on the thermal and mechanical properties of polyamide 6/anhydrite composites

“…It is well known that varieties of mineral fillers, such as calcium carbonate, talc, kaolin, mica, etc., are widely used in polymer matrix composites to improve properties, including mechanical, dimensional, permeability, thermal stability, and flame retardant enhancements with respect to the bulk polymer . Anhydrite (CaSO 4 ), one of the major minerals, has orthorhombic crystal symmetry and its crystal morphology is consisted of sharp needle shape .…”