Wollastonite-Reinforced Polypropylene Composites Modified With Novel Metallocene EPR Copolymers. I. Phase Structure and Morphology

摘要

Supermolecular structure of isotactic polypropylene/ wollastonite/metallocene propylene-ethylene copolymers (iPP/W/EPR) composites was studied as a function of elastomer content (from 0 to 20 vol%) by optical, scanning, and transmission electron microscopy, wide-angle X-ray diffraction, and differential scanning calorimetry. Both, woliastonite and dispersed EPR particles, homogeneously incorporated into the iPP matrix, and affected the final phase structure and morphology of the iPP/wollastonite/EPR composites. Woliastonite particles were orientated plane-parallel to the sample surface and hindered spherulite growth of the iPP matrix. EPRs enhanced plane-parallel orientation of woliastonite and simultaneously enhanced the spherulite and crystallite growth in the iPP matrix during the solidification of polymer melt. Ternary iPP/ wollastonite/EPR composites exhibited significant prevalence of separated microphase morphology (over core-shell morphology) because of constitution similarity of P-E and iPP chains.