Preparation of polypropylene/graphite nanocomposite with the aids of rotating solid‐state mixing and dynamic packing injection molding

In this work, to achieve good dispersion state of graphite in the nonpolar intractable polymer, polypropylene (PP), two specific compounding/molding techniques, rotating solid‐state mixing (RSSM), and dynamic packing injection molding (DPIM), were used during the preparation of PP/graphite nanocomposite. The enhanced dispersion/exfoliation of graphite substance in PP matrix induced by RSSM and/or DPIM treatment was well identified by a combination of polarized optical microscopy, wide‐angle X‐ray diffraction, and scanning electronic microscopy. A comparative analysis indicated that RSSM mainly pulverizes graphite pristine‐particles into tactoids with significantly decreased diameter‐size, while DPIM offers strong melt shear force for exfoliating graphite tactoids into nanosheets whose thicknesses are about tens nanometers and length of 1 micron. Uniform dispersion of graphite nanosheets leaded to substantial increase in heterogeneous crystallization rate and mechanical properties. Our present study proposes a facile effective approach for large‐scale preparation of polymer/graphite nanocomposite with high‐performances. POLYM. COMPOS., 35:1943–1951, 2014. © 2014 Society of Plastics Engineers