Synthesis by Polymerization in Situ and Properties of Composite Materials Based on Syndiotactic Polypropylene and Carbon Nanofillers

New composite materials based on a syndiotactic polypropylene (SPP) and nanosized carbon fillers of various types (graphene nanoplates (GNP) and fullerene) are obtained by polymerization in situ. It is shown that the introduction of nanocarbon particles did not lead to a significant decrease in the activity and stereo-specificity of a syndio-specific catalyst. Stress-strain and thermo- and electrophysical properties of the composites are studied. Composites based on SPP are characterized by a higher plasticity than those based on isotactic polypropylene (IPP) at the same filling degrees. An enhancement of the thermal stability of SPP in the presence of carbon nanofillers is demonstrated. A noticeable effect of GNP and fullerene on melting and crystallization of SPP in the composites is found. In SPP/GNP composites, the dielectric permeability is practically independent of the filler concentration. In this case, nanofillers play the role of dielectric probes, making it possible to identify relaxation transitions in the polymer matrix.