Melt mixing functionalized graphite nanoplates into PC/SAN blends

Abstract

The present work focusses on the analysis of the effect of chemical functionalization of graphite nanoplates (GNP) on the dispersion and localization of the GNP in polycarbonate (PC)/poly(styrene-acrylonitrile) (SAN) blends, the composite morphology, and the resulting electrical properties. For this, GNP have been chemically modified to covalently bond pyrrolidine groups at the graphene surface of the GNP. The amount and detailed structure of the functionalization has been analyzed by XPS. The dispersion of different GNP in the blends has been studied by light microscopy and the morphology of the blends and blend composites by SEM and TEM. At a composition of 60 wt.% PC and 40 wt.% SAN the blend and its composites form co-continuous structures. By means of TEM the selective localization of the GNP and f-GNP within the PC component or near the PC-SAN interface could be proven. The functionalization resulted in less agglomerated structures of the GNP in the composites. The electrical percolation concentration is not significantly influenced when comparing blend composites prepared with GNP or f-GNP. However, the conductivity in the composite blends containing f-GNP is always lower compared to the GNP composites.