Preparation and Properties of Exfoliated Graphite/Polystyrene Composite

ABSTRACTA composite based on exfoliated graphite (EG) and polystyrene was prepared by polymerization-filling technique. With the argument of the amount of filled EG, the molecular weight of polystyrene in the resulting composite increased and the molecular weight distribution decreased. The glass transition temperature of the polystyrene was determined by dynamic mechanical analysis (DMA) and showed the glass temperature of polystyrene increasing to 123.74°C. The thermal degradation behavior was studied using thermogravimetry (TG) and showed higher thermal stability of the composite than that of pure polystyrene and polystyrene//EG composite prepared by melt-blending. Four-probe instrument and high resistivity meter were used to measure the volume conductivity of the composites. Composites prepared by both polymerization-filling technique and melt-blending exhibit increased electrical conductivity, while composite prepared by polymerization-filling technique has a conductive percolation threshold lower than 2.5wt%.