Effect of filler orientation on thermal conductivity of polypropylene matrix carbon nanofiber composites

Polypropylene matrix carbon nanotiber composites were obtained by injection molding after kneading with a batch-type twin-screw kneader. The thermal conductivity of the composites in the thickness direction was evaluated, with particular focus on the effects of carbon nanofiber (CNF) content and filter orientation. The thermal conductivity of the composites increased with increasing CNF content, and was obtained as 3.46 W/(m(.)K) when the CNF content was 50% in weight fraction and the CNFs were highly oriented along the measuring direction of thermal conductivity. This value is approximately seventeenfold higher than that of neat polypropylene.