Effect of processing technology on the morphological, mechanical and electrical properties of conductive polymer composites

Abstract

Abstract Conducting carbon/polypropylene (PP) and carbon/poly(butylene terephthalate) (PBT) composites containing crystalline natural graphite and carbon black (CB) were prepared by compression and injection molding. The effect of the processing technology on the electrical, mechanical, and morphological properties was investigated. Determination of the constant torque at the end of the mixing process and differential scanning calorimetric (DSC) measurements showed that graphite had better connectivity with the more polar matrix (PBT) than with the less polar one (PP). Scanning electron microscopy (SEM) studies showed that compression molding results in a homogeneous structure, while injection molding results in a skin-core structure with different orientations. Layered electrical conductivity studies showed that the electrical conductivity of the compression molded samples did not change along the thickness of the sample, while that of the injection molded samples changed throughout the material, which is due to the different structures developed with each type of processing.