THE INVESTIGATION OF SOME PHYSICAL-PROPERTIES OF CARBON-BLACK POLYPROPYLENE COMPOSITES

The properties of polypropylene with three types of Polish-made carbon blacks are presented. The volume resistivity data show that the compo site of 10% las black is electrically conducting. The composites with other types of blacks, Sakap and Carbex, become conductive at 20% blac k. The increase in the composite black content usually results in a de crease in tensile strength, impact strength, and melt flow index, and an increase in the modulus of elasticity, hardness, and thermal conduc tivity. Increasing the carbon black content in the polypropylene compo sites results in a higher degree of crystallinity, as determined by WA XS wide-angle scattered X-radiation method.