| Abstract: | The electrical resistivities of a carbon-black-filled styrene–butadiene block copolymer (SB) and their blends with polystyrene were measured as a function of carbon content for specimens compression-molded at 200 and 250°C. The insulator–conductor point transition was greatly influenced by the mold temperature. This behavior associated to the scanning electronic microscopy investigations suggests the presence of some amount of the filler at the interface. A strong interaction between the filler and the polymer was also observed. The formation of bound rubber and a coherent rubber–filler gel depend on the molding conditions and the carbon black content in the composites. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 825–833, 1998 |
