Characteristics of NR/CB Composites: Preparation Methods and Correlations of Electrical and Mechanical Properties

Abstract

This work aims to correlate the electrical conductivity and mechanical properties of binary composites made of natural rubber (NR) and carbon black (CB). The samples were prepared using both a wet and dry mixing method before making the composites with a conventional rubber vulcanization process. The dry-mixing method was found to achieve higher electrical conductivity than the wet-mixing method. The composite made by efficient vulcanization (EV) had lower compression set than the composite made by conventional vulcanization (CV) and the compression set increased with an increase of CB. The highest tensile strength of the composite was found at CB content of 20 phr. The percolation threshold concentration of the binary composite was observed at 10 phr CB. Electrical conductivity of the composite depended on sample thickness where thinner samples had higher conductivity than the thick sample.