Breakage of Rubber-Filler Linkages and Energy Dissipation in Stressed Rubber

Abstract

Abstract The marked softening of reinforced rubber by applied stress can be interpreted in terms of a range of strengths of secondary linkages formed by rubber-filler attachments, and this can be described by one common distribution parameter K for several grades and types of filler in natural rubber, and also for at least one type of carbon black in Krylene (GR-S) synthetic rubber. Linkages of this type are of little significance in reinforcement, judged by tensile strength or abrasion resistance. The fact that the filler particle diameter had no influence in these experiments on the energy dissipated in breaking secondary linkages, or their number as reflected by their stiffening action, may be considered a serious objection to the presumption that specific surface or interfacial area determines linkage formation in rubber and, hence (supposedly), the reinforcement. There is evidence of primary (strong) linkages introduced by carbon blacks, and these are likely to have a more important role in determin- ing the breaking, tearing, and abrasion of rubber.