The Theory of Rubber Reinforcement: Interaction of Carbon Black with Sulfur and Rubber
Abstract Active channel black combines chemically with sulfur when heated with sulfur solutions. The amount of sulfur combined increases after hydrogenation of the carbon black. The dimensions of the carbon black aggregates increase as the result of the reaction with sulfur. Hydrogenation of channel black increases the content of insoluble rubber in the carbon-rubber gel formed during milling of a rubber-carbon black mixture. Hydrogenation of channel black increases the content of bound sulfur, the modulus, and tensile strength, in comparison with vulcanizates containing the original unhydrogenated channel black. These facts suggest that active carbon black enters the composition of the vulcanizate structure, and this is a factor in rubber reinforcement.