Structure and Dynamic Properties of Solution SBR Coupled with Tin Compounds

The relation between the structure of the Solution SBR and the dynamic properties of carbon-black-filled SBR vulcanizates have been studied. The results obtained were as follows: 1. The hysteresis of the Solution-SBR vulcanizates was reduced markedly by the introduction of tin—carbon bonds at the polymer chain end. 2. Among the structures of tin—carbon bonds, tin-butadienyl bonds were much more effective for the reduction of hysteresis than were tin—styryl bonds. 3. Solution SBR coupled with tin compounds with molecular weight of less than 105 was not so effective for the reduction of hysteresis. Furthermore, the mechanism of the improvement of dynamic properties was investigated. It was found that polymer—carbon-black bonds were formed through the reaction of tin—carbon bonds with the functional groups of carbon black. From model reactions, it is suggested that quinone groups on carbon black are involved.