Get access

Influence of TESPT content on crosslink types and rheological behaviors of natural rubber compounds reinforced with silica



Rheological behaviors in the rheographs and crosslink types of silica-filled natural rubber compounds with differing contents of silane coupling agent were investigated. Bis-(3-(triethoxysilyl)-propyl)-tetrasulfide (TESPT) was used as a silane coupling agent. In the rheographs of the silica-filled compounds containing TESPT, the local minimum torque regions after the maximum torque were observed, and the time to reach the local minimum torque was found to become faster with increase of the TESPT content. The reversion ratio, on the whole, was decreased by increasing the TESPT content. By increasing the TESPT content, the crosslink densities of the mono-, di-, and polysulfides were increased. Ratio of the polysulfides of the total crosslink density increased, while those of the mono- and disulfides decreased with increase of the TESPT content. Changes of the crosslink densities after thermal aging were also investigated. The experimental results were explained with the reduction of curatives adsorbed on the silica, increase of sulfur content, and crosslink formation between the silica and rubber by adding TESPT. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007

Get access to the full text of this article