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Mechanochemically devulcanized styrene‐butadiene rubber, prepared by bis[3‐(triethoxysilyl)propyl]‐tetrasulfide, was blended with fresh styrene‐butadiene rubber. The ultimate properties of the blend vulcanizate depend on a three‐dimensional network structure formed during vulcanization which relies mainly on the accelerator and the vulcanizing system used during compounding. The effect of monosulfide, disulfide, and poly sulfide cross‐links, which primarily gets controlled by different accelerators such as N‐cyclohexyl‐benzothiazyl‐sulfenamide (CBS), tetramethylthiuram disulfide, 2‐mercaptobenzothiazol, and N‐tert‐butyl‐2‐benzothiazyl‐sulfonamide on mechanical, thermal, and dielectric behavior of the blend vulcanizates, was studied. The results indicate that the semi‐efficient CBS vulcanizate has superior mechanical and thermal properties. Therefore, the effect of accelerator to sulfur ratio, that is, (accelerator/sulfur) on the properties of the blend vulcanizates was determined. It is to highlight that a distinctive correlation is observed between the cross‐link types and the fraction of immobilized polymer chains of the blend vulcanizates. Further, the effect of cross‐link types on segmental dynamics of the blend vulcanizates was studied through broadband dielectric spectroscopy. The SEM micrographs indicate the homogeneity of the blend vulcanizates. [ABSTRACT FROM AUTHOR]

More or less universally, bis(3-triethoxysilyl propyl) tetrasulfide (TESPT) has been used as a coupling agent during dispersion of silica filler in a virgin nonpolar rubber compound. It is for the first time that TESPT has been used as a devulcanizing agent and as-grown devulcanized rubber facilitates the silica dispersion in nonpolar rubber compound without any coupling agent. Dual functionalities of TESPT have been modeled and validated in this work. Various factors like the role of sol-gel content, inherent viscosity of sol rubber, crosslink density, and degree of devulcanization were investigated as a function of devulcanization time and amount of TESPT to optimize devulcanization time and TESPT amount. To study the silica reinforcement, revulcanization of devulcanized SBR was carried out with silica filler and the curing characteristics of the material were evaluated. From the mechanical properties and thermogravimetry analysis the optimum time for devulcanization is determined. Further, scanning electron microscopy (SEM) studies were undertaken to check the coherency and homogeneity of the material. POLYM. ENG. SCI., 58:74-85, 2018. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]