The torque development during vulcanization in silica-filled compounds is not only influenced by the cross-linking density but also by filler-filler interactions, silane-mediated reactions and by interactions of the silica with accelerators. This study quantifies these contributions by determining Mooney viscosity, filler flocculation rate, bound rubber content and cross-link density. Compounds containing functionalized and non-functionalized SSBRs at varying silica loadings with and without silane were investigated. The results show that polymer cross-linking dominates cure torque at low filler loadings, while filler-related interactions prevail at high silica contents, indicating that cure torque cannot be directly correlated with cross-link density in highly filled silica compounds.

• The fundamentals of vulcanization and its role in rubber strength, elasticity and durability
• The limitations of traditional compression molding in rubber vulcanization
• How microwave-assisted vulcanization serves as an efficient alternative to conventional methods
• How microwave-assisted vulcanization improves cure uniformity in rubber materials
• The potential of microwave vulcanization for silica-filled SSBR tire tread compounds