Alternatives of resorcinol in carbon black filled belt skim compound: A sustainable approach to make tire

As per global trends, new legislation, regulations, and restrictions on the use of hazardous materials with respect to environmental concerns, it has become necessary to eliminate resorcinol from the rubber compound as it was generating carcinogenic fumes during processing at high temperature. In this research, two non‐hazardous phenolic resins [A] and [B] were explored, in place of resorcinol, in a typical PCR tire belt skim compound. The entire study includes three phases. In Phase I, resorcinol was substituted with both the resins and it was revealed that they have potential to function as resorcinol in rubber‐brass bonding mechanism with few limitations, primarily as low cure rate. In Phase II, it was adjusted by incorporating TBBS as an additional accelerator but an abrupt loss in extent of adhesion retention was noticed for aged samples. It leads to further investigation in Phase II compositions. In Phase III, a little amount of precipitated silica was formulated, which results into a significant revival of adhesion retention. Eventually, both the compounds were showing faster vulcanizing characteristics, improved aged and un‐aged properties, higher dynamic stiffness, and lower hysteresis. Compound [B] showed best performance in all the properties except fatigue crack growth rate in low strain percentage.