Reducing Marching Cure in Chloroprene Rubber Using Anti‐Reversion Agents

Vulcanization is a process in which a rubber compound is irreversibly transformed into an elastic structure through chemical crosslinking agents under heat and pressure. This reaction is typically monitored using a moving die rheometer. Depending on the type of rubber, vulcanization temperature, and reaction duration, the vulcanization process can exhibit different curing behaviors, including plateau, reversion, or marching cure. In a marching cure, the torque value continuously increases over time, and this does not allow the reaction to reach an equilibrium. This prolonged curing time can limit industrial feasibility, making it necessary to optimize the vulcanization conditions for efficient processing. In this study, 1,3‐bis(citraconimidomethyl)benzene (CIMB) and N‐N’‐m‐phenylenedimaleimide (HVA‐2), which are commonly used as anti‐reversion agents in natural rubber (NR), were evaluated in terms of their ability to mitigate marching cure in chloroprene rubber (CR). Cure characteristics and marching modulus intensity (MMI) of the compounds prepared with various amounts of CIMB and HVA‐2 were analyzed at elevated temperatures. The physical and mechanical properties were also studied before and after thermal aging of the vulcanizates. Both additives were found to be successfully used for mitigating marching cure in CR‐based rubber compounds with a remarkable improvement in mechanical strength.