Cure pack aging study
In rubber compounding, it is common that cure packs are preweighed before mixing. The cure system plays a critical role in the crosslink density, mechanical properties and thermal stability of the final vulcanizate. However, on some occasions cure pack ingredients are pre-mixed and left idle for extended periods. There is an increased risk of not only degradation of individual components, such as accelerators and sulfur, from exposure to moisture and oxygen; but also of premature chemical interactions between ingredients within the pack. These interactions may induce unintended pre-reactions, altering the cure kinetics, potentially scorch safety, variations in cure time, and key physical properties such as tensile strength, elongation and hardness.