Impact of Thioamide Derivative Composite Preservation System on Vulcanization of Natural Rubber

The thioacetamide derivative (TD)-composite preservation system (TDCPS) exhibits superior preservation effects on natural rubber (NR) latex and significantly enhances its vulcanization efficiency and mechanical properties. This study assessed TDCPS for NR, with a particular focus on its effects in promoting vulcanization. The TD containing both pyridine and thioamide groups was evaluated against other additives, namely thione accelerator ETU, pyridine 3-HP, and thioacetamide TAA. The results indicated that TD significantly reduced vulcanization time and enhanced efficiency, surpassing the moderate effects of ETU and 3-HP, as well as the minimal activity of TAA. Furthermore, TD and 3-HP demonstrated a synergistic effect in enhancing the properties of vulcanized NR, including elongation stress, tensile strength, tear resistance, and hardness, with TD achieving more rapid and complete vulcanization at higher dosages. Both TD and 3-HP increased the energy storage modulus of raw NR, thereby enhancing rigidity, while maintaining low loss factor values. The superior performance of TD is attributed to the synergistic interaction of its pyridine and thioamide groups, which optimize vulcanization kinetics and mechanical integrity. These findings underscore TD’s potential as an efficient vulcanization promoter for NR.