Over the decades, ZnO has been the primary cure activator in the sulfur vulcanization of rubber, but due to its environmental impact on aquatic ecosystems, its use in rubber formulation must be reconsidered. This study explores the effects of MgO, known for its low toxicity, as a cure activator, either alone or in combination with ZnO, in carbon black-filled various vulcanization systems such as efficient, semi-efficient, and conventional vulcanization (EV, SEV, and CV). Curing, mechanical, and aging resistance properties were thoroughly examined. Curing studies indicate that incorporating MgO into binary cure activator systems significantly accelerates vulcanization. In the SEV vulcanization system, ZnO/MgO binary cure activators, with a 1:2 ratio totaling 3 phr (per hundred grams of rubber), exhibit a comparable tensile modulus at 100% elongation, along with higher tensile strength, elongation at break, and improved aging resistance compared to conventional ZnO as a sole cure activator. Notably, in ZnO-free compounds, MgO as a single cure activator demonstrates superior tensile strength, elongation at break, and excellent aging resistance. In conclusion, this study suggests that the usage of ZnO can be optimized in rubber vulcanization by considering the desired mechanical properties along with improved aging resistance performances.

中文翻译：

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在不同的硫化体系中使用 MgO 和 ZnO 共固化活化剂提高填充橡胶的机械和耐老化性能

几十年来，ZnO 一直是橡胶硫磺硫化中的主要固化活化剂，但由于其对水生生态系统的环境影响，必须重新考虑其在橡胶配方中的使用。本研究探讨了以低毒性着称的 MgO 作为硫化活化剂的效果，无论是单独使用还是与 ZnO 组合使用，在炭黑填充的各种硫化体系中的效果，例如高效、半高效和传统硫化（EV、SEV）和简历）。彻底检查了固化、机械和耐老化性能。硫化研究表明，将 MgO 加入二元硫化活化剂系统中可显着加速硫化。在 SEV 硫化体系中，ZnO/MgO 二元固化活化剂的比例为 1:2，总计 3 份（每百克橡胶），在 100% 伸长率下表现出相当的拉伸模量，以及更高的拉伸强度、断裂伸长率、与传统的 ZnO 作为唯一的固化活化剂相比，其耐老化性得到了改善。值得注意的是，在不含 ZnO 的化合物中，MgO 作为单一固化活化剂表现出优异的拉伸强度、断裂伸长率和优异的耐老化性。总之，本研究表明，通过考虑所需的机械性能以及改进的耐老化性能，可以优化 ZnO 在橡胶硫化中的使用。