This work highlights the relationship of crosslink density, entanglement points and various sulfide crosslinks with the thermogenesis properties of natural rubber (NR). The impact of cross‐link and entanglement on thermogenesis properties was evaluated by heat build‐up test, swelling behavior, statistical thermodynamic calculation, and classic viscoelastic theory. It was found that cross‐link and entanglement points have “pinning” effect to the rubber chain, thus remarkably restricting the motion of the rubber chain and reducing thermogenesis. Besides, the effects of various sulfide crosslinks and cross‐link length on thermogenesis were compared and discussed varying the sulfur vulcanization system. It was found that the semi‐effective vulcanization system using N‐cyclohexyl‐2‐benzothiazolesulfenamide (CZ) and 2‐Mercaptobenzothiazole (M) has the lowest thermogenesis (bottom temperature rise is 7.5°C, middle is 18.7°C), which on account of combined short crosslink length with high rigid rubber chain (crosslink network dominated by mono‐ and disulfides). As a result, the deformation degree of the rubber chain during curl up‐extension and the thermogenesis are further reduced. Finally, a combination of natural film coagulation and semi‐effective vulcanization system was used to prepare a low thermogenesis NR, in which bottom and middle temperature rise were only 5.0°C and 14.1°C, respectively.

中文翻译：

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天然橡胶在高速应变下的生热机理分析

这项工作强调了交联密度，缠结点和各种硫化物交联与天然橡胶（NR）的生热特性之间的关系。交联和缠结对生热特性的影响通过集热试验，溶胀行为，统计热力学计算和经典粘弹性理论进行了评估。发现交联点和缠结点对橡胶链有“钉扎”作用，因此显着限制了橡胶链的运动并减少了生热作用。此外，比较和讨论了各种硫化物交联和交联长度对生热的影响，并讨论了不同的硫磺硫化体系。结果发现，使用N-环己基-2-苯并噻唑亚磺酰胺（CZ）和2-巯基苯并噻唑（M）的半有效硫化体系产热最低（最低温度升高7.5°C，中间温度升高18.7°C）。结合了较短的交联长度和高刚性橡胶链（交联网络以一硫化物和二硫化物为主）的原因。结果，进一步减小了卷曲过程中橡胶链的变形程度和生热作用。最后，自然膜凝结和半有效硫化系统的组合被用于制备低生热降噪，其底部和中间温度升高分别仅为5.0°C和14.1°C。这是由于短的交联长度和高刚性的橡胶链（交联网络主要由一硫化物和二硫化物组成）共同导致的。结果，进一步减小了卷曲过程中橡胶链的变形程度和生热作用。最后，结合自然膜凝结法和半有效硫化体系制备了低生热降噪剂，其底部和中间温度分别升高了5.0°C和14.1°C。这是由于短的交联长度和高刚性的橡胶链（交联网络主要由一硫化物和二硫化物组成）共同导致的。结果，进一步减小了卷曲过程中橡胶链的变形程度和生热作用。最后，结合自然膜凝结法和半有效硫化体系制备了低生热降噪剂，其底部和中间温度分别升高了5.0°C和14.1°C。