白炭黑负载黄原酸盐硫化促进剂对天然橡胶的硫化促进作用及其机理研究

Vulcanization accelerator is one of the most important additives used in rubber processing. Currently, the widely employed vulcanization accelerators in rubber industry are mainly contained secondary amine such as sulfonamide and thiurams. However, these accelerators generate the nitrosamine compounds, which were deemed to be carcinogenic. Thus, it has become one of the major problems affecting on human health. So, the current domestic and overseas research tendency in rubber additives is to explore new types of vulcanization accelerators, with the characteristic of highly effectiveness, non-toxic and environmental protection. Because of the absence of nitrogen atoms in the xanthate, nitrosamines would not be formed during the vulcanization. Thus, the xanthate is a class of non-toxic, rapid, as well as environmentally friendly vulcanization accelerators, while it is seldom used in rubber industry for its poor thermal stability and easily decomposition. In this project, we will graft xanthate to the silica with chemical bonds, called silica-supported xanthate vulcanization accelerator, to enhance the dispersity and thermal stability of xanthate in natural rubber(NR). The effect from silica-supported xanthate accelerators on the vulcanization characteristics and related properties will be systematically exploration. Especially, the study on the mechanism of silica-supported xanthate accelerator will be mainly discussed. So, pursuant the thorough research, the conclusion will be achieved and organized, which will provide theoretical basis and guidance for the application of xanthate vulcanization accelerator in rubber engineering.

硫化促进剂是橡胶最重要的助剂之一。橡胶工业目前常用的硫化促进剂大多含有仲胺基（次磺酰胺类、秋兰姆类等），在橡胶制品生产过程中容易产生致癌性的亚硝胺类化合物，已成为影响人类健康的大问题之一。因此，研究高效、无毒、环保的新型硫化促进剂是国内外橡胶助剂的发展方向。黄原酸盐是一类不含氮原子，硫化过程不产生亚硝胺的无毒、环保快速硫化促进剂，但由于其热稳定性差、易分解，在橡胶工业中很难应用推广。本项目拟将黄原酸盐通过化学结合的方式负载于白炭黑上,制备白炭黑负载黄原酸盐硫化促进剂,以提高黄原酸盐硫化促进剂在天然橡胶中的热稳定性和分散性。深入探讨其对天然橡胶硫化特性的影响，系统研究白炭黑负载黄原酸盐对天然橡胶的硫化促进作用机理，得出规律性认识，为负载型黄原酸盐硫化促进剂在橡胶中的应用提供理论基础及指导。

硫化促进剂和补强剂是橡胶工业的重要助剂。目前常用的橡胶硫化促进剂(如噻唑类和秋兰姆类等)在硫化以及制品使用过程中由于仲胺基的存在容易产生致癌的亚硝胺类物质，危害人体健康，并对环境造成污染。黄原酸盐是一种环保型硫化促进剂，但由于热稳定性差，很难应用于橡胶工业。白炭黑作为橡胶工业中用量最大的浅色补强剂，由于表面大量的醇羟基使其产生严重的团聚现象而导致其对橡胶的补强效果降低。本项目依照项目计划书内容和目标，将白炭黑表面的羟基活化后，与二硫化碳反应，在白炭黑表面原位合成黄原酸盐，制备绿色环保的多功能橡胶助剂白炭黑负载黄原酸盐（SSX）。研究了SSX的结构与性能，考察其对天然橡胶的硫化促进作用以及对硫化胶性能的影响，分析其对天然橡胶的硫化和补强作用机理。研究结果表明，白炭黑表面羟基与二硫化碳反应后，表面的羟基减少，解决了白炭黑团聚严重的难题，同时将黄原酸盐原位生成在白炭黑表面后，其热稳定性显著提高，起始降解温度和终止降解温度分别提高了103.3℃、277.3℃。SSX对天然橡胶具有高效的硫化促进作用，在天然橡胶基体中的分散性明显改善，显著提高天然橡胶的力学性能，与相同用量的促M体系硫化胶相比较，SSX硫化胶的拉伸强度和撕裂强度分别提高了29.1%和33.4%，耐磨性明显优于促M体系硫化胶、其滚动阻力和生热性低于促M体系硫化胶。本项目制备的SSX硫化促进剂是一种兼具高效硫化促进作用和优异补强效果的绿色环保多功能橡胶助剂，将其应用于橡胶制品生产可以消除目前含仲胺基硫化促进剂对人体的危害，具有较好的应用前景;本项目的工作可以为价廉且资源丰富的含羟基天然化合物制备绿色环保的高性能、多功能橡胶助剂提供一定的理论基础。