A novel molecular model of vulcanized styrene-butadiene rubber (SBR) was developed and experimentally verified to elucidate the enhanced tribological performance of vulcanized SBR over raw SBR. Vulcanization was modeled by cross- or self-linkages of sulfur (S) atoms with carbon (C) atoms in molecular chains. Frictional models were developed for vulcanized and raw styrene-butadiene rubber-ferrum (SBR-Fe) to study the atomic behavior at the frictional interface. The results at the atomic scale show considerable reductions in the coefficient of friction (COF) and the interfacial temperature of approximately 45.8% and 13.27% for the vulcanized SBR matrix, respectively, from those of raw SBR. In addition, the relative concentration (RC), the radial distribution function (RDF) and interaction energy of the vulcanized SBR are 21.61%, 6.68% and 60.12% lower than those of the raw SBR, respectively. The resulting decrease in the real contact area, adhesion and contact temperature at the interface can significantly improve the tribological properties of the vulcanized SBR over those of raw SBR. The results of this research study show how vulcanization can enhance the tribological properties of polymer composites at the atomic scale.

Graphical Abstract

中文翻译：

---

原子级苯乙烯-丁二烯橡胶硫化模型及改善摩擦性能的机理

建立了一种新型的硫化丁苯橡胶分子模型，并进行了实验验证，以阐明硫化SBR的摩擦学性能优于原始SBR。硫化是通过分子链中硫（S）原子与碳（C）原子的交联或自连接建模的。开发了硫化模型和生丁苯橡胶-铁（SBR-Fe）摩擦模型，以研究摩擦界面处的原子行为。在原子尺度上的结果表明，与原始SBR相比，硫化SBR基体的摩擦系数（COF）和界面温度分别降低了约45.8％和13.27％。另外，硫化SBR的相对浓度（RC），径向分布函数（RDF）和相互作用能分别为21.61％，6.68％和60。分别比原始SBR低12％。界面处实际接触面积，粘附力和接触温度的降低可显着改善硫化SBR的摩擦学性能，而未加工的SBR则更好。这项研究的结果表明，硫化如何在原子尺度上增强聚合物复合材料的摩擦学性能。

图形概要