Sakaki Yuta, Usami Ryota, Tohsan Atitaya, Junkong Preeyanuch, Ikeda Yuko
Graduate School of Science and Technology, Kyoto Institute of Technology Matsugasaki, Sakyo Kyoto 606-8585 Japan.
Department of Materials and Production Technology Engineering, Faculty of Engineering, King Mongkut's University of Technology North Bangkok Wongsawang, Bangsue Bangkok 10800 Thailand.
RSC Adv. 2018 Mar 19;8(20):10727-10734. doi: 10.1039/c8ra00544c. eCollection 2018 Mar 16.
A linear combination fitting in sulfur K-edge X-ray absorption near edge structure (S-XANES) measurements reveals each fraction of monosulfidic, disulfidic and polysulfidic linkages in solvent extracted sulfur cross-linked isoprene rubbers. The sulfidic linkage of a disulfidic type is found for the first time to be dominant when zinc stearate and -(1,3-benzothiazol-2-ylsulfanyl)cyclohexanamine are used as the activator and accelerator, respectively, for the sulfur cross-linking reaction at 140 °C. The presence of the bridging bidentate zinc/stearate complex as an intermediate for the sulfur cross-linking reaction is supposed to induce the generation of abundant disulfidic linkages in the rubber networks. This unexpected observation is of use for the material design of high performance rubber products with anti-aging and thermal stabilities. S-XANES is a powerful tool that was used to reveal the characteristics of the sulfur cross-linking of rubber. These results will contribute to the development of rubber science and technology.
线性组合拟合硫 K 边 X 射线吸收近边结构（S-XANES）测量揭示了溶剂萃取硫交联异戊二烯橡胶中一硫化物、二硫化物和多硫化物键的各部分比例。首次发现，当分别使用硬脂酸锌和 -(1,3-苯并噻唑-2-基硫烷基)环己胺作为 140℃下硫交联反应的活化剂和促进剂时，二硫化物类型的硫化键占主导地位。硫交联反应中间体桥连双齿锌/硬脂酸络合物的存在被认为会在橡胶网络中诱导大量二硫化物键的生成。这一意外发现对于具有抗老化和热稳定性的高性能橡胶产品的材料设计具有重要意义。S-XANES 是一种用于揭示橡胶硫交联特性的强大工具。这些结果将有助于橡胶科学技术的发展。
