Luo Yanlong, Liu Haobei, Xiang Bo, Chen Xianling, Yang Wei, Luo Zhenyang
College of Science, Nanjing Forestry University Nanjing 210037 China
Institute of Polymer Materials, Nanjing Forestry University Nanjing 210037 China.
RSC Adv. 2019 Dec 3;9(68):40062-40071. doi: 10.1039/c9ra08325a. eCollection 2019 Dec 2.
Based on our previous studies on the modification of in-chain styrene butadiene rubber (SBR) using 3-mercaptopropionic acid as well as its composites filled with silica, we further constructed two types of models (amorphous and layered) to investigate the temperature dependence of the interfacial bonding characteristics of silica/SBR composites molecular dynamics (MD) simulation. The competing effects of rubber-rubber interactions and filler-rubber interactions were identified, and the relationship between the competing effects and the temperature was determined. Besides this, the effect of temperature on the mobility and distribution of SBR chains on the surface of silica was investigated. It was found that the stronger the interfacial interactions, the less sensitive the motion of SBR chains to temperature. Finally, the number and length of hydrogen bonds as a function of temperature were analyzed. These simulated results deepened the understanding of interface temperature dependence of the silica/SBR composites and gave a molecular level explanation for the existence of an optimum modifier content (14.2 wt%) that is temperature independent.
基于我们之前关于使用3-巯基丙酸对链内丁苯橡胶（SBR）进行改性及其二氧化硅填充复合材料的研究，我们进一步构建了两种模型（无定形和层状），以通过分子动力学（MD）模拟研究二氧化硅/SBR复合材料界面结合特性的温度依赖性。确定了橡胶-橡胶相互作用和填料-橡胶相互作用的竞争效应，并确定了竞争效应与温度之间的关系。除此之外，还研究了温度对二氧化硅表面SBR链的迁移率和分布的影响。发现界面相互作用越强，SBR链的运动对温度的敏感性越低。最后，分析了氢键数量和长度随温度的变化。这些模拟结果加深了对二氧化硅/SBR复合材料界面温度依赖性的理解，并从分子层面解释了存在与温度无关的最佳改性剂含量（14.2 wt%）的原因。
