Liu Jun, Wan Haixiao, Zhou Huanhuan, Feng Yancong, Zhang Liqun, Lyulin Alexey V
Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials People's Republic of China.
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology 100029 Beijing People's Republic of China
RSC Adv. 2018 Apr 9;8(23):13008-13017. doi: 10.1039/c8ra00405f. eCollection 2018 Apr 3.
Bound rubber plays a key role in the mechanical reinforcement of elastomer nanocomposites. In the present work, we reveal the formation mechanism of bound rubber in elastomer nanocomposites, using the coarse-grained molecular dynamics simulations. For the polymer-nanoparticle system, the "chain bridge" connected with neighboring nanoparticles forms, once the gap between two neighboring nanoparticles is less than the polymer size. The polymer-nanoparticle-solvent systems, mimicking the oil-swollen rubber in the experiment, are simulated with three models. From the analysis of the potential energy, the static structure and dynamic diffusing processes, all the models indicate that the increase of the volume fraction of the nanoparticles and the polymer-nanoparticle interaction strength could promote the formation of the bound rubber. The existence of solvent disrupts the bound rubber, and eventually deteriorates the mechanical properties. These simulations could provide some theoretical guidance for a better understanding of the formation mechanism of the bound rubber, which is helpful for designing the elastomer materials with excellent mechanical properties.
结合橡胶在弹性体纳米复合材料的机械增强中起着关键作用。在本工作中，我们使用粗粒度分子动力学模拟揭示了弹性体纳米复合材料中结合橡胶的形成机制。对于聚合物-纳米粒子体系，一旦两个相邻纳米粒子之间的间隙小于聚合物尺寸，与相邻纳米粒子相连的“链桥”就会形成。用三种模型模拟了模拟实验中油溶胀橡胶的聚合物-纳米粒子-溶剂体系。通过对势能、静态结构和动态扩散过程的分析，所有模型均表明纳米粒子体积分数的增加和聚合物-纳米粒子相互作用强度的增强可促进结合橡胶的形成。溶剂的存在会破坏结合橡胶，最终使机械性能恶化。这些模拟可为更好地理解结合橡胶的形成机制提供一些理论指导，这有助于设计具有优异机械性能的弹性体材料。
