硫化丁苯橡胶纳观界面耐磨机理及参数影响分析

硫化橡胶因其良好的力学和物理化学性能而被广泛作为摩擦副的基础材料. 本文提出了一种硫化交联算法, 实现了C—C键的硫化互交联和自交联, 构建了硫化丁苯橡胶的分子动力学磨损模型, 从微观摩擦学的角度阐明了硫化交联结构对改善丁苯橡胶磨损性能的机理, 研究了不同界面参数对硫化橡胶微观磨损性能的影响. 结果发现 硫化使丁苯橡胶分子链的界面黏附能力和活动能力更弱, 拉伸和解缠能力更低, 磨损过程中界面累积能量更低, 更不容易脱离橡胶基体, 因此可以表现出更好的摩擦学性能, 更强的抗磨损性能; 随着速度的增大, 硫化橡胶的磨损率降低, 与宏观实验结果一致, 原因是硫化橡胶的原子分布函数和相互作用能随着速度增大而降低, 说明橡胶分子链的黏附能力和活动能力随着速度增加趋弱, 温升更低, 导致较低的磨损率; 压入深度对磨损率的影响规律则呈现相反的结果和趋势.

Anti-wear mechanism of vulcanized SBR and its performance affected by parameters at nano scale

Vulcanized rubber is widely used as the frictional pair due to its excellent mechanism and physical- chemistry performance. The self- and cross-linkages were achieved by self-developed vulcanized crosslinking algorithm. A new vulcanized styrene-butadiene rubber (SBR) -Fe wear using a molecular model was developed to investigate the enhanced tribological mechanism of vulcanized SBR over raw SBR. The results show that the vulcanization makes the SBR of better tribological performance due to the weaker adhesion and motion ability, less extension and unwrapping ability, and less energy accumulation in the interface. The wear rate of vulcanized SBR decreases with increasing sliding velocity because both the radial distribution function value and the interaction energy decease with higher sliding velocity, leading to weaker adhesion and motion ability of rubber chains, and lower temperature rise. However, the influence of the pressing depth of Fe rod on wear rate has the opposite trend and results as complared with that of the sliding velocity.