改性石墨烯填充SSBR-BR橡胶材料的设计制备及摩擦学行为和磨损机理研究

The friction and wear of rubber composites are very complex process, and is the focus of tribology. Although numerous studies have been done on the wear mechanism of rubber composites at home and abroad, a systematic study on the microstructural evolution and wear mechanism of the rubber filled with graphene is extremely rare. Based on improving the dispersion of graphene in rubber matrix, to design and fabricate the SSBR-BR composites filled with the modified graphene, both numerical simulation and experiment will be adopted to research the friction coefficient, wear loss, debris topography and size distribution of particles of rubber composites in the conditions of different humidities, loads, speeds and friction pairs, the basic parameters of wear resistence and debris number concentration will be obtained. And then the microstructural changes, relieve stress concentration and restrain crack growth of graphene are revealed on the basis of molecular dynamics simulation. Bearing these aspects in mind, the wear resistence model of the rubber composites filled with the modified graphere is established in coupling of different working conditions and multiple factors. The acquisition of the tribological characteristics and wear mechanisms of the rubber composites filled with graphene can provide scientific basis and theoretical guidance for the design and fabrication of high-performance abrasive rubber materials.

橡胶材料的摩擦磨损本身是一个非常复杂的过程，是摩擦学研究的重点领域。虽然国内外关于橡胶材料耐磨损机理的研究很多，但对于石墨烯填充橡胶材料在摩擦磨损过程中微观结构演化及磨损机理的系统研究并不多见。本项目从改善石墨烯在橡胶基体中的分散性和改性石墨烯填充SSBR-BR材料的设计制备出发，采用实验研究和数值模拟相结合的方法，系统研究改性石墨烯填充橡胶材料在不同湿度、载荷、速度、摩擦副等条件下的摩擦系数、磨损量、磨屑形貌和粒径分布规律，获取反映不同橡胶复合材料耐磨损性能和磨屑释放量的基础数据；通过分子动力学模拟揭示石墨烯在动态摩擦过程中微观结构的演变规律及分散应力集中、抑制裂纹生长机制；在此基础上，建立改性石墨烯填充橡胶复合材料在不同工况、多因素耦合作用下的普适性抗磨损理论模型；最终掌握石墨烯填充橡胶复合材料的摩擦磨损特点和磨损机理，为后续研制高性能耐磨损橡胶复合材料提供科学依据和理论指导。

针对石墨烯新型填料在橡胶基体中分散性差、界面相互作用弱，以及石墨烯补强橡胶复合材料在摩擦磨损过程中微观结构演化规律和磨损机制尚不明确等问题，系统开展了白炭黑原位插层氧化石墨烯复合填料的设计制备及补强SSBR-BR橡胶复合材料后在不同载荷、速度、摩擦副、温湿度等复杂条件下的摩擦磨损性能、抗湿滑以及磨损机制等方面的研究内容。突破了白炭黑原位插层改性氧化石墨烯复合填料补强SSBR-BR橡胶复合材料的制备技术；提出了片层石墨烯在黏着疲劳磨损过程中分散应力集中,抑制裂纹扩展，以及降低橡胶材料磨损量的作用机制。同时，基于摩擦学和热力学理论知识，将SSBR-BR橡胶复合材料的磨损表面动态温度场的变化与磨损机制结合起来，建立了多因素耦合作用下橡胶材料动态磨损规律与磨损机理演化模型。最后，结合流体力学理论，建立了水存在条件下，动态水压变化与轮胎材料抗湿滑性能间的影响关系模型，并揭示了轮胎胎面橡胶材料抗湿滑性能的科学本质和调控原则。上述研究工作为高性能耐磨性、抗湿滑新型“绿色”胎面胶材料的设计制备提供了新思路，为石墨烯填料在新型轮胎胎面胶材料中的工程化应用奠定基础。