石墨烯/聚酰亚胺复合材料的力学和摩擦学性能

Mechanical and tribological performances of graphene reinforced polyimide composites

采用氧化石墨烯还原法制备了石墨烯,通过溶液共混法制备了石墨烯增强聚酰亚胺复合材料;研究了石墨烯/聚酰亚胺复合材料的力学和摩擦学性能及摩擦学作用机制。结果表明,随着石墨烯含量增加,复合材料的拉伸强度、断裂伸长率和硬度均呈先上升后下降的趋势,而冲击强度呈先升高而后降低,再升高的趋势。当添加1.0%(质量分数)的石墨烯时,复合材料的拉伸强度和断裂伸长率达到最大值,分别比纯聚酰亚胺提高了149%和652%。石墨烯的加入显著降低了聚酰亚胺复合材料的摩擦系数和磨损率;随石墨烯含量增加,复合材料的磨损率先下降后上升,而摩擦系数先显著降低,尔后平缓减小。随载荷增加,复合材料的磨损率呈平缓下降的趋势;而随滑动速率增加,磨损率呈上升趋势。石墨烯增强的聚酰亚胺复合材料的磨损机理为粘着磨损。

The graphene was prepared by reduction process of graphite oxide,and the polyimide（PI） composites reinforced by graphene were prepared by solution blending method.The mechanical and tribological properties of PI composites reinforced by graphene were evaluated,and the wear mechanism was also analyzed.The results show that the tensile strength,elongation at break and hardness of the composites increased and then decreased with the increasing content of graphene,while the impact strength increased and then decreased,and rose again.The polyimide composites filled with 1wt% graphene exhibited the ultimate value of the tensile strength and elongation at break,the two values had been increased by 149% and 652%,compared with the pure polyimide,respectively.The addition of graphene may effectively enhance the tribological properties of composites.Along with the graphene content increased,the wear rate of the composites declined and then rose,while the friction coefficient significantly reduce at first and then gently decrease.The wear rates of the composites display the gentle decline trend with an increase of load and ascendant trend with increasing sliding speed.The main wear mechanism of the composites modified by graphene was adhesive wear.