Study On Wear Behavior Of Graphene/Polymer Composites

The polymer material has the characteristics of light weight,high strength,good self-lubrication and low friction.It has gradually replaced partial metal materials in the field of tribology and has a wide range of applications.Among the polymer-based antifriction materials,polyimide(PI)is a heat-resistant polymer material with excellent overall performance.It has been paid much attention because of its unrivaled advantages in the field of tribology.However,there are still some problems,such as poor antistatic performance and wear rate,which will limit its further application in high-performance neighborhood.Graphene has a unique two-dimensional structure.Its outstanding mechanical,electrical and tribological properties can be complemented with PI formation,resulting in a multi-functional,high-performance wear-resistant PI composite.At present,the preparation method of the PI/graphene composite mainly utilizes a combination of graphene functionalization and in-situ polymerization.However,there are some problems such as complicated process,serious environmental pollution and difficulty in mass production.Therefore,in this paper,the ball-milling method was adopted to explore and study the large-scale preparation process for PI/graphene composite.The result shows that the graphene has a good dispersion and presents a highly ordered three-dimensional network structure in the PI matrix.When the content of graphene is 0.5wt%,the wear rate of the PI/graphene composite prepared by the ball-milling method reaches the lowest value,which is a 64.8% decrease compared to the pure PI.In order to further improve the wear resistance of PI,from the perspective of filler diversification,polytetrafluoroethylene(PTFE)is introduced and PI/PTFE/graphene composite is prepared by ball milling to investigate tribological properties.The result shows that graphene and PTFE have significant synergistic effects.The wear rate of PI/PTFE/graphene-0.5wt% composite is reduced by nearly one order of magnitude compared with PI.The significantly improved on anti-wear property is ascribed to the lower coefficient of friction,uniform dispersion of fillers,strong interface and the increase in mechanical properties.