Study On Surface Modification Of Basalt Microfibers To Reinforce Phenolic Resin Composites And Its Friction Properties

The development of the automotive industry requires that the friction material of the automotive brake system has better performance.Reinforcing fibers in friction materials have an important influence on the friction properties.The basalt microfiber is a new material with green environmental protection,wear resistance,sound absorption and noise reduction,high temperature resistance,chemical resistance and excellent mechanical properties.As a reinforcing fiber in friction materials,it has a positive effect on the development of the friction material industry.Since the matrix in the friction material is an organic phenolic resin,the basalt microfiber is an inorganic reinforcing fiber,and there is a problem of poor interface bonding with the matrix resin.Therefore,it is of positive significance to improve the interface and fully exert the comprehensive performance of the friction material.In this paper,silane coupling agent KH550 and different concentrations of emulsion HP302 were used to modify the surface of basalt microfibers.The KH550 can achieve good stress transfer at the interface.The HP302 can improve the interface compatibility.The effects of surface modification on the surface properties of basalt microfibers and the thermodynamic properties of basalt microfiber/phenolic resin composites were investigated.Friction materials were prepared to study the effects of modification on coefficient of friction and wear rates.At the same time,the fuzzy comprehensive evaluation method is used to comprehensively evaluate the friction and wear performance.The results show that KH550 and HP302 can improve the surface properties of basalt microfibers.When basalt microfibers are modified by KH550 with concentration of 0.8wt% and HP302 with concentration of 1wt%,basalt microfibers have the smallest polar component and the largest dispersion component,the surface deposition layer is more uniform;When the concentration of KH550 is 0.8wt% and the concentration of HP302 is 1wt%,the composite has the best flexural properties and tensile properties.When the concentration of emulsion is increased to 2wt%,the flexural properties and the tensile properties are reduced,the compression properyies and the impact performance are increased.As the concentration of the emulsion continues to increase,the flexural properties and tensile properties are reduced,the compression properties are weakened,the impact properties are slightly increased,and the composite exhibits brittle fracture behavior.When the concentration of coupling agent is 0.8wt% and the concentration of emulsion is 1wt%,the composite has the lowest thermal expansion coefficient,the thermal expansion coefficient is reduced by 66.24%,and the thermal performance is stable.The friction and wear properties of the friction material prepared by the unmodified basalt microfibers are poor,and the fuzzy comprehensive evaluation value of friction and wear performance was 0.3850.The coefficient of friction of friction material,prepared with microfibers which modified by 0.8wt% KH550 and 1wt% HP302,was more stable.And the wear rate was reduced by 25.7%.The fuzzy comprehensive evaluation value of friction and wear performance was 0.8005.