The Research On The Modification Of Palygorskite And Its Application As A Fiber-reinforced Component In Automotive Friction Material

Braking lining and pad are the key parts in the automotive braking system and play an important role on the stopping of vehicle. The traditional friction material fiber-reinforced by asbestos has been gone out due to harm to human health. Much more friction materials are needed to meet requirements of high-speed, heavy duty, comfortable performance and health harmlessness. Most important work in the research field of automotive friction materials is to find the fibers to replace the asbestos, which has good comprehensive performance as the reinforced material in the braking pad or lining. Some fibers, such as glass fiber, the steel fiber, the aramid fiber(Kevlar),mineral fiber etc. have been developed, but any can't replace asbestos, so two or more fibers are mixed in the friction material commonly.Palygorskite has been widely used in many industrial fields because it possesses high temperature resistance, good absorption ability, large surface area and its special mineral structure, no report about the application of palygorskite in the friction material has been founded so far, so some application researches of palygorskite as reinforced component in friction material are presented.The composites with different content of palygorskite (modified or unmodified) and phenolic resin are fabricated and the palygorskite's effect on friction coefficient (fade, recovery), wear resistance and impact strength are studied under different temperature by constant speed friction and wear tester. The test results and analysis of SEM we can find:1. the composites with proper palygorskite have good performance, and the friction coefficient is high under the high temperature;2. The friction coefficient differences of the fabricated composites with 24mesh palygorskite are more smaller than those with 40 mesh and 60 mesh;3. The material made of mixed mesh palygorskite, wich mass ratio of 24mesh and 40mesh is 3:7, possesses the best friction performance and impact strength than other ratios;4. The results of modification research of palygorskite by silane coupling agent KH-550 show that the modified palygorskite with l%wt KH-550 under 80℃ within the 60 min has the best performance;5. The modification of palygorskite can improve the interface between palygorskite and phenolic resin.The braking pads (linings) were fabricated by mixture of modified palygorskite...