The Fundamental Research On The Friction Materials Of Nano-modified Phenolic Resin And Modified Palygorskite

Brake 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 and health harmlessness. So, one of the most important works 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 constitute in the brake pad or lining. Palygorskite has been widely used in many industrial fields because it possesses its abundance, low price, large surface area, low density, high temperature resistance, good absorption ability and its special mineral structure. Some application researches of palygorskite as reinforced component in friction material are reported. Our university has already started the research about palygorskite as reinforced constitute in the brake pad.Phenolic resin is normally used as bonding constitute in the vehicle friction material, but its weak heat-stability can't stand more serious working enviorment. Some research results show that Nano-modified Phenolic resin can improve heat-stability.The present paper emphasize on the fundamental research on the friction materials of nano-modified phenolic resin and modified palygorskite. Main research contents and their results are as following:1,The optimal modification process parameters of coupling agents(XD-172 and Al-Zr coupling agent) modification of dehydrated palygorskite are obtained by the drop height method employed to evaluate the effects of surface modification.2,From friction-wear test results of dual friction material made of modified dehydrated-Palygorskite powder and the NBR modified phenolic resin mixture,we can find: dehydrated palygorskite can increase friction coefficient, ie palygorskiteâ… > palygorskiteâ…¡> palygorskite; the results show the trend of the friction coefficient of dehydrated palygorskite modified by XD-172 and Al-Zr coupling agent, is palygorskite > palygorskiteâ… > palygorskiteâ…¡; the more water loss of palygorskite , the more wear ratio and Al-Zr coupling agent modified palygorskite is better than XD-172 modified palygorskite for the performance of fabricated material.3,Al-Zr coupling modified nanoparticles and the modified phenolic resin by Al-Zr coupling agent modified nanoparticles are fabricated, and the dual friction materials are made by mixture of the modified phenolic resin and coupling modified palygorskite. The friction and wear performance of dual friction materials are better than those made of mixing phenolic resin and unmodified palygorskite;The friction and wear performance of dual friction materials made of nano modified phenolic resin and XD-172 modified palygorskite has are also better than those made of phenolic resin and XD-172 modified palygorskite in low-temperature stage; But the friction and wear performance of dual friction materials made of nano modified phenolic resin and Al-Zr coupling agent modified palygorskite haven't become better than those of phenolic resin and Al-Zr coupling agent modified palygorskite in low-temperature stage;This study did not take into account the interactive influence of multi-component materials and the dual friction materials that made of Al-Zr coupling agent modified palygorskite and nano modified phenolic resin didn't show the better properties of friction and wear, so the cause needs to study more.