Study On The Surface Treatment Of Carbon Fiber And Its Adhesive Properties With Rubber Composites

Fiber as a skeleton material part of rubber products plays a vital role,especially with the gradual popularization of today’s automobile lightweight concept and the strict national requirements for energy saving and emission reduction,it has become particularly important to achieve automobile weight reduction,and especially the sprung quality reduction is very important.The use of low-density and high-strength carbon fiber materials is a very effective way,but because the surface of carbon fiber materials lacks active groups,the interface adhesion performance with the rubber matrix is relatively poor,which also directly affects the service life of carbon fiber/rubber composite products and the comprehensive performance in all aspects.The interface between the carbon fiber and the rubber matrix and the rubber itself are two key factors that determine its adhesive properties.Now the Resorcinol-formaldehyde-latex(RFL)system is the most commonly used method with fiber surface treatment in the industry,but the process conditions for applying this system to the surface treatment of carbon fiber materials are not yet clear.Therefore,this paper from the two aspects of the interface between the carbon fiber and the rubber matrix and the formula of the rubber matrix,aims to explore the surface impregnation treatment system and rubber bonding system that suitable for carbon fiber cords,enhance the adhesion between carbon fiber and rubber matrix and achieve the goal of replacing traditional tire frame materials with carbon fiber materials.(1)Apply RFL impregnation system to the surface treatment of carbon fiber materials,and based on the adhesion mechanism of this system,the effects of conditions such as the solid content of the RF resin,the adhesion rate of the cord-impregnated surface,and the thermal curing process on the interfacial adhesion properties of the carbon fiber/rubber composite materials were explored.The suitable process conditions for the treatment of carbon fiber rope with RFL impregnation system are obtained:the immersion time is 5-10min,the surface adhesion rate is 25%,the RF resin solid content is 18%,the curing temperature is 240℃,the curing time is 4min.At this time,the surface microscopic morphology of the carbon fiber rope has a significant change,and the value of H pull-out force with the rubber composite can reach up to 256N.Compared with the untreated carbon fiber rope,its value of H pull-out force increased to about 310%,Effectively improve the interface adhesion performance between carbon fiber and rubber matrix.(2)Carbon fiber rope is impregnated with MMT suspension and closed isocyanate TDI modified traditional RFL system,explored the effect of the mass fraction of MMT and TDI on the interface adhesion properties of carbon fiber and rubber matrix.The results show that when the mass fraction of MMT is 2%,the maximum value of H pull-out force with carbon fiber rope from rubber matrix is 286N,the effect of impregnation treatment is the best;when the mass fraction of TDI is 4.5%,the maximum value of H pull-out force with carbon fiber cord from the rubber matrix is 289N,and the bonding performance is the best.(3)Using resorcinol-HMMM-SiO2 rubber bonding system to improve the interface bonding performance of carbon fiber/rubber composite.Explored the influence of the content of each component in the system on the adhesion performance.It is concluded that under the conditions of the component content of HMMM 7phr,SiO2 10phr,and sulfur 4phr,the maximum value of H pull-out force with carbon fiber and rubber is 348N,and the interface adhesion strength is the highest.