Reinforcement of Natural Rubber using Nanostructured Carbon Materials

Abstract

As the earliest applied elastomer material, natural rubber has undergone development for nearly I 00 years, and its performance has become a bottleneck. With the development of technology, industry increasingly needs higher performance natural rubber as a new generation of shock absorbing materials to improve the ride comfort of various vehicles, such as automobiles, trains, and aircraft. The performance of natural rubber is mainly related to the fillers and filling amounts used. Even though traditional fillers such as carbon black and silica have been well studied, improving the performance of natural rubber composites is difficult. This study used carbon nanomaterials as a new generation of fillers to prepare highperformance natural rubber composites. Since nanoparticles have strong van der Waals forces, carbon nanomaterials such as graphene and carbon nanotubes need to be modified before preparing the composite material so that they can be uniformly dispersed into the natural rubber matrix. This study used various modification methods, such as acidification, acyl chlorination, and ammoniation to modify the surface property of these carbon nanomaterials. After a variety of different polymers were grafted onto the nanomaterial surface, the modified carbon nanomaterials achieved good compatibility with the natural rubber matrix. Subsequently, different fillers ( carbon nanotubes, graphene, and carbon nanotubes & graphene) were mixed with natural rubber, and composites with different filling amounts were prepared by mechanical blending. The process, mechanical, fatigue and crack propagation properties of the natural rubber composites were investigated under dynamic and static conditions. The results show that only a small filling amount is required and that carbon nanomaterials have better reinforcing effects than conventional fillers, revealing that as a new rubber filler, carbon nanomaterials have superior enhancement efficiency. As the filling amount increases, the mechanical strength of the natural rubber composite material is significantly improved. However, due to factors such as hysteresis loss and tearing energy, overfilling may cause a decrease in the fatigue resistance of natural rubber composites. The experimental results show that when the loading mass ratio of carbon nanotubes to rubber is I :3, the overall performance of the natural rubber composites is optimized. For graphene, when the loading mass ratio is I: 1, the overall performance of the natural rubber composite material is optimal. This study also shows that carbon nanotubes and graphene have synergistic effects when they are simultaneously used as fillers to prepare natural rubber composites.