Rivet-Inspired Modification of Aramid Fiber by Decorating with Silica Particles to Enhance the Interfacial Interaction and Mechanical Properties of Rubber Composites

A rivet–inspired method of decorating aramid fiber (AF) with silica particles (SiO(2)) is proposed to produce SiO(2)@AF hybrid materials that have largely enhanced interfacial interaction with the rubber matrix. AF was firstly surface-modified with polyacrylic acid (PAA) to obtain PAA–AF, and SiO(2) was silanized with 3-aminopropyltriethoxysilane to obtain APES–SiO(2). Then, SiO(2)@AF was prepared by chemically bonding APES–SiO(2) onto the surface of PAA–AF in the presence of dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP). With the incorporation of SiO(2)@AF into the rubber matrix, SiO(2)@AF hybrid materials with high surface roughness can play a role as ‘rivets’ to immobilize large numbers of rubber chains on the surface. The tear strength and tensile strength of rubber composite that filling 4 phr SiO(2)@AF are dramatically increased by 97.8% and 89.3% compared to pure rubber, respectively. Furthermore, SiO(2)@AF has superiority in enhancing the cutting resistance of rubber composites, in contrast with unmodified AF and SiO(2). SiO(2)@AF is suitable to be applied as a novel reinforcing filler in rubber composites for high performance.