Epoxy resin modified maleic anhydride‐grafted‐liquid polybutadiene on the properties of short aramid fiber reinforced natural rubber composite

A novel compatibilizer with high grafting degree (GD%) of maleic anhydride (MA) onto liquid polybutadiene (LPB) was synthesized via a solution method, in particular, very low gel rate was produced by the synergetic effects of acetanilide and epoxy resin (EP), and the GD% was improved by adding the EP resin and acetanilide. The structure and thermal stability of the MA‐grafted‐liquid polybutadiene (LPB‐g‐MA) were characterized by acid base titrations, FTIR, and TGA techniques. The results showed that both MA and EP resin have been grafted onto the macromolecular chains of LPB with a good thermal stability. Then, it was used as compatibilizer in short aramid fiber (AF) reinforcing natural rubber (NR)/carbon black (CB). The synthetic compatibilizer (LPB‐g‐MA) enhanced the interfacial interaction between the fiber and the rubber matrix with a lower swelling degree and lower peak of loss factor, and the mechanical properties including tensile strength, tensile modulus 100%, tear strength and elongation at break of the final composites increased with the increase of m (E51)/m (LPB). AF and CB had a synergistic effect to reinforce the properties of NR. The dynamic stiffness of the rubber was obviously improved by the short AF, especially in the presence of the compatibilizer. POLYM. COMPOS., 39:E2006–E2015, 2018.