Synergistic Effect of Copper Sulfate and Tetramethylthiuram Monosulfide Induced Metal‐Coordination Cross‐Linking in Nitrile–Butadiene Rubber

Abstract

AbstractThe cross‐linking microstructure formed by the metal‐coordination bonds provides excellent properties for rubber materials. Copper sulfate (CuSO4) and tetramethylthiuram monosulfide (TMTM) are successfully compounded with nitrile–butadiene rubber (NBR) to fabricate vulcanizates by the coordination cross‐linking. The curing characteristics, mobility of macromolecular segment, mechanical properties, morphology analysis, swelling properties, and dynamic features under cyclic compression of the vulcanizates are investigated systematically. The results indicate that the microstructure of 3D cross‐linking is held together by the metal‐coordination bonds between Cu2+ and CN. The torque during static vulcanization, tensile strength, and cross‐linking density of the obtained NBR/CuSO4/TMTM vulcanizates are better than that of NBR/CuSO4 vulcanizates, which is attributed to the synergistic effect between the radicals formed by the splitting of TMTM under thermal activation and the Cu2+; moreover, the highly reactive [Cu(SnCNMe2)]•2+ complexes are formed by the synergistic effect and promote the coordination stability of NBR and CuSO4 effectively. The excellent tensile properties of the prepared NBR/CuSO4/TMTM vulcanizates via synergistic effect made the metal‐coordination cross‐linking attractive in the field of industrial application.