Polarization modification of <i>trans</i> ‐1,4‐butadiene‐co‐isoprene rubber through homogeneous chlorination and the chlorination mechanism

Abstract Polarization modification can improve performance and increase applications for a material, so polarization of nonpolar rubber materials has always been an important research and development direction for rubber modification. In this work, the preparation and chlorination mechanism of a chlorinated trans ‐1,4‐butadiene‐co‐isoprene rubber (CTBIR) was investigated. The chlorination reaction, micro‐structure analysis, and homogeneous chlorination mechanism have been discussed in detail. The chlorination process of TBIR is a free radical reaction and the chlorinated product structure is very complex with a diversified structure caused by the presence of two diolefin monomers, butadiene and isoprene, in TBIR. The free radical chlorination of TBIR includes chlorine substitution and double‐bond addition reactions, resulting in basic chlorinated structures including allyl chlorine, 1,2‐chloro, methyl‐chloride, and small amounts of vinylidene chloride, and ring structures. The structures of double‐bonded and allyl chlorine vary with the modification of the chlorine content, and can be controlled by chlorination reaction conditions, such as reaction time. Highlights Homogeneous chlorination of high trans ‐1,4‐butadiene‐co‐isoprene rubber (TBIR). Detailed structure characterization and analysis of the CTBIR. Mechanism of the homogeneous chlorination of TBIR.