Abstract: The structure of trans butadiene-isoprene copolymer rubber (TBIR) that can participate in chlorination reaction is complex, and its product chlorinated trans butadiene-isoprene copolymer rubber (CTBIR) can achieve rubber elasticity and polarity mainly depending on the double bond and allyl chloride structures. This article aims to regulate the double bond and allyl chloride structure in CTBIR by controlling the chlorination reaction conditions, such as chlorination reaction time, temperature, different ways of passing chlorine gas, free radical scavengers, and UV irradiation. A high initial reaction temperature can retain the double bond content in CTBIR, but reduce the chlorine content. The method of circulating chlorine gas input is beneficial for achieving high chlorine content while maintaining a high double bond content. Adding TEMPO is beneficial for maintaining the double bond content in CTBIR. The allyl chloride structure in CTBIR can be regulated by reaction temperature and time, as well as the addition of TEMPO. The regulation of the structure of the chlorination reaction product can provide a basis for the halogenation reaction of rubber. The regulation of halogenation products can provide the selection of reaction sites for the subsequent structural modification of CTBIR.

Key words: Chlorination, trans-1,4-Butadiene-co-isoprene rubber, Allyl chlorine, Structure regulation, Molecular weight