Study On The Metal-oxide Cure Systems Of Bromobutyl Rubber

Based on the bromobutyl rubber (BIIR) of Lanxess, the study focused on theeffect of two different cure systems, that was accelerated-zinc oxide system andsulfur-MgO combination, on processability, cure kinetics, mechanical properties andanti-hot air aging properties of BIIR. Besides, ΔH which was tested on DSC andcombination of different ingredients in the cure system of BIIR were also studied.The results showed that: in zinc oxide-accelerator vulcanization system, MBTS,CBS inhibited the crosslinking reaction of BIIR vulcanized by ZnO and decreasedthe mechanical properties of vulcanizates; TMTD, ZDMC promoted the crosslinkingreaction of BIIR vulcanized by ZnO and improved the mechanical properties ofvulcanizates; with the increasing dosage of accelerators, two first order reactionschanged into one, and activation energy decreased.Compared with ZnO-accelerator system, the rubber can have a bettermechanical properties and easier to processing with the sulfur, MTBS and CBSadded to it.Compared with S-ZnO system and sulfur curing system, the S-MgO system canprovide BIIR with higher crosslink density and better mechanical properties; Studyof curing kinetics showed that the curing reaction of BIIR with S-MgO system is afirst-order reaction with a lower reaction rate constant, the activation energy is lowerthan sulfur curing system.Under the condition of180oC, MgO cannot vulcanize BIIR alone, after addingS, comprehensive performance of BIIR significantly improved. Cured at180oC,BIIR can obtain optimum mechanical properties with7phr MgO and0.3phr sulfur.