Study On The Cure Systems And Coordinating Properties Of Bromobutyl Rubber

Base on the bromobutyl rubber (BIIR) BB2030of Lanxess, the effect of different cure systems such as zinc oxide, sulfur, peroxide and phenolic resin on the cure kinetics, cure characteristics, Mooney viscosity, mechanical properties and anti-hot air aging properties of BIIR were systemically studied. The combination of different ingredients in the cure system of BIIR was also studied.The results show that:the four systems showed different the vulcanization reaction characteristics,the vulcanization performance S/ZnO/MBTS is better, the vulcanization reaction rate of the system is faster,and the physical and mechanical properties and heat aging properties are better.For the zinc oxide curing system, the effect of zinc oxide content and stearic acid contend on the properties of BIIR were studied. The results show that the content of zinc oxide has little effect on the properties of BIIR, when its content varied from1to5phr. The cure kinetics of BIIR can be seen as two separated first order reaction, and lphr zinc oxide is enough to cure the BIIR effectively. When the content of the stearic acid is lower than1phr, the more the stearic acid content, the higher the cure rate, but the stearic acid level has little effect on other properties of BIIR. If the stearic acid content exceeds1phr, the main properties of BIIR deteriorate, which means that the stearic acid content should not exceed1phr.For sulfur cure system, the effect of sulfur, zinc oxide and accelerator2-mercaptobenzothiazole disulfide (MBTS) on the properties of BIIR. Unlike zinc oxide, the cure kinetics of BIIR can be seen as one first order reaction when only sulfur is used as cure system. When the sulfur content increases, the cure rate of BIIR also increase but high content of sulfur led to reversion. The sulfur bloom to the surface of the vulcanizate if the sulfur content is higher than0.75phr. If both sulfur and zinc oxide are used as cure system, the cure kinetics of BIIR can be divide to two separated one class reaction which is similar to zinc oxide cure system, the reversion resistance is significantly improved, at the same time other properties of BIIR are improved too. It should be noted that if the sulfur and MBTS are used as cure system for BIIR, the scorch time increases, the reversion becomes more apparent and the main properties of BUR became worse. If sulfur, zinc oxide and MBTS are used as cure system, synergic effect is achieved.For peroxide cure system, the effect of dicumyl peroxide (DCP) and co-agent N,N’-phenylene bismaleimide (HVA-2) and their content of the properties of BIIR were studied. The cure kinetics of BIIR cured by DCP can be seen a first order reaction. If the content of DCP is lower than lphr, the compound tends to stick to the mold surface which cause demoulding difficulty. For good properties, the optimized content of DCP is1.5phr. When HVA-2is used as co-agent, both the cure rate and the crosslinking density of BUR increase. The optimized content of DCP and HVA-2are lphr and2phr accordingly for good comprehensive properties.For phenolic cure system, the effect of the content of phenolic resin and zinc oxide on properties of BIIR was studied. The cure kinetics of BUR cured by phenolic resin can be divided into two separated first order reaction. The content of phenolic resin increases, the physical properties of BUR is improved, but BIIR exhibits improved hot air aging properties when3phr phenolic resin is used. The properties of BUR do not change much when the content of zinc oxide increase from2phr to3phr.