The Preparation Of Bromin Ated Butyl Rubber And Analysis Of Structure And Properties

With N-bromine generation succinimide (NBS) as the brominating agent, based on reaction processing method, with liquid bromine by the solution method, brominated butyl rubber was prepared respectively. Compared the microstructure charateristics of this two kinds of products, investigated the influence of reaction temperature on the brominated intensity through the DSC curve. Bromide reagent and IIR premixed at low temperature in HAAKE torque rheometer before bromination. Multianalysis the premixed disperse uniformity of brominated agent in rubber as well as the effect on the properties of BIIR product. Joined rarely magnesium oxide (0.3%-3.0%) and white carbon black(0.5%-4.5%) in the process of the preparation of BIIR. Analysis the influence on BIIR after adding alkaline and acidic oxides, analysis the effect on microstructure charateristics, vulcanization and mechanical properties. Investigated the processability of BIIR by DMA and RPA.Experimental results show that the way of join bromide agent had effect on the process of bromination, premixed at low temperature before bromination can improve dispersing uniformity of bromide in IIR. By premixed technology, the curing rate of BIIR increased and CI value up to 3.0, at the same time, the mechanical properties reached the level of goods BIIR. Based on the technology of premixed, the bromine atoms introduced into the molecular chain successfully by reaction processing method, and when the reaction temperature reached 60℃, reaction time was 15mintes, the quality percentage of bromide accounted for 5.0%, the primary and secondary allylic bromine structure was 57% and 43% respectively, bromine content was 2.47%, has reached the bromide level of goods BIIR(2%) as well as vulcanization characteristics and mechanical properties. Bromide has HBr molecules generated in the process, after washing, separation and drying of the BIIR produced by solution method, HBr was removed; by the reaction processing method, HBr was left int the rubber compound, so the acid and alkali substance of brominate process will have some impact. Joined the magnesium oxide to the process of bromination, the vulcanization rate of BUR was improved and the mechanical properties changed little; white carbon black has great effect on mechanical properties. When the BIIR prepared by solution method, the effect of bromination conditions on microstructures of BIIR was studied, bromide and NaOH aqueous solution both have effect on BIIR. Without NaOH aqueous solution, the primary allylic bromine structure always greater than secondary allylic structure; after adding NaOH aqueous solution, when the reaction time reached 60 and 120 minutes, secondary allylic bromine structure had largely increase, far more than primary allylic bromine structure. According to the microstructure characteristics of product BIIR, bromination reaction mechanism is proposed.