Effects of Assistant Solvents and Mixing Intensity on the Bromination Process of Butyl Rubber

A slow bromination process of butyl rubber （IIR） suffers from low efficiency and low selectivity （S） of target-product. To obtain suitable approach to intensify the process, effects of assistant solvents and mixing inten-sity on the bromination process were systemically studied in this paper. The reaction process was found constantly accelerated with the increasing dosage and polarity of assistant solvent. Hexane with 30%（by volume） dichloro-methane was found as the suitable solvent component, where the stable conversion of 1,4-isoprene transferring to target product （xA1s） of 80.2%and the corresponding S of 91.2%were obtained in 5 min. The accelerated reaction process was demonstrated being remarkably affected by mixing intensity until the optimal stirring rate of 1100 r＆#183;min-1 in a stirred tank reactor. With better mixing condition, a further intensification of the process was achieved in a ro-tating packed bed （RPB） reactor, where xA1s of 82.6% and S of 91.9% were obtained in 2 min. The usage of the suitable solvent component and RPB has potential application in the industrial bromination process intensification.

Brominated Butyl Rubber Anticorrosive Coating and its Self-healing Behaviors

Self-healing anticorrosive coatings in extreme environment have attracted considerable interest from researchers.In this work,4-tert-butylpyridine(TBP)was incorporated into brominated butyl rubber(BIIR)polymer networks to form a reversible ionic bond with the highly reactive bromine anion.Based on the low glass transition temperature of the BIIR polymer and the electrostatic effects,a robust self-healing anticorrosive coating of TBP-BIIR was prepared.TBP-BIIR coating showed a maximum protection efficiency(PE)of more than 94%(TBP-BIIR-acid,94.37%;TBP-BIIR-alkali,94.95%;TBP-BIIR-salt,95.49%)when treated with a strong acid(HNO_(3),pH=2),strong base(NaOH,pH=12)and high salt solution(3.5 wt%NaCl).In addition,the PE of coating repaired exceed 89%,and the maximum PE value was approximately 95%in different solutions,which demonstrated its extinguished self-healing abilities.These results indicated that the TBP-BIIR anticorrosive coating could provide excellent safety and durability in special environment,which would be extremely beneficial to improve the working life of metal parts used in aviation and shipping,oil and gas and related industries.