Abstract
Brominating butyl rubber (IIR) in the presence of oxidant, NaClO, and electrophilic solvent, CH2Cl2, is a promising preparation technique of bromobutyl rubber (BIIR), while there lacks comprehensive reports on this technique in the literature. In view of this, the present study paper systematically investigates the bromination conditions of IIR in a stirred tank reactor. The effects of process parameters on product quality in terms of the Br content (W) and the unsaturation degree (Ω) were obtained. Acceleration of the bromination and increase in W were realized by increasing the volume fraction of CH2Cl2(φCH2Cl2) in the solvent. With the optimum φCH2Cl2, 30%, the bromination reaction could be accomplished in 5 min. With the increase of NaClO dosage, W increased, which meant an increase in Br2 utilization. With the increase of Br2 dosage, W also increased, while the Br2 utilization decreased. Regarding W, a slight effect of IIR concentration, a significant effect of mixing intensity and no effect of temperature were found, respectively. Besides φCH2Cl2, the above bromination conditions exerted inverse and slight effects on Ω, comparing with their effects on W. These results have indicated methods to regulate the product quality of BIIR, and can be concluded as the development of a new preparation technique of BIIR.
