Bromination of butyl rubber in rotating packed bed reactor

• An RPB reactor was employed to intensify the bromination process of IIR.
• The time required to obtain high-quality BIIR was reduced to 1–2 min.
• Effects of bromination parameters were comprehensively studied.
• The potential of the RPB as an industrial bromination reactor was discussed.

Bromination of butyl rubber (isobutylene isoprene rubber, IIR) in a conventional stirred tank reactor suffers from low efficiency and low quality due to slow micro-mixing. This study reports bromination of IIR in a rotating packed bed (RPB) with intensified micro-mixing. By varying bromination parameters, such as reaction time, reactant concentration, temperature and high-gravity level (G), effects of these parameters on product quality in terms of the Br content (XBr) and the unsaturated degree (Ω) were investigated. Bromobutyl rubber (BIIR) with XBr of 1.84–1.92 wt% and Ω of more than 1.54 mol% was produced at an optimum range of G, 68–80 g. The time required to complete bromination was significantly reduced to 1.0–2.0 min (c.f. about hours in traditional industrial reactor). The results indicate that both high production efficiency and high quality of BIIR can be achieved in the RPB, which provides a new pathway for the industrial bromination process of IIR.