Bromination of butyl rubber in rotating packed bed reactor

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 (X-Br) and the unsaturated degree (Omega) were investigated. Bromobutyl rubber (BIIR) with X-Br of 1.84-1.92 wt% and Omega 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. (C) 2013 Elsevier B.V. All rights reserved.