Investigation of the effect of epoxide structure on the initiation efficiency in isobutylene polymerizations initiated by epoxide/TiCl4 systems |
| |
Authors: | JE Puskas Y Chen M Tomkins |
| |
Institution: | Department of Chemical and Biochemical Engineering, Faculty of Engineering, The University of Western Ontario, London, Ont., Canada N6A 5B9 |
| |
Abstract: | The effect of the chemical structure of styrene-based epoxides, namely, styrene epoxide (SE), α-methylstyrene epoxide (MSE), p-methylstyrene epoxide (pM-SE) and α-methyl-p-methylstyrene epoxide (pM-MSE), in conjunction with TiCl4, on the initiation efficiency (Ieff) in the carbocationic polymerization of isobutylene (IB) was investigated. SE yielded living polymerization, but the initiation efficiency was low when compared to MSE (Ieff=8% and 35%, respectively). pM-SE led to non-living IB polymerization, while pM-MSE revealed linear Mn-conversion plot and narrow MWD with a non-linear first order rate plot. Among the epoxides investigated, MSE was the best initiator to scale up the one-step synthesis of polyisobutylenes (PIBs) carrying one primary hydroxyl head group and one tertiary chloride end group. The hydroxyl functionality of these PIBs determined by 1H-NMR was Fn=1.09±0.16 from 24 experiments. |
| |
Keywords: | Carbocationic polymerization Living isobutylene polymerization Epoxide initiators Hydroxyl-functionalized polyisobutylene Direct functionalization |
本文献已被 ScienceDirect 等数据库收录! |
|