화학공학소재연구정보센터
Journal of Polymer Science Part A: Polymer Chemistry, Vol.55, No.10, 1784-1789, 2017
Quantitative Preparation of Allyl Telechelic Polyisobutylene under Reflux Conditions
Allyl telechelic polyisobutylene (allyl-PIB-allyl) is of great commercial and scientific interest produced by living polymerization of isobutylene followed by functionalization (allylation with allyltrimethylsilane) under external cooling, typically to -78 degrees C. Cooling is cumbersome and costly, and temperature control is far from ideal. Herein we describe the quantitative preparation of allyl-PIB-allyl under ideal internal temperature control at similar to-40 degrees C using refluxing propane/methyl chloride mixtures. The exact composition of the nonpolar/polar solvents and polymerization time crucially affect product quality. Well-defined allyl-PIB-allyl is obtained using 60/40 (v/v) refluxing propane/methyl chloride and terminating not more than 5min after monomer depletion. In pure refluxing propane or methyl chloride, or at longer reaction times, byproducts form that compromise product quality. A mechanism is presented to explain the observations. (C) 2017 Wiley Periodicals, Inc.