We have conducted a series of kinetic investigations on controlled cationic isobutylene (IB) polymerizations at high temperature, i.e., -10 ℃, utilizing in situ ATR-FTIR spectroscopy (ReactIR 1000, ASI Applied Systems, Inc.). Our goal was to produce nearly monodisperse polyisobutylene (PIB) with precise control over molecular weight and macromolecular architecture, including end groups. We have previously detailed the capabilities of the React IR 1000 reaction analysis system and demonstrated its usefulness in generating accurate kinetic data in isobutylene polymerizations. The current research effort was initiated as a result of subtle details seen in kinetic analysis of IB polymerization at low monomer conversion. Such discrepancies would have proved difficult to detect through the use of traditional, gravimetric analysis. The present investigation focuses specifically on isobutylene polymerizations carried out in 1,2 dichloroethane with boron trichloride as Lewis acid catalyst, and it examines the polymerization kinetics of reactions in the presence of the Lewis bases (LB) 2,4-lutidine, 2,6-lutidine, 2,6-di-tert-butylpyridine, and tetra-n-butyl ammonium chloride (Figure 1) to determine the most effective system for producing monodisperse polyisobutylene (PIB) with tert-chloride chain ends.
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