SYNTHESIS OF LINEAR AND 3-ARM STAR TERT-CHLORINE-TELECHELIC POLYISOBUTYLENES BY A 2-STEP CONVENTIONAL LABORATORY PROCESS

A two-step conventional laboratory process was developed for the synth esis of mono-and difunctional linear and three-arm star tert-chlorine- telechelic polyisobutylenes (PIE) with desired molecular weights (MW) and narrow molecular weight distribution (MWD) by living carbocationic polymerization (LCCP). This polymerization method applies easy to han dle operations and chemicals. LCCP of isobutylene (IB) was carried out in CH2Cl2 as solvent and with BCl3 as coinitiator in the first step t o obtain soluble low MW PIE prepolymer with narrow MWD. This was follo wed by addition of hexane, TiCl4 and additional monomer in the second step to prepare PIBs with desired MW and narrow MWD in practically any suitable MW region. Comparison of the one-step and two-step processes is also described.