Synthesis Of Block Copolymer Of Isobutylene And Styrene Coinitiated By AlCl₃

There is a great deal of interest in polystyrene-polyisobutylene -polystyrene(SIBS) due to their unique properties and potential commercial value in recent years. SIBS exhibiting both thermoplastic and elastomeric characteristics can be melt extruded like plastics, while retaining their beneficial rubbery properties upon cooling. And it has the superior oxidative, chemical and thermal stability, and the outstanding barrier and damping properties because of saturated inner block. In this paper, the carbocationic polymerization of isobutylene and copolymerization of isobutylene and styrene with DCC/AICl₃ initiating system by two-step sequential monomer addition were carried out in CH₂Cl₂/n-Hex (40/60, v/v) solvent mixtures in the presence of electron donor(ED).Firstly, the polymerization of IB with DCC/AlCl₃ initiating system was investigated systematically. The effects of concentrations of DCC, ED and AlCl₃ on monomer conversion, molecular weight and molecular weight distribution (MWD) of the product polyisobutylene (PIB) were studied in detail.