Cationic polymerization of p-methylstyrene in selected ionic liquids and polymerization mechanism. Issue 32 (28th June 2016) - Zhang, Xiaoqian
Abstract : Cationic polymerizations of p -methylstyrene were investigated in selected ionic liquids and the possible polymerization mechanism was proposed. Abstract : Cationic polymerization of p -methylstyrene ( p -MeSt) in imidazolium-based [NTf2 −1 ] ionic liquids (ILs) was investigated. The effects of the anions, cations, and alkyl chain length of ILs on p -MeSt solubility and viscosity were comprehensively studied. The COSMO-RS method, which is a valuable tool for screening and selecting ILs, was also applied to identify the most suitable solvent for p -MeSt cationic polymerization. The results revealed that p -MeSt cationic polymerization proceeded in a milder exothermic manner in ILs than in a traditional organic solvent. Controlled polymerizations were achieved in [Bmim][NTf2 ] with a CumOH/BF3 OEt2 initiating system at −25 °C when 2, 6-di- tert -butylpyridine was introduced. The cationic polymerization mechanism of p -MeSt in ILs was proposed on the basis of the results of density functional theory and the terminal structures of polymers.