Characterization and kinetics study of poly(α-methyl styrene) synthesized by living anionic polymerization

In this work, poly(alpha-methyl styrene) (PAMS) was synthesized through living anionic polymerization and characterized by 13C NMR, 1H NMR, GPC, TGA, DSC. The kinetics study was performed using multi-stage dosing of initiator. The results obtained via GPC analysis revealed that polydispersity index of the synthesized PAMS was close to the true value. Moreover, multi-stage dosing of initiator offers valuable and accurate method to determine propagation rate constant and initial impurities value of the system. 13C NMR analysis demonstrated that Bernoullian statics model exhibits a superior fit compared to 1st -order Markov statics model for the assigned sequence. Furthermore, the synthesized PAMS presents higher degree of racemic addition with Pm=0.439. 1H NMR spectroscopy was utilized to ascertain number-average molecular weight of the synthesized samples, corroborating the values estimated through GPC analysis. From the thermal analysis, it was shown that PAMS containing very low molecular weight demonstrates negative glass transition temperature and broad thermal decomposition range.