The anionic polymerization of styrene has been studied using dodecyl benzene sulfonic acid barium salt(SDBB)/tetrahydrofuran as ligands

nBuLi as initiator in cyclohexane.The results showed the remarkable effect of SDBB on polymerization. With increasing ［SDBB］/［Li］

the polymerization rate and monomer conversion decreased

and the gel formed gradually. The polymerization was completely retarded at ［SDBB］/［Li］ ≥ 0.8 at 60℃.The stereospecific polystyrene was obtained at 60℃

and its weight content of methyl ethyl ketone (MEK) insoluble fraction reached about 80%.The 13CNMR spectra indicated that its microstructure sequence was isotacticrich polystyrene.The contents of mm triad and mmmm pentad were equal to 57% and 45%

respectively.The Tg of 100℃ and melting temperature at 211℃ were observed in DSC curves.The isotactic content of MEK soluble fraction was also higher than that of PS obtained by conventional anionic polymerization.The GPC results displayed an obvious difference between the theoretical molecular weight and experimental molecular weight.It also indicated a much broader polydispersity of the experimental sample.