Linear and multi-arm atactic polystyrene with functional groups―OH was synthesized via living free radical polymerization promoted by titanocene complexes in the presence of glycidyl-4-methoxyphenyl ether (I1)

1

4-butanediol diglycidyl ether (I2)

4

4′-methylenebis(N

N-diglycidylaniline) (I4) and poly[(phenylglycidyl ether)-co-formaldehyde] (I5) as initiators

and Sn as reducing agent in this catalyst system. The polymerization mechanism was expatiated. In this article

for the first time

titanocene complexes

for example CpTi(Ⅳ)Cl3 was treated with Sn to form primary free radical CpTi’(Ⅲ)C12 at room temperature

this radical reacted with epoxide(initiator) to give the chain radical which initiated styrene to propagate successfully. The effect of polymerization conditions

such as the structure of the initiator and titanocene complexes

as well as the ratio of initiator to monomers on the performance was investigated. The properties of the obtained polymer were also characterized by GPC. These results showed that the structure of initiator had little influence on the conversion of monomer

the molecular weight and molecular weight distribution of the obtained polymer. Compared with (n-BuCp)2TiCl2 and SiMe2(Ind) 2TiCl2

half-titanocene

CpTICl3 was favorable for the polymerization of styrene via radical mechanism. The monomer conversion was more than 80%

the molecular weight of the polymer was higher than 1.0×105

and the molecular weight distribution was at the range of 1.18 to 1.42. However

when (n-BuCp)2TiCl2 and SiMe2(Ind) 2TiCl2 were used as catalysts

the monomer conversion and the molecular weight of the obtained polymer were lower. But the structure of titanocene complex had less impact on the molecular weight distribution (1.26~1.30). The effect of the ratio of monomer to initiator on the polymerization performance was also studied. A linear dependence of Mn of the obtained polymer on the monomer concentration was observed at the ratio of 250/1

500/1 and 750/1. Mn of the obtained polymer increased with increasing the ratio of monomer to initiator

and the molecular weight distribution of the obtained polymer kept at the range of 1.0 to 1.40. The obtained polymer was also characterized by 13C-NMR to confirm the atactic structure of the polymer. These results indicated living the free radical mechanism of polymerization.