US EPA

3854420 

Journal Article 

Cobalt-mediated Radical Polymerization(CMRP) of Chloroprene by Co-II(salen*) 

Li Weiwei; Shi Yan; Yang Wantai; Fu Zhifeng 

2016 

1 

Gaodeng Xuexiao Huaxue Xuebao / Chemical Journal of Chinese Universities
ISSN: 0251-0790 

37 

11 

2085-2091 

10.7503/cjcu20160496 

WOS:000388831400021 

Radical polymerization of chloroprene(CP) in the presence of N, N'-bis(3,5-di-tert-butylsalicylidene) - 1,2-cyclohexanediamine [Co-II (salen*)], as a mediator was investigated. The results show that the induction time is shortened and the polymerization rate is increased with the increase of ABVN concentrations. The linear increase in molecular weight with conversion, and molecular weight close to the theoretical value at low conversion in benzene, demonstrating the living process of CP radical polymerization mediated by [Co-II(salen*)]. In order to determine what effect, if any, the solvents had upon the control of the polymerization, various solvents were used in the CMRP of chloroprene, and the process in benzene efficiently controls the molar mass(characterized by size exclusion chromatography, SEC) at low monomer conversion. Then, the effect of electron donors(ED) on the [Co-II(Salen*)]-mediated radical polymerization of CP was examined by the addition of electron donors, water, pyridine(Py), NEt3, tetrahydrofuran(THF) and dimethylsulfoxide (DMSO) to the complex in the molar ratio [CP] / [Co] / [ABVN] / [ED] = 400/ 1/ 3/ 25. The induction periods became shorter with the addition of electron donors(ED). Obviously, the control of polymerization increased with the addition of THF, which was demonstrated by molecular weight close to the theoretical value and a relatively narrow molecular weight distribution at low monomer conversion. 

Chloroprene; Organometallic mediated radical polymerization; Electron donor; Co-II (salen*); Cobalt-mediated radical polymerization