Divalent Samarium Catalyst System Used In Polymerization Of Polar Monomers

Divalent samarium catalyst systems were firstly used with polymerization of acrylonitrile (AN) and 4-vinylpyridine (VPY) in this paper. Corresponding hoi" opolymers: poly-acrylonitrile (PAN), polyvinylpyridine (PVPY) were obtained successfully and their yields and molecular weight were measured. The reaction mechanism was discussed in-depth by analyzing products with ER and NMR spectra etc.Single-component samarium diiodide catalyst system was first used with polymerization of acrylonitrile (AN). Adding of hexamethylphosphoramide (HIMIPA) could greatly improve reaction activity of the catalyst system. AN/Sm12 and l{IVIPA1 Sm12 molar ratios, reaction time and temperature were mainly investigated with yields and molecular weights of resultant PAN. With analysis of ER and NMR spectra, it was confirmed that AN polymerized in dianion mechanism using Sm12/HM7PA catalyst system. Meanwhile, copolymers of AN with e -CL and DTC were obtained to confirm the supposed polymerization mechanism. N7MIR spectra of PAN polymerized under different temperatures were investigated to prove the change of mechanism with change of temperature.The complex of Sm(P(Ph)D2 which contains the ligand of P(Ph)2 ~vere4firstly used with polymerization of one polar monomer, 4-vinylpyridine (4-VPY) and resultant polymer-PVPY was obtained. Also, effect of several factors of the reaction, such as molar ratio of monomer/catalyst, dilution proportions and ways of monomer and reaction time on the yields and molecular weights were investigate. It was proved that the reaction mechanism doesn't change by dilution of monomer. Further, getting of copolymer of 4-VPY with E~ -CL were attempted.