III International Conference

PP-II-40halogen in NiX 2 (PPh 3 ) 2 does not exert any influence on the yield of polymer, that is indirectlyapproves the proposed mechanism, since abstraction of a halogen atom from the nickelcomplex with zinc occurs on the first step, and low valent nickel intermediates lead thepolymerization.The following molar ratio of the monomer and catalyst/ initiator components[Monomer]:[NiBr 2 (PPh 3 ) 2 ]:[PhI]:[Zn]=1:0.05:0.1:0.08 was selected for polymerization ofvinyl monomers that was resulted from experimental data. When concentration of the initiator(Ph-I), the nickel complex and zinc dust were diminished, the rate of polymerizationdecreased. On the contrary, on addition of 5 mol.% of zinc iodide (as the Lewis acid) in thepolymerizing mixture, the rate of the reaction increased.It was shown that the metal-complexed catalyst exerts a strong influence on thedependence of copolymer composition on the monomer mixture content. For instance, theсоpolymer is enriched with styrene in overall the curve of the composition and relative ratioof styrene considerably grows (r MMA =0.45, r Sty =1,70) in the presence of the nickel system,while using the classical initiators (AIBN or peroxides) the curve of composition is S-shaped,relative ratios of both monomers being less than unity (r MMA =0.46, r Sty =0.5).Study of kinetics of styrene соpolymerization with MMA in the presence of the nickelsystem showed that the rate of the reaction decreases upon introduction of methacrylicmonomer to the reaction mixture.This work was supported by the Russian Foundation for Basic Research (grantNo. 05-03-32688).Reference1. Grishin D.F., Valetova N.B., Ilitchev I.S., Prokhorova M.G., Beletskaya I.P.Russ.Chem.Bull.2006.(in press).237