INFLUENCE OF SOLVENT ON THE ENERGETICS OF CHAINS GROWTH IN RADICAL POLYMERIZATION OF N-VINYLPYRROLIDONE

Associates of monomeric vinylpyrrolidone and its radical with one and two water molecules were calculated by semiempirical quantum-chemical methods AM1 and PM3. Calculations were also performed for associates b etween the monomer and the radical and between two molecules of the mo nomer (as a model of solvation in a bulk). In the studies of model rea ctions of the monomer with the radical in a solvent, in bulk of monome r, and in gas phase permitted us to estimate the stabilization energie s for chain growth reactions in radical polymerization of vinylpyrroli done, It was found that association with a solvent does not affect the stabilization energies for the radical reactions considered. The data on solvation of reactants and the results of calculations of potentia l energy curves led to a conclusion that the rate constant for the ele mentary event of chain growth in a cage during radical polymerization of vinylpyrrolidone must be independent of the concentration of monome r, the nature of solvent, and the type of solvation.