Pseudoliving free-radical copolymerization of vinyl acetate with styrene under conditions of nitroxide-mediated reversible inhibition

It was shown that the free-radical copolymerization of vinyl acetate with styrene when carried out in the presence of common initiators and excess vinyl acetate proceeds with a low yield according to the dead-end mechanism. Upon addition of nitroxides, the reaction mechanism changes to the pseudoliving reversible inhibition mechanism. Not only does this increase the yield and molecular mass of copolymers but also opens the unique possibility of obtaining high-molecular-mass gradient copolymers with a low compositional heterogeneity at high conversions. The kinetics of copolymerization was studied in relation to the ratio of monomers, the nature and concentration of nitroxides, the temperature, and the addition of acetic anhydride, and the quantitative characteristics of the pseudoliving mechanism were calculated.