The influence of solvophobic effects of aprotic solvents on the reactivity of 1-(vinyloxyalkoxy)propylene oxides-2,3 in free-radical copolymerization with vinyl chloride has been studied by dynamic light scattering. It has been shown that the association of copolymer macromolecules in aprotic solvents results in the reduced reactivity of 1-(vinyloxyalcoxy)propylene oxides-2,3. This effect can be explained by a decrease in their local concentration in the vicinity of the reaction center.