Vinyl polymerization. VI. Polymerization of acrylonitrile in the presence of substituted benzoyl peroxides and dimethylaniline

The solution polymerization of acrylonitrile was carried out by dilatometry at 40 ± 0.02°C. Using benzene as solvent, and various substituted benzoyl peroxide derivatives as initiator, experiments were made both in the presence and in the absence of dimethylaniline. It was found that the initial rate of polymerization. R 0 , could be expressed by: The values of k 0 were determined. The applicability of Hammett's rule are observed. In the presence of DMA the reaction constant ρ was positive, but in the absence of DMA ρ was negative. Molecular weights of polymers obtained were nearly reversely proportional to the initial rate of polymerization.