Polymerization of styrene in N,N‐dimethylformamide and N,N‐dimethylacetamide

The polymerization of styrene in N,N‐dimethylformamide and N,N‐dimethylacetamide at 60°C. initiated by 2,2′‐azobisisobutyronitrile has been studied. Rates of polymerization were measured dilatometrically and gravimetrically, and degrees of polymerization were determined viscometrically. The transfer constants to N,N‐dimethylformamide and N,N‐dimethylacetamide are 4.0 × 10−4 and 4.6 × 10−4, respectively. None of the existing reaction mechanisms of vinyl polymerization can account for all the experimental results, and various alternatives are examined.