Coupled vinyl and acetal ring‐opening polymerization

Abstract 4‐Methylene‐1,3‐dioxolane and its derivatives were polymerized by cationic catalysts. Infrared and ultraviolet studies showed that the polymers of 2,2‐dimethyl‐ or 2‐methyl‐1,3‐dioxolane possess appreciable carbonyl content. This indicates that the polymerization takes place in such a manner that the carbon–carbon double bond opening is coupled with a concurrent acetal ring rearrangement in the propagation step to give “ketoether” sequences. 4‐Methylene‐1,3‐dioxolane, on the other hand, was found to polymerize mostly at the carbon–carbon double bond. Copolymerization of these monomers with acrylonitrile under ultraviolet irradiation was also studied.