| Abstract: | Preparation and radical ring-opening polymerization of the exo-methylene substituted cyclic ketene acetals, 2,4-dimethylene-1,3-dioxolane ( I ) and 2,5-dimethylene-1,3-dioxane ( II ), were carried out. Ketene acetals I and II were prepared by dehydrohalogenation of the corresponding cyclic haloacetal with potassium tert-butoxide in tetrahydrofuran at –78°C and ambient temperature, respectively. I underwent radical polymerization with essentially quantitative ring-opening with di-tert-butyl peroxide in dimethylformamide at 120°C. On the other hand, II underwent both ring-opening polymerization and vinyl polymerization under the same conditions of the polymerization of I . The differences of polymerization behavior between I and II were also discussed. |
