Studies on the polymerization of acrolein oxime, 6

Radiation-induced polymerization and copolymerization of acrolein oxime are investigated in different solvents and at a wide range of temperature for obtaining information on the reaction mechanism. Acrolein oxime is polymerized ionically, irrespective of dryness of the sample. Arrhenius plots for the polymerization rate, which do not yield a linear relation, can be adequately approximated by two straight lines. An anionic mechanism is operative above the room temperature, while a cationic mechanism predominates below -230C. The reaction in the intermediate temperature range proceeds by a competitive mechanism, and the rate of the anionic and cationic polymerizations becomes equal at the temperature near -50C. The reaction rate is proportional to the square root of dose rate at room temperature and -230C. On the basis of these data, it is proposed that the polymerization of acrolein oxime by γ-irradiation proceeds by free-ionic mechanisms. (author)