| Abstract: | The results of studying the radiation curing of methacryloyloxyalkyl carbonates (MC), a new type of oligomer, are presented. These oligomers are notable for their high rates of radiation curing. The radiation yield G(–M) is 2 × 105 for MC and 2 × 104 for triethylene glycol dimethyacrylate. The polymerization rate of MC appeared to be proportional, independent of the conversion degree, to the irradiation dose rate in the power of 0.9–1.0 (for dose rates ranging from 0.4 to 15 rad/s). In regard to the temperature dependence of the polymerization rate of MC for small conversion degrees, two temperature regions with different values of effective activation energy (18–20 kcal/mol and 2 kcal/mol, respectively) were observed. When an irradiated MC sample is being unfrozen, its polymerization occus in the region of devitrification (220–240°K). As distinct from mass polymerization, in the polymerization of MC solutions in acetone and benzol the mobility of growing chains increases so that the bimolecular termination becomes possible and the limiting conversion of double bonds is derived. Rather small irradiation doses necessary for curing MC and the proportionality of the radiation-induced polymerization rate to the dose rate make these oligomers valuable for various industrial applications. |
