17. スチレンリビングラジカル重合に対する超音波照射効果の検討

抄録

Effect of ultrasound on living radical polymerization of polystyrene was studied at the frequency of 27.5kHz. All the experiments were carried out under N_2 atmosphere at the constant of the ultrasonic intensity. TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy free radical) was used as the nitroxide stable free radical to reversibly terminate the propagating chains. The average-number molecular weights and polydispersity were evaluated by the gel permeation chromatograph. The induction period of polymerization under sonication decreased greater than that of thermal polymerization without sonication. Ultrasound irradiation made the rate of polymerization increase. The number-weight molecular weight increased with increasing the reaction time under sonication as observed in usual living free radical polymerization. The polydispersity obtained here was independent of the reaction time and was within the range from 1.3 to 1.4.