Poly(N-isopropylacrylamide-co-2-hydroxyethyl methacrylate) having low polydispersity was synthesized in mixed solvent of ethanol and water using ultrasonic irradiation without any chemical polymerization initiator. The effects of the volume fraction of ethanol in the solvent, the molar ratio of two monomers, the monomer concentration and the ultrasonic power intensity on the time courses of the conversion to the polymer, the number average molecular weight, and the polydispersity of synthesized polymer were investigated in order to determine the optimal conditions to synthesize the copolymers with a narrow molecular weight distribution (i.e. low polydispersity). The optimum volume fraction of ethanol in the solvent was 60 vol% to synthesize the copolymers with a low polydispersity. A higher ultrasonic power intensity resulted in a faster polymerization rate and a lower number average molecular weight. The polydispersity was less than 1.5 for all ultrasonic power intensities up to 450 W/dm³ applied in this work. A higher monomer concentration gave a faster polymerization rate and a higher number average molecular weight. The polydispersity was less than 1.5 when the monomer concentration was lower than 0.4 mol/dm³. A higher molar ratio of N-isopropylacrylamide resulted in a higher polymerization rate and a lower number average molecular weight. The copolymers with polydispersity less than 1.5 can be obtained regardless of the molar ratio of N-isopropylacrylamide. The copolymers synthesized by the ultrasonic polymerization method had a high temperature responsibility.

聚（Ñ -isopropylacrylamide-共在没有任何化学聚合引发剂的情况下，使用超声辐射在乙醇和水的混合溶剂中合成具有低多分散性的（甲基丙烯酸-2-羟乙酯）。溶剂中乙醇的体积分数，两种单体的摩尔比，单体浓度和超声功率强度对转化为聚合物的时间过程，数均分子量和合成聚合物的多分散度的影响为了确定最佳的条件来合成具有窄分子量分布（即低多分散性）的共聚物，进行了研究。乙醇在溶剂中的最佳体积分数为60 vol％，以合成具有低多分散性的共聚物。较高的超声功率强度导致较快的聚合速率和较低的数均分子量。对于高达450 W / dm的所有超声功率强度，多分散度均小于1.5³在这项工作中的应用。较高的单体浓度给出较快的聚合速率和较高的数均分子量。当单体浓度低于0.4mol / dm ³时，多分散度小于1.5 。N-异丙基丙烯酰胺的较高摩尔比导致较高的聚合速率和较低的数均分子量。不管N-异丙基丙烯酰胺的摩尔比如何，都可以得到多分散度小于1.5的共聚物。通过超声聚合方法合成的共聚物具有高温责任感。