Synthesis of poly(N-isopropylacrylamide-co-2-hydroxyethyl methacrylate) with low polydispersity using ultrasonic irradiation
Synthesis of poly(N-isopropylacrylamide-co-2-hydroxyethyl methacrylate) with low polydispersity using ultrasonic irradiation
复制标题
DOI：
10.1016/j.ultsonch.2018.08.022
复制
发表时间：
2018-12-01
影响因子：
8.4
通讯作者：
Tsukada, Takao
中科院分区：
文献类型：
--
作者：
Kubo, Masaki;Sone, Takuya;Tsukada, Takao
在无任何化学聚合引发剂的情况下，在乙醇和水的混合溶剂中，用超声波辐射合成了低分散度的聚(N-异丙基丙烯酰胺-甲基丙烯酸羟乙酯)。考察了乙醇在溶剂中的体积分数、两单体摩尔比、单体浓度和超声功率对聚合物转化时间、数均相对分子质量和聚合物多分散性的影响，以确定合成分子量分布窄(即低多分散度)的共聚物的最佳条件。乙醇在溶剂中的最佳体积分数为60%，合成的共聚物具有较低的多分散性。超声功率越大，聚合速度越快，数均相对分子质量越低。在本工作中使用的所有超声功率强度在450W/dm(3)以下时，多分散度小于1.5。单体浓度越高，聚合速度越快，数均相对分子质量越高。当单体浓度低于0.4mol/dm(3)时，多分散度小于1.5。N-异丙基丙烯酰胺的摩尔比越高，聚合速率越快，数均相对分子质量越低。无论N-异丙基丙烯酰胺的摩尔比如何，均可得到多分散度小于1.5的共聚物。超声法合成的共聚物具有较高的高温响应性。
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/dm(3) 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/dm(3). 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.