温度敏感性P(MEO2MA-co-OEGMA)共聚物的合成与性质
温度敏感性P(MEO2MA-co-OEGMA)共聚物的合成与性质
复制标题
DOI：
10.3866/pku.whxb201207161
复制
发表时间：
2012-10
期刊：
影响因子：
--
通讯作者：
王莉
中科院分区：
文献类型：
--
作者：
吕海燕;刘守信;徐超;田荣;王莉
以CuCl2，2-联吡啶(BPY)为催化剂体系，2，2-溴丙酸乙酯(EBP)为引发剂，在乙醇中通过原子转移自由基聚合(ATRP)合成了温度响应性P(MEO_2MA-co-OEGMA)甲基丙烯酸2-(2-甲氧基乙氧基)乙酯(MEO_2MA)和低聚(乙二醇基)甲基丙烯酸乙酯(OEGMA)共聚物。用质子核磁共振(1H核磁共振)和凝胶渗透色谱(GPC)对合成的共聚物进行了表征。用光学透过率、粘度和激光粒度分析等方法研究了共聚物在水溶液中的温度敏感性。考察了各种参数对共聚物水溶液相变温度的影响。包括OEGMA含量、溶液浓度、外加盐的浓度和种类。共聚物的最低临界溶解温度(LCST)随着OEGMA含量的增加和溶液浓度的降低而升高，通过调节MEO2-MA和OEGMA的摩尔分数也可以控制共聚物的最低临界溶解温度。此外，还观察到随着盐浓度和阴离子价态的增加，共聚物溶液的最低临界溶解温度降低。酸或碱的加入也影响共聚物溶液的最低临界溶解温度；加入盐酸会降低共聚物溶液的最低临界溶解温度，而加入氢氧化钠则会导致提高。
Temperature-responsive P(MEO2MA-co-OEGMA) copolymers of 2-(2-methoxyethoxy) ethyl methacrylate(MEO2MA) and oligo(ethylene glycol) methacrylate(OEGMA) were synthesized via atom transfer radical polymerization(ATRP) in ethanol using CuCl/2,2-bipyridyl(bpy) as the catalyst system and ethyl-2-bromopropionate(EBP) as an initiator.The synthesized copolymers were characterized by proton nuclear magnetic resonance spectroscopy(1H NMR) and gel permeation chromatography(GPC).Copolymer temperature sensitivities in aqueous solution were investigated by measurements of optical transmittance and viscosity as well as laser particle size analysis.The effects of various parameters on the phase transition temperatures of aqueous copolymer solutions were examined,including OEGMA content,solution concentration,and the concentrations and species of added salts.Results showed that the copolymers demonstrated temperature sensitivity;the lowest critical solution temperature(LCST) increased both with increasing OEGMA content and decreasing solution concentration.Copolymer LCST values could also be controlled by adjusting the mole fractions of MEO2MA and OEGMA.It was additionally observed that LCST values decreased as the salt concentration and anion valence increased.The addition of acid or base also affected the LCST of the copolymer solutions;addition of HCl decreased the LCST while addition of NaOH resulted in an increase.