侧链含偶氮吡啶的N-异丙基丙烯酰胺共聚物的制备及其多重响应性  

Preparation and Multiple Responsiveness of Copolymers of PNIPAM Containing Azo Pyridine in Side Chain

作　　者：薛小强 钱烽[1] 黄文艳 杨宏军 蒋其民 周磊 蒋必彪[1] Xiao-qiang Xue;Feng Qian;Wen-yan Huang;Hong-jun Yang;Qi-min Jiang;Lei Zhou;Bi-biao Jiang(Department of Materials Science and Engineering,Changzhou University,Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering,Changzhou 213164;Patent Examination Cooperation Jiangsu Center of the Patent Office,Suzhou 215011;School of Materials Science and Engineering,Nanjing University of Technology,Nanjing 210000)

机构地区：[1]江苏省材料表面科学与技术重点实验室常州大学材料科学与工程学院江苏省光伏科学与工程协同创新中心,常州213164 [2]南京工业大学材料科学与工程学院,南京210000 [3]国家知识产权局专利局专利审查协作江苏中心,苏州215011

出　　处：《高分子学报》2018年第9期1175-1183,共9页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号21104006);国家自然科学基金(基金号21504009); 国家博士后面上项目(项目号2016M601785); 江苏省博士后项目资助

摘　　要：经重氮偶合等步骤制备了新型偶氮吡啶单体—甲基丙烯酸-4-(4-吡啶基偶氮)苯酯(PAZO).PAZO、N-异丙基丙烯酰胺(NIPAM)和聚乙二醇甲醚甲基丙烯酸酯(EGMA)无规共聚得到多重响应三元共聚物P(NIPAM-co-PAZO-co-EGMA).采用凝胶渗透色谱和核磁共振氢谱对聚合物结构进行表征,经紫外光谱对聚合物进行研究,发现聚合物有良好的光致顺反异构.偶氮吡啶在酸性条件下,紫外光照反式吸收峰稳定存在,吸收峰衰弱被抑制;碱性条件下,紫外光照反式吸收峰衰弱明显,顺式吸收峰得到增强并且稳定存在.聚合物最低相转变温度(LCST)为49°C,经紫外光照LCST下降2°C,变为47°C,这是由于紫外光照改变了偶氮吡啶的顺反异构使得聚合物的尺寸增大,导致PNIPAM链段对温度更灵敏更易聚集,LCST下降.聚合物溶液通入CO_2后,LCST变为62°C,升高了13°C.向溶液中通入氩气排除CO_2,溶液的LCST再次变为49°C.交替通入CO_2和氩气,溶液LCST具有可逆性.表明该聚合物具有温度、光、pH以及气体响应性.A novel azopyridine monomer was prepared by diazo coupling：4-（4-pyridylazo）phenyl methacrylate（PAZO）.PAZO was randomly copolymerized with N-isopropylacrylamide（NIPAM）and ethylene glycol methyl ether methacrylate（EGMA）to obtain a multi-response terpolymer（P（NIPAM-co-PAZO-co-EGMA））.The structure of the polymer was characterized by 1H-NMR and gel permeation chromatography（GPC）,and the responsiveness of the polymer to UV spectroscopy was studied.Under the acidic conditions,the trans absorption peak of azo pyridine is stable and the weakness is inhibited.Under alkaline conditions,the trans absorption peak is weak,and the cis absorption peak is enhanced and stable.The lowest phase transition temperature（LCST）of the polymer was 49°C.The trans structure of azopyridine was changed to the cis structure by ultraviolet light irradiation.Before UV irradiation,the hydrodynamic radius of the polymer was 9.82 nm.After the UV illumination,the value became 11.07 nm,and increased by 1.25 nm,indicating that the polymer size was increased after UV illumination.The size of the polymer increased with the increased size of the azo pyridine structure,making the PNIPAM segment more sensitive to temperature and LCST decreased 2°C to 47°C.The LCST of polymer sites before introduction of CO2 was 49°C,and that was changed to 62°C after passing through CO2.Argon is bubbled through the polymer solution or the solution is left open at 60°C for a period of time to evacuate the CO2.The LCST of the solution changes to 49°C again.Before and after the introduction of CO2,there was no obvious change in the LCST point of the aqueous solution of PNIPAM,indicating that the carbonic acid did not affect the amine group on the PNIPAM group,but instead was protonated with the azopyridine group.The CO2 and argon gasses were repeatedly introduced.The LCST of the polymer solution changed reversibly between 49 and 62°C.

关 键 词：异丙基丙烯酰胺 偶氮吡啶 无规共聚 多重响应性 

分 类 号：O631[理学—高分子化学]