双重响应性核交联星型聚合物的合成及其性能研究  

Synthesis of Double-responsive Core Cross-linked Star Polymers

作　　者：童杰祥 罗静 董佳豪 刘晓亚 Jie-xiang Tong;Jing Luo;Jia-hao Dong;Xiao-ya Liu(Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122)

机构地区：[1]江南大学合成与生物胶体教育部重点实验室化学与材料工程学院,无锡214122

出　　处：《高分子学报》2018年第6期674-681,共8页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号51573072)资助项目

摘　　要：通过"臂优先"的途径和可逆加成-断裂转移(RAFT)自由基聚合制备了以p H响应性聚(3-丙烯酰胺基苯硼酸-co-丙烯酰胺)(PAA-DMP)为线性外臂,温敏性聚(N-异丙基丙烯酰胺-co-苯乙烯-co-N,N-亚甲基双丙烯酰胺)(PNSB)为核的核交联星型聚合物(PNSB@PAA-DMP).采用傅里叶红外光谱(FTIR)、核磁氢谱(1H-NMR)和凝胶渗透色谱(GPC)对产物进行了表征.粒径和形貌也分别通过动态光散射(DLS)和透射电子显微镜(TEM)做了表征.采用紫外可见光谱(UV-Vis)和动态光散射(DLS)考察了聚合物在水中的相变行为.结果表明,所制备的核交联星型聚合物具有p H和温度双重响应,其低临界溶解温度(LCST)可以通过改变核内聚苯乙烯的量来进行调节.除此之外,在高浓度(20 mg/m L)下,还可以通过控制温度和p H实现聚合物溶液溶胶-凝胶(sol-gel)的转化.A series of water-soluble double-responsive core cross-linked star polymers（PNSB@PAA-DMP）, in which poly（3-acrylamidophenylboronic acid-co-acrylamide）（PAA-DMP） served as the p H-responsive arm and poly（N-isopropyl acrylamide-co-styrene-co-N,N′-methylenebisacrylamide）（PNSB） as the thermoresponsive core,have been successively prepared via reversible addition-fragmentation chain transfer（RAFT） polymerization using the ＂arm-first＂ approach. Poly（AAPBA-co-AM） is first prepared via RAFT polymerization to give a welldefined linear hydrophilic macro-RAFT agent, which subsequently copolymerizes with thermosensitive monomer NIPAM（N-isopropyl acrylamide）, crosslinker Bis（N,N′-methylenebisacrylamide） and St（styrene） to give the desired p H and thermoresponsive star polymers（PNSB@PAA-DMP）. Fourier transform infrared spectroscopy（FTIR） and nuclear magnetic resonance spectroscopy（1 H-NMR） are empolyed to characterize the structure and composition of the resultant polymers. The molecular weight of the polymers are obtained by gel permeation chromatography（GPC）. The morphology and particle size of polymer under dry conditions are characterized by transmission electron microscopy（TEM）. In addition, the phase transition behavior of the polymers in aqueous solutions at low concentration is investigate by dynamic light scattering（DLS） and ultraviolet-visible spectroscopy（UV-Vis）. The results show that the obtained PNSB@PAA-DMP polymers exhibit reversible thermal-induced volume phase transition and p H responsibility. The lower critical solution temperature（LCST） of the core crosslinked star polymers in aqueous solutions can be tuned by changing the feeding ratio of the hydrophobic monomer St. In addition, the LCST of the polymer solution could also be affected by changing the p H of the polymer solution. What is most interesting is that sol-gel transition of the polymer solution can be achieved by controlling temperature and p H at a higher concentration.

关 键 词：双重响应 核交联星型聚合物 溶胶-凝胶的转化 

分 类 号：O631[理学—高分子化学]