Specific Thermoresponsive Behaviours Exhibited by Optically Active and Inactive Phenylalanine Modified Hyperbranched Polyethylenimines in Water  

作　　者：Wu-cheng Fang Ran Zhang Ye-feng Yao 刘华姬 陈宇 

机构地区：[1]Tianjin Key Laboratory of Molecular Optoelectronic Science,Department of Chemistry,School of Sciences,Tianjin University,and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) [2]Department of Physics & Shanghai Key Laboratory of Magnetic Resonance,East China Normal University

出　　处：《Chinese Journal of Polymer Science》2017年第8期1035-1042,共8页高分子科学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.20804027 and 21274106);Shanghai Key Laboratory of Magnetic Resonance

摘　　要：Optically active and inactive hyperbranched polymers with specific thermoresponsive behaviours in water were reported.Through two steps hyperbranched polyethylenimine（HPEI） polymers terminated with different amount of D-phenylalanine（D-Phe）,L-phenylalanine（L-Phe） or DL-phenylalanine（DL-Phe） were prepared and characterized.The analyses on the solution properties by turbidimetry,dynamic light scattering,fluorescence probe and 1H-NMR demonstrated that all the polymers exhibited specific thermoresponsive behaviours in water,including：（1） In the dilute polymer concentration region,increasing the polymer concentration led to the increase of phase transition temperature;（2） The optically inactive thermoresponsive hyperbranched polymers showed a higher cloud-point temperature（Tcp） than their corresponding optically active ones in a relatively higher polymer concentration;（3） At the same polymer concentration the hydrophobic groups of the optically inactive HPEI-DL-Phe formed more perfect hydrophobic domain than those of the optically active HPEI-L-Phe and HPEI-D-Phe.Optically active and inactive hyperbranched polymers with specific thermoresponsive behaviours in water were reported.Through two steps hyperbranched polyethylenimine（HPEI） polymers terminated with different amount of D-phenylalanine（D-Phe）,L-phenylalanine（L-Phe） or DL-phenylalanine（DL-Phe） were prepared and characterized.The analyses on the solution properties by turbidimetry,dynamic light scattering,fluorescence probe and 1H-NMR demonstrated that all the polymers exhibited specific thermoresponsive behaviours in water,including：（1） In the dilute polymer concentration region,increasing the polymer concentration led to the increase of phase transition temperature;（2） The optically inactive thermoresponsive hyperbranched polymers showed a higher cloud-point temperature（Tcp） than their corresponding optically active ones in a relatively higher polymer concentration;（3） At the same polymer concentration the hydrophobic groups of the optically inactive HPEI-DL-Phe formed more perfect hydrophobic domain than those of the optically active HPEI-L-Phe and HPEI-D-Phe.

关 键 词：optically phenylalanine terminated hydrophobic inactive dilute Modified hydrophilic responsive solubility 

分 类 号：O632.63[理学—高分子化学]