Acta Chimica Sinica ›› 2007, Vol. 65 ›› Issue (16): 1736-1740. Previous Articles    

Reports

基于原子转移自由基聚合技术的偶氮苯星形液晶聚合物的合成与表征

唐新德*,1,2, 高龙成2, 韩念凤1, 范星河2, 周其凤2   

  1. (1山东交通学院新材料研究所 济南 250023)
    (2北京大学化学与分子工程学院 北京 100871)
  • 投稿日期:2007-01-29 修回日期:2007-04-28 发布日期:2007-08-28
  • 通讯作者: 唐新德

Synthesis and Characterization of Tri-arm Star Side-chain Liquid Crystalline Polymers Containing Azobenzene via Atom Transfer Radical Polymerization

TANG Xin-De*,1,2; GAO Long-Cheng2; HAN Nian-Feng1; FAN Xing-He2; ZHOU Qi-Feng2   

  1. (1 Institute of New Materials, Shandong Jiaotong University, Jinan 250023)
    (2 College of Chemistry and Molecular Engineering, Peking University, Beijing 100871)
  • Received:2007-01-29 Revised:2007-04-28 Published:2007-08-28
  • Contact: TANG Xin-De

Tri-arm star side-chain liquid crystalline (LC) polymers containing azobenzene with different terminal substituents were synthesized by atom transfer radical polymerization. Trifunctional initiator prepared by the esterification between phloroglucinol and 2-bromoisobutyryl bromide was utilized to initiate the polymerization of 6-[4-(4-methoxyphenylazo)phenoxy]hexyl methacrylate or 6-[4-(4-ethoxyphenylazo)- phenoxy]hexyl methacrylate. The star polymers were characterized by 1H NMR, gel permeation chromatography, differential scanning calorimetry, and polarizing optical microscopy. The tri-arm star side-chain LC polymer with p-methoxyazobenzene moieties exhibits a smectic and nematic phase, while that with p-ethoxyazobenzene moieties shows only a nematic phase, which derives from different terminal substituents. The star polymers have similar LC behavior to the corresponding linear homopolymers. Both star polymers show photoresponsive isomerization under the irradiation with UV-Vis light in THF solution.

Key words: tri-arm star polymer, azobenzene, liquid crystalline polymer, linear homopolymer, atom transfer radical polymerization