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侧链型偶氮聚合物液晶在不同温度条件下的光致取向

PHOTOINDUCED ORIENTATION OF AZOBENZENE LIQUID CRYSTAL POLYMER UNDER IRRADIATION AT DIFFERENT TEMPERATURE

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【作者】 刘剑张其锦高建刚王沛明海

【Author】 LIU Jian 2, ZHANG Qijin 1,2 , GAO Jiangang 2, WANG Pei 3, MING Hai 3 ( 1Structure Research Laboratory, 2Department of Polymer Science and Engineering, 3Department of Physics, University of Science and Technology of China, Hefei\ 230026)

【机构】 中国科技大学高分子科学与工程系中国科技大学结构分析开放实验室中国科技大学物理系中国科技大学物理系 合肥230026高分子科学与工程系合肥230026合肥230026合肥230026

【摘要】 在高于和低于玻璃化转变温度 (Tg)的温度范围内 ,研究了聚甲基丙烯酸 ( 6 [4 ( 4 氰基偶氮苯 )苯氧基 ]己酯 ) (Poly( 6 [4 ( 4 cyanophenylazo)phenoxy]hexylmethacrylate) (PM6ABCN) )聚合物膜的光致取向行为 .实验结果表明 ,在温度低于Tg 时 ,实验温度对取向速率没有影响 ;高于Tg 温度时 ,取向的速率随温度升高而变大 ,取向过程的表观活化能为 3 2 76kJ mol.通过对Tg 温度以下的光致取向进行分析 ,对光致取向过程提出了一个新的微相模型 ,微相内的温度能够达到Tg 以上 ,而实验中控制的样品宏观温度不变 ;高于Tg 温度时的光致取向过程受到宏观温度的控制 ,其表观活化能远远小于热致的各向同性相I(Isotropicphase,I)到向列相N(Nematicphase,N)相转变表观活化能 ( 3 40 2kJ mol) ,表明光致取向过程对温度的依赖性较小

【Abstract】 A simple casting film of Poly(6 [4 (4 cyanophenylazo)phenoxy] hexyl methacrylate) (PM6ABCN) was made on an untreated surface of a glass substrate and adopted as a typical sample to study photoinduced orientation of azobenzene liquid crystalline side chain homopolymers.Photoinduced orientation process of the sample was examined.A novel domain model was proposed to give a qualitative analysis of the photoinduced orientation below T g.It was found that the experimental temperature had no effect on the rate of orientation, and within the domain the temperature higher than T g was resulted from radiationless decay of absorbed light energy, and the orientation behavior of microscopic domains was identical with that of the macroscopic sample above T g.An apparent activation energy of the orientation above T g was found to be 32 76 kJ/mol.It means that this orientation process has a lower temperature dependence than that of the thermal I N phase transition (340 2?kJ/mol).

【基金】 国家自然科学基金资助项目 (基金号 5 0 0 2 5 3 0 9);国家科技部重大基础研究项目 (项目号G19990 3 3 0 )
  • 【文献出处】 高分子学报 ,Acta Polymerica Sinica , 编辑部邮箱 ,2003年02期
  • 【分类号】O753
  • 【被引频次】20
  • 【下载频次】314
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