The conformation of a rubbed polyimide

被引:35
作者
Meister, R
Jérôme, B
机构
[1] FOM, Inst Atom & Mol Phys, NL-1098 SJ Amsterdam, Netherlands
[2] Univ Amsterdam, Inst Tech Scheikunde, NL-1018 WV Amsterdam, Netherlands
关键词
D O I
10.1021/ma980592u
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
We report second harmonic generation (SHG) measurements of rubbed and unrubbcd surfaces of the fluorinated main-chain polyimide PMDA/BDAF made from pyromellitic dianhydride (PMDB) and 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane (BDAF). Such rubbed polymers are commonly used as alignment materials for the nematic phases of liquid crystal display cells (LCD), although the rubbing process itself is not vet well understood. The SHG results are used to construct the full orientational distribution function of the noncentrosymmetric part of the polymer. This allows us to determine the preferred conformations of the polyimide at the surface and gives insight into the conformational changes of the polymer during rubbing.
引用
收藏
页码:480 / 486
页数:7
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