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Syntheses and characteristics of polyimides for the applications to alignment film for liquid crystal display
Author(s) -
Lee Sang Jin,
Ha ChangSik,
Lee Jin Kook
Publication year - 2001
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.2086
Subject(s) - rubbing , polyimide , zigzag , liquid crystal , materials science , planar , molecule , thermogravimetric analysis , fourier transform infrared spectroscopy , polymer , side chain , crystallography , infrared spectroscopy , polymer chemistry , chemistry , chemical engineering , organic chemistry , nanotechnology , composite material , layer (electronics) , geometry , optoelectronics , mathematics , computer graphics (images) , computer science , engineering
In this work, several polyimides (PIs) containing diphenyl ether group were synthesized and characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis. The relationship between the surface structures and the molecular chain conformations of the PIs, whether helical or zigzag, was discussed. The effects of the molecular chain conformations of the PIs on the pretilt angles of liquid crystal molecules were systematically investigated. The surface orientations of polyimides whose chains adopt zigzag and planar conformations were less improved by rubbing treatment than those of polyimides whose chains adopt helical and nonplanar conformations, because the polyimide chains of zigzag and planar conformation are easily packed. The polyimides, whose chains adopt helical and nonpolar conformations, gave larger pretilt angles than the polyimides whose chains adopt zigzag and planar conformations. The pretilt angles measured under the condition of rubbing depth of 0.5 mm were smaller than under the condition of rubbing depth of 0.3 mm. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2365–2371, 2001