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Enhanced, Perpendicular Liquid‐Crystal Alignment on Rubbed Films of a Coumarin‐Containing Polystyrene
Author(s) -
Kang Hyo,
Kwon KiSun,
Kang Daeseung,
Lee JongChan
Publication year - 2007
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200700270
Subject(s) - polystyrene , rubbing , polymer , coumarin , polymer chemistry , side chain , monomer , materials science , liquid crystal , perpendicular , copolymer , crystal (programming language) , chemistry , organic chemistry , composite material , optoelectronics , geometry , mathematics , computer science , programming language
Abstract We synthesized a series of polystyrene derivatives containing coumarin side groups using polymer analogous reactions. The liquid‐crystal (LC) alignment director for these polymer films was found to be perpendicular to the rubbing direction. The contrast ratio and anchoring‐energy values of these polystyrene derivatives were found to be much greater than those of polystyrene and poly(chloromethylstyrene), indicating that the coumarin side groups increase the aligning ability. For example, the anchoring energy of a polymer with 82 mol‐% of coumarin‐containing monomeric units, compared to polystyrene, is about 7 × 10 −5 J · m −2 and 1 × 10 −7 J · m −2 , respectively.