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Linearly polarized ultraviolet photoreaction of photocrosslinkable polymers comprising the p-phenylenediacrylate group and photoalignment control of liquid crystals on the resultant film

✍ Scribed by Nobuhiro Kawatsuki; Imin Sai; Tohei Yamamoto


Publisher
John Wiley and Sons
Year
1999
Tongue
English
Weight
180 KB
Volume
37
Category
Article
ISSN
0887-624X

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✦ Synopsis


We present (1) the linearly polarized (LP) ultraviolet (UV) photoreaction of block copolyesterethers comprising a hard segment of polyester and soft segment of poly(tetramethylene ether) (PTMG) and (2) the alignment behavior of liquid crystals (LCs) on the resultant photoreacted polymer films. Two kinds of copolyesterethers with different polyester segments of poly(hexamethylene p-phenylenediacrylate) (1a) or poly(hexamethylene p-phenylenediacrylate)-co-poly(hexamethylene 1,4-dibenzoate) (1b) were used in this study. The LP-UV irradiation resulted in a negative optical anisotropy for both polymer films, and a homogeneous photoalignment of LCs was achieved on the photoreacted polymer film. The LC alignment was perpendicular to the electric vector of the incident polarized light for 1a, whereas a reversion of the alignment from parallel to perpendicular was observed for 1b, depending on the irradiation doses.