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The influence of substituents on the orientational behaviour of novel azobenzene side‐chain polyesters
Author(s) -
Zebger Ingo,
Kulinna Christian,
Siesler Heinz W.,
Andruzzi Fulvio,
Pedersen Marianne,
Ramanujam P. S.,
Hvilsted SØRen
Publication year - 1995
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19950940114
Subject(s) - azobenzene , polyester , side chain , chain (unit) , polymer chemistry , materials science , chemistry , polymer science , organic chemistry , polymer , physics , astronomy
Abstract A series of new mesogenic azobenzene propanediols with nitro, methoxy, cyano and no substituent have been synthesized and their mesomorphic behaviour mapped. The diols are employed in a melt transesterification with diphenyl tetradecanedioate to produce side‐chain polyesters with high molar masses. Diols and polyesters have similar UV‐visible spectra reflecting the acceptor character of the substituent. Polarization FTIR spectroscopy has been used to determine the mesogenic order parameter for the polyesters with different substituents at four laser irradiation wavelengths (413, 458, 488 and 515 nm). Diffraction gratings in thin polyester films have been recorded through polarization holography. Cyano and unsubstituted azobenzene polyesters are shown to exhibit the highest diffraction efficiencies on the order of 13%.