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Dynamics of the photo‐induced orientation and relaxation of new polymethacrylates containing carbazolyl and azobenzene pendant groups
Author(s) -
Maertens Christophe,
Dubois Philippe,
Jerôme Robert,
Blanche PierreAlexandre,
Lemaire Philippe C
Publication year - 1999
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/(sici)1097-0126(199903)48:3<205::aid-pi92>3.0.co;2-l
Subject(s) - azobenzene , methacrylate , materials science , relaxation (psychology) , glass transition , copolymer , alkyl , polymer chemistry , azo compound , polymer , kinetics , methyl methacrylate , birefringence , thermodynamics , chemistry , composite material , organic chemistry , optics , physics , psychology , social psychology , quantum mechanics
Polarized‐light‐induced birefringence has beeninvestigated in copolymers of [ω‐( N ‐carbazolyl)alkyl methacrylate] and[2,5‐dimethylphenyl‐[(4‐nitrophenyl)azo]phenoxyalkyl methacrylate]. Optical properties of the side‐chain copolymers have been compared with materials in which the azo‐dye was merely dispersed in a poly[ω‐( N ‐carbazolyl)alkyl methacrylate] matrix. Increasing the temperature of the film has a dramatic depressive effect on the maximum of photo‐induced orientation near and above the glass transition temperature ( T g ) region, while its effect was restricted under this temperature. Kinetics of the photo‐orientation and the thermal relaxation as a function of temperature have been analysed by a biexponential model based on two rate constants. The universal Williams–Landel–Ferry (WLF) theory has been used to correlate the writing process and relaxation relative time constants with the relative temperature, i.e. T − T g . The validity of this model for the studied materials leads to the assumption that photo‐orientation and relaxation processes are mainly dependent on the free volume in the polymer matrix. This hypothesis has been assessed in the case of [11‐( N ‐carbazolyl)undecyl methacrylate]‐based materials. © 1999 Society of Chemical Industry