Title :
Study of the relaxation process in a side-chain copolymer functionalized with the nonlinear optical chromophore DR13
Author :
Ribeiro, P.A. ; Balogh, D.T. ; Giacometti, J.A.
Author_Institution :
Dept. de Fisica, Univ. Nova de Lisboa, Monte Caparica, Portugal
Abstract :
A side-chain copolymer of methylmethacrylate and a methacrylate functionalized with the nonlinear optical, NLO, chromophore 4-[N-ethyl-N-(2hydroxyethyl)]-2´-[chloro-4-nitroazobenzene], DR13, was investigated. The isothermal decay of the electro-optic coefficient, r 13, was fitted with the Kohlraush-Williams-Watts, KWW, stretched exponential allowing temperature, TG, to be determined. Above TG, τ was obtained from dielectric loss measurements also using the KWW equation. It was concluded that such relaxation, associated with the chromophore, follows the a relaxation of the copolymer. Its dependence on temperature has the Arrhenius behavior below TG and the Vogel-Fulcher-Tammann (VFT) behavior above T G. An attempt was also made to investigate the applicability of the Dissado-Hill model to account for the r13 decay
Keywords :
dielectric losses; dielectric relaxation; electro-optical effects; nonlinear optics; optical polymers; polymer blends; Arrhenius behavior; Dissado-Hill model; Kohlraush-Williams-Watts stretched exponential; Vogel-Fulcher-Tammann behavior; dielectric loss; dielectric relaxation; electro-optic coefficient; isothermal decay; methylmethacrylate; nonlinear optical chromophore DR13; side-chain copolymer; temperature dependence; Dielectric loss measurement; Dielectric losses; Dielectric measurements; Dielectric substrates; Equations; Glass; Loss measurement; Nonlinear optics; Temperature; Wavelength measurement;
Conference_Titel :
Electrets, 1999. ISE 10. Proceedings. 10th International Symposium on
Conference_Location :
Athens
Print_ISBN :
0-7803-5025-1
DOI :
10.1109/ISE.1999.832145
