INTEMA   05428
INSTITUTO DE INVESTIGACIONES EN CIENCIA Y TECNOLOGIA DE MATERIALES
Unidad Ejecutora - UE
artículos
Título:
Influence of Chromophore Concentration and Network Structure on the Photoorientation Properties of Crosslinked
Autor/es:
R. FERNÁNDEZ; I. MONDRAGON; M. GALANTE; P. OYANGUREN
Revista:
JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS
Editorial:
John Wiley & Sons Inc.
Referencias:
Año: 2008
ISSN:
0887-6266
Resumen:
An azo prepolymer (TAZ) was synthesized by reaction between Disperse
Orange-3 (DO3) and diglycidyl ether of bisphenol A (DGEBA). Selected amounts of
TAZ were blended with DGEBA and cured with an aliphatic diamine, either metaxilylenediamine
(MXDA) or polyetheramines (Jeffamine D series). The photoinduced
anisotropy and optical storage properties in two series of crosslinked epoxy-based azo
polymers with different architectures and chromophore contents (from 3 to 24 in
weight) have been investigated. Measurements of the birefringence (n) induced with
linearly polarized 488 nm light show that the n values increases with DO3 weight
fraction. Networks with the same chromophore concentration but different backbones
exhibit similar levels of induced anisotropy under the same irradiation conditions. The
remaining birefringence and relaxation times are influenced by the molecular weight
between crosslinks (Mc ) of networks. Higher Mc is reflected in shorter relaxation
times and lower remaining birefringence. In terms of the level of induced dichroism
measured on relaxed films, it was found an agreement with the remaining anisotropy.n) induced with
linearly polarized 488 nm light show that the n values increases with DO3 weight
fraction. Networks with the same chromophore concentration but different backbones
exhibit similar levels of induced anisotropy under the same irradiation conditions. The
remaining birefringence and relaxation times are influenced by the molecular weight
between crosslinks (Mc ) of networks. Higher Mc is reflected in shorter relaxation
times and lower remaining birefringence. In terms of the level of induced dichroism
measured on relaxed films, it was found an agreement with the remaining anisotropy.n values increases with DO3 weight
fraction. Networks with the same chromophore concentration but different backbones
exhibit similar levels of induced anisotropy under the same irradiation conditions. The
remaining birefringence and relaxation times are influenced by the molecular weight
between crosslinks (Mc ) of networks. Higher Mc is reflected in shorter relaxation
times and lower remaining birefringence. In terms of the level of induced dichroism
measured on relaxed films, it was found an agreement with the remaining anisotropy.Mc ) of networks. Higher Mc is reflected in shorter relaxation
times and lower remaining birefringence. In terms of the level of induced dichroism
measured on relaxed films, it was found an agreement with the remaining anisotropy.