FTIR
and UV-visible spectroscopy studies of thiol-ene / E7 composites showing
nanodispersions: Curing kinetics and Electro-optical properties
Réda Benmouna1,*,
Vincent Rachet2,
1.
University Aboubakr Belkaid, Faculty of
Sciences, Department of Physics, Tlemcen BP119,
2. Thales Research & Technology, Domaine
de Corbeville, F-91404 Orsay
Cedex,
3. Laboratoire
de Chimie Macromoléculaire (UMR CNRS 8009), Bâtiment C6, Université des
Sciences et Technologies de Lille, F-59655 Villeneuve d’Ascq Cedex, France.
Polymer
Dispersed Liquid Crystals exhibiting nanosized
droplet dispersions and prepared from thiol-ene
monomer / E7 liquid crystal systems were investigated. Photocured
samples were prepared according to the method of polymerization induced phase
separation using a standard halogen bulb light source in the presence of photoinitiators. FTIR spectroscopy was used to study the
kinetics of polymerization by monitoring the rate of conversion of the thiol S-H bond at 2570cm-1 and the allylic double bond C=C at 1647cm-1. With the
help of UV-visible spectroscopy, we investigated the spectral transmission of
these materials as a function of composition and curing conditions. A Fabry-Perot cell was used to explore the reflection
properties in the unaddressed and addressed states. A shift in the interferometric pattern corresponding to an increase in the
material birefringence was found and analysed in terms of the field strength and
frequency.
Keywords: PDLC, nanosized droplets, kinetics, spectral reflectivity, electro-optical response.
* To whom correspondence should be addressed
University Aboubakr
Belkaid, Faculty of Sciences, Department of Physics, Tlemcen BP119,
Email: red_benmouna@mail.univ-tlemcen.dz;
mobil. +213 7 96 03 54 ; Fax. +213 43 28 64 80