Phase diagrams of monomer and uv-cured difunctional-acrylate-nematic-liquid-crystal systems.
This paper deals with the thermal properties of systems made of the difunctional monomer 1,6-hexanedioldiacrylate (HDDA) and the low-molecular-weight liquid crystal E7. Experimental phase diagrams of uv-cured and uncured solutions of HDDA/E7 systems are established with a polarized optical microscope and a differential scanning calorimeter and the data analyzed within a theoretical formalism that combines the Flory-Huggins model of isotropic mixing and the Maier-Saupe model of nematic order. Ultraviolet-curing samples with a difunctional monomer such as HDDA leads to a crosslinked polymer network and consequently an elastic contribution to the free energy is introduced according to the Flory-Rehner theory of rubber elasticity. The amount of liquid crystal segregated is evaluated to assess the efficiency of the phase separation mechanism.
Roussel
Frédérick
F
Laboratoire de Thermophysique de la Matière Condensée, Equipe de l'UPRESA CNRS 8024, Université du Littoral Côte d'Opale, MREID, F-59140 Dunkerque, France. Frederick.Roussel@purple.univ-littoral.fr
Maschke
Ulrich
U
Buisine
Jean-Marc
JM
Coqueret
Xavier
X
Benmouna
Mustapha
M