Study of the photo-polymerization kinetics of PDLC composite systems based on acrylic copolymer and liquid crystal
Authors/Creators
- 1. Laboratory of Research on Macromolecules, University of Tlemcen, Faculty of Science, Department of Physics, BP 119 rocade pole, Tlemcen, 13000, Algeria
Description
PDLC (polymer Dispersed Liquid Crystals) composite materials [1], consist of a dispersion of micro or nano-droplets of liquid crystal in a polymer matrix [2]. These composites are of considerable interest for their vous applications such as opacity-controlled glazing, display screens and temperature maps in medicine [3,7]. In this work, these systems are elaborated using the polymerization-induced phase separation (PIPS) method under UV radiation [8]. The initial mixtures are composed of the monomer Ethylene Glycol Phenyl Ether Methacrylate (EGPEM), Polypropylene Glycol Di-Acrylate (PPGDA900) crosslinking agent and the nematic liquid crystal 5CB, in the presence of the photoinitiator Darocur 1173 at different mass percentages. Characterization by infrared spectroscopy (FTIR) [9] has shown that the presence of LC decreases the speed of the photopolymerization reaction [10]. The mass percentage in photoinitiator increases the conversion rate and thus the speed of polymerization