Investigation of the individual components of polymer dispersed liquid crystals and their resulting effects on the electro-optic properties
The interactions of the components of polymer dispersed liquid crystals (PDLCs) were investigated using maleimide and vinyl ether monomers. Initially, the reaction between the maleimide and vinyl ether was investigated. Next, the liquid crystal was introduced into the system and the effects of the liquid crystal with respect to both energy transfer and chain transfer on the polymerization kinetics were investigated. The pre-polymerization phase behavior of mixtures of difunctional maleimides and vinyl ethers with cyano-multiphenyl liquid crystals has been investigated. This phase behavior, which is responsible for the phase separation properties of the liquid crystal during polymerization, is highly dependent upon the structures of the maleimide and the vinyl ether components. The electro-optical switching properties of the resultant polymer dispersed liquid crystalline matrices (PDLCs) are discussed in terms of the pre-polymerization phase behavior. With respect to the phase separation behavior, different temperatures of polymerization were investigated to observe the effect that the temperature had on the final properties of the PDLCs. The polymerization temperature ranged from just above phase separation to up to 40°C above the phase separation temperature.