Analysis of polymerization with photo-Fries rearrangement in liquid crystal displays

Abstract

Polymer-sustained-alignment liquid crystal display has high potential for low power consumption, fast response, and low level of image sticking. In this study, we clarified the mechanism for a formation of a polymer layer with polymerization of the monomer 2,6-dimethacryloyl-oxy-naphthalene (2,6-DMANaph) without initiators under UV light exposure. Experimental results revealed that the polymerization of 2,6-DMANaph occurred with the generation of radicals from the monomer as reactive intermediates of a photo-Fries rearrangement. It took about 20 min for 0.5 wt. of the monomer in the LC to convert to the polymer, indicating that the generation of the radicals derived from the reactive intermediates of the photo-Fries rearrangement is effective for the formation of the polymer layer. Voltage holding ratio of the LC cell having the polymer layer formed from the monomer 2,6-DMANaph was over 99, which was comparably high value. © 2013 AIP Publishing LLC.