화학공학소재연구정보센터
Journal of Polymer Science Part B: Polymer Physics, Vol.50, No.13, 938-943, 2012
Effects of prepolymer structure in holographic polymer dispersed liquid crystal
Three different types of polyolspoly(ethylene glycol) (PEG), poly(propylene glycol) (PPG), and poly(tetramethylene glycol)with different molecular weights (Mn) were incorporated into the prepolymer structure, and the effects were examined with regard to the morphology and performance of holographic polymer dispersed liquid crystal. Among them, PEG showing the lowest glass transition temperature (Tg) exhibited the lowest threshold voltage (Vth), lowest operating voltage (Vop), and lowest diffraction efficiency with slow grating formation owing to its high viscosity of prepolymer mixture. The Tg decreased with increasing Mn because of the decreased crosslink density and hydrogen bonding, which reduced the anchoring strength, Vth and Vop. PPG400 gave Vth and Vop of approximately 7 and 24 V, respectively, with a contrast ratio of approximately 12. (C) 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012