새로운 에폭시계 반응성 액정 단량체의 합성과 특성

New epoxy-based reactive mesogens (RM) containing aromatic ester as a mesogenic core and cationic photo-polymerizable epoxy groups on either terminal were synthesized, and their structure was characterized by 1H-NMR and IR spectroscopy. The liquid crystalline properties of these RMs were investigated by cross polarized microscope (XPM) and DSC, which revealed that TCN and TNI of 2MPBE were measured to be 82 and 195 ℃, respectively, while those of 4MPBE are 88 and 168 ℃, respectively. XPM observation confirmed that these liquid crystalline compounds show nematic phase with Schlieren texture. Using these RMs, retardation films were fabricated by photo-curing the spin cast mixture of RM and cationic photoinitiator (diphenyliodonium hexafluorophosphate, 10 wt%) at 88 ℃, and the retardation value was compared with that from commercial RM (RM257, Merck), which were 153.08 and 150.49 nm, respectively. From the film thickness and the retardation values, refractive index anisotropy (Δn) were calculated for the synthesized RM and RM257, which were 0.172 and 0.173, respectively.