IR dichroism study of orientational ordering of liquid-crystalline acrylates

Orientational ordering of four liquid-crystalline acrylates induced by the surface of KBr plates over a wide temperature range was studied by the IR d ichroism technique. IR spectra of homogeneously aligned samples were used t o calculate the angles between the direction of the transition moment for a series of vibrations of the mesogenic fragment and its long axis. A method for calculation of the homeotropic orientation parameter of molecules was proposed. The orientation parameters of homogeneously and homeotropically a ligned samples in the nematic, smectic (A), and chiral smectic (I and H) ph ases were calculated. The in situ photopolymerization of acrylates in the s mectic phases occurs with retention of the orientational ordering in the po lymer films formed.