Effect of the Orientation of the Ester Bonds on the Properties of Three Isomeric Liquid Crystal Diacrylates before and after Polymerization

Abstract

<p>Three isomeric liquid crystal (LC) acrylates 1,4-bis((4-((6-(acryloyloxy)hexyl)oxy)benzoyl)-oxy(benzene, ((6-(acryloyloxy)hexyl)oxy)-4-((4-((4-((6-(acryloyloxy)hexyl)oxy)benzoyl)oxy)benzoyl)oxy)-benzene, and bis(4-((6-(acryloyloxy)hexyl)oxy)phenyl) terephthalate were Synthesized. The orientation of the ester links with respect to the central phenyl ring has a strong influence on the phase, optical, and dielectric behavior of the monomers. The polymerization behavior of the isomers was found to differ. Changes occurring in the microstructure during polymerization were studied using X-ray diffraction. In order to obtain an understanding of the observed differences, the phase behavior and polymerization behavior of various mixtures were studied. The results of the experiments and the molecular modeling suggested that the associations between the molecules is the origin of the formation of observed LC phases and the strength of the interactions determine whether the microstructure is preserved during polymerization.</p>