Orientational Ordering of Dyes in the Glassy State of Liquid-Crystalline Side Group Polymers

Abstract
Liquid-crystalline side group copolymers containing dyes can be macroscopic-ally oriented and the orientation can be locked-in below the glass transition temperature. The order parameters of anthraquinone dyes and a trisazo dye in nematic and smectic glasses were determined by optical absorption measurements. The dyes have higher degrees of order in the smectic glass than in the nematic glass. A comparison of order parameters of covalently bonded dyes with order parameters of monomeric dyes dissolved in the corresponding homopolymers demonstrates the influence of covalently anchoring the dye to the polymer.