Can the Rigidity of a Side Chain Liquid Crystalline Polymer Backbone Influence the Mechanism of Distortion of Its Random-Coil Conformation

摘要

The relationship between the isotropization transition temperatures and the associated entropy changes of two series of side chain liquid crystalline polymers based on three different polymer backbones (polymethacrylate, polyacrylate and polymethyl-siloxane) and 4-methoxy-4'-hydroxy-alpha-methylstilbene (4-MHMS) and 4-hydroxy-4'-methoxy-alpha- methylstilbene (4'-MHMS) mesogenic side groups attached to the polymer backbone through different flexible spacers is discussed. In the case of polymers containing long flexible spacers, isotropization transition temperatures, which are mostly dictated by the side groups, are higher for polymers based on flexible backbones, suggesting that they provide the highest degree of order in the mesophase. Therefore, their mesophase should exhibit the lowest entropy and the highest entropy change of isotropization. Side chain, Liquid crystal polymers, Isotropization, Entropy, Isotropization temperature, Acrylates, Polymers. (mjm)