Supramolecular main chain liquid crystalline polymers utilizing azopyridine derivatives

Abstract

A series of main chain liquid crystalline polymers were formed through intermolecular hydrogen bonding between a functionalized bisazopyridine phenol and aromatic bisacids. The behaviour of these complexes was studied through differential scanning calorimetry and thermal polarizing optical microscopy. The presence of the hydrogen bonds was confirmed through infrared spectroscopy. These complexes formed thermotropic mesophases. The phases were determined to be nematic in nature from the schlieren textures of the optical micrographs. As the length of flexible spacer groups separating the mesogenic portions increased, the clearing temperatures of the mesophases decreased. As the length of the rigid component increased, the clearing temperature increased. A new bisacid species based on 2‐hydroxy‐6‐naphthoic acid was used to increase clearing temperatures while remaining within an acceptable temperature window.

Acknowldegements

The authors would like to thank Research Corporation (CC5890), the Office of Research Services and Sponsored Programs at Georgia Southern University and The Office of Research and sponsored programs at the University of Wisconsin‐ Eau Claire for financial support of this work. The authors would also like to thank Larry David, Gregory Corradino, Thomas O'Lenick and Mark Wehunt for their contributions.