Supramolecular main-chain liquid crystalline polymers with competitive hydrogen bonding: Inclusion of structurally analogous hydrogen bond acceptors and the effects on liquid crystallinity

A series of liquid crystalline supramolecular copolymers formed through hydrogen bonding has been created. These polymers composed of bis-benzoic acids and two of pyridyl species- a small rigid bispyridyl capable of forming a mesophase and a small, flexible bis pyridyl non-mesogenic disruptor species. It was found that the polymers display monotropic nematic character at high concentrations of disruptors – up to 75% inclusion. Smectic phases were observed in loadings up to 50%. It is believed that the structural similarities between the mesogenic and non- mesogenic acceptors contributes significantly to the enhanced stability of the liquid crystalline phases at high composition.