Supramolecular main-chain liquid crystalline polymers and networks with competitive hydrogen bonding: a study of rigid networking agents in supramolecular systems

A set of supramolecular liquid crystalline networks and polymers are synthesised and analysed utilising a bis-functionalised hydrogen bond donor, a rigid bis-pyridyl species and non-mesogenic rigid polyfunctional networking agents in tetra, tri and bi functionalities. Networks utilising the shorter bisacid eliminated nematic phases in concentrations of 62.5%, 55% and 57.5% loadings, respectively. Smectic phases were observed in inclusions of 10%, 5% and 15%, respectively. It is believed that the increased rigidity of the networking agents allows liquid crystalline phases to form at higher concentrations than would normally be expected. In addition, the presence of the smectic phase at 15% inclusion of the 2SBZ would seem to indicate the bi-functionalised species assists in the formation of the more complex, layered mesogenic phase.