Liquid crystalline lonomers. I. Main‐chain liquid crystalline polymer containing pendant sulfonate groups

Liquid crystalline polymers containing sodium sulfonate groups pendant to the polymer backbone were synthesized by an interfacial condensation reaction of brilliant yellow, a sulfonate‐containing monomer, with 4,4′‐dihydroxy‐α,α′‐dimethyl benzalazine and a 50/50 mixture of sebacoyl and dodecanedioyl dichlorides. Polymers containing up to ca. 4 mol% brilliant yellow were characterized by elemental analysis and ultraviolet spectroscopy. The polymers were thermally stable to about 300°C, and they exhibited a broad nematic mesophase region of 70–100°C. The solution viscosity behavior in chloroform suggested that intramolecular associations of the sulfonate groups occurred at low polymer concentrations and intermolecular associations predominated at higher concentrations.