Synthesis and study of poly(8‐hydroxyquinoline‐7,5‐diylethylene)

Poly(8‐hydroxyquinoline‐7,5‐diylethylene) (3) was prepared both by Friedel‐Craft's condensation of 8‐hydroxyquinoline (1) with 1,2‐dichloroethane (2) in the presence of anhydrous aluminium chloride and by condensation of 1 with ethylene glycol in the presence of an acid catalyst. The polymer samples were found to be insoluble in acetic acid, sulfuric acid, conc. hydrochloric acid, or formic acid. They were characterized by IR and UV spectra. Their molecular weights were determined by conductometric titration in pyridine. Viscometric studies were carried out in formic acid and in glacial acetic acid at 35°C. Solutions of the polymer samples in formic acid showed normal behaviour, whereas those in glacial acetic acid showed an abnormal behaviour. Various empirical relations were applied to correlate the viscosity data of solutions in glacial acetic acid with the appropriate concentration function. Aqueous acetic acid and simple electrolytes were used as solvents to supress the abnormal behaviour.