Side-chain polyesters and polyester hydrochlorides were synthesized from alpha-(bis(2-hydroxyethyl)amino)-omega-(4'-methoxy biphenyl-4-oxy) alkanes with different spacer lengths (Cn-diol, n = 6, 8, 10) and terephthaloyl chloride. Since N-substituted diethanolamine acts as a stronger acid acceptor than triethylamine or pyridine, polyester hydrochlorides are formed during polyesterification instead of polyesters. Polyesters can be prepared from a chloroform solution of polyester hydrochlorides by extraction of HCl. During the polyesterification, linear polymers as well as cyclic oligomers are formed. All polymers were analyzed by H-1 NMR, size exclusion chromatography (SEC), differential scanning calorimetry (DSC), X-ray spectroscopy (XND) and polarizing optical microscopy (POM). Polyesters and polyester hydrochlorides differ greatly in solubility and thermal properties. Although no liquid crystalline phase transitions were detected for either kind of polymer, an ordered structure was observed in XRD experiments for both polymers and was ascribed to a crystal smectic E phase. (C) 2003 Elsevier Ltd. All rights reserved.