Synthesis and characterization of new polyesters containing imidazolidine-2,4,5-trione rings

New polyesters containing both aliphatic and aromatic units in the backbone were prepared by the reaction of 4,4'-[hexane-1,6-diyl bis(2,4,5-trioxoimi dazolidine-1,5-diyl)]dibenzoyl chloride (2) with various biphenols (4a-4f). A model compound diethyl-4,4'-[hexane-1,6-diyl bis(2,4,5-trioxoimidazolidi ne-1,5-diyl)]dibenzoate (3) was synthesized by the reaction of monomer (2) with ethanol. Monomer (2), model compound (3) and polymers (5a-5f) were con firmed structurally by IR and H-1-NMR spectroscopy and characterized by the ir viscosities, solubilities and thermal properties. A liquid crystalline b ehavior in the melting state was noticed for polymers containing hydroquino ne (5a) and 1,5-naphthoxy (5b) units in the backbone. (C) 2000 Elsevier Sci ence Ltd. All rights reserved.