Polyarylates based on 3,4'-disubstituted benzophenones

New thermotropic aromatic poly(ketoesters) have been obtained by copolymerization of 3-hydroxy-4'-carboxybenzophenone (3,4'-HCBP) or of the isomeric 4-hydroxy-3'-carboxybenzophenone (4,3'-HCBP) with some commercial aromatic hydroxyacids. The polymers have been prepared both by direct polycondensation in solution and in bulk. Homopolymers of 3,4'-HCBP and 4,3'-HCBP melt to an isotropic liquid, while a nematogenic behaviour is shown by samples with a comonomer content higher than 30%. A preliminary investigation has been carried out to determine the influence of the liquid-crystalline phase on their transport properties