Influence of intermolecular interactions on phase behaviour and miscibility of para‐linked aromatic polyesters with polycarbonate and mechanical properties of the blends

Abstract

The synthesis of aromatic liquid-crystalline polyesters soluble in common organic solvents is described. The polyesters carry methyl, tert-butyl, phenyl and 4-biphenyl substituents. The polyesters with biphenyl substituents have an isotropization temperature below 300 "C. Blends of these polyesters with polycarbonate show one glass transition temperature in differential scanning calorimetry whereas transmission electron microscopy indicates a homogeneous dispersion of the polyester in the polycarbonate, but not on a molecular level. The moduli of the components of the blends are additive. Properties of pure polyestersPolyesters 1-3 (Scheme 1) were synthesized by a melt polycondensation using the acyl chlorides of the corresponding terephthalic acids and a substituted hydroquinone. a) Present address: Zentrale Polymerforschung,