FULLY AROMATIC LIQUID-CRYSTALLINE POLYESTERS OF PHENYL-SUBSTITUTED 4,4'-BIPHENOLS AND 1,1'-BINAPHTHYL-4,4'-DIOL WITH EITHER 2-BROMOTEREPHTHALIC ACID OR 2-PHENYLTEREPHTHALIC ACID

Fully aromatic, thermotropic homopolyesters, derived from either phenyl-substituted 4,4'-biphenols or 1,1'-binaphthyl-4,4'-diol and 2-bromoterephthalic acid or 2-phenylterephthalic acid, were prepared by acidolysis condensation polymerization reactions and characterized for their liquid crystalline (LC) properties. The solubility behavior of these substituted homopolyesters in common organic solvents had also been investigated. The two homopolymers of substituted biphenols with 2-phenylterephthalic acid were soluble in common organic solvents. All of the polyesters had lower T(m)/T(f) values than those of respective unsubstituted homopolymers, as expected, and formed nematic LC phases which persisted up to 400-degrees-C, except those of phenyl-substituted biphenols with 2-phenylterephthalic acid. The homopolymer of 3-phenyl-4,4'-biphenol with 2-phenylterephthalic acid formed a nematic phase at or above 150-degrees-C and showed a T(i) at 290-degrees-C. That of 3,3'-bis(phenyl-4,4'-biphenol with 2-phenylterephthalic acid also formed a nematic phase at or above 200-degrees-C and also showed a T(i) at 280-degrees-C. They had glass transition temperatures, T(g), in the range of 133-151-degrees-C and high thermal stabilities in the range of 445-485-degrees-C, respectively.