Studies on thermotropic liquid crystalline polymers: 4. Synthesis and properties of poly(ether ester amide)s

Abstract

The thermotropic liquid crystalline behaviour of a series of aliphatic-aromatic poly(ether ester amide)s, which were prepared by direct polycondensation, was observed. Poly(ether ester amide)s I were prepared from 4,4′-diacrylic acid-α,ω-diphenoxyalkanes and 4-aminophenol or 4-amino-3-methylphenol in the presence of diphenylchlorophosphate (DPCP) and pyridine. Poly(ether ester amide)s II were prepared from 4,4′-dicarboxy-α,ω-diphenoxyalkanes and 4-aminophenol or 4-amino-3-methylphenol in the presence of DPCP and pyridine. The phase behaviour of the polymers was studied by differential scanning calorimetry and optical polarizing microscopy equipped with a heating stage. Poly(ether ester amide)s I exhibit thermotropic liquid crystalline characteristics, except in cases where methoxy or ethoxy groups were introduced into the benzene ring. All of the poly(ether ester amide)s II exhibit thermotropic liquid crystalline behaviour as observed by optical polarizing microscopy.