THERMOTROPIC POLYAMIDES CONTAINING THE BENZOPHENONE UNIT

The synthesis and structure-property relationship of fully aromatic ho mo- and copolyamides are described. They all contain the 3,4'-substitu ted benzophenone and diphenyl ether moiety in the main chain. The synt hesis of the polyamides was performed at low temperatures with silylat ed aromatic diamines and aromatic acid chlorides. The polymers possess good solubility in dipolar aprotic solvents. They display thermotropi c liquid crystalline properties. Based on results obtained by means of polarization microscopy, X-ray scattering, and molecular dynamics sim ulation a rather unusual structure is proposed. It consists of a super lattice composed alternatingly of smectic B layers and amorphous layer s. The formation of smectic B layers is untypical for main-drain LC po lymers without aliphatic spacers.