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Abstract
In continuation of earlier work, more polyesteramide systems with azo central linkage are synthesized and studied to evaluate the effect of chemical constitution on mesogenic polymers. Polymeric azo mesogens (I) are obtained by condensing substituted 4- amino-4′-hydroxy azobenzenes with different diacid chlorides.
Mono and di-substituted azobenzene moieties were incorporated in the polymer system - I. The diacid moiety was changed. The diacid moiety obtained from l, 2-bis (4′- carboxy phenoxy) ethane and 1, 4-bis (4′-carboxy phenoxy) butane was conducive to mesomorphism and the polymers exhibited nematic phases. p-Phenylene, m-phenylene and adipoyl moieties were not conducive to mesomorphism. The lateral substituents affect the solid-mesogenic transition temperatures markedly. The polymers were characterized by elemental analysis and IR spectra. Model compounds were prepared to understand the mesogenic behavior of polymers. Visible spectra and TGA studies were carried out for some of the mesogenic polymers.