Liquid crystalline polymers VIII:thermotropic liquid crystalline poly(hydrazone-ether)s containing bis-thiophene linked to the main chain through spacers of various lengths

摘要

A new series of poly(hydrazone-ether)s was synthesized from 3,4-dimethylthieno 2,3-b thiophene-2,5-dicarbohydrazide,II and 4,4'-diformyl-alpha,omega-diphenoxyalkanes or 4,4'-diformyI-2,2'-dimethoxy-alpha,omega-diphenoxyalkanes.The inherent viscosities of the polymers were in the range 0.22-0.56 dig~(-1).Majority of the polymers were soluble in concentrated H2SO4.Their thermotropic liquid crystalline properties were examined by DSC,an optical polarizing microscopy using a hot stage and thermo-gravimetric analyses.The polymers exhibited almost thermotropic liquid crystalline properties.In most cases,the mesophases extended up to 430°C,where thermal decomposition prevented further observation.