Polyimides based on 3-amino-5-(4-aminophenoxy)diphenyl ether

Aromatic phenoxy-substituted polyimides were prepared by the reaction of 3-amino-5-(4-aminophenoxy)diphenyl ether with dianhydrides of a number of aromatic tetracarboxylic acids. Effect of the structure of the prepared polymers on their major characteristics was studied. It was found that dianhydride-based polyimides containing hinge groups have large ''gaps'' between the glass transition and degradation temperatures, whereas high thermal stability remains invariable. Some of these polymers are well soluble in organic solvents. Calculated and experimental data show that, only in the case of polypyromellitimide, introduction of phenoxide groups markedly reduces the glass transition temperature. As the rigidity of polyimide chain decreases, phenoxide substituents cease to affect the glass transition temperature of the polymer.