Poly-2, 3, 5, 6-Pyridine Tetracarboxylic Acid Imide

Abstract

The thermal stabilities of the polyimides, which were prepared from 2, 3, 5, 6-pyridine tetracarboxylic acid and aromatic diamines in polyphosphoric acid have been stadied.
Polyphosporic acid was used as a condensation agent as well as a solvent for this reaction. The raection was carried out below 180°C, because the reactants decomposed and no polyimides were obtained above 220°C.
The presence of phoshorous in the polyimides prepared gave lower thermal stabilities. As these polimides have pyridine rings in the main chain, their thermal stabilities were lower than that of corresponding polypiromerit imides.