Highly transparent and organosoluble polyimides derived from 2,2′-bis[4-(5-amino-2-pyridinoxy) phenyl] propane

Two new isomers containing pyridine ring diamine monomers, 2,2′-bis[4-(5-amino-2-pyridinoxy)phenyl] propane (1b) and 2,2′-bis[4-(6-amino-3-pyridinoxy)phenyl] propane (2b), were prepared via a simple nucleophilic reaction of 2-chloro-5-nitropyridine and 5-bromo-2-nitropyridine with bisphenol A in the presence of potassium carbonate, respectively. A series of polyimides (PIs) were obtained from the heterocyclic diamine with various commercially available aromatic dianhydrides via the conventional two-step method. These obtained PIs were investigated in aspects of their solubility, thermal, mechanical, and optical properties for studying the effects of the heteroaromatic rings into the main chain. At the same time, the impact of the two isomers introduced into the PI was discussed in detail.