Blue light-emitting polynaphthaleneimides

Aromatic copolyimides have been prepared by solution polycondensation reaction of different aromatic diamines having preformed 1,3,4-oxadiazole ring with a mixture of naphthalene tetracarboxylic dianhydride and tetramethyl-disiloxane-[1,3-bis(4´-phthalic anhydride)]. Most of these copolymers possess good solubility in polar aprotic solvents and can be processed into thin coatings with a very strong adhesion to the glass support. The thermal stability and glass transition temperature of these copolyimides were measured and compared with regard to the influence of naphthalene and tetramethyldisiloxane units on these physical properties. All the polymers emitted an intense blue colour light upon irradiation with UV light.