SYNTHESIS AND BLUE-LIGHT-EMITTING CHARACTERISTIC OF ROD-LIKE POLY(4,4'-BIPHENYLENE PYROMELLITIMIDE) WITH FURYL SIDE-GROUPS

A new 2,2'-bis(furyl)benzidine (FurylBZ) with a well-defined conjugati on length was synthesized, and its polyimide was prepared through ther mal imidization of the poly(amide acid) obtained from the polymerizati on with pyromellitic dianhydride. FurylBZ monomer and its polyimide fi lm were characterized to exhibit intense blue light emission with a re latively narrow peak width in the photoluminescence. The relative fluo rescence quantum yield was measured at room temperature to be 0.52 for FurylBZ in 1,4-dioxane and 0.074 for the polyimide in films. The poly imide was thermally stable up to 400 degrees C. The polyimide is amorp hous, due to the bulky furyl side groups. However, the polyimide chain s were favorably aligned in the film plane due to the rod-like chain c haracteristic. (C) 1998 Elsevier Science Ltd. All rights reserved.