Synthesis and blue light-emitting characteristic of rod-like poly(4,4 '-biphenylene pyromellitimide) with furyl side groups

Abstract

A new 2,2'-bis(furyl)benzidine (FurylBZ) with a well-defined conjugation length was synthesized, and its polyimide was prepared through thermal imidization of the poly(amide acid) obtained from the polymerization with pyromellitic dianhydride. FurylBZ monomer and its polyimide film were characterized to exhibit intense blue light emission with a relatively narrow peak width in the photoluminescence. The relative fluorescence 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 polyimide was thermally stable up to 400 degrees C. The polyimide is amorphous, due to the bulky furyl side groups. However, the polyimide chains were favorably aligned in the film plane due to the rod-like chain characteristic. (C) 1998 Elsevier Science Ltd. All rights reserved.