Soluble Polymers with Laterally Attached Oligophenyl Units for Potential Use as Blue Luminescent Materials

Abstract

New blue luminescent polyethers were prepared by interfacial polymerization of 2,5-diphenyl-, 2-biphenyl-, and 2,5-bis(biphenyl)hydroquinone diacetates with α,ω- dibromides. These polymers were soluble in common solvents, show liquid crystallinity in some cases, and can be melt processed at relatively low temperatures where they are thermally stable. Moreover their solid structure and corresponding properties (e.g. optical) can be controlled by judicious choice of the monomer unit. The synthesized polyethers were characterized by viscosimetry, gel permeation chromatography, thermal analysis, mechanical analysis, and UV−vis luminescence spectroscopy. The polymers show blue photoluminescence and have relatively low liquid crystalline transition temperatures, or they are amorphous depending on the symmetry of the substitution. The photoluminescent maxima were in the range 390−407 nm depending on the monomer structure. Free standing films were casted from solutions for some polymers, and in one case the mechanical properties were examined.