Synthesis and characterization of polyacene quinone radical polymers with high-dielectric constant

Abstract

Polyacene quinone radical polymers (PAQRs) and their hydroxyl- or alkoxyl-modified derivates (HO-PAQR and RO-PAQR) were synthesized through the solid-state heating, the solution polymerization, and the improved process (pre-polymerization before solid-state heating). PAQRs synthesized by the improved process provided the higher yields than those from the other two methods. The high-dielectric constants were achieved for the PAQRs from the solid state and the improved process, due to the high polarization resulted from the existence of large amount of polar domains, which were the aggregation of the conjugated ladder-structured macromolecules with extended regions of associated π-orbital. The HO-PAQRs or RO-PAQRs showed good blending or solving features in polymer or solvent, but they were of low dielectric constants for the groups of hydroxyl and alkoxyl destroyed the planar conjugation of the associated π-orbital, and provided the steric hindrance to the formation of regular stacks of the conjugated macromolecules, which could produce huge polarization. The molecular and the aggregated structures of PAQRs with varied chemical modifications and from varied polymerization processes were confirmed by the analysis of X-ray, IR, TG, TEM and the dielectric measurement.