High performance polyimide-Yb complex with high dielectric constant and low dielectric loss

Novel polyimide-Yb complexes (PIYbCs) with high dielectric constant, low dielectric loss and low AC conductance were developed in this study. The PIYbCs were successfully prepared by thermal conversion from bipyrimidine contained polyamic acid with different amounts of Yb. The PIYbCs (molar ratio of Yb to bipyrimidine units=1:1) have shown high dielectric constant (above 150), low dielectric loss (below 0.04) and low AC conductance (lower than 7 x 10(-7)) at wide operational frequencies (100 Hz-100 kHz). The excellent dielectric properties could be well tuned by controlling the amount of polyimide complexing ytterbium (Yb) and obtained without sacrificing the mechanical properties and thermal stability. The excellent dielectric properties of PIYbCs can be attributed to the long-range and fast polaron delocalization among Yb (III) and the bipyrimidine units on the PI molecular backbones. The outstanding dielectric, mechanical and thermal properties make PIYbCs as promising candidate for high-technology electronic applications. (C) 2014 Elsevier B.V. All rights reserved.