Studies on Proton Conductivity of Acid Doped Polybenzimidazole/Polyimide and Polybenzimidazole/ Polyvinylpyrrolidone Blends

摘要

Polybenzimidazole (PBI)/polyimide (PI) and PBI/polyvi-nylpyrrolidone (PVP) blends were prepared.All of these polymers are suitable for acid doping as a matrix because of the existence of the N-heterocycle in the polymers,which can eventually be used as proton conductors.The miscibility of PBI/PVP blend is confirmed by Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM),while the miscibility of PBI/PI is already reported in references.Temperature dependence of proton conductivity of acid doped PBI/PI and PBI/PVP blends are studied.As the temperature increases,proton conductivity of H_3PO_4 doped PBI/PVP blends increases.Temperature dependence of proton conductivity of the blends can still be fitted by a simple Arrhenius relation.The proton transport of the blend is similar to that of PBI.The methanol permeability of PBI/PI blends is also studied.Methanol permeability in PBI/PI,PI,and PBI membranes decreases with increasing methanol concentration.