Synthesis And Performances Of Poly(Arylene Ether Ketone Sulfone) Containing Azole For Proton Exchange Membrane

Due to the problems of energy crisis and environmental pollution,the development of clean,high efficient and pollution-free energies has been becoming more and more important.Polymer electrolyte membrane fuel cells?PEMFC?have been extensively explored for the next generation of energy conversion device,largely due to their low pollution,high power density and high energy conversion efficiency.As the key module of PEMFC,the proton exchange membrane?PEM?affects the application of PEMFC immediately.Perfluorosulfonic acid membranes,such as DuPont's Nafion,are the most widely used proton exchange membranes?PEMs?,which have high proton conductivity and extraordinary chemical stability at a moderate temperature.But high cost,high methanol permeability,and reduced proton conductivity at higher temperatures have limited their more broad use for practical applications.Therefore,new materials with high proton conductivity and appropriate cost should been reported to alternate Nafion.Sulfonated poly?arylene ether ketone sulfone??SPAEKS?is one of the most hopeful materials for PEMFC.SPAEKS possesses excellent mechanical property and thermal property,also it is very cheap.However,similar to Nafion,the proton conduction of SPAEKS depends on sulfonic acid groups.High proton conductivity generally have a high degree of sulfonation,leading to an excessive swelling ratio of membranes along with mechanical failure and a high fuel permeability.Therefore,the modifications of SPAEKS have been becoming very important.In this study,we prepared a novel sulfonated poly?arylene ether ketone sulfone?containing both triazole and sulfonic acid groups.The triazole groups are the proton donors and acceptors.At the same time,the interactions of triazole and sulfonic acid groups imply the new proton transfer points.The introduction of triazole groups promotes proton conductivity according to Grotthuss mechanism at high temperatures or low relative humidity.The highest proton conductivity of 0.166 S cm^-1 has been observed from SPT-4 membrane at 120 oC,and it is larger than that of Nafion.In order to improve the methanol-resistance and proton conductivity,the sulfonated poly?arylene ether ketone sulfone?cross-linked hybrid membrane containing triazole-grafted polysiloxane and sulfonic acid groups?AMSP/GT?was prepared by via a previously reported sol-gel process with little modification.The cross-linked network structures made the AMSP/GT membranes exhibit favorable dimension stability,thermal property,oxidative stability and methanol permeability.At 60 oC,the methanol permeability coefficient of AMSP/GT-30 membrane was only 9.95×10^-7 cm² s^-1.Particularly,the introduction of triazole group led to the proton conductivity of AMSP/GT membranes increased obviously,when the temperature was above 80 oC.The highest proton conductivity of AMSP/GT-30 membrane could reach values as high as 0.106 S cm^-1 at 120 oC.All the results indicated that the AMSP/GT membranes will be potential PEMs for fuel cell applications.