Synthesis And Characterization Of Sulfonated Poly(arylene Ether Phosphine Oxide)s Proton Exchange Membrane Containing Bisphenol And Phenolphthalein Structure

The proton exchange membrane is one of the core components of proton exchange membrane fuel cells.At present,widely used commercial membrane is Nafion membranes.However,Nafion membranes can not meet its further commercial application due to the disadvantages of high cost,high methanol permeability and a sharp drop in proton conductivity under high temperature and low humidity.The sulfonated aromatic polymer proton exchange membrane is the current research hotspot of PEMFC and he sulfonated poly(arylene ether phosphine oxide)s are a kind of high performance polymer,and the phosphine group possess the oxidation resistance,the water retention and the adhesion with organic or inorganic particles etc.,so the polymer proton exchange membrane has excellent overall performance.In this paper,High-IEC sulfonated poly(arylene ether phosphine oxide)polymer proton exchange membrane containing bisphenol A and bisphenol AP were synthesized by direct polycondensation.Comparing the performance of the two series,the comprehensive performance of the sPOBAP-x membranes is better than that of the sPOBA-x membranes.By adjusting the structure and hydrophobicity of the hydrophobic group,the dimensional stability and thermal stability of the proton exchange membrane can be improved,thereby improving the overall performance.For example,the sPOBAP-100 polymer film possessed a water absorption rate of 24.6%,a swelling ratio of 16.2% and a proton conductivity of 0.061 S/cm at 80 °C.Secondly,the proton exchange membrane of phenolphthalein-containing sulfonated poly(arylene ether phosphine oxide)s was synthesized by direct polycondensation method.Via introducing a large hydrophobic group structure,not only oxidation resistance,thermal stability and dimensional stability can be improved,but also the microstructure of the membranes can be adjusted to have a distinct hydrophilic hydrophobic phase separation structure,which further improveed the overall performance of the sulfonated poly(arylene ether phosphine oxide)s.For example,the water absorption of sPAEPP-100 film is only 33.1% at 80 °C,which is equivalent to that of Nafion 117 film;The swelling ratio is only 11.7%,which is about 1/2 of Nafion 117 membrane and the proton conductivity is as high as 0.11 S/cm equivalent to that of Nafion 117 membrane.