Crosslinked proton exchange membranes were prepared based on sulfonated poly(ether ether ketone) (SPEEK) and diamine containing silicon (DMS).The crosslinked structure was confirmed by Fourier transform infrared spectroscopy (FTIR) and dissolution test.Thermal stability

mechanical properties and alternating current impedance measurements of crosslinked proton exchange membranes were conducted by using therogravimetric analyzer (TG)

universal material testing machine and electrochemical workstation.Methanol resistance performance

dimensional stability in water

water uptake

ion exchange capacity and proton conductivity were studied in detail.Mechanical properties

methanol resistance performance and dimensional stability of proton exchange membranes were enhanced obviously due to the crosslinking modification.Methanol permeability of SPEEK/DMS-0.5% was reduced from 5.79 10-5 cm2 s-1 to 9.42 10-6 cm2 s-1.Results of scanning electron microscope (SEM) observation showed the well dispersion state of DMS in SPEEK matrix.The properties comparisons were achieved between SPEEK/DMS crosslinked membranes and Nafion-117.The crosslinked proton membranes owned better comprehensive performance compared to Nafion-117.Methanol permeability of SPEEK modified with 20% DMS was 4.26 10-7 cm2 s-1

which was much lower than Nafion-117's 1.88 10-6 cm2 s-1.Moreover

the effective selectivity

tensile strength and Young modulus of SPEEK/DMS-20% crosslinked proton exchange membrane was 1.68

1.3 and 6.4 times of those of Nafion-117 respectively.