Synthesis and property of sulfonated poly(ether ether ketone) membrane

Sulfonated poly(ether ether ketone) (SPEEK) membranes with various degrees of sulfonation(DS) were prepared with H_2SO_4 (95%～98%) as sulfonating agent. The structure of the SPEEK was investigated by FT-IR and ~1 H NMR. The DS of the SPEEK was determined by using ~1 H NMR method and proton conductivity properties of the SPEEK membranes were studied.The proton conductivity of SPEEK membrane with 0.78 DS reached 5.8×10~(-2) S/cm at 115 ℃.The conductivity of SPEEK membranes was influenced by temperature and the activation energies for SPEEK membranes exceeded 25 kJ/mol at 25 ℃.