Synthesis Of Sulfonated Fuel Cell Proton Exchange Membrane

Three kinds of polymers with different degree of sulfonation are synthesized in this thesis. 4, 4'-difluorodiphenylsulfone and 4, 4'-difluorodiphenylketone are sulfonated by 50 % sulfuric acid. A new biphenol monomer containing six-membered ring imide is synthesized by reaction of 1, 4, 5, 8-naphthelenetetracarboxylic acid dianhydride with 3-aminophenol or 4-aminophenol sodium. Sulfonated poly(arylene ether sulfone) containing six-membered ring imide with different degree of sulfonation are prepared by direct polymerization of biphenol containing six-membered ring imide, disodium 4, 4'-difluoro-3, 3'-disulfonate-1, 1'-diphenylsulfone and 4, 4'-difluorodiphenylsulfone. The monomers and polymers are characterized with ¹H-NMR, FT-IR. Their intrinsic viscosity values vary from 1.37 to 1.66 dL·g^-1. Their membranes with good qualities are cast from dimetheyl sulfoxide polymer solution.Sulfonated poly(arylene ether nitrile ketone) are prepared by direct polymerization of biphenol A, disodium 4, 4'-difluoro-3, 3'-disulfonate-1, 1'-diphenylketone and 2, 6-difluorobezonitrile. The polymers are characterized with ¹H-NMR, FT-IR. Their intrinsic viscosity values vary from 1.16 to 2.93 dL·g^-1. Their yellowy membranes with good qualities are cast from dimetheyl sulfoxide polymer solution.Sulfonated poly(arylene ether ketone sulfone) are prepared by direct polymerization of biphenol A, disodium 4, 4'-difluoro-3, 3'-disulfonate-1, 1'-diphenylsulfone and 1, 3-(4-difluorophenyl)benzene. The polymers are characterized with ¹H-NMR, FT-IR. Their intrinsic viscosity values vary from 0.27 to 1.88 dL·g^-1. Their yellowy membranes with good qualities are cast from dimetheyl sulfoxide polymer solution.The solubilities of these three kinds of sulfonated polymers are tested. All of sulfonated polymers can dissolve in polar aprotic solvents and can easily be processed. Furthermore their mechanical properties are determined, and the tension strength at break vary from 53.29 to 92.42 MPa. These mechanical properties are good for the need of proton exchange membrane. Finally, the water uptake, swelling ratio and ion-exchange capacity of polymers are measured, and the values increase with the degree of sulfonation.