Synthesis of highly branched sulfonated polymers and the effects of degree of branching on properties of branched sulfonated polymers as proton exchange membranes

摘要: Abstract Branched sulfonated polymers exhibit excellent properties as proton exchange membranes (PEMs). However, very few highly branched are reported PEMs. The polymer, including the method to increase degree of branching (DB) and effects DB on PEMs, should be further studied. In this work, novel poly(fluorenyl ether ketone sulfone)s with different value synthesized by direct polycondensation reactions from bisphenol fluorene (A2), 4,4′-difluorobenzphenone, 1,3,5-tris(4-(4-fluorophenylsulfonyl)phenyl)benzene (B3-3) 4,4′-difluorodiphenyl sulfone. highest 10% agent is obtained using B3-3 monomer. discussed. It found that B3 scaffold long hard arms can effectively value. properties, oxidative stability, conductivity, water uptake, swelling ratio, thermal mechanical property microstructure, investigated. With increasing value, stability conductivity remarkably, but ratio tensile strength decrease slowly. membrane (10%) exhibits high (0.42 S cm−1) (327 min), well relatively low (16.2%) at 80 °C.