Synthesis and preparation of sulfonated hyperbranched poly(arylene ether sulfone)/poly(ether sulfone) blend membranes for proton exchange membranes

A series of sulfonated hyperbranched poly(arylene ether sulfone)s (SHPAESs) have been synthesized by aromatic nucleophilic substitution reaction of 1,1,1-tris(4-hydroxyphenyl)ethane (THPE), 4,4′-dichlorodiphenyl sulfone (DCDPS) and 3,3′-disulfonate-4,4′-dichlorodiphenyl sulfone (SDCDPS), and then the blend membranes of SHPAESs with sulfonated linear poly(ether sulfone) (SPES) (SHPAESs/SPES) have been prepared for proton exchange membrane. All the blends can be cast into tough membranes, and they are miscible in morphology confirmed by scanning electron microscopy. The thermal stability, mechanical property, oxidative stability, ionic exchange capacity (IEC), water uptake and proton conductivity of the blend membranes have been investigated. The results showed that the blend membranes have good thermal and mechanical properties, better stability in water comparing with the linear SPES membrane, and the other promising properties as a new proton exchange membrane for fuel cell application.

► A series of SHPAESs were synthesized by aromatic nucleophilic substitution reaction.
► We made SHPAES/SPES blend membranes and characterized their properties.
► Blend membranes are miscible and have characters of the globular and linear polymers.