Preparation and properties of bisphenol A‐based sulfonated poly(arylene ether sulfone) proton exchange membranes for direct methanol fuel cell

Abstract

Novel bisphenol A‐based sulfonated poly(arylene ether sulfone) (bi A‐SPAES) copolymers were successfully synthesized via direct copolymerization of disodium 3,3′‐disulfonate‐4,4′‐dichlorodiphenylsulfone, 4,4′‐dichlorodiphenylsulfone, and bisphenol A. The copolymer structure was confirmed by Fourier transform infrared spectra and 1H NMR analysis. The series of sulfonated copolymers based membranes were prepared and evaluated for proton exchange membranes (PEM). The membranes showed good thermal stability and mechanical property. Transmission electron microscopy was used to obtain the microstructures of the synthesized polymers. The membranes exhibit increased water uptake from 8% to 66%, ion exchange capacities from 0.41 to 2.18 meq/g and proton conductivities (25°C) from 0.012 to 0.102 S/cm with the degree of sulfonation increasing. The proton conductivities of bi A‐SPAES‐6 membrane (0.10–0.15 S/cm) with high‐sulfonated degree are higher than that of Nafion 117 membrane (0.095–0.117 S/cm) at all temperatures (20–100°C). Especially, the methanol diffusion coefficients of membranes (1.7 × 10−8 cm2/s–8.5 × 10−7 cm2/s) are much lower than that of Nafion 117 membrane (2.1 × 10−6 cm2/s). The new synthesized copolymer was therefore proposed as a candidate of material for PEM in direct methanol fuel cell. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Fluorinated Poly(Arylene Ether)s

“…TS as well as the Young's modulus values were much higher than those of Nafion ® 117 (tensile strength = 25.65 MPa and Young's modulus = 0.26 GPa) [153]. The T g s of BPAQSH-XX (where XX = 20 and 30) polymers measured by DSC showed an increasing trend (245-257 °C) with an increase in DS.…”

Preparation and characterization of sulfonated poly(aryl ether ketone)s containing 3,5-diphenyl phthalazinone moieties for proton exchange membrane

“…Tensile moduli of 1.2-1.5 GPa and tensile stresses at maximum loads of 70-80 MPa are both higher than those of Naon 117 membranes (0.26 GPa and 26.65 MPa, respectively). 31 The elongation at break (20-58%) of SPPEK-dP membranes was lower than that of Naon 117 membranes (>200%) because of the rigid phenyl and heterocyclic structures in the SPPEK-dPs polymer backbones. This suggests that Naon 117 membranes are more exible, however, SPPEK-dPs remain potential proton exchange membrane materials.…”

Sulfonated fluorinated-aromatic polymers as proton exchange membranes

“…All the BPAQSH-XX membranes maintained their dimensional shapes and mechanical strengths in the temperature range under investigation. It was noteworthy that BPAQSH-XX with the same DS (or IEC values) showed a lower water uptake than the value of 38% for Nafion 117 reported by Zhang et al (60). This was attributed to the higher rigidity of the aromatic chain of BPAQSH-XX and to the lower acidity of the sulfonic acid groups, together with the contributing hydrophobic character of the -CF 3 groups, which decreased the absorption of water compared to that of Nafion 117.…”

“…The tensile strength for BPAQSH-XX membranes was in the range of 27-57 MPa, and Young's modulus was in the range of 0.91-1.55 GPa. The tensile strength and Young's modulus values were much higher than those of Nafion 117 membrane (tensile strength 25.65 MPa and Young's modulus 0.26 GPa) (60). The elongation at break (5-59%) of these membranes was much lower than that of Nafion 117 membrane ( > 200%) because of rigid quadriphenyl moiety coming from QBF, in the BPAQSH-XX polymers.…”