Characterization and evaluation of commercial poly (vinylidene fluoride)‐g‐sulfonatedPolystyrene as proton exchange membrane

Abstract

The possibility of developing low-cost commercial grafted and sulfonated Poly(vinylidene fluoride) (PVDF-g-PSSA) membranes as proton exchange membranes for fuel cell applications have been investigated. PVDF-g-PSSA membranes were systematically prepared and examined with the focus of understanding how the polymer microstructure (degree of grafting and sulfonation, ion-exchange capacity, etc) affects their methanol permeability, water uptake, and proton conductivity. Fourier transform infrared spectroscopy was used to characterize the changes of the membrane's microstructure after grafting and sulfonation. The results showed that the PVDF-g-PSSA membranes exhibited good thermal stability and lower methanol permeability.The proton conductivity of PVDF-g-PSSA membranes was also measured by the electrochemical impedance spectroscopy method. It was found that the proton conductivity of PVDF-g-PSSA membranes depends on the degree of sulfonation. All the sulfonated membranes show high proton conductivity at 92°C, in the range of 27 to 235 mScm, which is much higher than that of Nafion212 (102 mScm −1 at 80°C). The results indicated that the PVDF-g-PSSA membranesare particularly promising membranes to be used as polymer electrolyte membranes due to their excellent stability, low methanol permeability, and high proton conductivity. has high stability and good proton conductivity in low temperatures and high relative-humidity conditions. However, the Nafion-based PEM is expensive, and its conductivity showed reduction at higher temperatures (>80°C) and low humidity (<40%) conditions. A lot of studies have been performed with the goal of developing alternative membranes, focusing on the reduction of the methanol permeability. Some of them have worked on developing new synthetic polymeric membranes that have ionic clusters, [14][15][16][17] or the modification of the Nafion membranes by surface treatment or by blending them with other

Polymer Electrolyte Membranes Prepared by Graft Copolymerization of 2-Acrylamido-2-Methylpropane Sulfonic Acid and Acrylic Acid on PVDF and ETFE Activated by Electron Beam Treatment

“…Aiming for better water retention other approaches have also been explored [12]. LT-PEM are mostly based on a stable fluorinated or polyaromatic backbone polymer, e.g., poly(ethylene-alt-tetrafluoroethylene) (ETFE) [13,14,15,16], poly (vinylidene fluoride) (PVDF) [17,18,19] or poly(ether ether ketone) (PEEK) [20,21,22,23]. Protogenic functional groups such as sulfonic acid groups are attached to these matrices [24,25,26,27,28,29].…”

Styrene grafted ethylene chlorotrifluoroethylene (ECTFE‐g‐PSSA) protonic membranes: Preparation, characterization, and transport mechanism

“…Currently, there is much ongoing research for developing membranes with improved characteristics such as sulfonated poly(ether ether ketone) (SPEEK), sulfonated polyimide, and polybenzimidazole . In addition, a great deal of work has been devoted to preparing different types of fuel cell membranes using radiation and chemical grafting techniques such as poly(vinylidene difluoride‐g‐styrene), polyfluorene, and polyethylene . Another effective approach to obtain high proton conductivity and low methanol permeability, PEMs turned into synthesized from graft copolymers including two chemically exceptional polymer segments (1) a primary chain grafted from a polymer with low methanol permeability and (2) facet chains made from a polymer having high proton conductivity.…”

Effect of a direct sulfonation reaction on the functional properties of thermally-crosslinked electrospun polybenzoxazine (PBz) nanofibers

“…In sulfonation, the reaction of the sulfonating agent with the electrospun nanobers occurred where sulfonic acid was added to the aromatic ring by electrophilic substitutions. 20,26 Based on the previous works, the reaction was found to be second order with respect to SO 3 and rst order with respect to aromatic compounds. 27 The substitution preferentially occurred at the ortho-position of the aromatic ring in the repeating unit of PBz, as shown in Fig.…”