Fluorenyl-containing sulfonated poly(aryl ether ether ketone ketone)s (SPFEEKK) for fuel cell applications

Abstract

A series of fluorenyl-containing sulfonated poly(aryl ether ether ketone ketone)s (SPFEEKK) were synthesized via aromatic nucleophilic substitution polymerization. The sulfonation content (SC) was controlled by the feed ratios of sulfonated and nonsulfonated monomers. Flexible and strong membranes in the sulfonic acid form were obtained from cast membranes in the sodium salt forms by treatment with acid. The thermal properties, water uptake, swelling ratio, water state, oxidative stability, proton conductivity and methanol permeability were investigated. All the polymers had proton conductivities greater than 1 × 10 −2 S/cm at room temperature, and the conductivity values of m-SPFEEKK-80 and p-SPFEEKK-80 were up to 1.86 × 10 −1 and 1.78 × 10 −1 S/cm at 100 • C. This series of polymers also possessed good dimensional stability in water and low methanol crossover.

Sulfonated naphthalenic polyimides containing ether and ketone linkages as polymer electrolyte membranes

“…All other chemicals were obtained from commercial sources, and used without further purification. [7]. A three-necked flask (250 mL) equipped with a mechanical stirrer and nitrogen inlet was charged with 1,4-bis(4-fluorobenzoyl) benzene (96.6 g) and fuming sulfuric acid (30%, 250 mL).…”

“…In this study, a new sulfonated monomer, 1,4-bis[3-sodium sulfonate-4-(4-aminophenoxy)benzoyl]benzene (BSAPBB) was prepared first by sulfonation of 1,4-bis(4-fluorobenzoyl)benzene [7], followed by nucleophilic aromatic substitution (SNAr) reaction between 1,4-bis(3-sodium sulfonate-4-fluorobenzoyl)benzene and 4-aminophenol, as shown in Scheme 1. Sulfonated diamine monomer, 4,4-bis[3-sodium sulfonate-4-aminophenoxy]benzophenone (BSAPBP), was similarly synthesized.…”

“…However, some deficiencies are well-recognized, such as its high cost, high fuel crossover, low operation temperature (≤80 • C) and environmental recycling uncertainty [3][4][5]. In this respect, much research effort is being directed to develop new PEMs with lower cost and good overall performance as alternatives to replace per-fluorosulfonic acid type membranes [6][7][8][9][10][11]. Acid functionalized poly(arylenes), such as sulfonated polyarylether-type polymers (SPAEs), sulfonated polyimides (SPIs), polybenzimidazoles (PBIs) doped with phosphoric acid and sulfonated PBIs, have been widely studied as promising candidates for the next-generation PEMs, and some of them have been demonstrated to have attractive fuel cell performance [1,11].…”

Proton exchange membranes modified with sulfonated silica nanoparticles for direct methanol fuel cells☆

“…One approach is to prepare new polyelectrolytes as Nafion ® alternatives. Most PEM materials are based on non-fluorinated or partially fluorinated aromatic polymers such as sulfonated polyimides [2][3][4][5][6] and sulfonated poly(aryl ether)s [7][8][9][10][11][12]. However, many of the reported hydrocarbonbased PEM prepared as alternatives to Nafion ® still do not ଝ NRCC Publication 49114.possess the full range or combination of desired properties for application in DMFC.…”

Fabrication of inorganic/polymer nanocomposite membranes containing very high silica content via in situ surface grafting reaction and reactive dispersion of silica nanoparticles: Proton conduction, water uptake, and oxidative stability

“…The oxidative stability to peroxide radical attack was investigated by measuring the elapsed times that a membrane began to dissolve or when the membrane was broken or lightly bent (s 1 ), and a membrane was dissolved completely (s 2 ) after immersion of each membrane into Fenton's reagent of the 30 wt % H 2 O 2 and 0.1 wt % ferrous ammonium sulfate solution at 80 C. [21][22][23] Thermal stability of the membranes was measured using thermogravimeric analyzer (TGA) (TA Instrument TGA 2050, New Castle, DE). TGA measurements were carried out under nitrogen atmosphere with a heating rate of 10 C from 20 to 700 C. For comparing oxidative stability, the sulfonated polyimide (SPI; Ion exchange capacity ¼ 1.90 meq g À1 ) with the chemical structure illustrated at Figure 2 was synthesized by solution-thermal imidization method, using 4 0 ,4 0 -diaminodiphenyl ether 2,2 0 -disulfonic acid (SODA, 1.6 mmol), 3,5-diaminobenzoic acid (DBA, 2.4 mmol), and 1,4,5, 8-naphthalenetetracarboxylic dianhydride (NTDA, 4 mmol).…”