• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.690-694
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• 2015

Recently, direct formic acid fuel cells (DFAFC) among direct liquid fuel cells is studied actively. Economical hydrocarbon membranes alternative to fluorinated membranes for DFAFC's membrane are receiving attention. In this study, characteristics of sulfonated poly(ether ether ketone, sPEEK) and sulfonated poly(arylene ether sulfone, PAES) membranes were compared with Nafion membrane at DFAFC operation condition. Formic acid crossover current density of hydrocarbon membranes were lower than that of Nafion 211 fluorinated membrane. I-V performance of sPEEK MEA(Membrane and Electrode Assembly) was similar to that of Nafion 211 MEA due to similar membrane resistance each other. sPEEK MEA with low formic acid crossover showed higher stability compared with Nafion 211 MEA.

• Journal of Energy Engineering
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• v.25 no.3
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• pp.66-72
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• 2016

In this study, a sulfonated poly(arylene ether ketone) block copolymer was prepared from hydrophilic oligomer and hydrophobic oligomer. The structure of the prepared membrane was characterized by $^1H$-NMR, FT-IR and GPC. The $M_w$(weight-average molecular weights) of the polymer was $209,700g\;mol^{-1}$ and the molecular weight distribution($M_w/M_n$) of 1.25 was obtained. The prepared membrane showed excellent thermal stability with gradual weight loss up to $200^{\circ}C$. The proton conductivity of SPAEK block copolymer reached the maximum of $9.0mS\;cm^{-1}$ at $90^{\circ}C$ under 100% relative humidity (RH). From the observed results, it is necessary to do more aggressive attempt to study the possibility of application as an ion-conductive composite electrolyte.

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3306-3310
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• 2011

A series of novel linear aromatic ether ketone polymers containing triazole units were synthesized by click chemistry and their structures and properties were characterized by FT-IR, $^1H$ NMR, GPC, TGA, DSC and WAXD. The results showed that these polymers exhibited relatively small molecular weights distributions, good thermal stability and solvent-repelling which could have potential applications as engineering thermoplastic.

• Proceedings of the Membrane Society of Korea Conference
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• 2008.05a
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• pp.162-162
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• 2008

• Macromolecular Research
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• v.14 no.4
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• pp.438-442
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• 2006

Novel sulfonated poly(aryl ether ketones) containing benzoxazole were directly synthesized by aromatic nucleophilic polycondensation using various ratios of 2,2'-bi[2-( 4-flurophenyl)benzoxazol-6-yl]hexafluoropropane to sodium 5,5'-carbonylbis(2-fluorobenzenesulfonate). The copolymers were soluble in polar aprotic solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and N,N-dimethylformamide at a relatively high solid composition (>15 wt%) and formed tough, flexible and transparent membranes. The membranes exhibited a degradation temperature of above $290^{\circ}C$. The exact dissolution times of these membranes at $80^{\circ}C$ in Fenton's reagent (3 wt% $H_2O_2$ containing 2 ppm $FeSO_4$) were undetectable, confirming their excellent chemical stability in fuel cell application. The membranes showed a moderate increase in water uptake with respect to increasing temperature. The proton conductivities of the membranes were dependent on the composition and ranged from $1.10{\times}10^{-2}$ to $5.50{\times}10^{-2}Scm^{-1}$ at $80^{\circ}C$ and 95% relative humidity (RH). At $120^{\circ}C$ without externally humidified conditions, the conductivities increased above $10^{-2}Scm^{-1}$ with respect to increasing benzoxazole content, which suggested that the benzoxazole moieties contributed to the proton conduction.