Phosphoric Acid-doped SDF-F/poly(VI-co-MPS)/PTFE Membrane for a High Temperature Proton Exchange Membrane Fuel Cell

Lee, Jongwon; Yi, Cheol Woo; Kim, Keon

doi:10.5012/bkcs.2011.32.6.1902

Cited by 7 publications

(1 citation statement)

References 32 publications

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“…This approach to the formation of composite membranes seems to be the most successful, since it leads to the formation of materials with a high degree of homogeneity and excludes the possibility of phase separation of components. The introduction of silicon-containing fragments into the structure of composites provides the increase in their thermal stability and proton conductivity [17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Copolymers of sodium 4-styrene sulphonate and vinyl derivatives of nitrogen-containing heterocycles

Малахова¹,

Лебедева²,

Emel’yanov³

et al. 2019

PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY

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The formation of ion-exchange composite materials based on high molecular weight precursors appears to be an intensively developing area in the synthesis of proton-conducting membranes for fuel cells. In such membranes, proton transfer is often provided by functional polymers simultaneously containing sulphonic acid groups in their composition units along with fragments of vinyl derivatives of nitrogen-containing heterocyclic bases. Proton exchange activity in the latter is determined by the possibility of doping with inorganic acids. In the framework of this study, for the further formation of hybrid composite membranes under conditions of radical initiation, copolymers of sodium 4-styrene sulphonate (SSt) with 4-vinylpyridine (VP) and 1-vinylimidazole (VIM) were obtained. The monomodal nature of the turbidimetric titration curves for solutions of copolymerisation reaction products indicates the presence of true copolymers during the process of formation. The composition and structure of the copolymers were characterised using data from elemental analysis, as well as from IR and 13 C NMR spectroscopy. Constants of the relative activity for the monomers and the microstructure parameters of the polymer chains are calculated according to the non-linear leastsquares method using the MathCAD package. The calculated copolymerisation constant values indicate a greater reactivity of SSt in comparison with nitrogen-containing monomers. The lengths of the monomer unit blocks depend on the composition of the initial mixture and vary over a wide range from 1 to 18. The possibility of varying the length of the unit blocks in the composition of the copolymers will affect the ion-conducting properties of hybrid composites formed on their basis. The stability of the copolymers to thermal oxidative degradation by heating in air was studied using the differential scanning calorimetry (DSC) method. The copolymers demonstrated significant thermo-oxidative stability. Decomposition temperatures were 350 °С and 400 °С for SSt-VIM and SSt-VP copolymers, respectively.

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Section: Introductionmentioning

confidence: 99%

Copolymers of sodium 4-styrene sulphonate and vinyl derivatives of nitrogen-containing heterocycles

Малахова¹,

Лебедева²,

Emel’yanov³

et al. 2019

PROCEEDINGS OF UNIVERSITIES APPLIED CHEMISTRY AND BIOTECHNOLOGY

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Study of CO2 adsorption onto poly(1–vinylimidazole) using quartz crystal microbalance and density functional theory methods

Mehrdad

Noorani

2019

Journal of Molecular Liquids

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Thermal Behavior, Stability, and Decomposition Mechanism of Poly(N-vinylimidazole)

et al. 2012

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Homo- and copolymers of N-vinylimidazole belong to a rapidly emerging class of polymeric materials. Because of the fact that these materials can be utilized in several high-temperature processes and applications, such as catalysis, fuel cells, polymeric ionic liquids (PIL), precursors for new materials by thermolysis, etc., and because fundamental details on the thermal behavior of such polymers are lacking, systematic investigations have been carried out to reveal the stability and the mechanism of thermal decomposition of poly(N-vinylimidazole) (PVIm) by using a variety of techniques, such as differential scanning calorimetry (DSC), thermogravimetry (TG), thermogravimetry–mass spectrometry (TG-MS), and pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS). The investigated PVIm was obtained by free radical polymerization initiated by AIBN in benzene at 70 °C. By the unique combination of the applied methods to investigate the thermal decomposition mechanism of PVIm, it was found that the thermal decomposition of PVIm takes place in one main step in the temperature range 340–500 °C. An initial mass loss of 4% occurs before the main endothermic decomposition step due to the evaporation of water and acetone physically bound to the polymer during purification. The major products of the thermal decomposition of PVIm are 1H-imidazole and 1-vinylimidazole accompanied by several minor products, such as benzene and several alkyl aromatics. The relative ratios between imidazoles and aromatics, i.e., the 2 orders of higher amounts of imidazoles, indicate that in contrast to other polymers with heteroatom pendant groups, e.g., poly(vinyl chloride) (PVC), poly(vinyl acetate), (PVAc) and poly(vinyl alcohol) (PVA), not zip-elimination of 1H-imidazole but homolytic scission of the carbon–nitrogen bond is the main reaction of its formation. 1-Vinylimidazole is formed by main chain scission followed by depolymerization. Both 1H-imidazole and 1-vinylimidazole formation lead in part to macroradicals and short conjugated double bond sequences (polyenes) in the chain, the thermolytic cyclization, isomerization, and aromatization of which result in the low amounts of aromatics. These findings served for the basis of formulating the mechanism of the thermal decomposition of PVIm, which can be utilized in the course of further investigations with this unique polymer.

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Phosphoric Acid-doped SDF-F/poly(VI-co-MPS)/PTFE Membrane for a High Temperature Proton Exchange Membrane Fuel Cell

Cited by 7 publications

References 32 publications

Copolymers of sodium 4-styrene sulphonate and vinyl derivatives of nitrogen-containing heterocycles

Copolymers of sodium 4-styrene sulphonate and vinyl derivatives of nitrogen-containing heterocycles

Study of CO2 adsorption onto poly(1–vinylimidazole) using quartz crystal microbalance and density functional theory methods

Thermal Behavior, Stability, and Decomposition Mechanism of Poly(N-vinylimidazole)

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