Preparation of new proton exchange membranes using sulfonated poly(ether sulfone) modified by octylamine (SPESOS (original) (raw)

Structures and properties of highly sulfonated poly(arylenethioethersulfone)s as proton exchange membranes

Polymer, 2007

A series of sulfonated poly(sulfonium cation) polymers, sulfonated poly(arylenethioethersulfone)s (SPTES)s possess up to two sulfonate groups per repeat unit, and can be easily converted into corresponding acid form of the SPTES polymer to form a tough, ductile, free-standing, pinhole-free membranes with excellent mechanical properties. The SPTES polymers exhibit good water affinity and excellent proton conductivity due to the high water uptake. Proton conductivities between 100 and 300 mS/cm (at 65 C, 85% relative humidity) were observed for the SPTES polymers with 50 mol% (SPTES-50) to 100 mol% (SPTES-100) of sulfonated monomer. The evaluation by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermomechanical analysis (TMA) showed that the SPTES polymers have excellent thermal stability, mechanical properties, and dimensional stability, making them excellent candidates for the next generation of proton exchange membranes (PEMs) in fuel cell applications. Published by Elsevier Ltd.

Proton-conducting membranes from poly(ether sulfone)s grafted with sulfoalkylamine

Journal of Membrane Science, 2013

Highly sulfonated poly(ether sulfone)s with densely populated flexible acid side chains were prepared for fuel cell applications by polycondensation of 3,3'-dihydroxybenzidine with bis(4-fluorophenyl)sulfone and 4,4 0 -biphenol, followed by postsulfonation using 1,4-butanesultone at room temperature. The sulfonated polymers gave tough, flexible, and transparent membranes by solvent casting. The membranes had high ion exchange capacity (IEC) values (2.47-2.95 mequiv/g) and displayed good proton conductivities in the range of 13.90-20.90 Â 10 À 2 and 1.08-2.21 Â 10 À 2 S/cm at 95% and 35% relative humidity (RH) (80 1C), respectively. In particular, the S-PES-55 membrane with the highest IEC value showed higher or comparable proton conductivity than that of Nafion 212 in the range of 35-95% RH. The morphologies of these membranes were investigated by TEM analysis, which exhibited wellconnected hydrophilic channels due to their high IEC values and densely populated flexible acid side chains. In contrast with many reported highly sulfonated polymers, the membranes showed good dimensional stability regardless of their high IEC values.

Studies on the SPEEK membrane with low degree of sulfonation as a stable proton exchange membrane for fuel cell applications

2017

Sulfonated poly (ether ether ketone) (SPEEK) with a low degree of sulfonation (DS = 40%) was prepared for proton exchange membrane fuel cells (PEMFC). Poly (ether ether ketone) (PEEK) was sulfonated in concentrated H2SO4 under N2 atmosphere and characterized by the hydrogen nuclear magnetic resonance (H-NMR) technique. After preparation of the SPEEK polymer, the obtained polymer was dissolved in dimethylacetamide (DMAC) solvent and then the solution casting method was applied for the fabrication of membranes. Water uptake behavior, ion exchange capacity (IEC), and the proton conductivity at different temperatures and different relative humidity were determined and compared with a commercial Nafion 117 membrane. The IEC and the proton conductivity results showed that the sulfonation process successfully created proton conduction channels. In addition, the thermal, mechanical, chemical, and hydrolytic stabilities were thoroughly investigated for the prepared membrane. The low degree...

Preparation and characterization of branched and linear sulfonated poly(ether ketone sulfone) proton exchange membranes for fuel cell applications

Journal of Polymer Science Part A: Polymer Chemistry, 2008

Branched sulfonated poly(ether ketone sulfone)s (Br-SPEKS) were prepared with bisphenol A, bis(4-fluorophenyl)sulfone, 3,3 0 -disodiumsulfonyl-4,4 0 -difluorobenzophenone, and THPE (1,1,1-tris-p-hydroxyphenylethane), respectively, at 180 8C using potassium carbonate in NMP (N-methylpyrrolidinone). THPE, as a branching agent, was used with 0.4 mol % of bisphenol A to synthesize branched copolymers. Copolymers containing 10-50 mol % disulfonated units were cast from dimethylsulfoxide solutions to form films. Linear sulfonated poly(ether ketone sulfone)s (SPEKS) were also synthesized without THPE. The films were converted from the salt to acid forms with dilute hydrochloric acid. A series of copolymers were studied by Fourier transform infrared, 1 H-NMR spectroscopy, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water and methanol. The ionexchange capacity (IEC), a measure of proton conductivity, was evaluated. The synthesized Br-SPEKS and SPEKS membranes exhibit conductivities (25 8C) from 1.04 3 10 À3 to 4.32 3 10 À3 S/cm, water swell from 20.18 to 62.35%, IEC from 0.24 to 0.83 mequiv/g, and methanol diffusion coefficients from 3.2 3 10 À7 to 4.7 3 10 À7 cm 2 /S at 25 8C.

Concentrated sulfonated poly (ether sulfone)s as proton exchange membranes

Journal of Power Sources, 2013

h i g h l i g h t s g r a p h i c a l a b s t r a c t < A series of new concentrated sulfonated poly (ether sulfone)s were synthesized. < These polymers own lower activation energy (E a) of conductivity compared to Nafion. < The membrane with IEC ¼ 1.66 mequiv g À1 exhibits higher conductivity than Nafion. < These membranes show considerable water management and proton conductivity.

Development of sulfonated polysulfone membranes as a material for Proton Exchange Membrane (PEM)

2004

This paper reports the development of sulfonated polysulfone (SPSU) membrane as potential candidates for proton exchange membrane through sulfonation process. Sulfonated polysulfone membranes have been prepared by conducting sulfonation reaction at room temperature with a mild sulfonating agent, trimethylsilyl chlorosulfonate (TMSCS). The membranes were sulfonated with different molar ratio of sulfonating agent to the polymer repeat unit. The degree of sulfonation was determined by elemental analysis and Fourier Transform Infrared (FTIR) was performed to verify the sulfonation reaction on the polysulfone polymer. The sulfonated polysulfone membranes have been characterized by ion exchange capacity (IEC), water uptake and proton conductivity as a function of molar ratio and degree of sulfonation. It was shown that increases in the molar ratio of the sulfonating agent to polysulfone repeat unit lead to an increasing degree of sulfonation. The water uptake of the sulfonated polysulfone membrane was increased with an increase in degree of sulfonation from 4.1 wt.% up to 26 wt.% with the value of IEC about 0.62 mmol/g and 1.78 mmol/g respectively. Area resistance of the sulfonated membranes were decreases as a function of temperature and degree of sulfonation. The conductivity values in the range of 10-4-10-3 S/cm were obtained for SPSU membranes. The conductivity of the membranes show similar increasing trend as a function of operating temperature.

Ionomeric membranes for proton exchange membrane fuel cell (PEMFC): sulfonated polysulfone associated with phosphatoantimonic acid

Journal of Membrane Science, 2001

Sulfonation of polysulfone strongly affects both protonic conductivity and lifetime of composite polyelectrolytes. Viscosimetric comparisons showed the effect of the sulfonating agent. Indeed, chlorosulfonic acid leads to chain cleavage while its trimethyl silyl ester does not affect the polymer backbone. Sampling aliquots allowed the sulfonation yield to be followed by 1 H NMR. From this study, one might infer that the conversion should not exceed 70% of the theoretical yield. Viscosimetric measurements performed on the same aliquots demonstrated that, even after 72 h reaction time, chain cleavage did not occur. Filling of sulfonated polysulfone with 8% of phosphatoantimonic acid resulted in a conductivity trebling 0.06 versus 0.02 S cm −1 at 80 • C and 98% of relative humidity (RH). Electrochemical performances, thermo-mechanical stability and low cost make this composite membrane an attractive material for proton exchange membrane fuel cell (PEMFC).

Proton exchange membranes based on sulfonated polyarylenethioethersulfone and sulfonated polybenzimidazole for fuel cell applications

2007

Review is dedicated to discussion of different types of proton-exchange membranes used in fuel cells (FC). One of the most promising electrolytes is polymer electrolyte membrane (PEM). In recent years, researchers pay great attention to various non-fluorinated or partially fluorinated hydrocarbon polymers, which may become a real alternative to Nafion. Typical examples are sulfonated polyetheretherketones, polyarylene ethers, polysulphones, polyimides. A class of polyimides-based hydrocarbon proton-exchange membranes is separately considered as promising for widespread use in fuel cell, such membranes are of interest for our further experimental development.

Multiblock sulfonated-fluorinated poly (arylene ether) s for a proton exchange membrane fuel cell

Polymer, 2006

New proton exchange membranes were prepared and evaluated as polymer electrolytes for a proton exchange membrane fuel cell (PEMFC). Sulfonated-fluorinated poly(arylene ether) multiblocks (MBs) were synthesized by nucleophilic aromatic substitution of highly activated fluorine terminated telechelics made from decafluorobiphenyl with 4,4 0-(hexafluoroisopropylidene)diphenol and hydroxyl-terminated telechelics made from 4,4 0-biphenol and 3,3 0-disulfonated-4,4 0-dichlorodiphenylsulfone. Membranes with various sulfonation levels were successfully cast from N-methyl-2-pyrrolidinone. An increase sulfonated block size in the copolymer resulted in enhanced membrane ion exchange capacity and proton conductivity. The morphological structure of MB copolymers was investigated by tapping mode atomic force microscopy (TM-AFM) and compared with those of Nafion w and sulfonated poly(arylene ether) random copolymers. AFM images of MBs revealed a very well defined phase separation, which may explain their higher proton conductivities compared to the random copolymers. The results are of particular interest for hydrogen/air fuel cells where conductivity at high temperature and low relative humidity is a critical issue.