Ion exchange membranes derived from sulfonated polyaramides

Partially Fluorinated Sulfonated Poly(ether amide) Fuel Cell Membranes: Influence of Chemical Structure on Membrane Properties

“…Sulfonated aromatic polyamides have been suggested as promising PEM materials because of their favorable mechanical properties and film-forming abilities [31][32][33]. Despite these potential advantages, however, their application in fuel cell membranes is hampered by their instability toward hydrolysis and heat.…”

Synthesis of crosslinked polystyrene-b-poly(hydroxyethyl methacrylate)-b-poly(styrene sulfonic acid) triblock copolymer for electrolyte membranes

“…Among them, block copolymers consisting of more than two domains with different chemical properties are considered to offer an effective approach for incorporating higher ionic properties into a material while retaining desirable mechanical properties of the polymer. 11,[16][17][18] The advantages of the use of microphase-separated block copolymers are as follows; 1) controlling of the swelling of the ion conducting domains by the surrounding non-conducting domains, 2) lowering of the methanol permeability due to decreased swelling, and 3) high mechanical stability due to the inert matrix of nonsulfonated segments.…”

Sulfonated poly(meta‐phenylene isophthalamide)s as proton exchange membranes

“…[5][6][7] However, Nafion V R and other perfluorinated polymer membranes suffer from their relatively high cost, environmental concerns about their manufacture, and decreased performance at lower humidity. 8,9 Sulfonated engineering polymers, including poly(aryl ether sulfone)s, [10][11][12][13][14][15][16][17][18][19][20] poly(aryl ether ketone)s, 6,7,21,22 polyimides, [23][24][25][26] and polyamides 15,[27][28][29][30][31][32][33] have been investigated as alternative PEMs to replace perfluorinated membranes. The aromatic backbone of these polymers provides good mechanical properties and imparts good chemical stability, and the aromatic groups offer the possibility to introduce various functional groups to the backbones in different positions on the rings.…”

“…[34][35][36][37][38] Polyaramides are high performance polymers with excellent mechanical properties, 39 and good thermal stabilities, 40 and can display good stability to acidic conditions as evidenced by the fact that poly(para-phenylene terephthalamide) (Kevlar V R ) is processed from concentrated sulfuric acid. The preparation of sulfonated polyaramides using sulfonated pphenylenediamine (2,5-diaminobenzenesulfonic acid) or sulfonated terephthalic acid (2-sulfoterephthalic acid) as sulfonated monomers has been investigated 15,[27][28][29][30][31][32] and their potential application as PEMs have been studied with varying results. Poly(para-phenylene terephthalamide)s (PPTA)s with sulfonated groups on each repeat unit display high proton conductivity, but are found to be water soluble and therefore unsuitable as PEMs.…”

“…[28][29][30][31] Random and block copolymers using sulfonated p-phenylene diamine with 4,4'-oxydianiline as an additional hydrophobic component successfully decreased the water solubility of sulfonated polyaramides, however, the polymers displayed low proton conductivities ( 3.0 mS/cm at 80 8C and 100 RH%). 27 Most recently, Bae and coworkers used sulfonated terephthalic acid along with terephthalic acid and 4,4'-oxydianiline as the monomers for the synthesis of PPTA-based aromatic copoly(ether amide)s. 32 They improved the proton conductivity of the PEMs to 105 mS/cm at 80 8C under 100% relative humidity for a polymer with 70 mole % sulfonated groups, while the water uptake of this membrane remained under 35 wt % at room temperature. The high conductivity was in part attributed to the sulfonic acid groups attached to the electron deficient carbonyl-containing rings as opposed to the electron donating p-phenylene diamine ring in other studies.…”