Synthesis and characterization of poly(aryl ether ketone) copolymers containing (hexafluoroisopropylidene)-diphenol moiety as proton exchange membrane materials

Abstract

Synthesis and characterization of poly(aryl ether ketone) copolymers containing (hexafluoroisopropylidene)-diphenol moiety as proton exchange membrane materialsAbstract Sulfonated poly(aryl ether ketone)s (SPAEK) copolymers were synthesized by aromatic nucleophilic polycondensation from 4,4 0 -(hexafluoroisopropylidene)-diphenol, 1,3-bis(4-fluorobenzoyl)benzene and di-sulfonated difluorobenzophenone. The copolymers exhibited good thermal and oxidative stability. The SPAEK membranes with sulfonic acid content (SC) ranging from 0.6 to 1.16 maintained adequate mechanical strength after immersion in water at 80 8C for 24 h. The proton conductivities of the SPAEK films increased with SC and temperature, reaching values above 3.3!10 K2 S/cm at 80 8C for SCR0.76. Tensile strength measurement indicated that SPAEK membranes with SC 0.76, 0.98 and 1.16 are tough and strong at ambient conditions. Consequently, these materials are promising as proton exchange membranes (PEM) for fuel cells operated at medium temperatures. q

Sulfonated hydrocarbon membranes for medium-temperature and low-humidity proton exchange membrane fuel cells (PEMFCs)

“…21 [104,105]. Various sulfonated poly(arylene ether nitrile)s (SPAENs) were synthesized as explained in Section 2.1.2 and shown in Fig.…”

Sulfonated fluorinated-aromatic polymers as proton exchange membranes

“…With increasing IEC, the isolated clusters came closer and formed bigger size ionic clusters, which resulted in increasing trend of proton conductivity values, together with low swelling, leading to a good dimensional stability of PAQSH membranes. For example, PAQSH-60 membrane exhibited a swelling ratio of 13% at 80°C, which was much lower than that of Nafion 117 (18,19), proving that the PAQSH-60 membrane exhibited better dimensional stability than Nafion 117, resulting from the bulky phthalimidine groups and hydrophobic -CF 3 groups, along with rigid quadriphenyl moiety. The proton conductivity of PAQSH-XX membranes was in the range of 5-28 mS/cm at 30°C and 11-50 mS/cm at 80°C.…”

“…Qing et al (98) synthesized fluorinated sulfonated polybenzimidazoles (sPBI)s, whose structure is shown in Scheme 15 (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). The sulfonated polymers showed good solubility in common organic solvents due to the presence of -CF 3 groups.…”

“…The direct polymerization of sulfonated monomer with other non-sulfonated monomers has produced statistical copolymers with better control of sulfonation content and more defined chain structures. The strategy of direct copolymerization of sulfonated monomers hence enables better control of morphology and of the number of sulfonic acid groups (18,19). The term "ion exchange capacity" (IEC) indicates the exchangeable ions of polymer membranes, which is an indirect measure of the degree of sulfonation.…”

Transport and Electro‐Optical Properties in Polymeric Self‐Assembled Systems

“…This may be due to the self-assembly between the sulfonated and hydrophobic blocks. Sulfonated poly(aryl ether ketone) copolymers based on 4,4'-(hexafluoroisopropylidene)diphenol, 1,3-bis(4-fluorobenzoyl)benzene and disulfonated difluorobenzophenone have good thermal and oxidative stability [211]. Amphiphilic block copolymers comprising sulfonated poly(vinylidene difluoride-co-hexafluoropropylene)-b-polystyrene were synthesized having moderately low polydispersity index [212,213].…”