Sulfonated polyarylene ethers

Xing, D. and Kerres, J. 2006. Improved performance of sulfonated polyarylene ethers for proton exchange membrane fuel cells. Polymers for Advanced Technologies 17 591-597. 

Sulfonated polyarylene ether sulfones Characterisation, adhesion studies [20]... 

The crosslinking of a sulfonylated polyarylene ether sulfone was accomplished by addition of CDI and bis-4-aminophenylsulfone as crosslinking agents [23] a) Activation of the sulfonic acid group... 

Of all the hydrocarbon-based PEMs, this group most likely has the largest variety of different systems. This is probably due to the wealth of prior knowledge of the nonsulfonated analogues that have been developed over the last several decades as well as the general expectation of higher thermal stability, better mechanical properties, and increased oxidative stability over polystyrene-based systems. Within the context of this section, polyarylenes are systems in which an aryl or heteroaryl ring is part of the main chain of the polymer. This section will, therefore, include polymers such as sulfonated poly (ether ether ketone) and sulfonated poly(imides) but will not include systems such as sulfonated polystyrene, which will be covered in Section 3.3.I.3. 

Ti and Zr containing polytetramethylene oxide (PTMO) ceramic hybrid materials have lately been prepared by a sol-gel technique [61, 62]. Trialkoxy silane capped organic oligomer (PTMO or polyarylene ether sulfones) backbones with titanium isopropoxide or Zr-(n-propoxide) are used in this process ... 

Sulfonation is very useful chemical modification of polymer, as it induces high polarity in the polymer changing its chemical as well as physical properties. Sulfonated polymers are also important precursors for ionomer formation [75]. There are reports of sulfonation of ethylene-propylene diene terpolymer (EPDM) [76, 77], polyarylene-ether-sulfone [78], polyaromatic ether ketone [79], polyether ether ketone (PEEK) [80], styrene-ethylene-butylene-styrene block copolymer, (SEBS) [81]. Poly [bis(3-methyl phenoxy) phosphozene] [82], Sulfonated polymers show a distinct peak at 1176 cm"1 due to stretching vibration of 0=S=0 in the -S03H group. Another peak appears at 881 cm 1 due to stretching vibration of S-OH bond. However, the position of different vibrational bands due to sulfonation depends on the nature of the cations as well as types of solvents [75, 76]. 

U. Eichenauer, E. Neufeld, A. Ludwig, T. Sauer, and A. Ulzhofer. Production of polyarylene-ether-sulfone useful for coating, especially to produce sliding surface. DE Patent 19 816955, assigned to Basf AG (DE), October 21,1999. 

Numerous ways to evaluate the degradation behaviour of polyarylene sulfones are reported in the literature. Danilina and co-workers [17] used infrared (IR) analysis for the pyrolysates of PES and PSF along with a change in the absorption peaks after two hours at 470 °C, they showed the formation of sulfur dioxide and phenol from the scission of sulfone and ether linkages. Crossland and co-workers [18] reported the results of TGA and Py-MS in the evaluation of the pyrolysis mechanism and pyrolysates of various PSF main-chain scission and hydrogen abstraction were indicated. However, the relative stability of the different PSF could not be postulated... 

Reactive flexibilizers such as polysulfldes, urethanes, polybutadienes, and polyesters are copolymerized with epoxies to increase flexibihty, improve adhesion, modify electrical properties, and improve resistance to chemicals. Nonreactive extenders such as thermoplastics, asphaltums, and waxes are used to modify properties and reduce the cost of the compounds. Polyarylene ether sulfone as an extender in epoxy resins increases the fracture toughness fivefold with only a slight drop in Tg. 

R. Viswanathan, "Synthesis and Characteristics of Polyarylene Ether Sulfones", Ph.D. Dissertation, Virginia Polytechnic Institute and State University, 1981 manuscripts in preparation. 

BPSH 40 (40% disul-fonated wholly aroma-tic polyarylene ether sulfone) 132 1 5 30 6.4 X 10 [14]... 

Wang, F., Kim, Y., Hickner, M., Zawodzinski, T.A., McGrath, J.E. (2001) Synthesis of polyarylene ether block copolymers containing sulfonate groups. In Abstracts of Papers of the American Chemical Society, Vol. 222, American Chemical Society, Washington, DC, p. U387. 

Another class of polyarylene-based PEMs that has been extensively studied, primarily by Hickner et al.,i44 is the sulfonated poly(aryl ether sulfone)s... 

Polyarylenes, in particular different types of poly(arylene ether ketone)s, have been the focus of much hydrocarbon membrane research in recent years. - - With good chemical and mechanical stability under PEM fuel cell operating conditions, the wholly aromatic polymers are considered to be the most promising candidates for high-performance PEM fuel cell applications. Many different types of these polymers are readily available and with good process capability. Some of these membranes are commercially available, such as poly(arylene sulfone)s and poly(arylene... 

HB polyarylenes were synthesized by two research groups via different C-C coupling methods. Smet et. al [65]. studied the condensation of isatins with a trifiinctional phenyl ether (see Formula 10.3). Trifluoromethane sulfonic acid served as catalyst and the low monomer concentration prevented gelation. This approach is, in principle, a variant of the acid catalyzed aldehyde-phenol polycondensation developed more than 100 years before for the production of Novolac and Bakelite (see Chap. 2). Possum et al. [66]. studied Pd-catalyzed polycondensations of 1,4-benzene diboronic acid with tri(4-bromophenyl)phosphioxide (see Formula 10.3). 

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