Sulfonated poly bis

Tang, H., Pintauro, P. N., Guo, Q. and O Connor, S. 1999. Polyphosphazene membranes. ni. Solid-state characterization and properties of sulfonated poly[bis(3-methylphenoxy)phosphazene]. Journal of Applied Polymer Science 71 387-399. 

Diffusion coefficients for methanol (concentration range 1.0-5.0 M) in ion-exchange membranes of UV-crosslinked sulfonated poly(bis-3-methoxyphenoxyphosphazene) (134) have been reported to be much smaller than those in Nafion perfluorosulfonic ion-exchange membranes. Application of polyphosphazene-based membranes in methanol-based fuel cells has been reported. ... 

H. Tang, P.N. Pintauro, Q. Guo and S. O Connor, Polyphosphazene membranes. III. Solid-state characterization and properties of sulfonated poly[bis(methylphenoxy)-phosphazene], J. Appl. Polym. Sci., 1999, 71, 389-399. 

Herrero and Acosta (80) investigated the microstmcture of poly(ethylene oxide)-poly[(octafluoropentoxy)(trifluoroethoxy)phosphazene] blends. Limited miscibility of both components was inferred, based on the observed shift of the components glass-transition temperatures. Wycisk and co-workers (81) prepared membranes from blends of sulfonated poly[bis(3-methylphenoxy)phosphazene] with polyimides, polyacrylonitrile, and Kynar FLEX PVDF. Morphology, electrochemical performance, and methanol permeabilities of the membranes were then evaluated as part of a program to investigate such blends in direct methanol fuel cells. The polymers were immiscible and a domain-type structure was observed. The best compatibility resulted when the tetrabutylammonium or sodium salt of the polyphosphazene was used (82). 

Li N, Zhang F, Wang J et al (2009) Dispersions of carbon nanotubes in sulfonated poly[bis(benzimida-zobenzisoquinolinones)] and their proton-conducting composite membranes. Polymer 50 3600-3608... 

Tang et al. [30] and Guo et al. [31] found that sulfonated poly[bis(3-methylphenoxy)phosphazene] (denoted as SPB3MPP) (Fig. 7b) offered an attractive combination of good proton conductivity, crosslinkability and low methanol permeability features especially important for direct methanol fuel-cell membranes. UV-crosslinked membranes prepared from SPB3MPP of lEC 1.4 mmol/g exhibited a methanol diffusion coefficient on the order of 1.0 X lO cm /s, which was significantly smaller than that in a Nation... 

Fig. 7 Example structures of polyphosphazene sulfonic acids a sulfonated poly[(me-thylphenoxy)(phenoxy)phosphazene], b sulfonated poly[bis(3-methylphenoxy)(phenoxy)-phosphazene], c sulfonated poly[bis(phenoxy)phosphazene] and d sulfonated poly[bis(2-phenoxyethoxylphosphazene]...

An interesting polyphosphazene derivative, sulfonated poly[bis(2-phen-oxyethoxy)phosphazene], was reported by Paulsdorf et al. [35] (Fig. 7d). Living cationic polymerization of CI3P = NSi(CH3)3 monomer was used to obtain PDCP, which was reacted with 2-phenoxyethanol. The aryl substituents... 

While promising results were reported with all of the above systems, especially encouraging direct methanol fuel-cell performance data were obtained with membrane prepared from blends of sulfonated poly[bis(phenoxy)phos-phazene] (SPBPP) and PBI [34]. The effect of FBI content on room-temperature membrane proton conductivity, room-temperature water uptake, and methanol permeability (at 60°) is shown in Fig. 12. 

Fig. 13 DSC thermograms of four blends of sulfonated poly[bis(phenoxy)phosphazene] with PBI (SPBPP-PBI), imsulfonated poly[bis(phenoxy)phosphazene] (PBPP) and pure sulfonated poly[bis(phenoxy)phosphazene] (SPBPP) with an IEC= 1.4mmol/g. The two vertical broken lines depict the glass transitions of the PBPP (-3 °C) and SPBPP (59°)...

Fig. 17 Direct methanol fuel-cell performance curves with blended membranes containing sulfonated poly[bis(3-methylphenoxy)phosphazene] and PAN. 1.0 M methanol feed, 60 °C, air at 50 seem and 30psi back pressure. Cross denotes the methanol crossover flux (mol/cm min) at open circuit, relative to that in Nafion 117...

Fig. 19 The effect of methanol feed concentration on the maximum power density in a direct methanol fuel cell, for Nafion 117 and two PBI-doped sulfonated poly[bis(phen-oxy)phosphazene] membranes...

Poiyphosphazene Biends Blends of sulfonated polyphosphazene, for example, sulfonated poly[bis(3-methylphenoxy)phosphazene] or poly[(bisphenoxy)phosphazene] (see Fig. 29.14) with either an inert organic polymer such as poly(vinylidene fluoride) (Pintauro and Wycisk, 2004 Wycisk et al., 2002) or polyacrylonitrile (Carter et al., 2002) or a reactive polymer (e.g., polybenzimidazole) (Wycisk et al., 2005) have been investigated. The resultant membranes had conductivities of 0.01-0.06 S/cm (in water at 25°C) and equilibrium water swelling from 20 to 60% (at 25°C). Blends of poly[(bisphe-noxy)phosphazene] and polybenzimidazole (where acid-base complexation occurred between the sulfonic acid and the imidazole nitrogen) exhibited good mechanical properties and low methanol permeability. MEAs with this membrane material outperformed Nafion 117 in a DMFC at 60°C with concentrated (5-10 M) methanol feeds. With 1.0 M methanol and 0.5 L/min ambient air at 60°C, the maximum power density was 97 mW/cm and the methanol crossover was 2.5 times lower than that with Nafion 117 (Wycisk et al., 2005). 

Tang H and Pintauro P N (2001) Polyphosphazene membranes IV. Polymer morphology and proton conductivity in sulfonated poly bis(3-methylphenoxy) phosphazene films. J Appl. Polym. Sci., 79, pp. 49-59. 

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