Polymers ionomers

Ion-exchanger membranes with fixed ion-exchanger sites contain ion conductive polymers (ionomers) the properties of which have already been described on p. 128. These membranes are either homogeneous, consisting only of a polyelectrolyte that may be chemically bonded to an un-ionized polymer matrix, and heterogeneous, where the grains of polyelectrolyte are incorporated into an un-ionized polymer membrane. The electrochemical behaviour of these two groups does not differ substantially. 

The linkage between two chains can also be ionic. Thus the copolymer between ethylene and methacrylic acid (MA) (up to 15% MA), made by free radical polymerisation, yields a polymer with pendant carboxyl groups. Neutralisation with zinc ions gives a crosslinked, thermo-reversible polymer (Surlyn ). The resulting polymer (ionomer) has limited properties, although it is the favoured material for the outer covering of golf balls. 

PEMFCs generally operate at temperatures <100°C. PFSA-based polymer ionomer membranes like Nafion, Gore, Aciplex, and Flemion are not significantly affected by temperatures up to 150°C where most of the water is lost and membranes may suffer irreversible dry out. Chemical degradation of these membranes in the form usually starts with the loss of sulfonate groups at over 220°C [7]. 

Bazuin CG, Eisenberg A (1981) Ion-containing polymers ionomers. J Chem Educ 58 938-943... 

Figure 1.3 illustrates the cathode catalyst layer. In the cathode catalyst layers, protons transfer in the polymer (ionomer), a material similar to the membrane, which covers the surface of carbon agglomerates. Electrons transfer in the carbon agglomerates in a chain structure. Oxygen transfers... 

The basic concept to use block co-polymer for the application to the DMFC is that ordered hydrophilic/hydrophobic phase separations offer a route for the selective transport of proton ions with reduced methanol crossover in the hydrophilic domains, because block co-polymers can be selectively sulfonated using post-sulfonation methods, and the block co-polymers can be verified over a wide range of structures during anionic polymerization. For example, methanol transport behaviors of a triblock co-polymer ionomer, sulfonated poly(styrene-isobutylene-styrene) (S-SIBS), were compared with Nafion to determine whether the sulfonated block co-polymer could serve as a viable alternative membrane for application to the DMFC [62]. The S-SIBS membranes showed approximately 5-10 times more methanol selectivity than that of Nafionll , although the S-SIBS membranes exhibited low conductivity compared with Nafion 117. 

Hybrid membranes produced from strongly interacting super acid inorganic components and superacid polymer ionomers (PFSA polymer imbibed HP A)... 

Polymer acid complexes (PAC) containing strong ionic interactirais between a basic polymer ionomer and an inorganic acid (hydrocarbon imbibed HPA)... 

The final section of the book deals with association of weakly ionic polymers (ionomers) in non-aqueous solvents. This area of study may bridge the gap between the fields of polyelectrolytes and ionomers. In the former case, the... 

Physical Spray Deposition on DM or Electrolyte Surface In this method, a slurry of catalyst, support, PTFE, solubilized polymer ionomer, and alcohol compounds (to... 

When ion-exchange polymers (ionomers), for which = 1, are used for the... 

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