Polymer groups acidic

The resins used are highly cross-linked organic polymers with acidic functional groups. The most common of the resins used are sulfonated copolymers of styrene and divinylben2ene (see Ion exchange). 

Membrane research is a rather diverse field, exploiting perfluorinated iono-mers, hydrocarbon and aromatic polymers, and acid-base polymer complexes. Polyether and polyketo polymers with statistically sulfonated phenylene groups such as sPEK, sPEEK, and sPEEKK or polymers on the basis of benzimidazole have been tested as well. Recent reviews on membrane synthesis and experimental characterization can be found in the literature. ... 

The overall objective of these studies is to unravel mechanisms of interfacial PT. This requires identification of collective coordinates (or reaction coordinates) and transition pathways of transferring protons. Differences in activation energies and rates of corresponding mechanism due to distinct polymer constituents, acid head groups, side chain lengths, side chain densities, and levels of hydration have to be examined. Comparison with experimental... 

Note 2 A polymer bearing acid or basic groups is called a polymer acid or a polymer base, respectively. 

ROMP polymers bearing acid chloride, phosphonate, carbodiimide, phosphonyl chloride, and phosphine groups have been used as platforms in phase-switching, sequestration, capture-release, and soluble support applications. 

It is also possible to fluorinate hydrocarbon polymers containing acid groups as a means toward functionalization. We have found that the most successful route is first to convert the acid to an acid fluoride and then to conduct the fluorination as shown in example (c) ... 

Recently, various kinds of solid superacids have been developed. The first group is metal oxides and mixed oxides containing a small amount of sulfate ion, and those modified with platinum. The second group is metal oxides, mixed oxides, graphite, metal salts, etc. treated or combined with antimony fluoride or aluminum chloride. The third group is perfluorinated polymer sulfuric acid (Nafion-H). The fourth and fifth groups are H-ZSM-5 and a type of heteropolyacids, respectively. The last group is simply mixed oxides. 

A substance later shown to be muramic acid (see Section IV,6) was clearly different from the product of Vi antigen, and, although the strain used in some of the Vi studies (Escherichia coli 5396/38) is one in which sialic acid has been detected, the properties of the Vi antigen are markedly different from the neuraminic acid pol3oner. Infrared spectra recorded for crystalline V-acetyl-neuraminic acid exhibit full detail and cannot be compared with that published for aminohexuronic acid, but that of the amorphous neuraminic acid polymer (colominic acid) is rather similar to that of the Vi antigen polymeric unit, since their functional groups are very similar. The relationship of these substances to the property of 0 -inagglutinability is discussed later (see p. 336). 

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