Polymer positive

Figure 18. Calculated polymerization dynamics of trcin -butadiene. Arrows indicate the electronic doublets that are moving from the 1-2 and 3 7t bonds characteristic of the isolated molecule, to the new polymer position. In particular, the doublets that migrated to the molecule ends and that are ready to give the new C—C bond with the neighboring molecule should be noted.

It is perhaps useful to mention that the use of electronically conducting polymers, such as poly(acetylene), (CH) poly(pyrrole), (C4H5N)X, and poly(aniline), (CeHgNf ), has been proposed for positives for lithium batteries. The electrochemical process of these lithium-polymer positives is somewhat similar to an intercalation reaction. On charging, the polymer (P) is oxidized by acquiring a positive charge to form a polaron, and this is... 

The assumption that the polymer spectra and structure correspond to those of the model compounds rests essentially on the approximate correspondence of peak positions. It is important that the spectra be compared at approximately the same temperature, as there is a marked dependence of the peak positions upon temperature. For the polymer at 150°, the peak positions, in -values with respect to the solvent as + 63.8 , are 104.2, 106.0, 125.6, and 127.8. At 25°, the solvent peak position was found to be +63.2 if>, and the model compound peak positions were 106.3, 108.8, 126.6, and 128.9, deviating substantially from the polymer positions. When the model compound spectra are observed at 150°, there is a marked down-field" shift, which brings the - values into much closer correspondence with those of the polymer 104.1, 106.2, 126.2, and 127.7. There appear to be some small relative changes as well, particularly for the meso compound, for the appearance of its AB-type CFa resonance is distinctly temperature dependent. The most likely explanation for this behavior is that it arises from changes in the relative populations of the internal-rotation energy levels, which correspond to changes in the time-averaged conformational structures of the molecules. 

Positional isomerism is not generally an important issue in syntheses of polymers with backbones which do not consist exclusively of enchained carbons. This is because the monomers which form macromolecules such as poly(ethylcne terephthalate) (1-5) or nylon-6,6 (1-6) are chosen so as to produce symmetrical polymeric structures which facilitate the crystallization needed for many applications of these particular polymers. Positional isomerism can be introduced into such macromoicculcs by using unsymmetrical monomers like 1,2-propylene glycol (4-8), for example. This is what is done in the synthesis of some film-forming polymers like alkyds (Section 5.4.2) in which crystallization is undesirable. 

Electron Beam Polymers POSITIVE - DEGRADING TYPE... 

Barthet, C., et al. 1997. A polyaniline - - polyethylene oxide mixture as a composite polymer positive electrode in solid-state secondary batteries. J Electroanal Chem 431 145. 

Novak, P., Inganas, O., and BJorklund, R., Composite polymer positive electrode in solid state lithium secondary batteries, J. Electrochem. Soc., 134, 1341-1345 (1987). 

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