Different natural polymer-based ionic

Table 3.3 Summary of the different natural polymer-based ionic conducting systems...

To be informative, it is desirable that the comparisons of these two different technologies be based on identical polymer backbones, having identical molecular weights, and having comparable levels of ionic functionality present. In addition, it is the purpose of these studies to make such comparisons with the same metal cation and thereby quantify, insofar as possible, the nature of the ionic interactions that exist. To do this, ionomers were prepared based on a polystyrene (PS) hydrocarbon backbone into which the ionic functionality was incorporated. PS was selected as the backbone because of the relative ease of functionalization and the relative freedom of side reactions during the sulfonation or carboxylation reactions. The polymers prepared were designed to come as close as possible in terms of ionic functionality for both sulfonate and carboxylate ionomers over a range of ionic contents. 

Abstract The development of new materials that can be apphed as solid electrolytes has led to the creation of modern systems of energy generation and storage. Among different poly(ethylene oxide)-based electrolytes, natural polymers, snch as hydroxyethylcellnlose, hydroxypropylcellulose or carboxymethylcellulose, starch and chitosan or proteins like gelatin, are also proposed. After salt or acid addition, the transparent membranes show ionic conductivity values of 10 S/cm and can be apphed with good stability results to electrochromic devices. 

Among the polymer electrolytes obtained from natural polymers, Klink-lai et reported ionic conductivity and NMR spectroscopy of polymer electrolytes formed by the mixture of liquid epoxidized natural rubber with Uthium salts. The authors discussed the correlation between the spin-lattice relaxation times with the solubility of the different lithium salts in the deprotonized liquid rubber. Based on the NMR chemical shift and the resonance half-width and the spin-lattice relaxation times results they concluded that lithium bis(trifiuoro methane sulfonyl)imide is a suitable salt for forming polymer electrolytes with deprotonized liquid natural rubber. 

The different behavior of the catalysts apparently arises from the nature of the transition metal of the catalyst. It seems reasonable to treat the mechanism of stereospecific olefin polymerization in terms of coordination ionic catalysts, regarding the valence state, coordination number, and nature of ligands of the transition metal as a matter of primary importance. In such an approach the polymerization mechanism is based on the character of metal—carbon bond by which a growing polymer chain is linked to the transition metal. 

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