Oxygen Polyethylene oxide

Deep fluonnation using the La-Mar technique was carried out on polymers such as polyethylene and polypropylene [M], on polyethers [19, 20, 21], and on polyesters subsequently treated with sulfur Cetrafluoride [22] Deep fluorinations carried out under conditions producing limited fragmentation produced oligomeric perlluoropolyethers from powdered polyethylene oxide [23] Deep fluorinations earned out in the limited presence of molecular oxygen result in the conversion of... 

The oxygen atoms in polyethylene oxide, POM, enhance the fra rotation of the atoms in the chain. Nevertheless, because of good structural symmetry, these polymers are crystalline. 

High-molecular-weight polymers of polyethylene oxide of MW > 100,000 are prepared by a coordination polymerization with alkali earth metal compounds. These catalysts activate the epoxide ring by forming complexes with the oxygen in the oxide with the alkali earth metal ... 

Typical examples of the first group are polyethylene oxide [140-144] and polypropylene oxide [145-146] mixed with lithium salts. The oxygen atoms of these polymers interact with the Li ions and solvate them, and thus the Li salt may be uniformly dissolved in these polymers. 

The most well-known member of this class is the polyether, polyethylene oxide, whose complexes with lithium perchlorate have been used commercially in lithium batteries.60-62 The good solvating power of polyethylene oxide is attributed to an optimal spacing of the electron-donating ether oxygens along a flexible backbone that allows multiple contacts between the polymer backbone and cations. When this distance is decreased, as in polymethylene oxide, chain flexibility is greatly reduced when it is increased, as in 1,3-polypropylene oxide, the distance between... 

Figure 4. Backbone structures of salt-solvating polymers. The figure shows the similarity of backbone structure, with optimal spacing between electron-donating oxygens, of polymers that form ion-conducting salt complexes. PPL-poly-3-propiolac-tone PEO polyethylene oxide PPO 1,2- polypropylene oxide.18...

A specific feature of these systems, as compared to vinyl monomers, is a reduced predisposition to dissociation and an enhanced predisposition to the association of ion pairs. This is explained by a greater localization of charge on the end oxygen atom of polyethylene oxide), as compared to the carbon atom in the polymerization of vinyl compounds. 

Consistent with the above observations is the recently proposed order of the intermolecular reaction rates in polyethylene oxide amorphous > interfacial > crystalline [Zhang et al., 1992]. The role of oxygen diffusion during the radiation-induced degradation was also brought out by the work of Burillo et al. [1992], who found that, because of the reduced diffusion of oxygen, the extent of oxidative reactions was lower in compressed PVC samples (P < 880 MPa) than in uncompressed ones. 

The introduction of oxygen into the hydrocarbon chain of polymers rednces their thermal stability. This trend is illustrated by the examples of polyformaldehyde (T g = 170 "C), polyethylene oxide (PEO Tjg= 345 °C), isotactic polypropylene oxide (iPPO Tjg = 195 °C) and atactic polypropylene oxide (T = 295 "C) here thermal resistances are lower than those in the corresponding hydrocarbon polymers, namely polyethylene (T g = 406 "C) and polypropylene (T g = 390 °C). 

Solid polymer electrolytes made of polyethylene oxide (PEO) and polypropylene oxide (PPO) are considered because of their strong thermal conduction and electrochemical properties over a wide operating temperature range [114,115]. However, the low room temperature ionic conductivities exhibited by PEO and PPO solid state polymer electrolytes prevents successful application in ESs. When PEO was incorporated into a gel electrolyte to boost conductivity, the result indicated that PEO and PPO are actually found inferior compared to PVA and PVdF for gel electrolytes because the oxygen atoms in the polymer backbone limit ion mobility [115]. 

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