Oxide fluoride glasses glass transition temperature

Copolymers from tetrafluoroethylene and 40% perfluorovinyl methyl ether are also elastomers (glass-transition temperature — 12°C). The copolymerization is carried out in aqueous emulsion with ammonium perfluoro-octanoate as emulsifier. Vulcanization is possible with hexamethylene diamine via the small amount of perfluoro(4-carboxy methyl butyl vinyl ether) also polymerized into the copolymer. This ether is produced from perfluoroglutaryl fluoride and hexafluoropropylene oxide. 

Fig. 15. Changes of the glass transition temperature for a series of poisoner solutions and an effort to fit the data to equations 42 to 44. [PMMA = poly(methyl methacrylate), PVF2 = polyfvinylidene fluoride), PEO = poly(ethylene oxide), PEA = poly(ethylene adipate), PBA = polyfbutylene adipate), PVC = poly(vinyl chloride), PCL = poly(e-caprolactone)].

First, studying different polar polymers [258,263-265] such as poly(ethylene oxide) (PEO), polyvinyUdene fluoride (PVdF), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), and polyvinyl chloride (PVC) in order to enhance the ionic conductivity of the SPEs. PEO has been foimd to be the most successful host material for SPEs due to its low glass transition temperature (-60 °C) [266]. Second, increasing the niunber of charge carriers by use of highly dissociable salts, and increasing the salt concentration. Third, suppressing the crystallization of the polymer chains reduces the conductivity at room temperature ([Pg.1101]

For all other oxide, fluoride, chalcogenide, metallic, polymer and molecular glasses, for which viscosity data is available in wide temperature ranges, log(77) vs 1/T plots have a negative curvature and thus the apparent values of decrease with temperature. The activation enthalphy for flow can vary by almost an order of magnitude between the melting point and the glass transition, as shown in Table 2 [1]. 

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