Methacrylate‐functionalized poly(ethylene oxide‐co‐ethylene carbonate) macromonomers were prepared in two steps by the anionic ring‐opening polymerization of ethylene carbonate at 180 °C, with potassium methoxide as the initiator, followed by the reaction of the terminal hydroxyl groups of the polymers with methacryloyl chloride. The molecular weight of the polymer went through a maximum after approximately 45 min of polymerization, and the content of ethylene carbonate units in the polymer decreased with the reaction time. A polymer having a number‐average molecular weight of 2650 g mol−1 and an ethylene carbonate content of 28 mol % was selected and used to prepare a macromonomer, which was subsequently polymerized by UV irradiation in the presence of different concentrations of lithium bis(trifluoromethanesulfonyl)imide salt. The resulting self‐supportive crosslinked polymer electrolyte membranes reached ionic conductivities of 6.3 × 10−6 S cm−1 at 20 °C. The coordination of the lithium ions by both the ether and carbonate oxygens in the polymer structure was indicated by Fourier transform infrared spectroscopy. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2195–2205, 2006

No abstract

No abstract

Salt-containing membranes based on polymethacrylates having poly(ethylene carbonate-co-ethylene oxide) side chains, as well as their blends with poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), have been studied. Self-supportive ion conductive membranes were prepared by casting films of methacrylate functional poly(ethylene carbonate-co-ethylene oxide) macromonomers containing lithium bis(trifluorosulfonyl)imide (LiTFSI) salt, followed by irradiation with UV-light to polymerize the methacrylate units in situ. Homogenous electrolyte membranes based on the polymerized macromonomers showed a conductivity of 6.3 Â 10 À6 S cm À1 at 20 8C. The preparation of polymer blends, by the addition of PVDF-HFP to the electrolytes, was found to greatly improve the mechanical properties. However, the addition led to an increase of the glass transition temperature (T g ) of the ion conductive phase by $5 8C. The conductivity of the blend membranes was thus lower in relation to the corresponding homogeneous polymer electrolytes, and 2.5 Â 10 À6 S cm À1 was recorded for a membrane containing 10 wt % PVDF-HFP at 20 8C. Increasing the salt concentration in the blend membranes was found to increase the T g of the ion conductive component and decrease the propensity for the crystallization of the PVDF-HFP component. V V C 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: [79][80][81][82][83][84][85][86][87][88][89][90] 2007

No abstract