Poly(ethylene oxide) containing segmented networks as precursors for ion-conducting solid-state materials

Segmented networks containing high contents of poly(ethylene oxide) (PEO) have been investigated as a new type of polymer architecture in the field of solid ion-conducting materials. Such networks have been synthesized by the radical copolymerization of alpha,omega-bis-methacrylate-terminated PEO with several types of methacrylates. DMA analysis showed that the phase behaviour of the segmented networks is determined by the fraction and molecular weight of the PEO chains and by the nature of the second component. It has been demonstrated by DSC that, under certain conditions, a small fraction of polymethacrylate is sufficient to prevent the PEO chains from crystallization. Complex impedance measurements of the networks with different concentrations of lithium salt over a wide range of temperatures demonstrated the influence of the nature of the polymethacrylate on the performance of the solid polymer electrolytes. Ionic conductivities at room temperature up to 6 x 10(-5) S cm(-1) could be achieved for segmented networks containing a minor fraction of poly(n-butyl methacrylate). (C) 2002 Society of Chemical Industry.