Blends of poly(meth)acrylates with 2-oxo-(1,3)dioxolane side chains and lithium salts as lithium ion conductors

A novel approach is described to obtain polymers which show significant lithium ion conductivity when blended with lithium salts. Polymerization of acrylates and methacrylates with 2-oxo-1,3-dioxolane (cyclic carbonate) containing side chains gives polymers which contain the structural element of the prototypical solvent propylene carbonate (PC) firmly attached to the polymer host. (2-Oxo-1,3-dioxolane-4-yl)methyl methacrylate (DOMA) and the corresponding acrylate (DOA) were obtained by reaction of the (meth)acryloyl chloride with glycerol carbonate while (2-oxo-1,3-dioxolane-4-yl)butyl methacrylate (DOBMA) and the respective acrylate (DOBA) were obtained from the ω-hexenyl esters by first epoxidation followed by CO2-insertion into the oxirane ring. Free radical polymerization in DMF gave the desired polymers. All homopolymers were thermally stable at least up to 200 °C; the glass transition temperature was found for PDOMA at 93 °C, for PDOA at 50 °C, for PDOBMA at 16 °C, and for PDOBA at 11 °C. Free radi...