Polymethacrylates carrying cyclic carbonate through urethane linkage were prepared by radical (co)polymerizations of 2-methacrylic acid 2-(2-oxo-[1,3]dioxolan-4-ylmethoxycarbonylamino)ethyl ester (CUMA). Although brittleness of typical polymers bearing cyclic carbonate groups has been limited their practical applications, some copolymers from CUNU can be cast as films with good flexibility. The copolymers from CUMA and diethyleneglycol methyl ether methacrylate are miscible with lithium bis(trifluoromethanesulfone)imide. The coordination of the lithium cation to the carbonyl groups was confirmed by infrared spectrometry. (c) 2007 Wiley Periodicals, Inc.