Allyl ether-functional polycarbonates, synthesized by organocatalytic ring-opening polymerization of the six-membered cyclic carbonate monomer 2-allyloxymethyl-2-ethyltrimethylene carbonate, were used to prepare non-polyether polymer electrolytes. UV-crosslinking of the allyl side groups provided mechanically stable electrolytes with improved molecular flexibility-T-g below -20 degrees C-and higher ionic conductivity-up to 4.3 x 10(-7) S/cm at 25 degrees C and 5.2 x 10(-6) S/cm at 60 degrees C-due to the plasticizing properties of the allyl ether side groups. The electrolyte function was additionally demonstrated in thin-film Li battery cells. (C) 2016 Wiley Periodicals, Inc.