AbstractThe addition of dialkyl (R = Me or Et) carbonates to poly(oxyethylene)‐based solid polymeric electrolytes resulted in enhanced ionic conductivities. Relatively high conductivities in lithium batteries with solutions of lithium salts in di(oligooxyethylene) carbonates such as R(OCH2CH2)nOC(O)O(CH2CH2O)mR (R = Et, n = 1, 2, or 3, m = 0, 1, 2, or 3) and related carbonates were obtained. In this respect, related comb‐shaped poly(oligooxyethylene carbonate) vinyl ethers of the type CH2CH(OR) were prepared [R = (OCH2CH2)nOC(O)O(CH2CH2O)mR′; (1) n = 2 or 3, m = 0, R′ = Et; (2) n = 2 or 3; m = 3, R′ = Me]. The direct preparation of derived target polymers of this class by polymerization of the corresponding vinyl ether‐type monomers could not be achieved because of a rapid in situ decarboxylative decomposition of these monomers (as formed) during the final step of their synthesis. Instead, a prepolymer was prepared by a living cationic polymerization of CH2CH(OCH2CH2)nOC(O)CH3 (n = 2 or 3). The hydrolysis of its pendant ester groups, followed by the reaction of the hydrolyzed prepolymer with each of several alkyl chloroformates of the type ClC(O)O(CH2CH2O)mR′ (m = 0, 2, or 3, R′ = Me or Et) resulted in the corresponding target polymers. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2171–2183, 2002