Ruthenium catalyzed step growth copolymerization of 4′-acetylbenzo-15-crown-5 and 4′-acetylbenzo-18-crown-6 and α,ω-dienes such as 1,3-divinyltetramethyldisiloxane or 3,3,6,6-tetramethyl-3,6-disila-1,7-octadiene give novel copolymers which incorporate crown ethers into the polymer backbone in a regular manner. The synthesis of these thermally stable copolymers and their characterization is reported. Lithium cation crown complexes have been formed.