Described herein are double-strand chain compositions suitable for use in the preparation of proton conductive membranes. The double-strand chains comprise a plurality of constitutional units joined to each other through two atoms on one side of the constitutional unit and two atoms on the other side of the constitutional unit. Constitutional units comprise a dibenzo-crown ether macrocycle fused with a bicyclic aliphatic linker. Polymers, membranes, and fuel cells comprising the double-strand chain are also described herein.