An article of footwear comprising a composition, wherein the composition comprises: a plurality of ionomeric copolymers, wherein each of the ionomeric copolymers comprises a plurality of a first repeat unit having a formula according to Formula I and a plurality of a second repeat unit having a formula according to Formula IIA, and a plurality of cations, wherein each of the cations is crosslinking two or more of the second repeat units; wherein each occurrence of R 1 is independently none, a substituted or unsubstituted C 1 -C 8 alkyl, or a substituted or unsubstituted C 2 -C 8 alkenyl; wherein each occurrence of R 2 is where each occurrence of R 4 is independently a hydrogen, a substituted or unsubstituted C 1 -C 8 alkyl; wherein each occurrence of R 3 is independently hydrogen, a substituted or unsubstituted C 1 -C 8 alkyl, or a substituted or unsubstituted C 2 -C 8 alkenyl; wherein each occurrence of R 5 is independently a hydrogen, a halogen, a substituted or unsubstituted C 1 -C 8 alkyl, a substituted or unsubstituted C 2 -C 8 alkenyl, a substituted or unsubstituted phenyl, a substituted or unsubstituted alkyl-phenyl, a substituted or unsubstituted C 1 -C 8 alkoxy, or a substituted or unsubstituted C 3 -C 12 alkyl ester; wherein each occurrence of R 6 is independently none, a substituted or unsubstituted C 1 -C 8 alkyl, a substituted or unsubstituted C 2 -C 8 alkenyl, a substituted or unsubstituted phenyl, a substituted or unsubstituted alkyl-phenyl, or a substituted or unsubstituted C 1 -C 8 alkoxy; wherein the composition is substantially free of covalent crosslinks between the ionomers; and wherein the composition is a foam having a specific gravity of 0.1 to 0.7. a plurality of ionomeric copolymers, wherein each of the ionomeric copolymers comprises a plurality of a first repeat unit having a formula according to Formula I and a plurality of a second repeat unit having a formula according to Formula IIA, and a plurality of cations, wherein each of the cations is crosslinking two or more of the second repeat units; wherein each occurrence of R 1 is independently none, a substituted or unsubstituted C 1 -C 8 alkyl, or a substituted or unsubstituted C 2 -C 8 alkenyl; wherein each occurrence of R 2 is where each occurrence of R 4 is independently a hydrogen, a substituted or unsubstituted C 1 -C 8 alkyl; wherein each occurrence of R 3 is independently hydrogen, a substituted or unsubstituted C 1 -C 8 alkyl, or a substituted or unsubstituted C 2 -C 8 alkenyl; wherein each occurrence of R 5 is independently a hydrogen, a halogen, a substituted or unsubstituted C 1 -C 8 alkyl, a substituted or unsubstituted C 2 -C 8 alkenyl, a substituted or unsubstituted phenyl, a substituted or unsubstituted alkyl-phenyl, a substituted or unsubstituted C 1 -C 8 alkoxy, or a substituted or unsubstituted C 3 -C 12 alkyl ester; wherein each occurrence of R 6 is independently none, a substituted or unsubstituted C 1 -C 8 alkyl, a substituted or unsubstituted C 2 -C 8 alkenyl, a substituted or unsubstituted phenyl, a substituted or unsubstituted alkyl-phenyl, or a substituted or unsubstituted C 1 -C 8 alkoxy; wherein the composition is substantially free of covalent crosslinks between the ionomers; and wherein the composition is a foam having a specific gravity of 0.1 to 0.7. <EOS>