A polyamphoteric superabsorbent copolymer made up of polymerizerable acid monomer and of polymerizable base monomer and optionally a supplemental monomer. In particular, the invention includes a radiation curable coating composition that comprises from about 20 weight % to about 80 weight % of polymerizerable acid monomer and from about 20 weight % to about 80 weight of polymerizable base monomer; and from 0 weight % to about 50 weight % of supplemental monomer. On exposure to radiation the coating composition forms a polyamphoteric superabsorbent copolymer. The radiation curable coating composition may be used with suitable substrates.
