摘要 |
An amphipathic crosslinked polymer combining high pure-water absorption with high brine absorption; and a water-swellable sheet and water-swellable rubber each comprising the amphipathic crosslinked polymer. The amphipathic crosslinked polymer is characterized by being obtained by copolymerizing, as essential ingredients, a tertiary-amino-containing vinyl monomer as a basic vinyl monomer with a carboxylated vinyl monomer and a sulfonated vinyl monomer as acid vinyl monomers, and by having a pure-water absorption of 50 times or more and a 1.0 mol/L aqueous CaCl2 solution absorption of 10 times or more. |