Porous, absorbent, polymeric macrostructures and methods of making the same

A method for producing a porous, absorbent, polymeric macrostructure comprising an interparticle crosslinked aggregate having pores interconnected by intercommunicating channels so that the macrostructure is liquid permeable, the method comprising the steps of:

• (a) providing a multiplicity of substantially dry precursor particles of substantially water-insoluble, absorbent, hydrogel-forming, polymer material, said polymer material of said precursor particles being selected from the group consisting of hydrolyzed starch-acrylonitrile graft copolymer;
• partially neutralized starch-acrylonitrile graft copolymer;
• starch-acrylic acid graft copolymer;
• partially neutralized starch-acrylic acid graft copolymer;
• saponified vinyl acetate-acrylic ester copolymers;
• hydrolyzed acrylonitrile or acrylamide copolymers;
• slightly network crosslinked products of any of the foregoing copolymers;
• partially neutralized polyacrylic acid;
• or slightly network crosslinked products of partially neutralized polyacrylic acid;
• (b) applying an interparticle crosslinking agent onto said precursor particles, said interparticle crosslinking agent being selected from the group consisting of polyhydric alcohol compounds, polyglycidyl ether compounds, polyfunctional aziridine compounds, polyfunctional amine compounds, and polyfunctional isocyanate compounds;
• (c) physically associating said precursor particles to form an aggregate having pores interconnected by intercommunicating channels;
• (d) shaping the aggregate to a desired shape, size, and/or density;
• and
• (e) subsequently heating said interparticle crosslinking agent and said aggregate to react said interparticle crosslinking agent with said polymer material of said precursor particles of said aggregate, while maintaining the physical association of said precursor particles, to form crosslink bonds between said precursor particles to form an interparticle crosslinked aggregate macrostructure.