A bio-compatible, biodegradable macromolecular water-absorbent polymeric
material having a three-dimensional configuration with intermolecular
covalent bonds and containing free functional groups selected from OH, SH,
NH.sub.2, and COOH. The polymer is formed by polymer-polymer
inter-coupling interaction between a natural water-soluble polymer A or
its derivatives having a molecular weight between 20,000 and 500,000 Da,
and a synthetic polymer B in a ratio of A:B of 15:85 to 85:15. The natural
polymer A can be selected from--a non-ionic natural, partially denatured
or chemically modified polymer that does not dissociate in water and which
can undergo polymer-polymer intercoupling reactions, or an anionic
natural, partially denatured or chemically modified polymer, that
dissociates in water to form anions and which can undergo polymer-polymer
intercoupling reactions, --or a cationic natural, partially denatured or
chemically modified polymer, that dissociates in water to form cations and
which can undergo polymer-polymer intercoupling reactions or an amphoteric
natural, partially denatured or chemically modified polymer, that
dissociates in water to form both anions and cations and which can undergo
polymer-polymer intercoupling reactions, or mixtures thereof.
