A coating having a hydrogel layer of a hydrogel of a polysaccharide and polymer brushes attached to the hydrogel layer. A process for making the coating, having the steps of: a) providing the hydrogel layer on a substrate, b) attaching an initiator having a radically transferable atom on the hydrogel layer and c) reacting monomers with the initiator to form the polymer brushes attached to the hydrogel layer.

A coating having a hydrogel layer of a hydrogel of a polysaccharide and polymer brushes attached to the hydrogel layer. A process for making the coating, having the steps of: a) providing the hydrogel layer on a substrate, b) attaching an initiator having a radically transferable atom on the hydrogel layer and c) reacting monomers with the initiator to form the polymer brushes attached to the hydrogel layer.

A water-soluble and/or water-swellable hybrid polymer comprising: (i) from 5 wt.-% to 95 wt.-% water-soluble and/or water-swellable polysaccharide polymer; (ii) from 5 wt.-% to 95 wt.-% synthetic polymer comprising: (a) from 40 mol-% to 99.9 mol-% repeating units according to Formula (1)

##STR00001## (b) from 0.01 mol-% to 5 mol-% crosslinking or branching units, wherein the crosslinking or branching units result from the incorporation of a monomer comprising at least two olefinically unsaturated double bonds; (c) from 0.01 mol-% to 88.51 mol-% of neutral structural units; (d) from 1.98 mol-% to 20 mol-% of anionic structural units, wherein the repeating anionic structural units result from the incorporation of a monomer comprising at least one carboxylate anion, and wherein the repeating anionic structural units are different from units (a);
wherein components (i) and (ii) are polymerized by radical precipitation polymerization in a polar solvent.

A water-soluble and/or water-swellable hybrid polymer comprising: (i) from 5 wt.-% to 95 wt.-% water-soluble and/or water-swellable polysaccharide polymer; (ii) from 5 wt.-% to 95 wt.-% synthetic polymer comprising: (a) from 40 mol-% to 99.9 mol-% repeating units according to Formula (1)

##STR00001## (b) from 0.01 mol-% to 5 mol-% crosslinking or branching units, wherein the crosslinking or branching units result from the incorporation of a monomer comprising at least two olefinically unsaturated double bonds; (c) from 0.01 mol-% to 88.51 mol-% of neutral structural units; (d) from 1.98 mol-% to 20 mol-% of anionic structural units, wherein the repeating anionic structural units result from the incorporation of a monomer comprising at least one carboxylate anion, and wherein the repeating anionic structural units are different from units (a);
wherein components (i) and (ii) are polymerized by radical precipitation polymerization in a polar solvent.

A water-soluble and/or water-swellable hybrid polymer comprising: (i) from 5 wt.-% to 95 wt.-% water-soluble and/or water-swellable polysaccharide polymer; (ii) from 5 wt.-% to 95 wt.-% synthetic polymer comprising: (a) from 40 mol-% to 99.9 mol-% repeating units according to Formula (1)

##STR00001## (b) from 0.01 mol-% to 5 mol-% crosslinking or branching units, wherein the crosslinking or branching units result from the incorporation of a monomer comprising at least two olefinically unsaturated double bonds; (c) from 0.01 mol-% to 88.51 mol-% of neutral structural units; (d) from 1.98 mol-% to 20 mol-% of anionic structural units, wherein the repeating anionic structural units result from the incorporation of a monomer comprising at least one carboxylate anion, and wherein the repeating anionic structural units are different from units (a);
wherein components (i) and (ii) are polymerized by radical precipitation polymerization in a polar solvent.

A water-soluble and/or water-swellable hybrid polymer comprising: (i) from 5 wt.-% to 95 wt.-% water-soluble and/or water-swellable polysaccharide polymer; (ii) from 5 wt.-% to 95 wt.-% synthetic polymer comprising: (a) from 40 mol-% to 99 mol-% of repeating units according to Formula (1)

##STR00001## (b) from 0.01 mol-% to 5 mol-% crosslinking or branching units, wherein the crosslinking or branching units result from the incorporation of a monomer comprising at least two olefinically unsaturated double bonds; (c) from 0.99 mol-% to 59.99 mol-% of repeating neutral structural units;
wherein components (i) and (ii) are polymerized by radical precipitation polymerization in a polar solvent.

A water-soluble and/or water-swellable hybrid polymer comprising: (i) from 5 wt.-% to 95 wt.-% water-soluble and/or water-swellable polysaccharide polymer; (ii) from 5 wt.-% to 95 wt.-% synthetic polymer comprising: (a) from 40 mol-% to 99 mol-% of repeating units according to Formula (1)

##STR00001## (b) from 0.01 mol-% to 5 mol-% crosslinking or branching units, wherein the crosslinking or branching units result from the incorporation of a monomer comprising at least two olefinically unsaturated double bonds; (c) from 0.99 mol-% to 59.99 mol-% of repeating neutral structural units;
wherein components (i) and (ii) are polymerized by radical precipitation polymerization in a polar solvent.

A water-soluble and/or water-swellable hybrid polymer comprising: (i) from 5 wt.-% to 95 wt.-% water-soluble and/or water-swellable polysaccharide polymer; (ii) from 5 wt.-% to 95 wt.-% synthetic polymer comprising: (a) from 40 mol-% to 99 mol-% of repeating units according to Formula (1)

##STR00001## (b) from 0.01 mol-% to 5 mol-% crosslinking or branching units, wherein the crosslinking or branching units result from the incorporation of a monomer comprising at least two olefinically unsaturated double bonds; (c) from 0.99 mol-% to 59.99 mol-% of repeating neutral structural units;
wherein components (i) and (ii) are polymerized by radical precipitation polymerization in a polar solvent.

A water-soluble and/or water-swellable hybrid polymer comprising: (i) from 5 wt.-% to 95 wt.-% water-soluble and/or water-swellable polysaccharide polymer; (ii) from 5 wt.-% to 95 wt.-% synthetic polymer comprising: (a) from 90 mol-% to 99.9 mol-%, preferably 95 mol-% to 99.5 mol-% of repeating units according to Formula (1)

##STR00001## (b) from 0.01 mol-% to 10 mol-%, preferably to 5 mol-%, more preferably to 3 mol-% of crosslinking or branching units, wherein the crosslinking or branching units result from the incorporation of a monomer comprising at least two olefinically unsaturated double bonds;
characterised in that the components (i) and (ii) are polymerised by radical precipitation polymerisation in a polar solvent.

A water-soluble and/or water-swellable hybrid polymer comprising: (i) from 5 wt.-% to 95 wt.-% water-soluble and/or water-swellable polysaccharide polymer; (ii) from 5 wt.-% to 95 wt.-% synthetic polymer comprising: (a) from 90 mol-% to 99.9 mol-%, preferably 95 mol-% to 99.5 mol-% of repeating units according to Formula (1)

##STR00001## (b) from 0.01 mol-% to 10 mol-%, preferably to 5 mol-%, more preferably to 3 mol-% of crosslinking or branching units, wherein the crosslinking or branching units result from the incorporation of a monomer comprising at least two olefinically unsaturated double bonds;
characterised in that the components (i) and (ii) are polymerised by radical precipitation polymerisation in a polar solvent.