Process for the modification of a material surface

Process for coating a material surface, comprising the steps of:

• (a) covalently binding polymerization initiator radicals to the material surface;
• (b) graft polymerizing a vinyl monomer carrying a reactive group onto the initiator-modified material surface to form a primary polymer coating comprising a plurality of polymer chains bound to the material surface, each polymer chain having reactive groups;
• and
• (c) covalently attaching hydrophilic side chains to each polymer chain by reacting the reactive groups of the primary polymer coating with a hydrophilic telomer having a functional group that is coreactive with the reactive groups of the polymer chains to form a polymeric coating having a bottle brush type structure, wherein the hydrophilic telomer has the formula of
• (oligomer)-X (3),
• wherein X is hydroxy, amino, C1-C6-alkylamino, carboxy or a carboxy derivative, and (oligomer) denotes
• (i) the radical of a telomer of formula
• -(alk)-S[Brketopenst]B[Brketclosest]p[Brketopenst]B′[Brketclosest]qQ (3a),
• wherein
• (alk) is C2-C12-alkylene,
• S is a sulfur atom,
• Q is a monovalent group that is suitable to act as a polymerization chain-reaction terminator,
• p and q are each independently of another an integer from 0 to 350, wherein the total of (p+q) is an integer from 2 to 350, and
• B and B′ are each independently of the other a 1,2-ethylene radical derivable from a copolymerizable vinyl monomer by replacing the vinylic double bond by a single bond, at least one of the radicals B and B′ being substituted by a hydrophilic substituent.