Method of making ligand functionalized substrates
View Patent ↗Ligand functionalized substrates, methods of making ligand functionalized substrates, and methods of using functionalized substrates are disclosed. The ligand functionalized substrate may be described as the grafted reaction product of a substrate and a ligand monomer of Formula I:
1. A method of making a ligand functionalized substrate, the method comprises the steps of:
1) providing a base substrate;
2) coating the substrate with a solution comprising (a) at least one grafting monomer having an acryloyl group and a photoinitiator group; (b) one or more ligand monomers of the formula:
wherein
R 1 is H or C 1 -C 4 alkyl,
R 2 is a divalent alkylene optionally containing an ester, amide, urethane or urea linking group;
each R 3 is independently H or C 1 -C 4 alkyl,
R 4 is H, C 1 -C 4 alkyl or —N(R 3 ) 2 ; and
X 1 is —O— or —NR 3 —, (c) optionally one or more monomers having at least one acryloyl group and at least one additional ethylenically unsaturated, free-radically polymerizable group; and (d) optionally one or more hydrophilic monomers;
3) exposing the coated base substrate to ionizing radiation to form a first functionalized substrate comprising grafted photoinitiator groups attached to the surface of the base substrate and unreacted (b), (c) and (d) monomers having ethylenically unsaturated, free-radically polymerizable groups, and
4) exposing the base substrate comprising grafted photoinitiator groups to UV radiation to polymerize the remaining ethylenically unsaturated, free-radically polymerizable groups of the (b), (c) and (d) monomers.
2. The method of claim 1 wherein said substrate is a porous substrate having interstitial and outer surfaces.
3. The method of claim 2 wherein the step of coating comprises imbibing the porous base substrate with the solution.
4. The method of claim 1 wherein said ionizing radiation is gamma or electron beam radiation.
5. The method of claim 1 wherein said monomers (c) having least one acryloyl group and at least one additional ethylenically unsaturated, free-radically polymerizable group comprises a first acryloyl group for grafting to said porous base substrate and a second methacryloyl group for subsequent UV polymerization.
6. The method of claim 1 wherein said monomer c) is of the formula:
[CH 2 ═CH—C(O)—X 1 ] a —R 10 -Q-Z b ,
where Z is an acryloyl or non-acryloyl, ethylenically unsaturated polymerizable group,
X 1 is —O— or —NR 3 , where R 3 is H or C 1 -C 4 alkyl,
Q is a divalent linking group selected from a covalent bond, —O—, —NR 1 —, —CO 2 — and —CONR 1 —, where R 1 is H or C 1 -C 4 alkyl; and
R 10 is an alkylene group, and optionally containing one or more ether oxygen atoms and/or one or more hydroxyl groups;
and a and b are each at least one.
7. The method of claim 1 , wherein the base substrate is microporous.
8. The method of claim 1 , wherein the base substrate is selected from a porous membrane, porous non-woven web, or porous fiber.
9. The method of claim 1 , wherein the monomer c) comprises a poly(alkylene oxide) compound having at least one acryloyl group and at least one additional ethylenically unsaturated, free-radically polymerizable group.
10. The method of claim 9 , wherein the monomer c) is of the formula:
Z-Q-(CH(R 1 )—CH 2 —O) n —C(O)—CH═CH 2 ,
wherein Z is an acryloyl or non-acryloyl, polymerizable ethylenically unsaturated group, R 1 is a H or a C 1 to C 4 alkyl group, and n is from 2 to 100, and Q is a divalent linking group selected from a covalent bond, —O—, —NR 1 —, —CO 2 — and —CONR 1 —, where R 1 is H or C 1 -C 4 alkyl.
11. The method of claim 1 , wherein said solution comprises one or more additional monomers having a free-radically polymerizable group and a hydrophilic group.
12. The method of claim 1 wherein said hydrophilic monomers are of the formula:
CH 2 ═CR 1 —C(O)—X 1 —(CH(R 1 )—CH 2 —O) n —R 1 ,
wherein each R 1 is independently H or C 1 -C 4 alkyl, X 1 is —O— or —NR 3 —, where R 3 is H or C 1 -C 4 alkyl.
13. The method of claim 7 , wherein the microporous base substrate is formed by a thermally-induced phase separation (TIPS) method.
14. The method of claim 7 , wherein the microporous base substrate comprises poly(vinylidine fluoride) microporous base substrate.
15. The method of claim 1 , wherein the ionizing radiation is electron beam radiation at a dosage of less than 80 kGy.
16. The method of claim 1 wherein said ligand monomer is the formula:
where
R 1 is H or C 1 -C 4 alkyl,
each R 3 is independently H or C 1 -C 4 alkyl,
R 4 is H, C 1 -C 4 alkyl or —N(R 3 ) 2 ,
X 1 is —O— or —NR 3 —, where R 3 is H or C 1 -C 4 alkyl,
R 7 and R 8 are each independently is C 1 to C 10 alkylene; and
Z is an ester, amide, urea, or urethane group.