Acrylamide-based crosslinking monomers, their preparation, and uses thereof
A process for preparing an acrylamide-based crosslinking monomer comprising reacting in the presence of a catalyst an isocyanate compound containing at least two isocyanate groups with one of acrylic acid or methacrylic acid. These acrylamide-based crosslinking monomers are used in the preparation of coating compositions, adhesive compositions curable by applying thermal or radiation energy, and in the preparation of cation or anion exchange membranes.
1. A process for preparing a highly crosslinked ion exchange membrane comprising:
polymerizing a homogenous solution comprising:
an ionic monomer having an ionic group selected from the group consisting of sulfonic acid groups, sulfonate groups, and quaternary ammonium groups; and
an acrylamide-based crosslinking monomer having a chemical structure shown in Formula 1;
wherein R is selected from the group consisting of isophorone groups, methylene dicyclohexyl groups, methylene diphenyl groups, and trimethylhexamethylene groups;
wherein R′ is a hydrogen atom or a methyl group; and
wherein the acrylamide-based crosslinking monomer percentage in mixed monomers of ionic monomer and the acrylamide-based crosslinking monomer is above 44 wt %.
2. The process according to claim 1 , wherein the ion exchange membrane is a cation exchange membrane; and
wherein the ionic monomer is selected from the group consisting of sodium 4-vinylbenzenesulfonate, 3-sulfopropyl acrylate potassium salt, 2-acrylamido-2-methyl-1-propanesulfonic acid, and 2-acrylamido-2-methyl-1-propanesulfonic acid salts.
3. The process according to claim 1 , wherein the ion exchange membrane is an anion exchange membrane; and
wherein the ionic monomer is selected from the group consisting of 3-acrylamidopropyl trimethylammonium chloride, 2-acryloyloxyethyl trimethylammonium chloride, 2-methacryloyloxyethyl trimethylammonium chloride, 3-methacryloylaminopropyl trimethylammonium chloride, and vinylbenzyl trimethylammonium chloride.
4. A process for preparing a highly crosslinked ion exchange membrane according to claim 1 ,
wherein the acrylamide-based crosslinking monomer is produced through a process comprising:
preparing a first solution comprising:
one of acrylic acid and methacrylic acid;
a solvent selected from the group consisting of chloroform, dichloromethane, dimethylacetamide, ethylene glycol dimethyl ether, N-methylpyrrolidone, and tetrahydrofuran; and
a catalyst selected from the group consisting of organometallic compounds, metal salts, tertiary amines, and combinations thereof;
preparing a second solution by adding into and mixing with the first solution an isocyanate compound having at least two isocyanate groups, the isocyanate compound selected from the group consisting of aliphatic isocyanates, cycloaliphatic isocyanates, oligomer isocyanates, and combinations thereof; and
mixing the second solution at a selected temperature for a period of time sufficient for formation of the acrylamide-based crosslinking monomer.