Alkylation of crosslinked polymers containing N or amino or ammonium groups
View Patent ↗The invention relates to a method for alkylating cross-linked polymers containing N- or amino, ammonium or spiro-bicyclic ammonium groups. According to said method, the gelated polymers, obtained by polymerization and cross-linking, are a) optionally, deprotonated in water, an organic solvent or in a mixture of an organic solvent and water, by adding a base, b) optionally, washed once or more with water, an organic solvent or a mixture of an organic solvent and water, then c) one or more alkylators are added to the gel suspension which is stirred in water, an organic solvent or in a mixture of an organic solvent and water, at a temperature of between 5 and 160° C. at normal or increased pressure, with a base being added after a short mixing time and d) reprotonation is carried out using a mineral acid, optionally after one or more washing steps, resulting in the alkylated, cross-linked polymers containing N- or amino, ammonium or spirobicyclic ammonium groups, accordingly.
1. A process for the alkylation of crosslinked polymers containing an amine N atom which comprises:
a) deprotonating a gelled polymer obtained by polymerization and crosslinking in water, an organic solvent or in an organic solvent/water mixture by addition of a base,
b) optionally washing the gelled polymer one or more times with water, an organic solvent or an organic solvent/water mixture, then
c) adding one or more alkylators at atmospheric or elevated pressure at a temperature of between 5 and 160° C. to a gel suspension formed by stirring said gel polymer in water, an organic solvent or in an organic solvent/water mixture, and, after a mixing time of 1 to 60 minutes, adding the base continually or in plural portions in such a way that the pH is between 8 and 13.5, and
d) reprotonating by means of a mineral acid, after one or more optional washing steps, whereby the correspondingly alkylated, crosslinked polymers containing an amine N atom is obtained.
2. The process as claimed in claim 1 , wherein the polymers containing an amine N atom are crosslinked, cationic polymers which contain primary, secondary or tertiary amine groups or salts thereof and/or quatemary ammonium groups and/or spirobicyclic ammonium groups, amidino groups, guanidino groups or imino groups, and also negatively charged inorganic and/or organic counterions selected from the group consisting of halides, phosphates, phosphites, carbonates, bicarbonates, sulfates, bisulfates, hydroxides, nitrates, persulfates, sulfites and sulfides, acetates, ascorbates, benzoates, lactates, fumarates, maleates, pyruvates, citrates, dihydrogencitrates, hydrogen citrates, propinonates, butyrates, oxalates, succinates, tartrates and cholates.
3. The process as claimed in claim 1 , wherein the polymers containing an amine N atom are crosslinked polyvinylamines, polyallylamines, polydiallylamines, polyvinylimidazoles, polydiallylalkylamines or polyethylenimines having suitable counterions.
4. The process as claimed in claim 1 , wherein said gel employed in step a) optionally is comminuted or cut and treated at a temperature of 1 to 100° C. with water, an organic solvent from the group consisting of C 1 –C 10 -alcohol, formamide, dimethylformamide, tetrahydrofuran, acetonitrile, dimethyl sulfoxide and hexamethylphosphoramide or with a mixture thereof or with a mixture with water and a base suitable for deprotonation from the group consisting of NaOH, KOH, LiOH, Ca(OH) 2, NH 4 OH, Na 2 CO 3 and K 2 CO 3, wherein 0.1 to 5 mol of base are added per mol of counterion.
5. The process as claimed in claim 1 , wherein in step b) the gelled polymer is washed 1 to 3 times at a temperature of 1 to 100° C. with water or with an organic solvent selected from the group consisting of C 1 –C 10 -alcohol, formamide, dimethylformamide, tetrahydrofuran, acetonitrile, dimethyl sulfoxide and hexamethylphosphoramide or with a mixture thereof or with a mixture with water.
6. The process as claimed in claim 1 , wherein in step c) one or more alkylators of the formula RX are added at a temperature between 5 and 1600C to the gelled polymer stirred in water, in an organic solvent from the group consisting of C 1 –C 10 -alcohol, formamide, dimethylformamide, tetrahydrofuran, acetonitrile, dimethy 1 sulfoxide and hexamethylphosphoramide or in a mixture thereof or in a mixture with water, wherein the formula RX R is a linear, branched or cyclic alkyl radical having 1 to 24 C atoms, a C 1 –C 20 -hydroxyalkyl group, a C 7 –C 20 -aralkyl group, a C 1 –C 20 -alkylammonium group or a C 1 –C 20 -aklylamido group and X is an electrophilic leaving group from the group consisting of fluoride, chloride, bromide, iodide, epoxy, tosylate, mesylate or triflate, the alkylator optionally containing one or more leaving groups.
7. The process as claimed in claim 6 , wherein the suspended gel is heated to 35 to 120° C. before or after the addition of the alkylator.
8. The process as claimed in claim 1 , wherein in step c) the base employed is NaOH, KOH, NH 4 OH, LiOH, Ca(OH) 2 , Ba(OH) 2 , NaH and NaNH 2 .
9. The process as claimed in claim 1 , wherein in step d) the gel suspension from step c) is firstly stirred at 1 to 100° C. for a few minutes to a number of hours in water, the organic solvent or the solvent/water mixture, and is then treated with that amount of mineral acids or organic acids which leads to the counterions originally present in the polymer and to partial to complete reprotonation.
10. The process as claimed in claim 1 , wherein the reprotonation in step d) is carried out after one or more alcohol and/or alcohol/salt washes and/or water and/or water/salt washes.
11. The process according to claim 1 wherein said amine N atom is present as an amino, ammonium or spirobicyclic ammonium group.