LATEX HYPERBRANCHED ANION EXCHANGERS

Abstract

A method for making modified latex particles, wherein the particles comprise condensation polymers bonded to functional groups on the latex particles and the method for forming the condensation polymer comprises reacting the amino groups present on the latex particles with (i) at least a first polyfunctional compound, having at least two functional moieties reactive with said functional groups of the latex, or (ii) at least a first polyfunctional compound, having at least two functional moieties reactive with said functional groups of the latex and at least a first amine compound, comprising amino groups selected from the group consisting of ammonia, a primary and a secondary amine to form a first condensation polymer reaction product comprising ion exchanging sites and a first unreacted excess of functional moieties.

Claims

1. A method for making modified latex particles, wherein the particles comprise condensation polymers bonded to functional groups on the latex particles and the method for forming the condensation polymer comprises: (a) reacting the functional groups present on the latex particles with: (i) at least a first polyfunctional compound, having at least two functional moieties reactive with said functional groups of the latex, or (ii) at least a first polyfunctional compound, having at least two functional moieties reactive with said functional groups of the latex and at least a first amine compound, comprising amino groups selected from the group consisting of ammonia, a primary and a secondary amine to form a first condensation polymer reaction product comprising ion exchanging sites and a first unreacted excess of functional moieties.

2. A method according to claim 1, wherein the functional groups on the latex particles are primary and/or secondary or tertiary amino groups or hydroxyl groups.

3. The method according to claim 1, wherein the at least two functional moieties of the at least a first polyfunctional compound include at least one functional moiety selected from the group consisting of epoxides, alkyl halides, benzyl halides, tosylates, methyl sulphides and mixtures thereof.

4. The method according to claim 3, wherein the at least two functional moieties of the at least a first polyfunctional compound comprise epoxide moieties.

5. The method according to claim 1, wherein the method further comprises step (b) (i) or (b) (ii), wherein in step (b) (i) the unreacted excess of functional moieties on the CPRP of step (a) (i) may be reacted with at least a second amine compound or both at least a second polyfunctional compound and at least a second amine compound to form a second CPRP; and in step (b) (ii) the unreacted excess of functional moieties on the CPRP of step (a) (ii) may be reacted with at least a second polyfunctional compound or both at least a second polyfunctional compound and at least a second amine compound to form a second CPRP.

6. The method according to claim 1, further comprising reacting a further amine compound and/or polyfunctional compound with unreacted excess amine compound moieties or polyfunctional compound moieties from the first or second condensation polymer reaction product in step (a) or (b).

7. The method of claim 5 further comprising repeating step (b) (i) or (ii) at least one more time and reacting amine reactive functional moieties on the exterior condensation polymer reaction product with an amine containing cation functional compounds to convert the latex to a cation-exchange material.

8. The method according to claim 1, in which the first, second or subsequent condensation polymers includes functional groups which are cross-linked.

9. The method according to claim 1, in which the first, second or subsequent condensation polymers includes functional groups comprising branched polymer chains.

10. The method according to claim 1, in which step for forming the first, second or subsequent condensation polymers is performed in a flow-through chamber by sequentially flowing (i) said at least a first polyfunctional compound, or (ii) said at least a first polyfunctional compound and at least a first amine compound, past the latex particles or the first, second or subsequent condensation polymer reaction product.

11. The method according to claim 1, in which the substrate comprises a flow-through monolithic medium or a wall of a flow-through hollow tube.

12. The method according to claim 1, wherein the latex particles have a mean diameter of from about 0.01 to about 0.5 microns.

13. The method according to claim 1, wherein the latex particles comprise styrenic and/or methacrylate-based monomers.

14. Modified latex particles wherein the latex particles comprise: (i) A first condensation reaction polymer product comprising ion exchanging sites and a first unreacted excess of functional moieties, wherein the first condensation reaction polymer is formed by reacting functional groups on the latex particles with: i. At least a first polyfunctional compound having at least two functional moieties; or ii. At least a first polyfunctional compound having at least two functional moieties and at least a first amine compound, comprising amino groups selected from the group consisting of ammonia, a primary and a secondary amine.

15. The modified latex of claim 14, wherein the particles have a median diameter of from about 0.01 to about 0.5 microns.

16. The modified latex particles of claim 14, wherein the modified latex particles comprise styrenic or methacrylate-based monomers.

17. The modified latex particles according to claim 14, wherein the two functional moieties of said polyfunctional compound include at least one functional moiety selected from the group consisting of epoxide, alkyl halides, benzylhalides, tosylates, methylsulfides, and mixtures thereof.

18. The modified latex particles according to claim 14, wherein at least one of said two functional moieties of the polyfunctional compounds comprise epoxide moieties.

19. The modified latex particles according to claim 14, wherein the unreacted excess of functional moieties on the first CPRP may be (i) reacted with at least a second amine compound or both at least a second polyfunctional compound and at least a second amine compound to form a second CPRP or (ii) may be reacted with at least a second polyfunctional compound or both at least a second polyfunctional compound and at least a second amine compound to form a second CPRP comprising ion exchanging sites.

20. The modified latex particles according to claim 14, further comprising repeating step (i) or (ii) at least one more time and reacting amine reactive functional moieties on the exterior condensation polymer reaction product with an amine containing cation functional compounds to convert the packing to a cation exchange substrate.

21. A method for making an ion-exchange chromatographic packing material, wherein the method for making the packing material comprises making latex particles as defined in any one of claim 14, wherein the latex particles are: (i) Ionically bonded to the support resin before step (a); or (ii) ionically bonded to the support resin after the formation of the first, second or subsequent condensation polymer products.

22. The method of claim 21, wherein the support resin is a synthetic ion-exchange resin.

23. The method of claim 21, wherein the support resin has a surface comprising an organic polymer, preferably selected from the group consisting of ethylvinylbenzene-divinylbenzene (EVB-DVB), polystyrene-divinylbenzene (PS-DVB), and polyvinylalcohol (PVA).

24. The method according to claim 21, wherein the support resin comprises negatively charged functional groups, preferably sulfonic, carboxylic and/or phosphonic functional groups.

25. The method according to claim 21, wherein the ionic bond is formed between ion-exchanging sites, at least on the outer surface of the latex, and sites of opposite charge on the support resin.

26. The method according to claim 21, wherein the support resin is substantially spherical.

27. The method according to claim 21, wherein the support resin has a particle size of from about 2 to about 100 microns, preferably from about 4 to about 10 microns.

28. An ion-exchange chromatographic packing material comprising: (i) Support resin having ion-exchange sites at least on its available surface; and (ii) Modified latex particles as defined in any one of claims 14 to 19, wherein an ionic attraction is formed between the ion exchanging sites on the support resin and ion exchanging sites on the latex particles.

29. The packing material of claim 28, wherein the support resin is substantially spherical.

30. The packing material of claim 28, wherein the support resin has a particle size of from about 2 to about 100 microns, preferably from about 4 to about 10 microns.

31. The packing material according to claim 28, wherein the support resin is a synthetic ion exchange resin.

32. The packing material according to claim 28, wherein the support resin has a surface comprising an organic polymer, preferably selected from the group consisting of ethylvinylbenzene-divinylbenzene (EVB-DVB), polystyrene-divinylbenzene (PS-DVB), and polyvinylalcohol (PVA).

33. The packing material according to claim 28, wherein the support resin comprises negatively charged functional groups, preferably sulfonic, carboxylic and/or phosphonic functional groups.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0096] FIG. 1: Shows a chromatogram of the separation of inorganic anions using ion chromatography packing formed by the method of the invention comprising sulfonated EVB-DVB as the substrate, vinylbenzyl chloride-based latex and 1 cycle of hyperbranching using methylamine (4% solution in water) and 1,4-butanediol diglycidyl ether (10% solution in water).

[0097] FIG. 2: Shows a chromatogram of the separation of inorganic anions using ion chromatography packing formed by the method of the invention comprising sulfonated EVB-DVB as the substrate, vinylbenzyl chloride-based latex and 2 cycles of hyperbranching using methylamine (4% solution in water) and 1,4-butanediol diglycidyl ether (10% solution in water).

[0098] FIG. 3: Shows a chromatogram of the separation of small organic acids using ion chromatography packing formed by the method of the invention comprising sulfonated EVB-DVB as the substrate, vinylbenzyl chloride-based latex as well as dimethylamine and 1,4-butanediol diglycidyl ether for forming condensation polymer.

[0099] In order to illustrate the present invention, the following non-limited examples of its practice are given

Example 1

[0100] 10 g of latex based on vinylbenzene chloride (VBC) and divinylbenzene (DVB) was mixed with 3.1 g of 40% solution of methylamine (MA) and 6.9 g of deionized water and left to react for 4 h at 65? C. Glacial acetic acid was then added to the aminated latex until pH 5 was reached. The resulting sulfonated ethylvinylbenzene-dilvinylbenzene substrate particles with 55% crosslink, average diameter of 6.45 ?m and surface area of 20 m2/g were then packed into 4?250 mm column and prepared latex was passed through the column.

[0101] The hyperbranched layer on top of the latex was formed by using the following procedure to run one reaction cycle: passing a 10% solution of 1,4-butanediol diglycidyl ether for 20 min through the column with the flow rate of 0.25 mL/min, allowing it to react in the column for 40 min; rinsing the column with deionized water for 10 min, passing a 4% solution of methylamine through the column for 20 min, allowing it to react for 40 min and rinsing the column with deionized water for 10 min. The column was then rinsed with 10 mM KOH. The chromatogram of the separation of some monovalent inorganic anions in suppressed ion chromatography mode with prepared column using 10 mM KOH as eluent with a flow of 1 mL/min is presented in FIG. 1.

Example 2

[0102] Same as Example 1, but number of reaction cycles in hyperbranching process was 2. The chromatogram of the separation of some monovalent inorganic anions in suppressed ion chromatography mode with prepared column using 20 mM KOH as eluent with a flow of 1 mL/min is presented in FIG. 2.

Example 3

[0103] 10 g of latex based on vinylbenzene chloride (VBC) and divinylbenzene (DVB) was placed into scintillation vial.

[0104] Solution 1 containing 9 g of 40% dimethylamine (DMA) in 20 g of deionized waster and solution 2 containing 14.7 g of 1,4-butanediol diglycidyl ether in 20 g of deionized water were added simultaneously to the latex with a flow of 0.25 mL/min each at 65? C. while stirring. The process was run for 40 min, then the reaction mixture was kept in the oven for 2 h at 65? C. The prepared latex with bonded polymer chains was passed through 4?250 mm column packed with sulfonated ethylvinylbenzene-dilvinylbenzene substrate particles with 55% crosslink, average diameter of 6.45 ?m and surface area of 20 m2/g. Column is rinsed with 10 mM KOH.

[0105] The chromatogram of the separation of some small organic acids in suppressed ion chromatography mode with prepared column using 20 mM KOH as eluent with a flow of 1 mL/min is presented in FIG. 3.

Example 4

[0106] Electrostatically bonded basement layer was prepared according to the U.S. Pat. No. 7,291,395 (4.5 g of sulfonated ethylvinylbenzene-dilvinylbenzene substrate particles with 55% crosslink, average diameter of 6.45 ?m and surface area of 20 m2/g were placed into a scintillation vial; 0.368 g of 1.4-butanediol diglycidyl ether, 3.277 g of water, and 1.5 g of 4% methylamine was added to the substrate and mixed well. The mixture was then placed in the tumbler in a 65? C. oven for 2 h, then removed from the oven and cooled for 10-15 min. 6 g of deionized water are added to the vial, mixed and the slurry is packed into 4?250 mm column). A reaction cycle described in Example 1 for forming hyperbranched layer was run 3 times on the basement coating. The capacity of such column is comparable to the latex-based one prepared in Example 1 using only 1 reaction cycle, which shows that attachment of hyperbranched layer to the latex allows one to prepare higher capacity columns with a fewer number of steps.