IMPROVED PROCESS FOR PREPARING POLYMERIC, IONIC IMIDAZOLIUM COMPOUNDS

Abstract

A process for preparing polymeric, ionic compounds comprising imidazolium groups (polymeric, ionic imidazolium compounds for short) comprising reacting an a-dicarbonyl compound, an aldehyde, —at least one amino compound having at least two primary amino groups (referred to as oligoamine), if appropriate an amino compound having only one primary amino group (referred to as monoamine) and a protic acid, wherein the protic acid is placed in the reactor and the oligoamine or the aldehyde and o dicarbonyl compound or the oligoamine, the aldehyde and α-dicarbonyl compound are fed to the protic acid.

Claims

1. A process for preparing polymeric, ionic compounds comprising imidazolium groups, the process comprising reacting: an α-dicarbonyl compound, an aldehyde, at least one oligoamine, which is an amino compound having at least two primary amino groups, if appropriate optionally a monoamine, which is an amino compound having only one primary amino group; and a protic acid, wherein the protic acid is placed in the reactor and the oligoamine or the aldehyde and α-dicarbonyl compound or the oligoamine, the aldehyde and α-dicarbonyl compound are fed to the protic acid.

2. The process according to claim 1, wherein a pH value of the reaction solution is from 1 to 6.

3. The process according to claim 1, wherein a molar ratio of the protic acid to the oligoamine is from 1.05:1 to 10:1.

4. The process according to claim 1, wherein a molar ratio of the α-dicarbonyl compound to the oligoamine is greater than 1.

5. The process according to claim 1, wherein a molar ratio of the aldehyde to the oligoamine is greater than 1.

6. The process according to claim 1, wherein the α-dicarbonyl compound is a compound of formula I:
R1-CO—CO—R2 wherein R1 and R2 are each, independently of one another, an H atom or an organic radical having from 1 to 20 carbon atoms.

7. The process according to claim 1, wherein the aldehyde is an aldehyde of formula II:
R3-CHO wherein R3 is an H atom or an organic radical having from 1 to 20 carbon atoms.

8. The process according to claim 1, wherein the aldehyde is formaldehyde.

9. The process according to claim 1, wherein the oligoamine is a compound of formula III:
(NH2-).sub.nR4 wherein n is an integer greater than or equal to 2 and R4 is any n-valent organic radical.

10. The process according to claim 1, wherein the oligoamine is an aliphatic or aromatic diamine or triamine.

11. The process according to claim 1, wherein the oligoamine is a C2-C20-alkylenediamine.

12. The process according to claim 1, wherein the protic acid is an acid with a pK.sub.a greater than 1.

13. The process according to claim 1, wherein the protic acid is acetic acid.

14. The process according to claim 1, wherein the process is carried out in water, in a water-miscible solvent or a mixture thereof.

Description

EXAMPLES

[0085] The molecular weight of the polymeric ionic compounds was determined by Size-exclusion chromatographie (SEZ) using polymaltotriose as standard and water comprising 0.02 mol/l formic acid and 0.2 mol/l KCl as effluent. The temperature of the column was 35° C., the injected volume 100 μL (μliter), the concentration 1.5 mg/mL and the flow rate 0.8 mL/min.

[0086] The weight average molecular weight (Mw), the number average molecular weight (Mn) and the polydispersity PDI (Mw/Mn) of the polymeric ionic compounds obtained are listed in the table.

Comparison Example

[0087] 1 mol formaldehyde (49% aq. Solution), 1 mol glyoxal (40% aq. Solution) and 1 mol acetic acid dissolved in 4.5 mol of water are placed in flask. 1 mol of 1,4 diaminobutane (dissolved in 6.7 mol of water) are added at room temperature (ice bath cooling) to the reaction mixture. A white precipitate occurs during the addition, which dissolves again upon continued addition of the monomer. The reaction is stirred at 100° C. for 1-3 hours. An aqueous solution of the polymeric, ionic imidazolium compound is obtained, which was analyzed.

Example 1

[0088] 1 mol acetic acid dissolved in 4.5 mol of water is placed in a flask. A mixture of 1 mol formaldehyde (49% aq. Solution) and 1 Mol glyoxal (40% aq. Solution) is added via a dropping funnel to the solution. In parallel, 1 mol of 1,4 diaminobutane (dissolved in 6.7 mol of water) is added to the solution via a separated dropping funnel. During addition of the monomers the reaction mixture is held at room temperature by ice bath cooling, no precipitate is observed. After completion of the addition the reaction mixture is heated to 100° C. for 1-3 hours. No precipitates have been observed during or after the reaction. An aqueous solution of the polymeric, ionic imidazolium compound is obtained, which was analyzed.

Example 2

[0089] 2 mol acetic acid are placed in a flask. A mixture of 1 mol formaldehyde (49% aq. Solution) and 1 mol glyoxal (40% aq. Solution) are added via a dropping funnel to the solution. In parallel, 1 mol of molten hexamethylene diamine (˜40° C.) is added to the solution via a separated dropping funnel. During addition of the monomers the reaction mixture is held at room temperature by ice bath cooling. After completion of the addition the reaction mixture is heated to 100° C. for 1-3 hours. An aqueous solution of the polymeric, ionic imidazolium compound is obtained, which was analyzed. No precipitates have been observed during or after the reaction.

Example 3

[0090] The procedure of example 2 has been repeated using 1.05 mol formaldehyde and 1.05 mol glyoxal. No precipitates have been observed during or after the reaction.

TABLE-US-00001 TABLE performance details and results of example 1 and comparison examples 1-3 Form- Acetic No. Diamine aldehyde Glyoxal acid Mw Mn PDI precipitate comparison 1 mol 1 mol 1 mol 1 mol 7870 2860 2.8 yes example 1,4-diaminobutane example 1 1 mol 1 mol 1 mol 1 mol 5930 2300 2.6 no 1,4-diaminobutane example 2 1 mol hexa- 1 mol 1 mol 2 mol 78670 26430 3.0 no methylenediamin example 3 1 mol hexa- 1.05 mol 1.05 mol 2 mol 278800 35330 7.9 no methylenediamin