Process for preparing polymeric, ionic imidazolium compounds of high molecular weight

Abstract

A process for preparing polymeric, ionic compounds comprising imidazolium groups (polymeric, ionic imidazolium compounds for short) comprising reactingan -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 aprotic acid, wherein the molar ratio of the -dicarbonyl compound to the oligoamine is greater than 1.

Claims

1. A process for preparing a polymeric, ionic compound comprising an imidazolium group, the process comprising reacting: an -dicarbonyl compound, an aldehyde, a diamine of formula III:
(NH.sub.2).sub.nR.sub.4, wherein n is 2 and R.sub.4 is any n-valent organic radical, if appropriate, a monoamine, an amino compound having only one primary amino group; and at least one protic acid, wherein the molar ratio of the -dicarbonyl compound to the diamine is greater than 1 and the molar ratio of the aldehyde to the diamine is greater than 1.

2. The process according to claim 1, wherein the molar ratio the of -dicarbonyl compound to the oligoamine is from 1.001:1 to 2:1.

3. The process according to claim 1, wherein the molar ratio of the aldehyde to the diamine is from 1.001:1 to 2 to 1.

4. The process according to claim 1, wherein the -dicarbonyl compound is a compound of formula I
R1-COCOR2 where R1 and R2 are each, independently of one another, an H atom or an organic radical having from 1 to 20 carbon atoms.

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

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

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

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

9. The process according to claim 1, wherein the at least one protic acid is an acid with a pK.sub.a greater than 1 measured at 25 C. at 1 bar in water or dimethyl sulfoxide.

10. The process according to claim 1, wherein the at least one protic acid is acetic acid.

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

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

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

14. The process according to claim 1, wherein the protic acid is placed in the reactor first and the diamine, aldehyde and -dicarbonyl compound are fed to the protic acid in a rate that the temperature of the reaction mixture is kept below 30 C.

Description

EXAMPLES

(1) 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 L (liter), the concentration 1.5 mg/mL and the flow rate 0.8 mL/min.

(2) 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.

Example 1

(3) 2 mol acetic acid are placed in a flask. A mixture of 1.05 mol formaldehyde (49% aq. Solution) and 1.05 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.

Comparison Example 1

(4) 1 mol formaldehyde (49% aq. Solution), 1 mol glyoxal (40% aq. Solution) and 1 mol acetic dissolved in 4.5 mol water acid are placed in flask. 1 mol of 1,4 diaminobutane (dissolved in 6.7 mol water) is 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.

Comparison Example 2

(5) 1 mol acetic acid dissolved in 4.5 mol 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 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.

Comparison Example 3

(6) The procedure of example 1 has been repeated using 1 mol formaldehyde and 1 mol glyoxal. No precipitates have been observed during or after the reaction.

(7) TABLE-US-00001 TABLE performance details and results of example 1 and comparison examples 1-3 No. Diamine Formaldehyde Glyoxal Acetic acid Mw Mn PDI comparison 1 mol 1 mol 1 mol 1 mol 7870 2860 2.8 example 1 1,4-diaminobutane comparison 1 mol 1 mol 1 mol 1 mol 5930 2300 2.6 example 2 1,4-diaminobutane comparison 1 mol 1 mol 1 mol 2 mol 78670 26430 3.0 example 3 hexamethylenediamin example 1 1 mol 1.05 mol 1.05 mol 2 mol 278800 35330 7.9 hexamethylenediamin