N,N,N',N'-TETRADODECYL-SUBSTITUTED DIPHENYL ETHER SULFONATE ANIONIC GEMINI SURFACTANT AND SYNTHESIS METHOD THEREOF

Abstract

The present invention discloses a N,N,N,N-tetradodecyl-substituted diphenyl ether sulfonate anionic Gemini surfactant and the synthesis method thereof. It has a structural formula of:

##STR00001## and is prepared in a two-step reaction comprising: S1. subjecting 4,4-diaminodiphenyl ether and bromododecane to an amine alkylation reaction to obtain N,N,N,N-tetradodecyl-substituted diphenyl ether; and S2. sulfonating the N,N,N,N-tetradodecyl-substituted diphenyl ether with concentrated sulfuric acid to produce the target product, N,N,N,N-tetradodecyl-substituted diphenyl ether sulfonate. The surfactant of the present invention has a high surface activity and can be synthesized with a simple procedure under mild reaction conditions, and can be easily separated and purified. The surfactant of the present invention is promising in applications for alkaline/surfactant in tertiary oil recovery, for polymer/surfactant binary compound flooding, alkaline/surfactant/polymer tertiary compound flooding, microemulsion emulsifier, and the like, and may also be compounded with common surfactants to lower the cost, thereby enabling its application in a large scale.

Claims

1. A N,N,N,N-tetradodecyl-substituted diphenyl ether sulfonate anionic Gemini surfactant, having the structural formula: ##STR00004##

2. A method for synthesis of the anionic Gemini surfactant according to claim 1, comprising: S1. subjecting 4,4-diaminodiphenyl ether and bromododecane to an amine alkylation reaction to obtain N,N,N,N-tetradodecyl-substituted diphenyl ether; and S2. sulfonating the N,N,N,N-tetradodecyl-substituted diphenyl ether with concentrated sulfuric acid to produce the target product N,N,N,N-tetradodecyl-substituted diphenyl ether sulfonate.

3. The method for synthesis according to claim 2, wherein the alkylation reaction is carried out in an atmosphere of a protective gas.

4. The method for synthesis according to claim 3, wherein the protective gas includes nitrogen and one or more inert gases.

5. The method for synthesis according to claim 2, wherein the molar ratio of 4,4-diaminodiphenyl ether to bromododecane is 1:(4.1-4.4).

6. The method for synthesis according to claim 2, wherein in the alkylation reaction, N,N-dimethyl formamide is used as a solvent, and K.sub.2CO.sub.3 is used as an acid binding agent to keep the system at a pH of 7-10.

7. The method for synthesis according to claim 6, wherein the content of K.sub.2CO.sub.3 added in the system is 20 wt %.

8. The method for synthesis according to claim 2, wherein the alkylation reaction is carried out at 60 C. to 70 C.; and after the reaction is complete, post-treatment purification is conducted to obtain N,N,N,N-tetradodecyl-substituted diphenyl ether.

9. The method for synthesis according to claim 8, wherein the post-treatment purification comprises: adding water to allow partitioning, extracting with an organic extracting agent, concentrating the organic phase until dryness, purifying by column chromatography, and drying to obtain N,N,N,N-tetradodecyl-substituted diphenyl ether.

10. The method for synthesis according to claim 9, wherein the organic extracting agent is ethyl acetate.

11. The method for synthesis according to claim 9, wherein the developing solvent for the column chromatographic purification is a system of petroleum ether and ethyl acetate.

12. The method for synthesis according to claim 11, wherein the developing solvent comprises a volume of petroleum ether to a volume of ethyl acetate having a ratio of 10:1.

13. The method for synthesis according to claim 2, wherein step S2 comprises: adding N,N,N,N-tetradodecyl-substituted diphenyl ether to a solvent, adding concentrated sulfuric acid dropwise thereto to carry out reaction; quenching the system by adding water after the reaction is complete, separating the aqueous phase, adding NaOH to the aqueous phase to adjust the pH to a basic pH, and concentrating the aqueous phase until dryness to obtain N,N,N,N-tetradodecyl-substituted diphenyl ether sulfonate.

14. The method for synthesis according to claim 13, wherein the solvent is acetic acid.

15. The method for synthesis according to claim 13, wherein after separating the aqueous phase, the method further comprises extracting the aqueous phase with an extracting agent, separating the aqueous phase and concentrating it until dryness, and purifying it by column chromatography, so as to obtain the intermediate product; dissolving the intermediate product in water and then adding NaOH to adjust the pH to a basic pH.

16. The method for synthesis according to claim 15, wherein the organic extracting agent is ethyl acetate.

17. The method for synthesis according to claim 13, wherein during the dropwise addition of concentrated sulfuric acid, the reaction system is placed in an ice water bath, and after completion of the dropwise addition, warmed to room temperature to carry out reaction.

18. The method for synthesis according to claim 13, wherein NaOH is added to adjust the pH to 10.

19. The method for synthesis according to claim 15, wherein NaOH is added to adjust the pH to 10.

20. The method for synthesis according to claim 18, wherein the NaOH is provided as a 1 mol/L NaOH aqueous solution.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0036] FIG. 1 is the IR spectrum of the target product of the present invention, N,N,N,N-tetradodecyl-substituted diphenyl ether sulfonate.

[0037] FIG. 2 is the .sup.1H NMR spectrum of the target product of the present invention, N,N,N,N-tetradodecyl-substituted diphenyl ether sulfonate.

[0038] FIG. 3 is a surface tension-concentration diagram (at 25 C.) of the target product of the present invention, N,N,N,N-tetradodecyl-substituted diphenyl ether sulfonate.

DETAILED DESCRIPTION OF THE INVENTION

[0039] The present invention will be further illustrated with reference to preferred examples in order to provide a clearer explanation of the present invention. The detailed description provided hereinafter is merely illustrative and not limiting, which is not to be construed as limitation to the scope of protection of the present invention.

Preparation of N,N,N,N-tetradodecyl-Substituted diphenyl ether sulfonate

(1) Synthesis of N,N,N,N-tetradodecyl-Substituted diphenyl ether

[0040] To a three-neck flask equipped with a stirring device and placed in a water bath at a constant temperature, 25.00 g (124.85 mmol) 4,4-diamino diphenyl ether, 10.46 g (41.95 mmol) bromododecane, and 5.80 g K.sub.2CO.sub.3 (20 wt %) as an acid-binding agent were sequentially added. The system pH was kept at 7-10, and 150 mL DMF as a solvent was added under nitrogen protection. The system was stirred and warmed to 60 C., and a reaction was allowed to proceed for 24 h before it was completed (the reaction end point was monitored by TLC, using a developer of V (petroleum ether):V (ethyl acetate)=10:1). Water was added to allow partitioning. The aqueous phase was extracted three times with ethyl acetate, and the organic phase was washed once with water, concentrated until dryness, purified through a column, and dried to give 80 g (91.58 mmol) of a yellow oily intermediate product, N,N,N,N-tetradodecyl-substituted diphenyl ether.

(2) Synthesis of N,N,N,N-tetradodecyl-Substituted diphenyl ether sulfonate

[0041] In the same reaction apparatus as in (1), 2.00 g (9.158 mmol) N,N,N,N-tetradodecyl-substituted diphenyl ether and 50 mL acetic acid as a solvent were sequentially added to a three-neck flask, to which 10 mL concentrated sulfuric acid was added dropwise under stirring on an ice bath. Upon completion of the dropwise addition, the temperature was raised to room temperature, and a reaction was carried out for 6 h (the reaction end point was monitored by TLC). After the reaction was completed, the mixture was quenched by water and partitioned. The aqueous phase was extracted three times with ethyl acetate, and the organic phase was washed once with water, concentrated until dryness, and purified through a column. The product was dissolved in water, to which a 1 mol/L NaOH aqueous solution was slowly added dropwise until the system pH was adjusted to 10, and the aqueous phase was collected and concentrated until dryness, to obtain 1.8 g (1.75 mmol) of a brown viscous product, N,N,N,N-tetradodecyl-substituted diphenyl ether sulfonate.

IR Spectrum of N,N,N,N-tetradodecyl-Substituted diphenyl ether sulfonate

[0042] The IR spectrum of the target product is shown in FIG. 1, from which it can be seen that:

[0043] 2946, 2869 are stretching vibration peaks of CH.sub.3, CH.sub.2; 1610, 1591, 1507, 1450 are vibration peaks of the benzene-ring core; 873, 828 are characteristic peaks of p-substitutions on the benzene ring; 1274, 1241 are CN stretching vibration peaks; 1100, 1049 are CO stretching vibration peaks; 1091 is the SO stretching vibration peak; 719 is the (CH.sub.2).sub.n (n4) in-plane wagging vibration peak; and 622 is the SO stretching vibration peak.

.SUP.1.H-NMR Spectrum of N,N,N,N-tetradodecyl-Substituted diphenyl ether sulfonate

[0044] The .sup.1H-NMR spectrum of the target product is shown in FIG. 2, from which it can be seen that:

[0045] .sup.1H-NMR (400 MHz, CDCl.sub.3): : 0.82-0.99 [3H, CH.sub.3CH.sub.2], 1.12-1.29 [16H, CH.sub.3(CH.sub.2).sub.8CH.sub.2CH.sub.2], 1.46-1.69 [2H, (CH.sub.2).sub.10CH.sub.2CH.sub.2N], 3.19-3.24 [2H, (CH.sub.2).sub.10CH.sub.2CH.sub.2N], 6.60-6.64 [1H, NCCH], 6.88-6.91 [1H, OCCH].

Surface Activity of N,N,N,N-tetradodecyl-Substituted diphenyl ether sulfonate

[0046] The ability of a surfactant to lower the surface tension of water is an important parameter for evaluation of its surface activity. The surface tension of aqueous solutions of the target product at different concentrations at 25 C. was measured by the hanging plate method, and a curve of the concentration-dependent surface tension of aqueous solution of the N,N,N,N-tetradodecyl-substituted diphenyl ether sulfonate Gemini surfactant was plotted (FIG. 3). The surface activity parameter of this Gemini surfactant can be calculated from this curve: a critical micelle concentration (cmc) of 0.016wt %, and surface tension at cmc (.sub.cmc) of 23 mN/m.

[0047] Obviously, the above examples of the present invention are merely exemplified for the purpose of clearly illustrating the present invention, and the embodiments of the present invention are not limited thereto. For those skilled in the art, various modifications or alterations can be made on the basis of the above description, and any obvious modifications or alterations as extension of the technical solutions of the present invention are also intended to be included within the scope of protection of the present invention.