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##

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is the IR spectrum of the target product of the present invention, N,N,N′,N′-tetradodecyl-substituted diphenyl ether sulfonate.

(2) 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.

(3) 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

(4) 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

(5) 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

(6) 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

(7) The IR spectrum of the target product is shown in FIG. 1, from which it can be seen that:

(8) 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 C—N stretching vibration peaks; 1100, 1049 are C—O stretching vibration peaks; 1091 is the S═O stretching vibration peak; 719 is the (CH.sub.2).sub.n (n≥4) in-plane wagging vibration peak; and 622 is the S—O stretching vibration peak.

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

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

(10) .sup.1H-NMR (400 MHz, CDCl.sub.3): δ: 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

(11) 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 0.016 wt %, and surface tension at cmc (γ.sub.cmc) of 23 mN/m.

(12) 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.