A low-foaming environmentally friendly cleaning surfactant and a preparation method thereof

Abstract

The application discloses a low-foam environment-friendly cleaning surfactant and a preparation method thereof. The surfactant is an amphoteric surfactant with a symmetrical structure, and the preparation method comprises the following steps: in the first step, a substitution reaction is performed on 2-chloropropenyl ester and 3-morpholine propyl sulfonic acid to obtain a sulfobetaine type amphoteric surfactant; in the second step, a silicon-hydrogen addition reaction is performed on the sulfobetaine type amphoteric surfactant obtained in the first step and dimethyl silicone oil to obtain a surfactant-2; and in the third step, the surfactant-2 is salified in an alkali solution to obtain a surfactant-3. The surfactant-2 and the surfactant-3 both have good low-foam performance and excellent dirt removal capacity, so that in the cleaning process, a large amount of foam can be avoided from rising to cause overflow of cleaning liquid, material waste is avoided, and further, dirt on the surface of the cleaned object is avoided from being generated again, the surfactant has certain environmental protection, and can be applied to multiple fields such as daily-use chemicals.

Description

Technical Field

[0001] This invention relates to the field of surfactants, specifically to a low-foaming, environmentally friendly cleaning surfactant and its preparation method. Background Technology

[0002] Amphoteric surfactants possess a variety of excellent properties, such as foaming ability, strong calcium soap dispersing power, and low irritation. These excellent properties make betaine-type surfactants occupy a major position in formulations. Since the 1960s, they have been widely used in daily chemical personal care products and are ubiquitous in daily life, such as in shower gels, serums, shampoos, cosmetics, and various conditioning shampoos.

[0003] Dimethyl silicone oil possesses advantages such as resistance to high and low temperatures, low foaming properties, low surface tension, oxidation resistance, and non-toxicity. Its low foaming properties and low surface tension are the main reasons why it can be used in defoamers. Dimethyl silicone oil is hydrophobic; after emulsification, it can significantly reduce the surface tension of aqueous solutions, becoming an important active component in defoamers. It requires only a small amount to fully exert its defoaming function.

[0004] Currently, the method used to reduce foam is to add defoamers. Although this can achieve the defoaming effect, defoamers actually have an "expiration date" during use. Their defoaming ability will gradually decrease and eventually be lost, requiring continuous addition of defoamers. There are many types of cleaning surfactants commonly used on the market. Among them, sulfobetaine-type amphoteric surfactants, because they have both anionic and cationic hydroxyl groups in their structure, not only have all the advantages of amphoteric surfactants, but also have resistance to high concentrations of acids, alkalis and salts, good emulsification, dispersibility and antistatic properties, as well as bactericidal, antifungal and viscoelastic properties. When compounded with other surfactants in a wide pH range, they also show excellent foaming performance and thickening effect.

[0005] This invention focuses on defoaming and environmentally friendly cleaning, and has prepared a low-foaming, environmentally friendly cleaning surfactant. It is a symmetrical sulfobetaine-type amphoteric surfactant with good cleaning performance and excellent low-foaming properties. This avoids excessive foaming during the cleaning process, which could lead to overflow of the cleaning solution and waste of materials. It also prevents the re-generation of stains on the surface of the cleaned object, thus exhibiting certain environmental benefits and being applicable to various fields such as daily chemical products. Summary of the Invention

[0006] The purpose of this invention is to provide a low-foaming, environmentally friendly cleaning surfactant and its preparation method. This objective can be achieved through the following technical solutions:

[0007] A low-foaming, environmentally friendly cleaning surfactant, which is an amphoteric surfactant with a symmetrical structure, is shown in the following structural formula:

[0008]

[0009] Where R = H or Na.

[0010] A method for preparing a low-foaming, environmentally friendly cleaning surfactant includes the following steps:

[0011] Step 1: Preparation of Surfactant-1

[0012] Add 200-300 ml of isopropanol solvent to a three-necked flask, then weigh 2.8-3.0 g of 2-chloroacrylate and 4.0-4.4 g of 3-morpholinopropanesulfonic acid and add them to the flask. Place the three-necked flask in a heating mantle and heat to 100-105 °C. Keep the temperature and stir for 2.5-3.5 h. After the reaction is complete, remove the solvent by rotary evaporation. Recrystallize the crude product to obtain surfactant-1.

[0013] Step 2: Preparation of Surfactant-2

[0014] In a three-necked flask equipped with a reflux condenser, a constant-pressure dropping funnel, and a nitrogen purging device, the constant-pressure dropping funnel contains a toluene solution containing hydrosilicone oil. 50 mL of solvent toluene is added, followed by the weighing of 4.0-4.2 g of surfactant-1 and 0.4-0.55 g of catalyst chloroplatinic acid-isopropanol. Nitrogen gas is introduced, and the mixture is heated to 75-85°C. The toluene solution containing hydrosilicone oil is added dropwise over 15-20 minutes. The mixture is then stirred and reacted for 3-5 hours. After the reaction is complete, the nitrogen gas is turned off, and low-boiling substances are removed by vacuum distillation to obtain an oily liquid. The catalyst is separated, and the product is dried to obtain surfactant-2.

[0015]

[0016] Step 3: Preparation of Surfactant-3

[0017] Prepare a sodium carbonate solution with a concentration of 10-20%. Place 0.3-0.4g of surfactant-2 into 100ml of the above sodium carbonate solution and stir at room temperature for 2-3 hours. Add 200-250ml of anhydrous ethanol to precipitate the solid. Filter the solid, wash it with anhydrous ethanol, and dry it to obtain surfactant-3.

[0018]

[0019] Furthermore, in step one, the recrystallization is performed on the crude product using ethanol:diethyl ether:ethyl acetate = 5:2:3.

[0020] Furthermore, in step two, the hydrogen-containing silicone oil is 1,1,3,3,5,5-hexamethyltrisiloxane, and the amount added is 2.0-2.2g.

[0021] Furthermore, in step two, the mass fraction of toluene in the toluene solution containing hydrogen silicone oil is 30-40%.

[0022] Furthermore, in step two, the chloroplatinic acid content in the catalyst chloroplatinic acid-isopropanol is 2.0-3.0%.

[0023] Furthermore, in step two, the separation of the catalyst and the drying of the product are specifically carried out by adding 50 ml of a mixed solution of petroleum ether and tetrahydrofuran (20:1) to the oily liquid to precipitate the catalyst. After rotary evaporation, the solution is placed in a vacuum drying oven at 50-55°C for drying for 10-12 hours to obtain surfactant-2.

[0024] The beneficial effects of this invention are:

[0025] This invention provides a low-foaming, environmentally friendly cleaning surfactant, a symmetrical sulfobetaine-type amphoteric surfactant with an organosilicon structure, which uses organosilicon as a connecting bridge to link the disulfonyl group and the dibetaine. Compared with existing commercially available sulfobetaine-type amphoteric surfactants, it theoretically has twice the cleaning power and twice the other potential functions. The biggest difference between it and existing sulfobetaine-type amphoteric surfactants is that it has excellent low-foaming properties. Verification has shown that the symmetrical sulfobetaine-type amphoteric surfactant prepared by this invention performs well in detergency, which is of certain breakthrough significance in the research of amphoteric surfactants.

[0026] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention have been clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1: Preparation of Surfactant-1

[0029] 250 ml of isopropanol was added to a three-necked flask. Then, 3.0 g of 2-chloroacrylate and 4.2 g of 3-morpholinopropanesulfonic acid were weighed and added to the flask. The flask was placed in a heating mantle and heated to 100 °C. The mixture was stirred and kept at this temperature for 3 hours. After the reaction was complete, the solvent was removed by rotary evaporation. The crude product was recrystallized from ethanol:diethyl ether:ethyl acetate in a ratio of 5:2:3 to obtain surfactant-1, with a yield of 78.2%. HRMS(ESI):Calcd.for C 12 H 22 ClNO6S[M] + :343.0636; found:343.0635.

[0030]

[0031] Example 2 Preparation of Surfactant-2

[0032] In a three-necked flask equipped with a reflux condenser, a constant-pressure dropping funnel, and a nitrogen purging system, the constant-pressure dropping funnel contains a toluene solution containing hydrosilicone oil (2.2 g of 1,1,3,3,5,5-hexamethyltrisiloxane and 40% toluene by mass). 50 ml of toluene solvent is added, followed by the weighing of 4.0 g of surfactant-1 and 0.5 g of catalyst chloroplatinic acid-isopropanol (2.0% chloroplatinic acid content) and added to the flask. Nitrogen gas is then introduced, and the mixture is heated to 80°C. At ℃, a toluene solution containing hydrosilicone oil was added dropwise over 20 minutes. The mixture was then stirred for 4.5 hours. After the reaction was complete, nitrogen was turned off, and low-boiling substances were removed by vacuum distillation to obtain an oily liquid. 50 ml of a 20:1 mixture of petroleum ether and tetrahydrofuran was added to this oily liquid, precipitating the catalyst. The solution was then rotary evaporated and dried in a vacuum oven at 50℃ for 10 hours to obtain surfactant-2. HRMS(ESI):Calcd.forC 30 H 64 Cl2N2O 14 S2Si3[M] + :896.1325; found:896.1325.

[0033]

[0034] Example 3 Preparation of Surfactant-3

[0035] Prepare a 15% sodium carbonate solution. Add 0.3g of surfactant-2 to 100ml of the sodium carbonate solution and stir at room temperature for 2.5h. Add 200ml of anhydrous ethanol, precipitate a solid, filter, wash with anhydrous ethanol, and dry to obtain surfactant-3; HRMS (ESI):

[0036] Calcd.forC 30 H 62 Cl2N2Na2O 14 S2Si3[M] + :940.0921; found:940.0919.

[0037]

[0038] Comparative Example

[0039] Commercially available amphoteric surfactant: 3-sulfopropylhexadecyl dimethyl betaine.

[0040] Foam performance test

[0041] The experimental methods are described in GB / T7462-1994, and the results are shown in Table 1.

[0042] Foaming power / ml Example 1 Example 2 Example 3 Comparative Example 30s 45 18 11 65 60s 34 12 9 53 4min 22 6 3 36

[0043] Stain removal ability test

[0044] The experimental methods are described in GB / T6371-2008, and the results are shown in Table 2.

[0045] Performance test results Example 1 Example 2 Example 3 Comparative Example Detergent power / % 88.3 96.5 97.3 84.4

[0046] As shown in Tables 1 and 2, the surfactant-2 prepared in Example 2 and the surfactant-3 prepared in Example 3 both have small initial foam volumes and defoam quickly, exhibiting good low-foaming properties. At the same time, they also endow the surfactants with good detergency, showing promising application prospects.

[0047] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A low-foaming surfactant, characterized in that, The structural formula is as follows:

2. A method for preparing a low-foaming surfactant as described in claim 1, characterized in that, Includes the following steps: Step 1: Preparation of Surfactant-1 Add 200-300 ml of isopropanol solvent to a three-necked flask, then weigh 2.8-3.0 g of 2-chloroacrylate and 4.0-4.4 g of 3-morpholinopropanesulfonic acid and add them to the flask. Place the three-necked flask in a heating mantle and heat to 100-105 °C. Keep the temperature and stir for 2.5-3.5 h. After the reaction is complete, remove the solvent by rotary evaporation. Recrystallize the crude product to obtain surfactant-1. Step 2: Preparation of Surfactant-2 In a three-necked flask equipped with a reflux condenser, a constant-pressure dropping funnel, and a nitrogen purging device, the constant-pressure dropping funnel contains a toluene solution containing hydrosilicone oil. 50 ml of toluene solvent is added, followed by the weighing of 4.0-4.2 g of surfactant-1 and 0.4-0.55 g of catalyst chloroplatinic acid-isopropanol. Nitrogen gas is introduced, and the mixture is heated to 75-85°C. The toluene solution containing hydrosilicone oil is added dropwise over 15-20 minutes. The mixture is then stirred and reacted for 3-5 hours. After the reaction is complete, the nitrogen gas is turned off, and low-boiling-point substances are removed by vacuum distillation to obtain an oily liquid. The catalyst is separated, and the product is dried to obtain surfactant-2. The hydrosilicone oil is 1,1,3,3,5,5-hexamethyltrisiloxane, and the amount added is 2.0-2.2 g. Step 3: Preparation of Surfactant-3 Prepare a sodium carbonate solution with a concentration of 10-20%. Place 0.3-0.4g of surfactant-2 into 100ml of the above sodium carbonate solution and stir at room temperature for 2-3 hours. Add 200-250ml of anhydrous ethanol to precipitate the solid. Filter the solid, wash it with anhydrous ethanol, and dry it to obtain surfactant-3.

3. The method for preparing a low-foaming surfactant according to claim 2, characterized in that, In step one, the recrystallization is performed on the crude product using ethanol:diethyl ether:ethyl acetate = 5:2:

3.

4. The method for preparing a low-foaming surfactant according to claim 2, characterized in that, In step two, the mass fraction of toluene in the toluene solution containing hydrogen silicone oil is 30-40%.

5. The method for preparing a low-foaming surfactant according to claim 2, characterized in that, In step two, the chloroplatinic acid content in the catalyst chloroplatinic acid-isopropanol is 2.0-3.0%.

6. The method for preparing a low-foaming surfactant according to claim 2, characterized in that, In step two, the separation of the catalyst and the drying of the product are specifically carried out by adding 50 ml of a mixed solution of petroleum ether and tetrahydrofuran (20:1) to the oily liquid to precipitate the catalyst. After rotary evaporation, the solution is placed in a vacuum drying oven at 50-55°C for 10-12 hours to obtain surfactant-2.

Images