Gemini type silicon-containing surfactant as well as synthesis and compound mixture thereof

Abstract

The invention discloses a gemini type silicon-containing surfactant as well as synthesis and a compound mixture thereof, belongs to the technical field of surfactants, and relates to a compound capable of being used as a surfactant and a synthesis method thereof. When the surfactant is combined with a hydrocarbon surfactant, the problems that the existing silicon-containing surfactant is low in cost and low in activity are solved; the gemini surfactant has the performance of reducing surface tension, the lowest surface tension can reach 20 cm / N, after the gemini surfactant is compounded with a hydrocarbon surfactant, the foaming power is high, the cost is remarkably reduced, and the economic value is very good.

Description

Technical Field

[0001] The invention relates to a surfactant, in particular to a Gemini silicon-containing surfactant and a synthesis and compound mixture thereof, belonging to the technical field of surfactants. Background Art

[0002] Surfactants, also known as interfacial agents, are compounds that can significantly reduce the surface tension or interfacial tension between two liquids, between liquid and gas, and between liquid and solid. The molecular structure of surfactants has two properties: one end is a hydrophilic group and the other end is a hydrophobic group; the hydrophilic group is often a polar group, such as carboxylic acid, sulfonic acid, sulfuric acid, amino or amine group and its salt, hydroxyl, amide, ether bond, etc. can also be used as polar hydrophilic groups; while the hydrophobic group is often a non-polar hydrocarbon chain, such as a hydrocarbon chain with more than 8 carbon atoms.

[0003] Fluorosurfactant, FSA for short, is a surfactant with fluorocarbon chain as non-polar group, that is, fluorine atoms partially or completely replace hydrogen atoms on hydrocarbon chain. Fluorocarbon surfactant has high surface activity, high thermodynamic and chemical stability. It is widely used in fire protection, chemical industry, pesticide, mineral processing, papermaking, leather, textile and other fields; Silicon-containing surfactant is an excellent surfactant category besides fluorine-containing surfactant. Silicon-containing surfactant, i.e. siloxane surfactant, can reduce the surface tension of water to 0.02-0.022N / m (20-22dyn / cm) depending on the structure and concentration of the surfactant. Compared with fluorine-containing surfactant, siloxane surfactant has better oil-water surface tension reduction ability, and can easily wet solids that are difficult to wet with water. It is a good wetting agent for polyethylene. Siloxane surfactant can be used as foam stabilizer (foam stabilizer) for polyurethane foam. In addition, it can also be used as softener for polyacrylic acid and polyester fiber in fiber industry, and can also be used as additive for polyoxyethylene foam and additive for cosmetics; However, the current fluorine-containing surfactant has the following problems:

[0004] First, fluorinated surfactants are difficult to degrade. Such compounds are almost non-biodegradable in nature and will remain in the environment for a long time, posing a potential threat to the ecosystem. Second, fluorinated surfactants may cause health problems after contact with the human body. For example, some dental floss brands use fluorinated surfactants as coating materials, which may lead to abnormal PFAS concentrations in the user's blood, posing health risks. In addition, fluorinated surfactants do not work well when used in hard water and heavy metal salt solutions because they react with high-valent metal ions to form insoluble carboxylates.

[0005] Silicone-containing surfactants are different from fluorine-containing surfactants. They are eco-friendly and low-foaming, and are used more and more widely. In recent years, the research on silicone-containing surfactants has become more and more in-depth, and many new silicone-containing surfactants such as gemini surfactants have been developed. Gemini surfactants are a new type of surfactants. They are composed of two or more monomer surfactants connected together by a connecting group through a chemical bond, thereby producing a series of properties such as excellent surface activity, such as: easier to adsorb on the gas / liquid surface, thereby more effectively reducing the surface tension of the aqueous solution, thus gaining a wide range of applications. It is of great significance to obtain surfactants with low surface tension and high surface activity and their compound mixtures through molecular structure design. Summary of the invention

[0006] The technical problem to be solved by the present invention is to propose a Gemini silicon-containing surfactant and its synthesis and compound mixture in view of the shortcomings of the above prior art, which effectively solves the problem of environmental pollution caused by fluorinated surfactants, reduces costs and has high activity.

[0007] The technical solution of the present invention to solve the above technical problems is:

[0008] A Gemini silicon-containing surfactant, the general structural formula of which is:

[0009]

[0010] The technical solution further defined in the present invention is:

[0011] Furthermore, in the aforementioned Gemini silicon-containing surfactant, it is characterized in that: when R1 = nonane, R2 = 1,1,1,3,5,5,5-heptamethyltrisiloxane, the surfactant is N,N,N',N'-tetramethyl-N,N'-bis[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,9-dibromononanediamine, and the specific structural formula is:

[0012]

[0013] In the aforementioned Gemini silicon-containing surfactant, when R1 = octane and R2 = 1,1,1,3,5,5,5-heptamethyltrisiloxane, the surfactant is N,N,N',N'-tetramethyl-N,N'-bis[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,8-dibromide octanediamine, and the specific structural formula is:

[0014]

[0015] In the aforementioned Gemini silicon-containing surfactant, when R1 = decane and R2 = 1,1,1,3,5,5,5-heptamethyltrisiloxane, the surfactant is N,N,N',N'-tetramethyl-N,N'-bis[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,10-dibromide decanediamine, and the specific structural formula is:

[0016]

[0017] In the aforementioned Gemini silicon-containing surfactant, when R1 = nonane and R2 = tetrasiloxane, the surfactant is N,N,N',N'-tetramethyl-N,N'-bis[(tetrasiloxane)-3-propyl]-1,9-dibromononanediamine, and the specific structural formula is:

[0018]

[0019] In the aforementioned Gemini silicon-containing surfactant, when R1 = decane and R2 = tetrasiloxane, the surfactant is N,N,N',N'-tetramethyl-N,N'-bis[(tetrasiloxane)-3-propyl]-1,10-dibromide decanediamine, and the specific structural formula is:

[0020]

[0021] In the aforementioned Gemini silicon-containing surfactant, when R1 = dodecane and R2 = tetrasiloxane, the compound is N,N,N',N'-tetramethyl-N,N'-bis[(tetrasiloxane)-3-propyl]-1,12-dibromododecyl diamine, and the specific structural formula is:

[0022] The present invention also relates to a method for synthesizing the above-mentioned gemini silicon-containing surfactant, which specifically comprises the following steps:

[0023] (1) Add siloxane compound I, enamine compound II, and Custer catalyst into a three-necked flask, slowly raise the temperature to 100° C. under nitrogen protection, react at this temperature for 3-12 hours, and evaporate the solvent under reduced pressure to obtain a liquid silicon-containing amine intermediate III;

[0024] (2) Add the liquid intermediate III obtained in step (1), the dibromoalkyl compound IV and N,N-dimethylformamide into a flask, slowly raise the temperature to 80° C. under a nitrogen atmosphere, react at this temperature for 24-48 hours, and evaporate the solvent under reduced pressure to obtain a yellow solid, which is then recrystallized with a mixed solution of butanone and ether to obtain a white solid gemini silicon-containing surfactant V;

[0025] Wherein: siloxane compound I is 1,1,1,3,5,5,5,-heptamethyltrisiloxane or tetrasiloxane; enamine compound II is N,N-dimethylallylamine;

[0026] The dibromohydrocarbon compound IV is one of 1,8-dibromooctane, 1,9-dibromononane, 1,10-dibromodecane or 1,12-dibromodecane.

[0027] The synthetic process route is as follows:

[0028]

[0029] Six gemini silicon-containing surfactants conforming to the general formula (V) of the present invention are used as main components in the field of fire protection.

[0030] The technical solution further defined in the present invention is:

[0031] Furthermore, in the aforementioned method for synthesizing gemini-type silicon-containing surfactants, the temperature in step (1) is controlled at 100° C. by using an oil bath; and the temperature in step (2) is controlled at 80° C. by using an oil bath.

[0032] The present invention also designs a compound mixture of a Gemini-type silicon-containing surfactant, and the mixture obtained by compounding the Gemini-type silicon-containing surfactant with a hydrocarbon surfactant is applied to a fire extinguishing agent.

[0033] Technical effect: The present invention compounds a gemini silicon-containing surfactant with a hydrocarbon surfactant. Compared with ordinary hydrocarbon surfactants, the compounded surfactant has a significant effect of reducing surface tension, which can reach a minimum of 20cm / N. Compared with other silicon-containing surfactants, it has better foaming performance and heat stability, can significantly reduce costs, and has excellent application value.

[0034] The beneficial effects of the present invention are:

[0035] The surfactant of the present invention and the interactions between the components produce the following corresponding effects:

[0036] The gemini silicon-containing surfactant provided by the present invention is a cationic gemini surfactant, which is combined with an enamine compound through the addition reaction of silane and then gemini-ized with a dibromoalkyl compound to give it a claw-type structure. It can interact with other hydrocarbon surfactants through charge to obtain a more stable dispersion system.

[0037] The present invention firstly synthesizes a silicon-containing amine intermediate product through an addition reaction of a silane compound and N, N-dimethylallylamine, and then performs a substitution reaction between the intermediate product and a dibromoalkyl group to synthesize six gemini-type silicon-containing surfactants. The six gemini-type silicon-containing surfactants are compounded with hydrocarbon surfactants such as sodium octyl sulfonate, sodium octyl sulfate, cocamidopropyl betaine, etc., and exhibit good foaming properties, and can be widely used in the field of fire protection.

[0038] The diquaternary ammonium cation of the present invention acts as a good hydrophilic group, generates interaction force with the anion in the hydrocarbon surfactant, and better enhances the stability of the surfactant, so that the surfactant molecules are closely arranged in the aqueous solution, and micelles and micelles are formed in the aqueous phase, thereby playing a role in reducing the surface tension.

[0039] The Gemini surfactant of the present invention has the performance of reducing surface tension, which can reach a minimum of 20cm / N. After being compounded with a hydrocarbon surfactant, the Gemini surfactant has strong foaming power, significantly reduces the cost, and has good economic value. DETAILED DESCRIPTION

[0040] The present invention will be described clearly and completely below in conjunction with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Example 1

[0042] This embodiment provides a method for synthesizing a Gemini-type silicon-containing surfactant N,N,N',N'-tetramethyl-N,N'-bis[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,9-dibromide nonanediamine, which specifically comprises the following steps:

[0043] (1) Add 0.2 mol 1,1,1,3,5,5,5-heptamethyltrisiloxane and 0.2 mol N,N-dimethylallylamine in a nitrogen atmosphere, mix well, slowly heat the mixture in an oil bath to 100° C., then dropwise add 5000 ppm of Custer catalyst, stir and react at 100° C. for 3-12 hours, evaporate the solvent under reduced pressure to obtain a liquid, and then obtain N,N-dimethyl-N-[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]amine by column chromatography (petroleum ether: dichloromethane = 7:1);

[0044] (2) Add 250 ml of N,N-dimethylformamide and 0.1 mol 1,9-dibromononane into a three-necked flask, and then add 0.2 mol N,N-dimethyl-N-[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]amine obtained in step (1), and control the reaction temperature to 80° C. in an oil bath. After reacting for 24-48 hours, evaporate the solvent to obtain a solid phase. The solid phase is recrystallized using a mixed solution of butanone and ether, and filtered to obtain N,N,N',N'-tetramethyl-N,N'-bis[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,9-dibromononanediamine.

[0045] The yield of N,N-dimethyl-N-[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]amine obtained in step (1) of this embodiment is 86.2%, the purity is 98.1%, and the final N,N,N',N'-tetramethyl-N,N'-dimethyl

[0046] The content of [(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,9-dibromononanediamine is 80.3% and the purity is 95.2%. Its nuclear magnetic resonance hydrogen spectrum data are 1H-NMR (400Hz, CD3OD) δ3.30 (s, 12H), δ3.22 (t, 8H), δ1.71 (m, 8H), δ1.30 (s, 10H), δ0.63 (t, 4H), δ0.21 (s, 36H), δ0.14 (s, 4H).

[0047] In summary, the synthetic route of N,N,N',N'-tetramethyl-N,N'-bis[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,9-dibromononanediamine is as follows:

[0048]

[0049] Example 2

[0050] The present embodiment provides a method for synthesizing a Gemini-type silicon-containing surfactant N,N,N',N'-tetramethyl-N,N'-bis[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,8-dibromide octanediamine, which specifically comprises the following steps:

[0051] (1) Add 0.2 mol 1,1,1,3,5,5,5-heptamethyltrisiloxane and 0.2 mol N,N-dimethylallylamine in a nitrogen atmosphere, mix well, slowly heat the mixture in an oil bath to 100° C., then dropwise add 5000 ppm of Custer catalyst, stir and react at 100° C. for 3-12 hours, evaporate the solvent under reduced pressure to obtain a liquid, and then obtain N,N-dimethyl-N-[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]amine by column chromatography (petroleum ether: dichloromethane = 7:1);

[0052] (2) Add 250 ml of N,N-dimethylformamide and 0.1 mol of 1,8-dibromooctane into a three-necked flask, and then add 0.2 mol of N,N-dimethyl-N-[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]amine obtained in step (1), and control the reaction temperature to 80° C. in an oil bath. After reacting for 24-48 hours, evaporate the solvent to obtain a solid phase, and use a mixed solution of butanone and ether to recrystallize the solid phase, and filter to obtain N,N,N',N'-tetramethyl-N,N'-bis[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,8-dibromooctanediamine.

[0053] The yield of N,N-dimethyl-N-[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]amine obtained in step (1) of this embodiment is 86.2%, the purity is 98.1%, and the final N,N,N',N'-tetramethyl-N,N'-dimethyl

[0054] The content of [(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,8-dibromooctanediamine is 81.5% and the purity is 95.8%. Its nuclear magnetic resonance hydrogen spectrum data are 1H-NMR (400Hz, CD3OD) δ3.30 (s, 12H), δ3.22 (t, 8H), δ1.71 (m, 8H), δ1.30 (s, 8H), δ0.63 (t, 4H), δ0.21 (s, 36H), δ0.14 (s, 4H).

[0055] In summary, the synthetic route of N,N,N',N'-tetramethyl-N,N'-bis[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,8-dibromooctanediamine is as follows:

[0056]

[0057] Example 3

[0058] The present embodiment provides a method for synthesizing a Gemini-type silicon-containing surfactant N,N,N',N'-tetramethyl-N,N'-bis[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,10-dibromide decanediamine, which specifically comprises the following steps:

[0059] (1) Add 0.2 mol 1,1,1,3,5,5,5-heptamethyltrisiloxane and 0.2 mol N,N-dimethylallylamine in a nitrogen atmosphere, mix well, slowly heat the mixture in an oil bath to 100° C., then dropwise add 5000 ppm of Custer catalyst, stir and react at 100° C. for 3-12 hours, evaporate the solvent under reduced pressure to obtain a liquid, and then obtain N,N-dimethyl-N-[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]amine by column chromatography (petroleum ether: dichloromethane = 7:1);

[0060] (2) Add 250 ml of N,N-dimethylformamide and 0.1 mol 110-dibromodecane into a three-necked flask, and then add 0.2 mol N,N-dimethyl-N-[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]amine obtained in step (1), and control the reaction temperature to 80° C. in an oil bath. After reacting for 24-48 hours, evaporate the solvent to obtain a solid phase. The solid phase is recrystallized using a mixed solution of butanone and ether, and filtered to obtain N,N,N',N'-tetramethyl-N,N'-bis[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,10-dibromide decanediamine.

[0061] The yield of N,N-dimethyl-N-[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]amine obtained in step (1) of this embodiment is 86.2%, the purity is 98.1%, and the final N,N,N',N'-tetramethyl-N,N'-dimethyl

[0062] The content of [(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,10-dibromodecanediamine is 82.5% and the purity is 96.2%. Its nuclear magnetic resonance hydrogen spectrum data are 1H-NMR (400Hz, CD3OD) δ3.30 (s, 12H), δ3.22 (t, 8H), δ1.71 (m, 8H), δ1.30 (s, 12H), δ0.63 (t, 4H), δ0.21 (s, 36H), δ0.14 (s, 4H).

[0063] In summary, the synthetic route of N,N,N',N'-tetramethyl-N,N'-bis[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,10-dibromide decanediamine is as follows:

[0064]

[0065] Example 4

[0066] This embodiment provides a method for synthesizing a Gemini-type silicon-containing surfactant N,N,N',N'-tetramethyl-N,N'-bis[(tetrasiloxane)-3-propyl]-1,9-dibromononanediamine, which specifically comprises the following steps:

[0067] (1) Add 0.2 mol tetrasiloxane and 0.2 mol N, N-dimethylallylamine in a nitrogen atmosphere, mix well, slowly heat the mixture in an oil bath to 100° C., then dropwise add 5000 ppm of Custer catalyst, stir and react at 100° C. for 6-18 hours, evaporate the solvent under reduced pressure to obtain a liquid, and then obtain N, N-dimethyl-N-[(tetrasiloxane)-3-propyl]amine by column chromatography (petroleum ether: dichloromethane = 7:1);

[0068] (2) Add 250 ml of N, N-dimethylformamide and 0.1 mol 1,9-dibromononane into a three-necked flask, and then add 0.2 mol N, N-dimethyl-N-[(tetrasiloxane)-3-propyl]amine obtained in step (1), and control the reaction temperature to 80° C. in an oil bath. After reacting for 24-48 hours, evaporate the solvent to obtain a solid phase. The solid phase is subjected to column chromatography (petroleum ether: dichloromethane = 6:1), and the solid phase is spin-dried to obtain N, N, N', N'-tetramethyl-N, N'-bis[(tetrasiloxane)-3-propyl]-1,9-dibromononane. The yield of N,N-dimethyl-N-[(tetrasiloxane)-3-propyl]amine obtained in step (1) of this embodiment is 88.3%, and the purity is 98.6%. The yield of N,N,N',N'-tetramethyl-N,N'-bis[(tetrasiloxane)-3-propyl]-1,9-dibromide nonanediamine finally obtained is 83.2%, and the purity is 96.3%.

[0069] Its nuclear magnetic resonance hydrogen spectrum data are 1H-NMR (400Hz, CD3OD) δ3.30 (s, 12H), δ3.22 (t, 8H), δ1.71 (m, 8H), δ1.30 (s, 10H), δ0.63 (t, 4H), δ0.21 (s, 54H).

[0070] In summary, the synthetic route of N,N,N',N'-tetramethyl-N,N'-bis[(tetrasiloxane)-3-propyl]-1,10-dibromide decanediamine is:

[0071]

[0072] Example 5

[0073] This embodiment provides a method for synthesizing a Gemini-type silicon-containing surfactant N,N,N',N'-tetramethyl-N,N'-bis[(tetrasiloxane)-3-propyl]-1,10-dibromide decanediamine, which specifically comprises the following steps:

[0074] (1) Add 0.2 mol tetrasiloxane and 0.2 mol N, N-dimethylallylamine in a nitrogen atmosphere, mix well, slowly heat the mixture in an oil bath to 100° C., then dropwise add 5000 ppm of Custer catalyst, stir and react at 100° C. for 6-18 hours, evaporate the solvent under reduced pressure to obtain a liquid, and then obtain N, N-dimethyl-N-[(tetrasiloxane)-3-propyl]amine by column chromatography (petroleum ether: dichloromethane = 7:1);

[0075] (2) Add 250 ml of N, N-dimethylformamide and 0.1 mol 1,10-dibromodecane into a three-necked flask, and then add 0.2 mol N, N-dimethyl-N-[(tetrasiloxane)-3-propyl]amine obtained in step (1), and control the reaction temperature to 80° C. in an oil bath. After reacting for 24-48 hours, evaporate the solvent to obtain a solid phase. The solid phase is subjected to column chromatography (petroleum ether: dichloromethane = 6:1), and the solid phase is dried by spin drying to obtain N, N, N', N'-tetramethyl-N, N'-bis[(tetrasiloxane)-3-propyl]-1,10-dibromide decanediamine. The yield of N,N-dimethyl-N-[(tetrasiloxane)-3-propyl]amine obtained in step (1) of this embodiment is 88.3%, and the purity is 98.6%. The yield of N,N,N',N'-tetramethyl-N,N'-bis[(tetrasiloxane)-3-propyl]-1,10-dibromide decanediamine finally obtained is 82.5%, and the purity is 96.1%.

[0076] Its nuclear magnetic resonance hydrogen spectrum data are 1H-NMR (400Hz, CD3OD) δ3.30 (s, 12H), δ3.22 (t, 8H), δ1.71 (m, 8H), δ1.30 (s, 12H), δ0.63 (t, 4H), δ0.21 (s, 54H).

[0077] In summary, the synthetic route of N,N,N',N'-tetramethyl-N,N'-bis[(tetrasiloxane)-3-propyl]-1,10-dibromide decanediamine is:

[0078]

[0079]

[0080] Example 6

[0081] This embodiment provides a method for synthesizing a Gemini silicon-containing surfactant N,N,N',N'-tetramethyl-N,N'-bis[(tetrasiloxane)-3-propyl]-1,12-dibromododecyl diamine, which specifically comprises the following steps:

[0082] (1) Add 0.2 mol tetrasiloxane and 0.2 mol N, N-dimethylallylamine in a nitrogen atmosphere, mix well, slowly heat the mixture in an oil bath to 100° C., then dropwise add 5000 ppm of Custer catalyst, stir and react at 100° C. for 6-18 hours, evaporate the solvent under reduced pressure to obtain a liquid, and then obtain N, N-dimethyl-N-[(tetrasiloxane)-3-propyl]amine by column chromatography (petroleum ether: dichloromethane = 7:1);

[0083] (2) Add 250 ml of N, N-dimethylformamide and 0.1 mol 1,12-dibromododecane into a three-necked flask, and then add 0.2 mol N, N-dimethyl-N-[(tetrasiloxane)-3-propyl]amine obtained in step (1), and control the reaction temperature to 80° C. in an oil bath. After reacting for 24-48 hours, evaporate the solvent to obtain a solid phase. The solid phase is subjected to column chromatography (petroleum ether: dichloromethane = 6:1), and the solid phase is spin-dried to obtain N, N, N', N'-tetramethyl-N, N'-bis[(tetrasiloxane)-3-propyl]-1,12-dibromododecanediamine. The yield of N,N-dimethyl-N-[(tetrasiloxane)-3-propyl]amine obtained in step 1 of this embodiment is 88.3% and the purity is 98.6%. The yield of N,N,N',N'-tetramethyl-N,N'-bis[(tetrasiloxane)-3-propyl]-1,10-dibromide decanediamine finally obtained is 82.5% and the purity is 96.1%.

[0084] Its nuclear magnetic resonance hydrogen spectrum data are 1H-NMR (400Hz, CD3OD) δ3.30 (s, 12H), δ3.22 (t, 8H), δ1.71 (m, 8H), δ1.30 (s, 16H), δ0.63 (t, 4H), δ0.21 (s, 54H).

[0085] In summary, the synthetic route of N,N,N',N'-tetramethyl-N,N'-bis[(tetrasiloxane)-3-propyl]-1,12-dibromododecyl diamine is as follows:

[0086]

[0087] The first three gemini silicon-containing surfactants of the present invention were compounded with common hydrocarbon surfactants SOS, CAB, sodium octyl sulfonate, etc. on the market to obtain a compound mixture to explore its surface tension properties.

[0088] The experimental results of the mixture of three Gemini-type silicon-containing surfactants are shown in Table 1

[0089] Table 1 Performance data of compound mixture

[0090]

[0091]

[0092]

[0093] The experimental results in Table 1 show that the synthesized gemini silicon-containing surfactant has a good effect of reducing surface activity. When the compounding ratio with SOS, CAB, sodium n-octyl sulfonate, etc. is 0.33, the effect is significantly improved, and it has a good synergistic effect. Compounding with commonly used hydrocarbon surfactants can significantly reduce costs and increase foaming ability. It can be used in fire extinguishing agents and has good practical application value.

[0094] It can be seen that the compound mixture of silicon-containing surfactants and hydrocarbon surfactants has excellent foaming ability and can replace aqueous film-forming foam (AFFF) in the fire scene and be used in the fire protection field. It is worth noting that these compound surfactants have low critical micelle concentration (CMC), low surface tension, excellent foam inhibition and rich aggregation modes, while common hydrocarbon surfactants have good foaming properties. Their combined use can improve foam activity and has become a hot spot of surfactants.

[0095] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope required by the present invention.

Claims

1. A Gemini silicon-containing surfactant, characterized in that: The general structural formula of the surfactant is:

2. The Gemini silicon-containing surfactant according to claim 1, characterized in that: When R1 = nonane, When R2=1,1,1,3,5,5,5-heptamethyltrisiloxane, the surfactant is N,N,N',N'-tetramethyl-N,N'-bis[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,9-dibromononanediamine, and the specific structural formula is:

3. The Gemini silicon-containing surfactant according to claim 1, characterized in that: When R1 = octane, When R2=1,1,1,3,5,5,5-heptamethyltrisiloxane, the surfactant is N,N,N',N'-tetramethyl-N,N'-bis[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,8-dibromooctanediamine, and the specific structural formula is:

4. The Gemini silicon-containing surfactant according to claim 1, characterized in that: When R1 = decane, When R2=1,1,1,3,5,5,5-heptamethyltrisiloxane, the surfactant is N,N,N',N'-tetramethyl-N,N'-bis[(1,1,1,3,5,5,5-heptamethyltrisiloxane)-3-propyl]-1,10-dibromide decanediamine, and the specific structural formula is:

5. The Gemini silicon-containing surfactant according to claim 1, characterized in that: When R1 = nonane and R2 = tetrasiloxane, the surfactant is N,N,N',N'-tetramethyl-N,N'-bis[(tetrasiloxane)-3-propyl]-1,9-dibromononanediamine, and the specific structural formula is:

6. The Gemini silicon-containing surfactant according to claim 1, characterized in that: When R1 = decane and R2 = tetrasiloxane, the surfactant is N,N,N',N'-tetramethyl-N,N'-bis[(tetrasiloxane)-3-propyl]-1,10-dibromide decanediamine, and the specific structural formula is:

7. The Gemini silicon-containing surfactant according to claim 1, characterized in that: When R1 = dodecane and R2 = tetrasiloxane, the compound is N,N,N',N'-tetramethyl-N,N'-bis[(tetrasiloxane)-3-propyl]-1,12-dibromododecyl diamine, and the specific structural formula is:

8. A method for synthesizing the gemini silicon-containing surfactant according to any one of claims 1 to 7, characterized in that: The specific steps include: (1) Add siloxane compound I, enamine compound II, and Custer catalyst into a three-necked flask, slowly raise the temperature to 100° C. under nitrogen protection, react at this temperature for 3-12 hours, and evaporate the solvent under reduced pressure to obtain a liquid silicon-containing amine intermediate III; (2) Add the liquid intermediate III obtained in step (1), the dibromoalkyl compound IV and N,N-dimethylformamide into a flask, slowly raise the temperature to 80° C. under a nitrogen atmosphere, react at this temperature for 24-48 hours, and evaporate the solvent under reduced pressure to obtain a yellow solid, which is then recrystallized with a mixed solution of butanone and ether to obtain a white solid gemini silicon-containing surfactant V; Wherein: the siloxane compound I is 1,1,1,3,5,5,5,-heptamethyltrisiloxane or tetrasiloxane; the enamine compound II is N,N-dimethylallylamine; The dibromo hydrocarbon compound IV is one of 1,8-dibromooctane, 1,9-dibromononane, 1,10-dibromodecane or 1,12-dibromododecane.

9. The method for synthesizing a gemini-type silicon-containing surfactant according to claim 8, characterized in that: In step (1), the temperature is raised by using an oil bath to control the temperature to 100° C.; in step (2), the temperature is raised by using an oil bath to control the temperature to 80° C.

10. The compounded mixture of the Gemini silicon-containing surfactant according to any one of claims 1 to 7, characterized in that: The mixture obtained by compounding the gemini silicon-containing surfactant and the hydrocarbon surfactant is applied as a fire extinguishing agent.

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