Polyquaternary ammonium salt surfactants, methods of making and industrial adjuvants

Abstract

The application discloses a polyquaternary ammonium salt surfactant, a preparation method and an industrial aid, and belongs to the technical field of surfactants. The polyquaternary ammonium salt surfactant comprises the following structural formulae: wherein, in the structure I, n is a hydrocarbon group with 5-13 carbon atoms, and X is a positive integer of 1-2; in the structure II, n is a hydrocarbon group with 5-13 carbon atoms. In the technical scheme, the polyquaternary ammonium salt surfactant provided by the application has a hydrophilic main chain of a quaternary ammonium salt and a hydrophobic alkyl chain as a branch chain, so that the polyquaternary ammonium salt surfactant is of a hydrophilic main chain type. Meanwhile, the polyquaternary ammonium salt surfactant has good water solubility and emulsifying capacity and excellent bacteriostatic activity.

Description

Technical Field

[0001] This invention relates to the field of industrial additives and materials technology, and in particular to a polyquaternary ammonium salt surfactant, its preparation method, and an industrial additive. Background Technology

[0002] Quaternary ammonium salt surfactants possess excellent surfactant properties and broad-spectrum antibacterial activity, and are widely used in pharmaceuticals, hygiene, textiles, agriculture, and water treatment. However, as small organic molecules, they suffer from drawbacks such as volatility, poor chemical stability, difficulty in processing, and high toxicity and irritation. In particular, their bactericidal activity is significantly reduced in the presence of large molecular weight anionic compounds. Summary of the Invention

[0003] The main objective of this invention is to provide a polyquaternary ammonium salt surfactant, its preparation method, and an industrial additive, which has excellent emulsifying, foaming, and antibacterial activities.

[0004] To achieve the above objectives, the present invention provides a polyquaternary ammonium salt surfactant, wherein the polyquaternary ammonium salt surfactant comprises the following structural formula:

[0005]

[0006] In structure I, n is a hydrocarbon group with 5 to 13 carbon atoms, and X is a positive integer from 1 to 2; in structure II, n is a hydrocarbon group with 5 to 13 carbon atoms.

[0007] Optionally, n is an alkyl group with 5, 9, or 12 carbon atoms.

[0008] This invention provides a method for preparing a polyquaternary ammonium salt surfactant, comprising the following steps:

[0009] S10. Mix glycidyl ether with an ethanol solution of alkylamine to obtain a single-chain alkylglycerolamine;

[0010] S20. Under alkaline conditions, the single-chain alkylglycerolamine is mixed with dibromoalkane or 1,3-dichloropropanol to obtain an alkylglycerolamine gemini surfactant.

[0011] S30. The alkylglycerol amine gemini surfactant is mixed with dibromoalkane to obtain a polyquaternary ammonium salt surfactant.

[0012] Optionally, in step S10, the molar ratio of the alkylamine to glycidol is 1:1; and / or,

[0013] In step S20, the monoalkylglycerolamine is mixed with dibromoalkane or 1,3-dichloropropanol, wherein the molar ratio of the monoalkylglycerolamine to the dibromoalkane or 1,3-dichloropropanol is 2:1; and / or,

[0014] In step S30, the molar ratio of the alkylglycerol amine gemini surfactant to the dibromoalkane is 2 to 2.2:1.

[0015] Optionally, in step S20, the alkaline conditions are prepared by adding an alkaline substance, which includes any one of triethylamine, sodium carbonate, and potassium carbonate; and / or,

[0016] The dibromoalkane includes any one of 1,3-dibromopropane and 1,4-dibromobutane.

[0017] Optionally, in step S10, the mixing time is 2–10 hours; and / or,

[0018] The mixing temperature is 20–30℃.

[0019] Optionally, in step S20, the mixing time is 5–20 hours; and / or,

[0020] The mixing temperature is 50–80℃.

[0021] Optionally, in step S30, the mixing time is 5–10 hours; and / or,

[0022] The mixing temperature is 70–80℃.

[0023] This invention provides an industrial additive, comprising the aforementioned polyquaternary ammonium salt surfactant, or a polyquaternary ammonium salt surfactant prepared by the aforementioned method.

[0024] Optionally, the industrial additives include antibacterial agents, emulsifiers, or foaming agents.

[0025] In the technical solution provided by this invention, the main chain of the polyquaternary ammonium salt surfactant is a hydrophilic quaternary ammonium salt, and the side chain is a hydrophobic alkyl chain. Therefore, the polyquaternary ammonium salt surfactant is a hydrophilic main chain type. At the same time, the polyquaternary ammonium salt surfactant of the invention has good water solubility and emulsifying ability as well as excellent antibacterial activity. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0027] Figure 1 A flowchart illustrating the preparation method of the polyquaternary ammonium salt surfactant provided by the present invention;

[0028] Figure 2 The images show the appearance of the polyquaternary ammonium salt surfactants prepared in Examples 8-16 of this invention.

[0029] Figure 3 The following are surface tension diagrams of the polyquaternary ammonium salt surfactants prepared in Examples 8-13 of this invention at different concentrations;

[0030] Figure 4 The surface tension diagrams of the polyquaternary ammonium salt surfactants prepared in Examples 14-16 of this invention at different concentrations are shown.

[0031] Figure 5 The graph shows the emulsification performance of the polyquaternary ammonium salt surfactants prepared in Examples 8-13 of this invention at a concentration of 2 mg / mL.

[0032] Figure 6 The diagram shows the emulsification performance of the polyquaternary ammonium salt surfactants prepared in Examples 14-16 of this invention at a concentration of 2 mg / mL.

[0033] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially. Furthermore, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, or solution B, or a solution where both A and B are satisfied simultaneously. In addition, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention. 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.

[0035] Quaternary ammonium salt surfactants possess excellent surfactant properties and broad-spectrum antibacterial activity, leading to their widespread application in pharmaceuticals, hygiene, textiles, agriculture, and water treatment. However, as small organic molecules, they suffer from drawbacks such as volatility, poor chemical stability, difficulty in processing, and significant toxicity and irritation. Their bactericidal activity is particularly reduced in the presence of large anionic compounds. To overcome the shortcomings of traditional quaternary ammonium salt surfactants, polyquaternary ammonium salt surfactants have emerged. These surfactants exhibit excellent adsorption, flocculation, solubilization, antibacterial, and detergency properties, thus becoming a research hotspot.

[0036] In view of this, the present invention provides a polyquaternary ammonium salt surfactant, wherein the polyquaternary ammonium salt surfactant comprises the following structural formula:

[0037]

[0038] In structure I, n is a hydrocarbon group with 5 to 13 carbon atoms, and X is a positive integer from 1 to 2; in structure II, n is a hydrocarbon group with 5 to 13 carbon atoms.

[0039] In the above technical solutions, when x is 1 or 2 and n is 5, 9, or 13 carbon atoms, the resulting novel polyquaternary ammonium salt surfactant has better foaming properties.

[0040] In the technical solution provided by this invention, the main chain of the polyquaternary ammonium salt surfactant is a hydrophilic quaternary ammonium salt, and the side chain is a hydrophobic alkyl chain. Therefore, the polyquaternary ammonium salt surfactant is a hydrophilic main chain type. At the same time, the polyquaternary ammonium salt surfactant of the invention has good water solubility and emulsifying ability as well as excellent antibacterial activity.

[0041] Furthermore, n can be 5, 6, 7, 8, 9, 10, 11, 12, or 13. Preferably, n is an alkyl group with 5, 9, or 13 carbon atoms. When n is 5, 9, or 13, the corresponding alkyl chain lengths are 8, 12, and 16, respectively. These are three common and widely available raw materials with moderate chain lengths, suitable for use as hydrophobic chains in surfactants. It should be noted that the side chain groups can be the same alkyl group or different alkyl groups, but the same alkyl group is preferred, as this results in novel polyquaternary ammonium salt surfactants with better emulsifying properties.

[0042] This invention also proposes a method for preparing polyquaternary ammonium salt surfactants, such as... Figure 1 As shown, it includes the following steps:

[0043] S10. Mix glycidyl ether with an ethanol solution of alkylamine to obtain a single-chain alkylglycerolamine;

[0044] Alkylamines react with glycidyl at room temperature for a certain period of time to generate single-chain alkylglycerolamines. In some embodiments of this application, alkylamines refer to straight-chain or branched, saturated or unsaturated hydrocarbon amines with 8 to 16 carbon atoms. Preferably, glycidyl is added dropwise to an ethanol solution of alkylamines to react and generate single-chain alkylglycerolamines, resulting in a single-chain alkylglycerolamine product with higher purity.

[0045] S20. Under alkaline conditions, the single-chain alkylglycerolamine is mixed with dibromoalkane or 1,3-dichloropropanol to obtain an alkylglycerolamine gemini surfactant.

[0046] S30. The alkylglycerol amine gemini surfactant is mixed with dibromoalkane to obtain a polyquaternary ammonium salt surfactant.

[0047] The polyquaternary ammonium salt surfactant prepared by this invention can be efficiently synthesized through a simple three-step method. The process is simple, the yield is high, and the product is pure. The polyquaternary ammonium salt surfactant has excellent emulsifying ability, foaming ability, and antibacterial activity, and has a wide range of applications.

[0048] Furthermore, in step S10, the molar ratio of the alkylamine to glycidyl is 1:1, and the resulting product, single-chain alkylglycerolamine, has a high purity. This is because the strong nucleophilicity of the alkylamine will cause a ring-opening reaction with the glycidyl, and the product will not continue to react. Therefore, the alkylamine and glycidyl undergo a complete ring-opening addition reaction, and the product with equimolar amounts of both reacts has a higher purity.

[0049] Furthermore, in step S20, the single-chain alkylglycerolamine is mixed with dibromoalkane or 1,3-dichloropropanol, and the molar ratio of the single-chain alkylglycerolamine to the dibromoalkane or 1,3-dichloropropanol is 2:1. Under this ratio, the resulting alkylglycerolamine gemini surfactant has higher purity.

[0050] Furthermore, in step S30, the molar ratio of the alkylglycerol amine gemini surfactant to the dibromoalkane is 2 to 2.2:1. Under this ratio, the obtained product, polyquaternary ammonium salt surfactant, has higher purity.

[0051] Furthermore, in step S20, the alkaline conditions are prepared by adding an alkaline substance, which includes any one of triethylamine, sodium carbonate, and potassium carbonate, preferably triethylamine. Under these alkaline conditions, the reaction rate is faster.

[0052] Furthermore, the dibromoalkane includes any one of 1,3-dibromopropane and 1,4-dibromobutane, and the alkylglycerol amine gemini surfactant prepared from the dibromoalkane under these conditions has better surface activity, emulsifying properties, foaming properties, and antibacterial properties.

[0053] Furthermore, in step S10, the mixing time is 2 to 10 hours; and / or the mixing temperature is 20 to 30°C. Under these mixing reaction conditions, the yield of mono-chain alkylglycerolamine is higher and the purity is better. The mixing reaction time is preferably 5 hours, which results in a higher yield and higher purity of mono-chain alkylglycerolamine.

[0054] In the technical solution of the present invention, in step S20, the mixing time is 5 to 20 hours; and / or the mixing temperature is 50 to 80°C. Under these reaction conditions, the obtained product alkylglycerolamine gemini surfactant has higher purity and better reaction efficiency. Preferably, at 80°C, the obtained product alkylglycerolamine gemini surfactant has higher purity and higher reaction efficiency.

[0055] In step S20, the mixing time is 5 to 20 hours; and / or the mixing temperature is 50 to 80°C. Under these reaction conditions, the obtained polyquaternary ammonium salt surfactant has higher purity and better reaction efficiency.

[0056] The present invention also proposes an industrial additive, comprising the aforementioned polyquaternary ammonium salt surfactant, or a polyquaternary ammonium salt surfactant prepared by the aforementioned method.

[0057] The industrial additive has all the technical solutions of the polyquaternary ammonium salt surfactant, and therefore also has all the beneficial effects brought about by the above technical solutions, which will not be elaborated here.

[0058] Furthermore, the industrial additives include, but are not limited to, antibacterial agents, emulsifiers, or foaming agents.

[0059] The technical solution of the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0060] Example 1

[0061] A polyquaternary ammonium salt surfactant with the structural formula P C8-3-C8, i.e., n-octyl polyquaternary ammonium salt surfactant.

[0062]

[0063] Example 2

[0064] A polyquaternary ammonium salt surfactant with the structural formula P C9-3-C9, namely n-nonyl polyquaternary ammonium salt surfactant.

[0065]

[0066] Example 3

[0067] A polyquaternary ammonium salt surfactant with the structural formula P C16-3-C16, i.e., n-hexadecyl polyquaternary ammonium salt surfactant.

[0068]

[0069] Example 4

[0070] A polyquaternary ammonium salt surfactant with the structural formula P C8-4-C8, i.e., n-octyl polyquaternary ammonium salt surfactant.

[0071]

[0072] Example 5

[0073] A polyquaternary ammonium salt surfactant with the structural formula P C11-4-C11, i.e., n-undecyl polyquaternary ammonium salt surfactant.

[0074]

[0075] Example 6

[0076] A polyquaternary ammonium salt surfactant with the structural formula P C16-4-C16, i.e., n-hexadecyl polyquaternary ammonium salt surfactant.

[0077]

[0078] Example 7

[0079] A polyquaternary ammonium salt surfactant with the structural formula P C15-3-C15, i.e., pentadecyl polyquaternary ammonium salt surfactant.

[0080]

[0081] Example 8: Preparation of n-octyl polyquaternary ammonium salt surfactant (P C8-3-C8)

[0082] 70.9 g of n-octylamine was dissolved in 50 mL of ethanol and stirred at 20 °C until dissolved. Then, 40.7 g of glycidyl was slowly added dropwise. After the addition was complete, the mixture was stirred at room temperature for 5 hours. After the reaction was complete, the ethanol was removed by rotary evaporation under reduced pressure to obtain an oily single-chain n-octylglycerol.

[0083] 40.6 g of single-chain n-octylglycerolamine and 20.2 g of 1,3-dibromopropane were mixed in a round-bottom flask, and 22.3 g of triethylamine was added. The mixture was then reacted in an oil bath at 50 °C for 12 hours. 100 mL of ethyl acetate was then added and stirred for 30 min. The insoluble triethylamine hydrobromide was removed by filtration, and the ethyl acetate was removed by vacuum distillation of the filtrate to obtain an oily bis-n-octylglycerolamine gemini surfactant, i.e., R is a hydrocarbon group with 8 carbon atoms and X is 1 (C8-3-C8).

[0084] 44.7 g of C8-3-C8 and 20.2 g of 1,3-dibromopropane were mixed in a round-bottom flask. After mixing thoroughly, the mixture was reacted in an oil bath at 80 °C for 8 hours. Then, 50 mL of ethyl acetate was added and stirred for 30 min. The organic phase was removed by separation to obtain an oily n-octyl polyquaternary ammonium salt surfactant, namely P C8-3-C8 (structure 1: n = 5, x = 1).

[0085]

[0086] Example 9: Preparation of dodecanoic polyquaternary ammonium salt surfactant (P C12-3-C12)

[0087] 51.0 g of dodecylamine was dissolved in 60 mL of ethanol and stirred at 25 °C until dissolved. Then, 20.4 g of glycidyl was slowly added dropwise. After the addition was complete, the mixture was stirred at room temperature for 10 hours. After the reaction was complete, the ethanol was removed by rotary evaporation under reduced pressure to obtain a white solid single-chain dodecylglycerolamine.

[0088] 51.9 g of single-chain dodecylglycerolamine and 20.2 g of 1,3-dibromopropane were mixed in a round-bottom flask, and 22.3 g of triethylamine was added. The mixture was then reacted in an oil bath at 80 °C for 20 hours. 100 mL of ethyl acetate was then added and stirred for 30 min. The insoluble triethylamine hydrobromide was removed by filtration, and the ethyl acetate was removed by vacuum distillation of the filtrate to obtain an oily dodecylglycerolamine gemini surfactant, i.e., R is a hydrocarbon group with 12 carbon atoms and X is 1 (C12-3-C12).

[0089] 55.9 g of C12-3-C12 and 20.2 g of 1,3-dibromopropane were mixed in a round-bottom flask. After mixing thoroughly, the mixture was reacted in an oil bath at 80 °C for 9 hours. Then, 50 mL of ethyl acetate was added and stirred for 30 min. The organic phase was removed by separation to obtain an oily dodecane polyquaternary ammonium salt surfactant, namely P C12-3-C12 (structure 1: n = 9, x = 1).

[0090]

[0091] Example 10 Preparation of hexadecane polyquaternary ammonium salt surfactant (PC16-3-C16)

[0092] 66.4 g of hexadecylamine was dissolved in 60 mL of ethanol and stirred at 25 °C until dissolved. Then, 20.4 g of glycidyl was slowly added dropwise. After the addition was complete, the mixture was stirred at room temperature for 10 hours. After the reaction was complete, the ethanol was removed by rotary evaporation under reduced pressure to obtain a white solid single-chain hexadecylglycerolamine.

[0093] 63.0 g of single-chain hexadecylglycerolamine and 20.2 g of 1,3-dibromopropane were mixed in a round-bottom flask, and 22.3 g of triethylamine was added. The mixture was then reacted in an oil bath at 80 °C for 20 hours. 100 mL of ethyl acetate was then added and stirred for 30 min. The insoluble triethylamine hydrobromide was removed by filtration, and the ethyl acetate was removed by vacuum distillation of the filtrate to obtain an oily hexadecylglycerolamine gemini surfactant, i.e., a hydrocarbon group with n = 13 carbon atoms and X = 1 (C16-3-C16).

[0094] 67.2 g of C16-3-C16 and 20.2 g of 1,3-dibromopropane were mixed in a round-bottom flask. After mixing thoroughly, the mixture was reacted in an oil bath at 80 °C for 10 hours. Then, 50 mL of ethyl acetate was added and stirred for 30 min. The organic phase was removed by separation to obtain a viscous hexadecane polyquaternary ammonium salt surfactant, namely P C16-3-C16 (structure 1: n = 13, x = 1).

[0095]

[0096] Example 11 Preparation of n-octyl polyquaternary ammonium salt surfactant (P C8-4-C8)

[0097] 70.9 g of n-octylamine was dissolved in 50 mL of ethanol and stirred at 28 °C until dissolved. Then, 40.7 g of glycidyl was slowly added dropwise. After the addition was complete, the mixture was stirred at room temperature for 2 hours. After the reaction was complete, the ethanol was removed by rotary evaporation under reduced pressure to obtain an oily single-chain n-octylglycerolamine.

[0098] 40.6 g of single-chain n-octylglycerolamine and 21.6 g of 1,4-dibromobutane were mixed in a round-bottom flask, and 22.3 g of triethylamine was added. The mixture was then reacted in an oil bath at 60 °C for 8 hours. 100 mL of ethyl acetate was then added and stirred for 30 min. The insoluble triethylamine hydrobromide was removed by filtration, and the ethyl acetate was removed by vacuum distillation of the filtrate to obtain an oily bis-n-octylglycerolamine gemini surfactant, i.e., a hydrocarbon group with n = 5 carbon atoms and X = 2 (C8-4-C8).

[0099] 46.1 g of C8-4-C8 and 21.6 g of 1,4-dibromobutane were mixed in a round-bottom flask. After mixing thoroughly, the mixture was reacted in an oil bath at 80 °C for 8 hours. Then, 50 mL of ethyl acetate was added and stirred for 30 min. The organic phase was removed by separation to obtain an oily n-octyl polyquaternary ammonium salt surfactant, namely P C8-4-C8 (structure 1: n = 5, x = 2).

[0100]

[0101] Example 12 Preparation of dodecane polyquaternary ammonium salt surfactant (P C12-4-C12)

[0102] 51.0 g of dodecylamine was dissolved in 60 mL of ethanol and stirred at 30 °C until dissolved. Then, 20.4 g of glycidyl was slowly added dropwise. After the addition was complete, the mixture was stirred at room temperature for 8 hours. After the reaction was complete, the ethanol was removed by rotary evaporation under reduced pressure to obtain a white solid single-chain dodecylglycerolamine.

[0103] 51.9 g of single-chain dodecylglycerolamine and 21.6 g of 1,4-dibromobutane were mixed in a round-bottom flask, and 22.3 g of triethylamine was added. The mixture was then reacted in an oil bath at 70 °C for 5 hours. 100 mL of ethyl acetate was then added and stirred for 30 min. The insoluble triethylamine hydrobromide was removed by filtration, and the ethyl acetate was removed by vacuum distillation of the filtrate to obtain an oily dodecylglycerolamine gemini surfactant, i.e., a hydrocarbon group with n = 9 carbon atoms and X = 2 (C12-4-C12).

[0104] 57.3 g of C12-4-C12 and 21.6 g of 1,4-dibromobutane were mixed in a round-bottom flask and reacted in an oil bath at 80 °C for 9 hours. Then, 50 mL of ethyl acetate was added and stirred for 30 min. The organic phase was removed by separation to obtain an oily dodecane polyquaternary ammonium salt surfactant, namely P C12-4-C12 (structure 1: n = 9, x = 2).

[0105]

[0106] Example 13 Preparation of hexadecane polyquaternary ammonium salt surfactant (PC16-4-C16)

[0107] 66.4 g of hexadecylamine was dissolved in 60 mL of ethanol and stirred at 25 °C until dissolved. Then, 20.4 g of glycidyl was slowly added dropwise. After the addition was complete, the mixture was stirred at room temperature for 10 hours. After the reaction was complete, the ethanol was removed by rotary evaporation under reduced pressure to obtain a white solid single-chain hexadecylglycerolamine.

[0108] 63.0 g of single-chain hexadecylglycerolamine and 21.6 g of 1,4-dibromobutane were mixed in a round-bottom flask, and 22.3 g of triethylamine was added. The mixture was then reacted in an oil bath at 80 °C for 20 hours. 100 mL of ethyl acetate was then added and stirred for 30 min. The insoluble triethylamine hydrobromide was removed by filtration, and the ethyl acetate was removed by vacuum distillation of the filtrate to obtain an oily hexadecylglycerolamine gemini surfactant, i.e., a hydrocarbon group with n = 13 carbon atoms and X = 1 (C16-4-C16).

[0109] 68.6 g of C16-4-C16 and 21.6 g of 1,4-dibromobutane were mixed in a round-bottom flask. After mixing thoroughly, the mixture was reacted in an oil bath at 80 °C for 10 hours. Then, 50 mL of ethyl acetate was added and stirred for 30 min. The organic phase was removed by separation to obtain a viscous hexadecane polyquaternary ammonium salt surfactant, namely P C16-4-C16 (structure 1: n = 13, x = 2).

[0110]

[0111] Example 14 Preparation of n-octyl polyquaternary ammonium salt surfactant (P C8-3(OH)-C8)

[0112] 70.9 g of n-octylamine was dissolved in 50 mL of ethanol and stirred at 20 °C until dissolved. Then, 40.7 g of glycidyl was slowly added dropwise. After the addition was complete, the mixture was stirred at room temperature for 5 hours. After the reaction was complete, the ethanol was removed by rotary evaporation under reduced pressure to obtain an oily single-chain n-octylglycerolamine.

[0113] 60.9 g of single-chain n-octylglycerol and 20.7 g of 1,3-dichloropropanol were mixed in a round-bottom flask, and 62.1 g of potassium carbonate was added. The mixture was then reacted in an oil bath at 80 °C for 12 hours. After the reaction was completed, water (150 mL) was added and stirred for 30 min. After standing for 1 hour, the mixture was separated to obtain an oily bis-n-octylglycerol gemini surfactant with glycerol as the linker, namely C8-3(OH)-C8 (n is a hydrocarbon group with 5 carbon atoms).

[0114] 46.2 g of C8-3(OH)-C8 and 20.2 g of 1,3-dibromopropane were mixed in a round-bottom flask. After mixing thoroughly, the mixture was reacted in an oil bath at 80 °C for 8 hours. Then, 50 mL of ethyl acetate was added and stirred for 30 min. The organic phase was removed by separation to obtain an oily n-octyl polyquaternary ammonium salt surfactant, namely P C8-3(OH)-C8 (structure II: n = 5).

[0115]

[0116] Example 15 Preparation of dodecane polyquaternary ammonium salt surfactant (P C12-3(OH)-C12)

[0117] 51.0 g of dodecylamine was dissolved in 60 mL of ethanol and stirred at 25 °C until dissolved. Then, 20.4 g of glycidyl was slowly added dropwise. After the addition was complete, the mixture was stirred at room temperature for 10 hours. After the reaction was complete, the ethanol was removed by rotary evaporation under reduced pressure to obtain a white solid single-chain dodecylglycerolamine.

[0118] 51.9 g of single-chain dodecylglycerolamine and 20.2 g of 1,3-dibromopropane were mixed in a round-bottom flask, and 22.3 g of triethylamine was added. The mixture was then reacted in an oil bath at 80 °C for 12 hours. After the reaction was completed, water (150 mL) was added and stirred for 30 min. After standing for 1 h, the mixture was separated to obtain an oily didodecylglycerolamine gemini surfactant with glycerol as the linker, namely C12-3(OH)-C12 (n is a hydrocarbon group with 12 carbon atoms).

[0119] 57.4 g of C12-3(OH)-C12 and 20.2 g of 1,3-dibromopropane were mixed in a round-bottom flask. After mixing thoroughly, the mixture was reacted in an oil bath at 80 °C for 9 hours. Then, 50 mL of ethyl acetate was added and stirred for 30 min. The organic phase was removed by separation to obtain an oily dodecane polyquaternary ammonium salt surfactant, namely P C12-3(OH)-C12 (structure II: n = 9).

[0120]

[0121] Example 16 Preparation of hexadecane polyquaternary ammonium salt surfactant (PC16-3(OH)-C16)

[0122] 66.4 g of hexadecylamine was dissolved in 60 mL of ethanol and stirred at 25 °C until dissolved. Then, 20.4 g of glycidyl was slowly added dropwise. After the addition was complete, the mixture was stirred at room temperature for 10 hours. After the reaction was complete, the ethanol was removed by rotary evaporation under reduced pressure to obtain a white solid single-chain hexadecylglycerolamine.

[0123] 63.0 g of single-chain hexadecylglycerolamine and 21.6 g of 1,4-dibromobutane were mixed in a round-bottom flask, and 22.3 g of triethylamine was added. The mixture was then reacted in an oil bath at 80 °C for 20 hours. After the reaction was completed, water (150 mL) was added and stirred for 30 min. After standing for 1 h, the mixture was filtered. The filter cake was washed with water to obtain a white solid dihexadecylglycerolamine gemini surfactant with glycerol as the linker, namely C16-3(OH)-C16 (n is a hydrocarbon group with 13 carbon atoms).

[0124] 68.7 g of C16-3(OH)-C16 and 20.2 g of 1,3-dibromopropane were mixed in a round-bottom flask. After mixing thoroughly, the mixture was reacted in an oil bath at 80 °C for 10 hours. Then, 50 mL of ethyl acetate was added and stirred for 30 min. The organic phase was removed by separation to obtain a viscous hexadecane polyquaternary ammonium salt surfactant, namely P C16-3(OH)-C16 (structure II: n = 13).

[0125]

[0126] Comparative Example 1: Preparation of hexadecylglycerolamine gemini surfactant (C16-3-C16)

[0127] 66.4 g of n-hexadecylamine was dissolved in 50 mL of ethanol and stirred at 20 °C until dissolved. Then, 20.4 g of glycidyl was slowly added dropwise. After the addition was complete, the mixture was stirred at room temperature for 5 hours. After the reaction was complete, the ethanol was removed by rotary evaporation under reduced pressure to obtain single-chain n-hexadecylglycerolamine.

[0128] 63.0 g of single-chain n-hexadecylglycerolamine and 20.2 g of 1,3-dibromopropane were mixed in a round-bottom flask, and 22.3 g of triethylamine was added. The mixture was then reacted in an oil bath at 50 °C for 12 hours. 100 mL of ethyl acetate was then added and stirred for 30 min. The insoluble triethylamine hydrobromide was removed by filtration, and the ethyl acetate was removed by vacuum distillation of the filtrate to obtain a solid hexadecylglycerolamine gemini surfactant, which is a hydrocarbon group with 16 carbon atoms in the alkyl chain (C16-3-C16).

[0129]

[0130] Comparative Example 2

[0131] A surfactant, structure 1: the structural formula when x=1, n=4 is as follows:

[0132]

[0133] Comparative Example 3

[0134] A surfactant, structure 1: the structural formula when x=1, n=14 is as follows:

[0135]

[0136] Comparative Example 4

[0137] A surfactant, structure 1: the structural formula when x=2, n=4 is as follows:

[0138]

[0139] Comparative Example 5

[0140] A surfactant, structure 1: the structural formula when x=2, n=14 is as follows:

[0141]

[0142] Comparative Example 6

[0143] A surfactant, structure II: the structural formula for n=14 is as follows:

[0144]

[0145] Comparative Example 7

[0146] A surfactant, structure II: the structural formula for n=4 is as follows:

[0147]

[0148] Performance testing

[0149] Determination of surface tension and critical micelle concentration of polyquaternary ammonium salt surfactants

[0150] Aqueous solutions of polyquaternary ammonium salt surfactants of different concentrations were prepared and stirred at room temperature for 2 hours. Surface tension was measured using an interfacial rheometer via the drop weight method at a test temperature of (25.0±0.1)℃. The results are as follows: Figure 3 and 4 As shown.

[0151] Depend on Figure 3 and 4 It can be seen that the surface tension values ​​of the novel polyquaternary ammonium salt surfactants in Examples 8 (PC8-3-C8), 9 (PC12-3-C12), 10 (PC16-3-C16), 11 (PC8-4-C8), 12 (PC12-4-C12), 13 (PC16-4-C16), 14 (PC8-3(OH)-C8), 15 (PC12-3(OH)-C12), and 16 (PC16-3(OH)-C16) decreased with increasing concentration and then tended to stabilize. Their critical micelle concentrations were 1.00 mg / mL, 0.87 mg / mL, 2.40 mg / mL, 2.00 mg / mL, 0.86 mg / mL, 0.80 mg / mL, 0.46 mg / mL, 0.27 mg / mL, and 0.58 mg / mL, respectively. The surface tensions at the critical micelle concentrations L were 26.69 mN / m, 28.28 mN / m, 36.12 mN / m, 28.19 mN / m, 29.84 mN / m, 33.70 mN / m, 25.69 mN / m, 27.38 mN / m, and 31.79 mN / m, respectively. The decrease in surface tension is because the hydrophobic chains of the surfactant are easily aggregated and dispersed in the aqueous solution, thereby reducing the surface tension and enhancing the water permeability.

[0152] Determination of emulsifying properties of polyquaternary ammonium salt surfactants

[0153] To prepare an aqueous solution of the surfactant obtained in Examples 8-16 at a concentration of 2 mg / mL under constant temperature conditions of 25°C, 20 mL of the above solution was poured into a 100 mL graduated cylinder with a stopper. 20 mL of the carbon-chain triglycerides from the oil phase was then added to the graduated cylinder. The stoppered graduated cylinder was vigorously shaken up and down for 60 seconds to ensure complete mixing of the novel polyquaternary ammonium salt surfactant aqueous solution with the oil phase. The mixture was allowed to stand for 1 hour, and the corresponding volumes of the resulting oil phase, aqueous phase, and emulsion phase were recorded. The results are as follows: Figure 5 and 6 As shown.

[0154] according to Figure 5 and 6It is evident that the emulsifying properties of the surfactant with n=3 linker groups are significantly higher than those of the polyquaternary ammonium salt surfactant with n=4 linker groups and glycerol. Compared to the emulsifiers in other examples, only PC8-3-C8 (Example 8) and PC12-3-C12 (Example 9) have complete emulsifying ability for medium-chain triglycerides, forming a homogeneous emulsion system.

[0155] Determination of the foaming properties of polyquaternary ammonium salt surfactants

[0156] The foaming property was determined using the graduated cylinder method. 20 mL of the surfactant aqueous solutions prepared in Examples 8-16 and Comparative Examples 1-7 with a concentration of 2 mg / mL were poured into a 100 mL stoppered graduated cylinder. The initial foam volume (V0) was recorded immediately after vigorous shaking for one minute. After standing for 5 minutes, the foam volume (V5) was recorded. The results are shown in Table 1.

[0157] Table 1. Results of foaming test of surfactants

[0158] Example 8 (P C8-3-C8) 29.5 28.8 Example 9 (P C12-3-C12) 89.5 78.5 Example 10 (P C16-3-C16) 59.5 49.3 Example 11 (P C8-4-C8) 43.5 27.8 Example 12 (P C12-4-C12) 52 43.7 Example 13 (P C16-4-C16) 24.1 24.1 Example 14 (P C8-3(OH)-C8) 36.3 22.7 Example 15 (P C12-3(OH)-C12) 36 30.3 Example 16 (P C16-3(OH)-C16) 27.7 25.3 Comparative Example 1 (C16-3-C16) 12.5 11.7 Comparative Example 2 16.4 6.6 Comparative Example 3 20.7 18.4 Comparative Example 4 13.5 11.8 Comparative Example 5 19.7 17.5 Comparative Example 6 13.4 12.6 Comparative Example 7 14.3 13.6

[0159] As shown in Table 1, the foaming properties of the linker groups with n=3 and n=4 are generally better than those with glycerol linker groups. Furthermore, the foaming properties are enhanced with the increase of the hydrophobic alkyl chain (C8 to C12). While the foaming property (H0) of P C12-4-C12 decreases by 41.9% as the carbon chain length of the linker group increases from 3 to 4 carbons, the foaming ability of P C8-4-C8 is significantly enhanced. Experimental results indicate that the foaming property of this type of polyquaternary ammonium salt surfactant is determined by both the alkyl chain length and the linker group length. The foaming properties of Comparative Examples 1-7 are weaker than those of the corresponding structural examples, indicating that the side-chain alkyl groups of the synthesized polyquaternary ammonium salt surfactant are preferred.

[0160] Determination of antibacterial activity of polyquaternary ammonium salt surfactants

[0161] Using Escherichia coli and Staphylococcus aureus as target bacterial species, the antibacterial activity of the novel polyquaternary ammonium salt surfactant was measured by optical density (OD) method. The OD value at 596 nm was measured by ultraviolet spectrophotometer, and its antibacterial rate was calculated.

[0162] Table 2 Antibacterial rate of polyquaternium salt surfactants

[0163]

[0164] - indicates that the inhibition rate was not measured; T indicates that 100% inhibition rate was achieved.

[0165] Table 2 shows that five polyquaternary ammonium salt surfactants—PC12-3-C12, PC16-3-C16, PC8-4-C8, PC16-4-C16, and PC8-3(OH)-C8—exhibited excellent antibacterial effects against *Escherichia coli* and *Staphylococcus aureus*. In particular, PC16-3-C16 and PC16-4-C16 showed 100% inhibition rates against both *E. coli* and *Staphylococcus aureus* at relatively low concentrations (20 ppm and 40 ppm, respectively). Among the polyquaternary ammonium salt surfactants with glycerol as the linker (Examples 14-16), only PC8-3(OH)-C8 exhibited excellent antibacterial activity. The experimental results indicate that the synthesized polyquaternary ammonium salt surfactants can be used as excellent novel antibacterial materials. The antibacterial activity of Comparative Examples 1-7 was weaker than that of the corresponding examples, suggesting that the side-chain alkyl groups of the synthesized polyquaternary ammonium salt surfactants are preferred for antibacterial activity.

[0166] In summary, the novel hydrophilic main-chain polyquaternary ammonium salt surfactant provided by this invention has the characteristics of excellent performance, simple synthesis process, and novel structure. It has functional groups with strong affinity for water, and at the same time has good water solubility, emulsifying ability, foaming ability and excellent antibacterial activity.

[0167] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A polyquaternary ammonium salt surfactant, characterized in that, The polyquaternary ammonium salt surfactant includes the following structural formula: In structure I, n is a hydrocarbon group with 5 to 13 carbon atoms, and X is a positive integer from 1 to 2; in structure II, n is a hydrocarbon group with 5 to 13 carbon atoms.

2. The polyquaternary ammonium salt surfactant as described in claim 1, characterized in that, n is an alkyl group with 5, 9, or 12 carbon atoms.

3. A method for preparing a polyquaternary ammonium salt surfactant as described in any one of claims 1-2, characterized in that, Includes the following steps: S10. Mix glycidyl ether with an ethanol solution of alkylamine to obtain a single-chain alkylglycerolamine; S20. Under alkaline conditions, the single-chain alkylglycerolamine is mixed with dibromoalkane or 1,3-dichloropropanol to obtain an alkylglycerolamine gemini surfactant. S30. The alkylglycerol amine gemini surfactant is mixed with dibromoalkane to obtain a polyquaternary ammonium salt surfactant.

4. The method for preparing the polyquaternary ammonium salt surfactant as described in claim 3, characterized in that, In step S10, the molar ratio of the alkylamine to glycidol is 1:1; and / or, In step S20, the monoalkylglycerolamine is mixed with dibromoalkane or 1,3-dichloropropanol, wherein the molar ratio of the monoalkylglycerolamine to the dibromoalkane or 1,3-dichloropropanol is 2:1; and / or, In step S30, the molar ratio of the alkylglycerol amine gemini surfactant to the dibromoalkane is 2 to 2.2:

1.

5. The method for preparing the polyquaternary ammonium salt surfactant as described in claim 3, characterized in that, In step S20, the alkaline conditions are prepared by adding an alkaline substance, which includes any one of triethylamine, sodium carbonate, and potassium carbonate; and / or, The dibromoalkane includes any one of 1,3-dibromopropane and 1,4-dibromobutane.

6. The method for preparing the polyquaternary ammonium salt surfactant as described in claim 3, characterized in that, In step S10, the mixing time is 2–10 h; and / or, The mixing temperature is 20–30℃.

7. The method for preparing the polyquaternary ammonium salt surfactant as described in claim 3, characterized in that, In step S20, the mixing time is 5–20 h; and / or, The mixing temperature is 50–80℃.

8. The method for preparing the polyquaternary ammonium salt surfactant as described in claim 3, characterized in that, In step S30, the mixing time is 5–10 hours; and / or, The mixing temperature is 70–80℃.

9. An industrial additive, characterized in that, This includes polyquaternary ammonium salt surfactants as described in any one of claims 1-2, or polyquaternary ammonium salt surfactants prepared by the preparation method of polyquaternary ammonium salt surfactants as described in any one of claims 3-8.

10. The industrial additive as described in claim 9, characterized in that, The industrial additives include antibacterial agents, emulsifiers, or foaming agents.

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