A cardanol-based quaternary ammonium salt surfactant and its preparation method and application

Abstract

The present invention discloses a cardanol-based quaternary ammonium salt surfactant, a preparation method and application thereof. The cardanol-based quaternary ammonium salt has a structural formula as shown below, and can be used as a cationic surfactant or a bactericide. The present invention also discloses a preparation method of the cardanol-based quaternary ammonium salt surfactant. The method uses cardanol, a natural product that is cheap, easily available and widely available, as a raw material, reacts with a secondary amine under the action of a catalyst to prepare a corresponding tertiary amine, and then uses a commonly used alkylating agent, benzyl chloride or methyl chloride, to perform a quaternization reaction to obtain a cardanol-based quaternary ammonium salt. The synthesis process is simple, the product yield is high, and the method is suitable for industrial production and has broad application prospects. 1 , R 2 Each independently selected from -CH 3 , –CH 2 CH 3 , –CH 2 CH 2 CH 3 , –CH 2 CH 2 CH 2 CH 3 , –CH 2 CH 2 OH, –CH 2 CH(CH 3 )OH.

Description

Technical Field

[0001] The present invention relates to the technical field of surfactants, and in particular to a cardanol-based quaternary ammonium salt surfactant, a preparation method thereof, and applications thereof. Background Art

[0002] Quaternary ammonium surfactants are excellent cationic surfactants with a wide range of applications, including as fungicides, antistatic agents, corrosion and scale inhibitors, fabric softeners, asphalt emulsifiers, mineral flotation agents, dye retardants, and phase transfer catalysts. Currently, industrially produced quaternary ammonium surfactants primarily use long-chain fatty alcohols as raw materials to prepare fatty tertiary amines, which are then quaternized with alkylating agents such as benzyl chloride or methyl chloride. This results in a single raw material source. With resource scarcity and growing environmental awareness, natural, green, bio-based raw materials are attracting increasing attention. Cardanol, a green, natural biophenol, is inexpensive and abundantly available, and is the primary component of cashew nut shell liquid. Due to its structure containing phenolic hydroxyl groups, aromatic rings, and long-chain unsaturated double bonds, cardanol can be used as a renewable resource to prepare various cardanol-based derivatives for use in various fields.

[0003] Patent CN 108530307A reports a functionalized cardanol cationic surfactant. Cardanol and epichlorohydrin are used as the main raw materials to prepare an intermediate, which is then reacted with a functionalized ammonium salt to obtain a functionalized cardanol cationic surfactant. Patent CN 110105284A discloses a cardanol quaternary ammonium salt and its use. Cardanol is reacted with a corresponding halogenated alkane or halogenated epoxy compound to obtain an intermediate, which is then reacted with a corresponding quaternary ammonium salt or nitrogen-containing heterocyclic salt to prepare the cardanol quaternary ammonium salt. Patent CN 107321263A also discloses a cardanol-based cationic surfactant. Cardanol is used as a substrate, and its phenolic hydroxyl groups are etherified with a dihalogenated linear alkane. After etherification, the intermediate is further quaternized to obtain a cardanol-based cationic surfactant. Although the above patents all use cardanol as the raw material to prepare the corresponding cardanol-based quaternary ammonium salts, they all require the synthesis of intermediates through halogenated hydrocarbons or halogenated epoxides. The reactions in this process are complex and difficult to control, and the post-processing requires column chromatography separation to obtain the target intermediates. The yield is low, making them unsuitable for industrial production and having limited application prospects.

[0004] At the same time, as the application fields of cardanol derivatives gradually expand, the demand for obtaining new cardanol quaternary ammonium salts with excellent performance is also increasing. Summary of the Invention

[0005] In view of the above-mentioned problems existing in the prior art, the purpose of the present invention is to provide a cardanol-based quaternary ammonium salt surfactant and a preparation method thereof, which directly uses cardanol and secondary amine as raw materials to synthesize a class of cardanol-based tertiary amines, and then quaternizes them with an alkylating agent to prepare a cardanol-based quaternary ammonium salt surfactant.

[0006] The present invention provides a cardanol-based quaternary ammonium salt having good surface properties and can be used as a cationic surfactant. In addition, antibacterial tests have found that the cardanol-based quaternary ammonium salt of the present invention has bactericidal activity (Staphylococcus aureus (Bio-52471) and Escherichia coli (Bio-52507)) and can be used as a bactericide. The structure of the cardanol-based quaternary ammonium salt surfactant is shown in Formula (I) or Formula (II):

[0007]

[0008] Where: R is R1 and R2 are each independently selected from -CH3,

[0009] –CH2CH3, –CH2CH2CH3, –CH2CH2CH2CH3, –CH2CH2OH or

[0010] –CH2CH(CH3)OH.

[0011] Another object of the present invention is to disclose a method for preparing a defined cardanol-based quaternary ammonium salt surfactant, which specifically comprises the following steps:

[0012] 1) Adding the cardanol raw material represented by formula (III) to an organic solvent, and directly reacting with the secondary amine represented by formula (IV) in a hydrogen atmosphere in the presence of a catalyst to obtain the cardanol-based tertiary amine represented by formula (V). The reaction process is as follows:

[0013]

[0014] 2) The cardanol-based tertiary amine represented by formula (V) obtained in step 1) is mixed with a solvent and added to a reaction kettle. A quaternizing agent, benzyl chloride or methyl chloride, is added and reacted at 70-120° C. to obtain a cardanol-based quaternary ammonium salt surfactant represented by formula (I) or formula (II). The reaction process is as follows:

[0015]

[0016] Where: R is R1 and R2 are each independently selected from -CH3, -CH2CH3, -CH2CH2CH3, -CH2CH2CH2CH3, -CH2CH2OH or

[0017] –CH2CH(CH3)OH.

[0018] Furthermore, the present invention also defines that in step 1), the molar ratio of the cardanol represented by formula (III) to the secondary amine represented by formula (IV) is 1:1-1.5; the reaction temperature is 80-200°C, and the reaction time is 5-24h; the catalyst is Raney nickel, and the amount of the catalyst is 3-10wt% of the cardanol represented by formula (III); the hydrogen pressure is 0.01-0.4MPa; the solvent is selected from one or more combinations of methanol, ethanol, isopropanol or ethyl acetate, and the amount of the solvent is 2-20 times the weight of the cardanol represented by formula (III).

[0019] Furthermore, the present invention also defines the molar ratio of the cardanol-based tertiary amine represented by formula (V) in step 2) to benzyl chloride as 1:0.98-1; the molar ratio of the tertiary amine to methyl chloride is 1:1-1.5; the reaction pressure is 0.1-0.4 MPa; the solvent is methanol, ethanol, isopropanol or propylene glycol, and the amount of the solvent is 2-20 times the weight of the cardanol-based tertiary amine represented by formula (V).

[0020] The structures of the cardanol-based quaternary ammonium salt surfactants in the embodiments of the present invention are shown in formulas (1, 2, 3, 4, 5, and 6):

[0021]

[0022] The cardanol-based quaternary ammonium salt obtained by the present invention has bactericidal (Escherichia coli Bio-52507 and Staphylococcus aureus Bio-52471) activity, can be used as a bactericide, and has good application prospects.

[0023] By adopting the above technology, compared with the prior art, the advantages of the present invention are:

[0024] 1) The present invention directly uses cardanol and secondary amine as raw materials to first synthesize cardanol tertiary amine, and then obtains a cardanol-based quaternary ammonium salt surfactant through a quaternization reaction. The preparation method is simple, the raw material source is wide, the cost is low, the product is easy to separate, and it is suitable for industrial production;

[0025] 2) The cardanol-based quaternary ammonium salt surfactant disclosed in the present invention can be used to prepare quaternary ammonium salt surfactants with various functional groups based on the corresponding secondary amine, so that it has good surface properties and can be used as a cationic surfactant. In addition, antibacterial tests have found that the cardanol-based quaternary ammonium salt of the present invention has bactericidal (Escherichia coli Bio-52507 and Staphylococcus aureus Bio-52471) activity, and can be used as a bactericide, with good application prospects. DETAILED DESCRIPTION

[0026] To further illustrate the invention, the following series of specific embodiments are given, but the present invention is not limited to these specific embodiments. Any modifications to the present invention by those skilled in the art will be able to achieve similar results, and these modifications are also included in the present invention.

[0027] Example 1 Preparation of Cardanol Quaternary Ammonium Salt Represented by Formula (1)

[0028]

[0029] Preparation of Intermediate 1: 30g of cardanol (0.1mol) was dissolved in 300g of ethyl acetate and added to an autoclave. 1.5g of Raney nickel catalyst and 15g of a 45% aqueous dimethylamine solution (0.15mol) were then added. The atmosphere was purged with nitrogen three times and hydrogen three times, then filled with hydrogen at a pressure of 0.05MPa. The temperature was rapidly raised to 120°C and stirred for 5h. After the reaction was completed, the mixture was cooled to room temperature, the catalyst was filtered out, and the solvent and excess dimethylamine were removed by distillation under reduced pressure to obtain Intermediate 1 with a yield of 99.7%.

[0030] 1 H NMR(500MHz, CDCl3) δ7.09(t,J=7.7Hz,1H),6.97(ddq,J=7.8,2.1,0.9Hz,1H),6.59(tt,J=2.1,1.0Hz,1 H),6.55(ddd,J=7.2,2.0,1.2Hz,1H),5.77(tt,J=16.0,6.9Hz,0.2H),5.49–5.37(m,2.6H),5.09–4.98( m,0.4H),2.96(s,6H),2.55(tt,J=7.9,0.9Hz,2H),2.43(ddq,J=7.0,5.0,1.0Hz,1H),2.16(tdd,J=7.9, 7.0,1.0Hz,0.4H),2.06–1.95(m,3.2H),1.62–1.52(m,2H),1.40–1.23(m,13.8H),0.94–0.85(m,2.4H).

[0031] 13 C NMR (125MHz, CDCl3) δ150.91,142.59,136.97,130.69,130.61,130.29,130.15,129.33,121.91,115.34,115.10 ,112.32,40.41,34.72,32.36,31.84,31.32,29.82–29.67(m)29.08,28.29,26.32,22.68,22.42,22.32,14.03.

[0032] 2) Preparation of Compound 1: 100 g of intermediate 1 (0.31 mol) was added to a reactor, 500 g of ethanol was added, and the atmosphere was replaced with nitrogen three times. Stirring was started while the temperature was raised to 60°C. 37.9 g of benzyl chloride (0.30 mol) was added dropwise, and the temperature was controlled at 60-80°C. After the addition was complete, the temperature was raised to 100°C and the reaction was continued for 2 h. After the reaction was completed, the free amine content was detected to be less than 1.5%, which was considered acceptable. The ethanol was removed by distillation under reduced pressure to obtain Compound 1.

[0033] HRMS (ESI-TOF) m / z: [M+Na] + Calcd for C 30 H 48 ClN 480.34, Found480.45; [M+Na] + Calcd for C 30 H 46 ClN 478.32, Found 478.55; [M+Na] + Calcd for C 30 H 44 ClN 476.31, Found476.35; [M+Na] + Calcd for C 30 H 42 ClN 474.29,Found 474.33.

[0034] Example 2 Preparation of Cardanol Quaternary Ammonium Salt Represented by Formula (2)

[0035]

[0036] 1) Preparation of Intermediate 2: 30 g of cardanol (0.1 mol) was dissolved in 300 g of ethanol and added to an autoclave. 3.0 g of Raney nickel catalyst and 10.5 g of diethanolamine (0.1 mol) were then added. The atmosphere was purged with nitrogen three times and hydrogen three times, then filled with hydrogen at a pressure of 0.1 MPa. The temperature was rapidly raised to 150° C. and stirred for 10 hours. After the reaction was completed, the reaction was cooled to room temperature, the catalyst was filtered, and the solvent was removed by distillation under reduced pressure. After washing with water several times to remove diethanolamine, Intermediate 2 was obtained with a yield of 97.6%.

[0037] 1H NMR (500MHz, CDCl3) δ7.13(t,J=7.7Hz,1H),7.00–6.92(m,2H),6.71(dp,J=2.2,1.1Hz,1H),5.77(tt,J=1 6.0,6.9Hz,0.2H),5.49–5.40(m,2.6H),5.09–4.98(m,0.4H),3.64(q,J=5.9Hz,4H),3.39(t,J=5.8Hz,4H ),3.31(t,J=6.1Hz,2H),2.55(tt,J=7.9,0.9Hz,2H),2.43(ddq,J=7.0,5.0,1.0Hz,1H),2.16(tdd,J=7.9 ,7.0,1.0Hz,0.4H),2.06–1.95(m,3.2H),1.62–1.52(m,2H),1.40–1.23(m,13.8H),0.94–0.85(m,2.4H).

[0038] 13 C NMR (125MHz, CDCl3) δ149.66,142.51,137.16,130.36,130.01,129.75,129.65,129.03,121.85,116.44,115.31,11 4.45,60.31,54.17,34.76,32.24,31.83,31.48,29.82–29.67(m),29.10,26.99,26.32,22.68,22.42,22.32,14.03.

[0039] 2) Preparation of Compound 2: 100 g of intermediate 2 (0.26 mol) was weighed and added to a reactor. 450 g of isopropanol was added and the atmosphere was replaced with nitrogen three times. Stirring was started while the temperature was raised to 80°C. 31.9 g of benzyl chloride (0.25 mol) was added dropwise while controlling the temperature at 80-90°C. After the addition was complete, the temperature was raised to 100°C and the reaction was continued for 2 h. After the reaction was complete, the free amine content was tested to be less than 1.5%, which was considered acceptable. The isopropanol was then removed by distillation under reduced pressure to obtain Compound 2.

[0040] HRMS (ESI-TOF) m / z: [M+Na] + Calcd for C 32 H 52 ClNO2540.36 Found540.35; [M+Na] + Calcd for C 32 H 50 ClNO2 538.36, Found 438.41; [M+Na] +Calcd for C 32 H 48 ClNO2536.33, Found 536.38; [M+Na] + Calcd for C 32 H 46 ClNO2534.31,Found 534.32.

[0041] Example 3 Preparation of Cardanol Quaternary Ammonium Salt Represented by Formula (3)

[0042]

[0043] 1) Preparation of Intermediate 3: 30 g of cardanol (0.1 mol) and 16 g of diisopropanolamine (0.12 mol) were dissolved in 400 g of ethyl acetate and added to an autoclave. 3.0 g of Raney nickel catalyst was then added. The atmosphere was purged with nitrogen three times and hydrogen three times, and then filled with hydrogen at a pressure of 0.2 MPa. The temperature was rapidly raised to 180° C. and stirred for 15 hours. After the reaction was completed, the reaction was cooled to room temperature, the catalyst was filtered, and the excess diisopropanolamine was removed by washing with water several times. The solvent was then removed by distillation under reduced pressure to obtain Intermediate 3 with a yield of 95.5%.

[0044] 1 H NMR (500MHz, CDCl3) δ7.13(t,J=7.7Hz,1H),7.02–6.93(m,2H),6.56(tt,J=2.3,1.0Hz,1H),5.77(tt,J=16.0,6.9Hz,0.2 H),5.59–5.37(m,2.6H),5.09–4.98(m,0.4H),3.91(qq,J=6.7,5.0Hz,2H),3.50(d,J=5.5Hz,2H),3.35(dd,J=12.2,5.2H z,2H),3.28(dd,J=12.2,4.9Hz,2H),2.55(tdt,J=8.0,2.0,0.9Hz,2H),2.42(dddd,J=6.1,5.0,2.1,1.1Hz,1H),2.23–2. 09(m,0.4H),2.06–1.94(m,3.2H),1.62–1.52(m,2H),1.40–1.19(m,13.8H),1.21(d,J=6.7Hz,6H),0.94–0.81(m,2.4H).

[0045] 13C NMR (125MHz, CDCl3) δ149.02,142.53,137.16,130.36,130.01,129.67(d,J=5.2Hz),129.03,121.90,116.65,115.31,114 .66,65.15,57.99,34.76,32.24,31.83,31.48,29.82–29.67(m),29.10,26.99,26.32,22.68,22.42,22.32,20.20,14.03.

[0046] 2) Preparation of compound 3: 100 g of intermediate 3 (0.24 mol) was weighed and added to a reactor, 450 g of ethanol was added, and after nitrogen replacement three times, stirring was started and the temperature was raised to 60° C. 13 g of chloromethane (0.26 mol) was started. During the addition process, the reaction temperature was controlled at 80-100° C. and the pressure was below 0.4 MPa. After the addition, the temperature was raised to 100° C. and the reaction was continued for 2 h. After the reaction was completed, the free amine content was detected to be less than 1.5%, which was qualified. The ethanol and chloromethane were removed by distillation under reduced pressure to obtain compound 3.

[0047] HRMS (ESI-TOF) m / z: [M+Na] + Calcd for C 28 H 52 ClNO2492.36 Found492.45; [M+Na] + Calcd for C 28 H 50 ClNO2 490.34, Found 490.43; [M+Na] + Calcd for C 28 H 48 ClNO2488.33, Found 488.39; [M+Na] + Calcd for C 28 H 46 ClNO2486.31,Found 486.37.

[0048] Example 4 Preparation of Cardanol Quaternary Ammonium Salt Represented by Formula (4)

[0049]

[0050] 1) Preparation of Intermediate 4: 30 g of cardanol (0.1 mol) was dissolved in 300 g of ethanol, followed by the addition of 3.0 g of Raney nickel catalyst and 12.9 g of di-n-butylamine (0.1 mol). The atmosphere was purged with nitrogen three times and hydrogen three times, then filled with hydrogen at a pressure of 0.05 MPa. The temperature was rapidly raised to 120° C. and stirred for 8 h. After the reaction was completed, the mixture was cooled to room temperature, the catalyst was filtered, and the solvent was removed by distillation under reduced pressure to obtain Intermediate 4 with a yield of 96.9%.

[0051] 1 H NMR (500MHz, CDCl3) δ7.13(t,J=7.7Hz,1H),7.00–6.94(m,1H),6.94–6.88(m,1H),6.72(tt,J=2.1,0. 9Hz,1H),5.77(tt,J=16.0,6.9Hz,0.2H),5.59–5.37(m,2.6H),5.09–4.98(m,0.4H),3.11(t,J=6.4Hz ,4H),2.59–2.51(m,2H),2.42(ddt,J=6.0,5.0,1.3Hz,1H),2.16(tdd,J=8.0,6.9,1.2Hz,0.4H),2.06 –1.98(m,3.2H),1.62–1.52(m,6H),1.42–1.23(m,17.8H),0.95(t,J=7.4Hz,6H),0.92–0.83(m,2.4H).

[0052] 13 C NMR (125MHz, CDCl3) δ150.61,142.50,137.16,130.36,130.01,129.73,129.65,129.03,121.81,116.41,115.31,114.0 6,51.17,34.76,32.24,31.83,31.48,29.82–29.67(m),29.62,29.10,26.99,26.32,22.68,22.42,22.32,14.03,13.77.

[0053] 2) Preparation of compound 4: 100 g of intermediate 4 (0.24 mol) was weighed and added to a reactor, 400 g of ethanol was added, and after nitrogen replacement three times, stirring was started and the temperature was raised to 60° C. 13 g of chloromethane (0.26 mol) was started to be introduced. During the introduction process, the reaction temperature was controlled at 80-100° C. and the pressure was below 0.4 MPa. After the addition, the temperature was raised to 100° C. and the reaction was continued for 2 h. After the reaction was completed, the free amine content was detected to be less than 1.5%, which was qualified. The ethanol and chloromethane were removed by distillation under reduced pressure to obtain compound 4.

[0054] HRMS (ESI-TOF) m / z: [M+Na] + Calcd for C 30 H 56 ClN 488.40Found488.46;[M+Na] + Calcd for C 30 H 54 ClN 486.38, Found 486.46; [M+Na] + Calcd for C 30 H 52 ClN 484.37, Found484.39; [M+Na] + Calcd for C 30 H 50 ClN482.35,Found 482.39.

[0055] Example 5 Preparation of Cardanol Quaternary Ammonium Salt Represented by Formula (5)

[0056]

[0057] 1) Preparation of Intermediate 5: 30 g of cardanol (0.1 mol) was dissolved in 400 g of ethyl acetate and added to an autoclave. 3.0 g of Raney nickel catalyst and 10.2 g of di-n-propylamine (0.1 mol) were then added. The atmosphere was purged with nitrogen three times and hydrogen three times. The hydrogen pressure was then increased to 0.1 MPa. The temperature was rapidly raised to 130° C. and the reaction was stirred for 6 h. After the reaction was completed, the reaction was cooled to room temperature, the catalyst was filtered out, and the solvent was removed by distillation under reduced pressure to obtain Intermediate 5 with a yield of 97.6%.

[0058] 1H NMR (500MHz, CDCl3) δ7.16–7.09(m,1H),7.00–6.94(m,1H),6.94–6.88(m,1H),6.72(tt,J=2.1,1.0 Hz,1H),5.77(tt,J=16.0,6.9Hz,0.2H),5.59–5.40(m,2.6H),5.09–4.98(m,0.4H),3.28(t,J=6.5Hz ,4H),2.55(tt,J=8.0,1.1Hz,2H),2.42(ddt,J=6.0,5.0,1.2Hz,1H),2.16(tdd,J=8.2,7.1,1.3Hz,0 .4H),2.06–1.98(m,3.2H),1.67–1.54(m,6H),1.40–1.23(m,13.8H),0.97-0.81(t,J=7.7Hz,8.4H).

[0059] 13 C NMR (125MHz, CDCl3) δ150.31,142.50,137.16,130.36,130.01,129.73,129.65,129.03,121.81,116.41,115.31,114.0 6,52.69,34.76,32.24,31.83,31.48,29.82–29.67(m),29.10,26.99,26.32,22.68,22.42,22.32,20.60,14.03,11.44.

[0060] 2) Preparation of Compound 5: 100 g of intermediate 5 (0.26 mol) and 300 g of isopropanol were added to a reactor. After nitrogen replacement three times, stirring was started and the temperature was raised to 60° C. 15 g of chloromethane (0.30 mol) was introduced. During the introduction process, the reaction temperature was controlled at 80-100° C. and the pressure was below 0.4 MPa. After the addition, the temperature was raised to 100° C. and the reaction was continued for 2 h. After the reaction was completed, the free amine content was detected to be less than 1.5%, which was qualified. The solvent and chloromethane were removed by distillation under reduced pressure to obtain Compound 5.

[0061] HRMS (ESI-TOF) m / z: [M+Na] + Calcd for C 28 H 52 ClN 460.37Found440.36;[M+Na] + Calcd for C 28 H 50 ClN 458.35, Found 458.39; [M+Na] +Calcd for C 28 H 48 ClN 456.34, Found456.59; [M+Na] + Calcd for C 28 H 46 ClN454.32,Found 454.48.

[0062] Example 6 Preparation of Cardanol Quaternary Ammonium Salt Represented by Formula (6)

[0063]

[0064] 1) Preparation of Intermediate 6: 30 g of cardanol (0.1 mol) was dissolved in 300 g of ethanol and added to an autoclave. 1.5 g of Raney nickel catalyst and 7.3 g of diethylamine (0.1 mol) were then added. The atmosphere was purged with nitrogen three times and hydrogen three times. The hydrogen pressure was then increased to 0.06 MPa. The temperature was rapidly raised to 120° C. and the mixture was stirred and reacted for 5 h. After the reaction was completed, the mixture was cooled to room temperature, the catalyst was filtered, and the solvent was removed by distillation under reduced pressure to obtain Intermediate 6 with a yield of 98.3%.

[0065] 1 H NMR(500MHz, CDCl3)δ7.13(t,J=7.7Hz,1H),7.00–6.94(m,1H),6.80–6.74(m,1H),6.62(dq,J=3.2,1.0Hz,1H), 5.77(tt,J=16.0,6.9Hz,0.2H),5.59–5.37(m,2.6H),5.04(dddd,J=17.2,15.9,2.5,1.2Hz,0.4H),3.48(q,J=7 .0Hz,4H),2.55(tt,J=8.0,1.1Hz,2H),2.42(ddt,J=6.0,5.0,1.2Hz,1H),2.16(tdd,J=7.9,6.9,1.1Hz,2H),2. 06–1.95(m,2H),1.60–1.52(q,J=7.8Hz,2H),1.40–1.23(m,13.8H),1.16(t,J=7.1Hz,6H),0.92–0.81(m,2.4H).

[0066] 13C NMR (125MHz, CDCl3) δ149.41,142.77,136.97,130.69,130.61,130.29,130.15,129.70,121.91,116.84,115.34,113.48,44 .62,34.72,32.36,31.84,31.32,29.84(d,J=5.7Hz),29.08,28.29,26.99,26.32,22.68,22.42,22.32,20.60,14.03,12.36.

[0067] 2) Preparation of Compound 6: 100 g of intermediate 6 (0.28 mol) and 300 g of ethanol were weighed and added to a reactor. After nitrogen replacement three times, stirring was started and the temperature was raised to 60°C. 34.9 g of benzyl chloride (0.27 mol) was added dropwise, and the temperature was controlled at 60-80°C. After the addition was complete, the temperature was raised to 100°C and the reaction was continued for 2 h. After the reaction was completed, the free amine content was detected to be less than 1.5%, which was acceptable. The ethanol was removed by distillation under reduced pressure to obtain Compound 6.

[0068] HRMS (ESI-TOF) m / z: [M+Na] + Calcd for C 32 H 52 ClN 508.37Found508.46;[M+Na] + Calcd for C 32 H 50 ClN 506.35, Found 506.45; [M+Na] + Calcd for C 32 H 48 ClN 504.34, Found504.41; [M+Na] + Calcd for C 32 H 46 ClN502.32,Found 502.48.

[0069] Example 7 Determination of Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the Compounds Represented by Formula 1-6

[0070] The antibacterial activity of the above-synthesized series of surfactants was tested by the antibacterial process against Escherichia coli (Bio-52507) and Staphylococcus aureus (Bio-52471). The specific process is as follows:

[0071] MIC determination: 1024 μg / mL test solutions of the compounds of Formulas 1-6 were prepared using sterile water. Two-fold dilutions were then used to prepare test dilutions at concentrations of 512 μg / mL, 256 μg / mL, 128 μg / mL, 64 μg / mL, 32 μg / mL, 16 μg / mL, 8 μg / mL, 4 μg / mL, 2 μg / mL, and 1 μg / mL, respectively. The test solutions and dilutions at varying concentrations were added to a sterilized 96-well polystyrene plate. 10 μL of each test solution and dilution was added to wells 1 through 11, respectively. 10 μL of sterile deionized water was added to well 12 as a growth control. 90 μL of a 105 cfu / mL bacterial suspension (Bio-52507 and Bio-52471) was then added to each well. After culturing the 96-well plate in a 37°C incubator for 24 hours, observe whether the bacteria grow. The lowest concentration in the well where no bacteria grow is the MIC.

[0072] The minimum inhibitory concentration (MIC) is the lowest concentration of a sample that inhibits 90% bacterial cell growth. Specific results are shown in Table 1 (MIC and MBC of compounds represented by Formula 1-6).

[0073] Determination of MBC: The compounds of Formulas 1-6 were prepared into 2048 μg / mL test stock solutions using sterile water, and then the two-fold dilution method was used to obtain test dilutions with concentrations of 1024 μg / mL, 512 μg / mL, 256 μg / mL, 128 μg / mL and 64 μg / mL, respectively. Take 15 mL of sterilized liquid agar medium and add 1 mL of the test solution, two-fold dilution (the concentrations of the test solution and the two-fold dilution are 2048 μg / mL, 1024 μg / mL, 512 μg / mL, 256 μg / mL, 128 μg / mL and 64 μg / mL) and sterilized deionized water (blank control) to prepare the compound represented by Formula 1-6 while it is hot. Mix well and pour into a culture dish to solidify to obtain test groups with concentrations of 128 μg / mL, 64 μg / mL, 32 μg / mL, 16 μg / mL, 8 μg / mL and 4 μg / mL in the culture medium and a blank control (sterilized deionized water). Add 100 μL of 105 cfu / mL bacterial (Bio-52507 and Bio-52471) suspension to the above culture medium, spread it evenly with a spreader, and culture the culture dish in a 37°C incubator for 24 hours. Observe whether the bacteria grow and count the number of strains in all samples and the control group.

[0074] The minimum bactericidal concentration (MBC) is the minimum sample concentration at which more than 99.9% of bacteria are killed, as measured by the ratio of the number of strains in the sample to the number of strains in the control group. Specific results are shown in Table 1 (MIC and MBC of compounds represented by Formula 1-6).

[0075] Table 1

[0076]

[0077] As can be seen from Table 1, the compounds represented by Formulas 1 to 6 have good antibacterial activity against Escherichia coli and Staphylococcus aureus.

Claims

1. A cardanol-based quaternary ammonium salt surfactant, characterized in that The structure of the cardanol-based quaternary ammonium salt surfactant is shown in formula (I) or formula (II): Where: R is R1 and R2 are each independently selected from –CH3, –CH2CH3, –CH2CH2CH3, –CH2CH2CH2CH3, –CH2CH2OH or –CH2CH(CH3)OH.

2. A method for preparing a cardanol-based quaternary ammonium salt surfactant according to claim 1, characterized in that The steps include: 1) Adding the cardanol raw material represented by formula (III) into an organic solvent, directly reacting with the secondary amine represented by formula (IV) in a hydrogen atmosphere under the action of a catalyst to obtain the cardanol-based tertiary amine represented by formula (V), and the reaction process is as follows: 2) The cardanol-based tertiary amine represented by formula (V) obtained in step 1) is mixed with a solvent and added to a reaction kettle, and a quaternizing agent, benzyl chloride or methyl chloride, is added to react at 70-120° C. to obtain a cardanol-based quaternary ammonium salt represented by formula (I) or formula (II). The reaction process is as follows: Where: R is R1 and R2 are each independently selected from -CH3, -CH2CH3, -CH2CH2CH3, -CH2CH2CH2CH3, -CH2CH2OH or –CH2CH(CH3)OH.

3. The method for preparing a cardanol-based quaternary ammonium salt surfactant according to claim 2, wherein In step 1), the molar ratio of the cardanol represented by formula (III) to the secondary amine represented by formula (IV) is 1:1-1.

5.

4. The method for preparing a cardanol-based quaternary ammonium salt surfactant according to claim 2, wherein The reaction temperature in step 1) is 80-200° C. and the reaction time is 5-24 h.

5. The method for preparing a cardanol-based quaternary ammonium salt surfactant according to claim 2, characterized in that The catalyst in step 1) is Raney nickel, and the amount of the catalyst used is 3-10wt% of the cardanol shown in formula (III).

6. The method for preparing a cardanol-based quaternary ammonium salt surfactant according to claim 2, characterized in that The hydrogen pressure in step 1) is 0.01-0.4 MPa.

7. The method for preparing a cardanol-based quaternary ammonium salt surfactant according to any one of claims 2 to 6, characterized in that The solvent in step 1) is selected from one or a combination of methanol, ethanol, isopropanol or ethyl acetate, and the amount of the solvent used is 2-20 times the weight of the cardanol represented by formula (III).

8. A method for preparing a cardanol-based quaternary ammonium salt surfactant according to any one of claims 2 to 6, characterized in that In step 2), the molar ratio of the cardanol-based tertiary amine represented by formula (V) to benzyl chloride is 1:0.98-1; the molar ratio of the tertiary amine to methyl chloride is 1:1-1.5; and the reaction pressure is 0.1-0.4 MPa.

9. The method for preparing a cardanol-based quaternary ammonium salt surfactant according to any one of claims 2 to 6, characterized in that The solvent in step 2) is methanol, ethanol, isopropanol or propylene glycol, and the amount of the solvent used is 2-20 times the weight of the cardanol-based tertiary amine represented by formula (V).

10. Use of the cardanol-based quaternary ammonium salt surfactant according to claim 1 in the preparation of a bactericide for inhibiting Escherichia coli and Staphylococcus aureus.

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