Quaternary ammonium salt type cationic etherifying agent and preparation method thereof

Abstract

The invention relates to the technical field of cationic etherifying agents, and discloses a quaternary ammonium salt type cationic etherifying agent and a preparation method thereof.3-chloro-2-hydroxypropyl trimethyl ammonium chloride and sulfaguanidine modified quaternized chitosan are added into a reactor and stirred, and the quaternary ammonium salt type cationic etherifying agent is obtained. Quaternary ammonium salt, guanidyl and chitosan groups contained in the sulfaguanidine modified quaternized chitosan all have better antibacterial effects; wherein the quaternary ammonium salt is adsorbed to the surfaces of bacteria, and hydrophobic groups are inserted into lipoid layers, so that the permeability of cell membranes is changed, the membrane structure is destroyed, intracellular substances are leaked, and the bacteria are dead; guanidyl can be combined with protein and nucleic acid in bacterial cells to interfere the normal metabolic process of bacteria and further inhibit growth and reproduction of the bacteria, so that a natural antibacterial effect is achieved; and the chitosan group has a relatively good antibacterial effect.

Description

Technical Field

[0001] The invention relates to the technical field of cationic etherifying agents, in particular to a quaternary ammonium salt type cationic etherifying agent and a preparation method thereof. Background Art

[0002] Cationic etherifying agents are commercially available in two forms: solid and aqueous solutions, and are widely used in the fields of papermaking, daily chemical industry, petroleum industry, water treatment industry, etc. This product is used to prepare cationic starch, cationic polyacrylamide, electroplating additives, antistatic agents, and papermaking aids, etc. It can also be used as a cationic surfactant, water treatment flocculant, textile, conductive coating, cosmetics, etc., but its antibacterial effect is not good, which will affect its use in many fields. For example, patent CN112010768A discloses a method for preparing a high-quality solid cationic etherifying agent. The cationic etherifying agent of the invention has a short synthesis time and few by-products, but its antibacterial performance has not been improved. Summary of the invention

[0003] 1. Technical issues to be resolved In view of the deficiencies of the prior art, the present invention provides a quaternary ammonium salt type cationic etherifying agent and a preparation method thereof, which has good antibacterial effect.

[0004] (II) Technical solution To achieve the above object, the present invention provides the following technical solution: a quaternary ammonium salt type cationic etherifying agent, comprising the following weight components: 5-12 weight parts of 3-chloro-2-hydroxypropyltrimethylammonium chloride and 8-15 weight parts of sulfaguanidine modified quaternized chitosan.

[0005] Preferably, the preparation method of the sulfaguanidine modified quaternary ammonium chitosan is: (1) In a nitrogen atmosphere, 1,2,4-trimellitic anhydride chloride and 4-((dimethylamino)methyl)phenol were added to an acetonitrile solvent, and ultrasonic dispersion was performed uniformly. Pyridine catalyst was then added thereto to carry out a substitution reaction. The reaction was carried out at 75-90°C for 6-9h. After the reaction was completed, the reaction was cooled to room temperature, the solvent was removed by rotary evaporation, and the reaction was washed and dried to obtain an intermediate 1; (2) adding 5-12 parts by weight of sulfaguanidine to a reactor filled with anhydrous ethanol, then heating, and after it is completely dissolved, adding 6-10 parts by weight of 2,4-dihydroxybenzaldehyde and continuing to stir and react for 8-10 hours, and then dropping 4-6 parts by weight of sodium borohydride for reduction for 5-9 hours. After the reduction is completed, the mixture is concentrated under reduced pressure and washed with ether to obtain hydroxy-modified sulfaguanidine; (3) Add hydroxy-modified sulfaguanidine, intermediate 1, and p-toluenesulfonic acid catalyst into deionized water, stir and disperse, and carry out esterification reaction at 110-130° C. for 12-16 hours. After the reaction, cool, wash, and dry to obtain intermediate 2; (4) Add 10-18 parts by weight of benzyl chloride chitosan and 12-15 parts by weight of intermediate 2 to N,N-dimethylformamide solvent, stir and react at 120-135° C. for 14-18 hours, add distilled water to precipitate after the reaction, filter, wash and purify with distilled water and acetone to obtain sulfaguanidine modified quaternary ammonium chitosan.

[0006] Preferably, the mass ratio of 1,2,4-trimellitic anhydride chloride, 4-((dimethylamino)methyl)phenol and pyridine catalyst in (1) is 1:1.1-1.3:0.01-0.02.

[0007] Preferably, the temperature of the heating reaction in (2) is 70-80°C.

[0008] Preferably, the mass ratio of the hydroxy-modified sulfaguanidine, the intermediate 1, and the p-toluenesulfonic acid catalyst in (3) is 0.6-0.9:1:0.03-0.05.

[0009] Preferably, the preparation method of the benzyl chloride chitosan in (4) is as follows: chitosan, chloromethylbenzoyl chloride and triethylamine are added to N,N-dimethylformamide, the temperature is raised to 60-85°C and stirred for reaction for 10-15h, after the reaction, distilled water is added to precipitate, the solvent is filtered, and the benzyl chloride chitosan is washed and purified with distilled water and acetone to obtain the benzyl chloride chitosan.

[0010] Preferably, the mass ratio of chitosan, chloromethylbenzoyl chloride and triethylamine is 4-10:1:0.01-0.04.

[0011] Preferably, the preparation method of the quaternary ammonium salt type cationic etherifying agent is: adding 3-chloro-2-hydroxypropyltrimethylammonium chloride and sulfaguanidine modified quaternary ammonium chitosan into a reactor, stirring at a speed of 400-550rmp for 6-10min, to obtain a quaternary ammonium salt type cationic etherifying agent.

[0012] 3. Beneficial technical effects The invention prepares a quaternary ammonium salt type cationic etherifying agent by adding 3-chloro-2-hydroxypropyltrimethylammonium chloride and sulfaguanidine modified quaternized chitosan into a reactor and stirring the mixture.

[0013] The acyl chloride group in 1,2,4-trimellitic anhydride chloride reacts with the phenolic hydroxyl group in 4-((dimethylamino)methyl)phenol to introduce anhydride groups and tertiary amine groups, thereby obtaining intermediate 1; the amino group in sulfaguanidine and the aldehyde group in 2,4-dihydroxybenzaldehyde undergo condensation reaction, and then sodium borohydride is added for reduction reaction to introduce hydroxyl groups, thereby obtaining hydroxyl-modified sulfaguanidine; the hydroxyl group in hydroxyl-modified sulfaguanidine reacts with the anhydride group in intermediate 1 to obtain intermediate 2; the benzyl chloride in benzyl chloride chitosan and the tertiary amine group in intermediate 2 undergo quaternization reaction to generate a large amount of quaternary ammonium salt, thereby increasing the degree of substitution of the quaternary ammonium salt, thereby obtaining sulfaguanidine-modified quaternized chitosan.

[0014] The quaternary ammonium salt, guanidine group and chitosan group contained in sulfaguanidine modified quaternary ammonium chitosan all have good antibacterial effects; the quaternary ammonium salt is adsorbed to the surface of the bacteria, and the hydrophobic group is inserted into the lipid layer, which changes the permeability of the cell membrane, destroys the membrane structure, and causes the leakage of intracellular substances, leading to bacterial death; the guanidine group can interfere with the normal metabolic process of the bacteria by combining with the proteins and nucleic acids in the bacterial cells, further inhibiting the growth and reproduction of the bacteria, thereby playing a natural antibacterial effect; the chitosan group itself has a good antibacterial effect. DETAILED DESCRIPTION Example 1

[0015] (1) Under a nitrogen atmosphere, 1,2,4-trimellitic anhydride chloride and 4-((dimethylamino)methyl)phenol were added to an acetonitrile solvent, and ultrasonic dispersion was performed uniformly. A pyridine catalyst was added thereto, wherein the mass ratio of 1,2,4-trimellitic anhydride chloride, 4-((dimethylamino)methyl)phenol and pyridine catalyst was 1:1.1:0.01, and a substitution reaction was carried out. The reaction was carried out at 75°C for 6 hours. After the reaction was completed, the reaction was cooled to room temperature, the solvent was removed by rotary evaporation, and the reaction was washed and dried to obtain an intermediate 1; (2) Add 5 parts by weight of sulfaguanidine into a reactor filled with anhydrous ethanol, then heat it to 70°C. After it is completely dissolved, add 6 parts by weight of 2,4-dihydroxybenzaldehyde and continue to stir and react for 8 hours. Continue to drop 4 parts by weight of sodium borohydride for reduction for 5 hours. After the reduction is completed, concentrate under reduced pressure and wash with ether to obtain hydroxy-modified sulfaguanidine; (3) adding hydroxy-modified sulfaguanidine, intermediate 1, and p-toluenesulfonic acid catalyst into deionized water, wherein the mass ratio of hydroxy-modified sulfaguanidine, intermediate 1, and p-toluenesulfonic acid catalyst is 0.6:1:0.03, stirring and dispersing, and performing esterification reaction at 110° C. for 12 h. After the reaction, cooling, washing, and drying to obtain intermediate 2; (4) Add chitosan, chloromethylbenzoyl chloride and triethylamine to N,N-dimethylformamide, wherein the mass ratio of chitosan, chloromethylbenzoyl chloride and triethylamine is 4:1:0.01, heat to 60°C and stir to react for 10 hours, add distilled water to precipitate after the reaction, filter the solvent, wash and purify with distilled water and acetone to obtain benzyl chloride chitosan; (5) Add 10 parts by weight of benzyl chloride chitosan and 12 parts by weight of intermediate 2 to N,N-dimethylformamide solvent, stir and react at 120° C. for 14 h, add distilled water after the reaction to precipitate, filter, and wash with distilled water and acetone for purification to obtain sulfaguanidine modified quaternary ammonium chitosan; (6) Add 5 parts by weight of 3-chloro-2-hydroxypropyltrimethylammonium chloride and 8 parts by weight of sulfaguanidine-modified quaternized chitosan into a reactor, and stir at 400 rpm for 6 minutes to obtain a quaternary ammonium salt type cationic etherifying agent. Example 2

[0016] (1) Under a nitrogen atmosphere, 1,2,4-trimellitic anhydride chloride and 4-((dimethylamino)methyl)phenol were added to an acetonitrile solvent, and ultrasonic dispersion was performed uniformly. A pyridine catalyst was added thereto, wherein the mass ratio of 1,2,4-trimellitic anhydride chloride, 4-((dimethylamino)methyl)phenol and pyridine catalyst was 1:1.3:0.02, and a substitution reaction was carried out at 90°C for 9h. After the reaction was completed, the reaction was cooled to room temperature, the solvent was removed by rotary evaporation, and the reaction was washed and dried to obtain an intermediate 1; (2) adding 12 parts by weight of sulfaguanidine into a reactor filled with anhydrous ethanol, and then heating to 80°C. After it is completely dissolved, adding 10 parts by weight of 2,4-dihydroxybenzaldehyde and continuing to stir and react for 10 hours, and then dropping 6 parts by weight of sodium borohydride for reduction for 9 hours. After the reduction is completed, the mixture is concentrated under reduced pressure and washed with ether to obtain hydroxy-modified sulfaguanidine; (3) adding hydroxy-modified sulfaguanidine, intermediate 1, and p-toluenesulfonic acid catalyst into deionized water, wherein the mass ratio of hydroxy-modified sulfaguanidine, intermediate 1, and p-toluenesulfonic acid catalyst is 0.9:1:0.05, stirring and dispersing, and performing esterification reaction at 130° C. for 16 h. After the reaction, cooling, washing, and drying to obtain intermediate 2; (4) Add chitosan, chloromethylbenzoyl chloride and triethylamine to N,N-dimethylformamide, wherein the mass ratio of chitosan, chloromethylbenzoyl chloride and triethylamine is 10:1:0.04, heat to 85°C and stir to react for 15 hours, add distilled water to precipitate after the reaction, filter the solvent, wash and purify with distilled water and acetone to obtain benzyl chloride chitosan; (5) adding 18 parts by weight of benzyl chloride chitosan and 15 parts by weight of intermediate 2 to N,N-dimethylformamide solvent, stirring and reacting at 135° C. for 18 h, adding distilled water to precipitate after the reaction, filtering, washing and purifying with distilled water and acetone to obtain sulfaguanidine modified quaternary ammonium chitosan; (6) 12 parts by weight of 3-chloro-2-hydroxypropyltrimethylammonium chloride and 15 parts by weight of sulfaguanidine-modified quaternized chitosan were added to the reactor and stirred at 550 rpm for 10 min to obtain a quaternary ammonium salt type cationic etherifying agent. Example 3

[0017] (1) Under a nitrogen atmosphere, 1,2,4-trimellitic anhydride chloride and 4-((dimethylamino)methyl)phenol were added to an acetonitrile solvent, and ultrasonic dispersion was performed uniformly. A pyridine catalyst was added thereto, wherein the mass ratio of 1,2,4-trimellitic anhydride chloride, 4-((dimethylamino)methyl)phenol, and pyridine catalyst was 1:1.2:0.015, and a substitution reaction was carried out. The reaction was carried out at 82°C for 7 hours. After the reaction was completed, the reaction was cooled to room temperature, the solvent was removed by rotary evaporation, and the reaction was washed and dried to obtain an intermediate 1; (2) adding 9 parts by weight of sulfaguanidine to a reactor filled with anhydrous ethanol, and then heating to 75° C., adding 8 parts by weight of 2,4-dihydroxybenzaldehyde to the reactor after it is completely dissolved, and continuing to stir and react for 9 hours, and then dropping 5 parts by weight of sodium borohydride for reduction for 7 hours. After the reduction is completed, the reaction is concentrated under reduced pressure and washed with ether to obtain hydroxy-modified sulfaguanidine; (3) adding hydroxy-modified sulfaguanidine, intermediate 1, and p-toluenesulfonic acid catalyst into deionized water, wherein the mass ratio of hydroxy-modified sulfaguanidine, intermediate 1, and p-toluenesulfonic acid catalyst is 0.8:1:0.03-0.05, stirring and dispersing, and performing esterification reaction at 120° C. for 14 h. After the reaction, cooling, washing, and drying to obtain intermediate 2; (4) Add chitosan, chloromethylbenzoyl chloride and triethylamine to N,N-dimethylformamide, wherein the mass ratio of chitosan, chloromethylbenzoyl chloride and triethylamine is 7:1:0.03, heat to 73°C and stir to react for 14 hours, add distilled water to precipitate after the reaction, filter the solvent, wash and purify with distilled water and acetone to obtain benzyl chloride chitosan; (5) adding 14 parts by weight of benzyl chloride chitosan and 13 parts by weight of intermediate 2 to N,N-dimethylformamide solvent, stirring and reacting at 126° C. for 16 h, adding distilled water to precipitate after the reaction, filtering, washing and purifying with distilled water and acetone to obtain sulfaguanidine modified quaternary ammonium chitosan; (6) Add 10 parts by weight of 3-chloro-2-hydroxypropyltrimethylammonium chloride and 12 parts by weight of sulfaguanidine-modified quaternized chitosan into a reactor, and stir at 450 rpm for 8 minutes to obtain a quaternary ammonium salt-type cationic etherifying agent. Example 4

[0018] (1) Under a nitrogen atmosphere, 1,2,4-trimellitic anhydride chloride and 4-((dimethylamino)methyl)phenol were added to an acetonitrile solvent, and ultrasonic dispersion was performed uniformly. A pyridine catalyst was added thereto, wherein the mass ratio of 1,2,4-trimellitic anhydride chloride, 4-((dimethylamino)methyl)phenol and pyridine catalyst was 1:1.1:0.01, and a substitution reaction was carried out. The reaction was carried out at 75°C for 6 hours. After the reaction was completed, the reaction was cooled to room temperature, the solvent was removed by rotary evaporation, and the reaction was washed and dried to obtain an intermediate 1; (2) Add 5 parts by weight of sulfaguanidine into a reactor filled with anhydrous ethanol, then heat it to 70°C. After it is completely dissolved, add 6 parts by weight of 2,4-dihydroxybenzaldehyde and continue to stir and react for 8 hours. Continue to drop 4 parts by weight of sodium borohydride for reduction for 5 hours. After the reduction is completed, concentrate under reduced pressure and wash with ether to obtain hydroxy-modified sulfaguanidine; (3) adding hydroxy-modified sulfaguanidine, intermediate 1, and p-toluenesulfonic acid catalyst into deionized water, wherein the mass ratio of hydroxy-modified sulfaguanidine, intermediate 1, and p-toluenesulfonic acid catalyst is 0.9:1:0.05, stirring and dispersing, and performing esterification reaction at 130° C. for 16 h. After the reaction, cooling, washing, and drying to obtain intermediate 2; (4) Add chitosan, chloromethylbenzoyl chloride and triethylamine to N,N-dimethylformamide, wherein the mass ratio of chitosan, chloromethylbenzoyl chloride and triethylamine is 10:1:0.04, heat to 85°C and stir to react for 15 hours, add distilled water to precipitate after the reaction, filter the solvent, wash and purify with distilled water and acetone to obtain benzyl chloride chitosan; (5) adding 14 parts by weight of benzyl chloride chitosan and 13 parts by weight of intermediate 2 to N,N-dimethylformamide solvent, stirring and reacting at 126° C. for 16 h, adding distilled water to precipitate after the reaction, filtering, washing and purifying with distilled water and acetone to obtain sulfaguanidine modified quaternary ammonium chitosan; (6) Add 10 parts by weight of 3-chloro-2-hydroxypropyltrimethylammonium chloride and 12 parts by weight of sulfaguanidine-modified quaternized chitosan into a reactor, and stir at 450 rpm for 8 minutes to obtain a quaternary ammonium salt-type cationic etherifying agent. Example 5

[0019] (1) Under a nitrogen atmosphere, 1,2,4-trimellitic anhydride chloride and 4-((dimethylamino)methyl)phenol were added to an acetonitrile solvent, and ultrasonic dispersion was performed uniformly. A pyridine catalyst was added thereto, wherein the mass ratio of 1,2,4-trimellitic anhydride chloride, 4-((dimethylamino)methyl)phenol and pyridine catalyst was 1:1.3:0.02, and a substitution reaction was carried out at 90°C for 9h. After the reaction was completed, the reaction was cooled to room temperature, the solvent was removed by rotary evaporation, and the reaction was washed and dried to obtain an intermediate 1; (2) adding 12 parts by weight of sulfaguanidine into a reactor filled with anhydrous ethanol, and then heating to 80°C. After it is completely dissolved, adding 10 parts by weight of 2,4-dihydroxybenzaldehyde and continuing to stir and react for 10 hours, and then dropping 6 parts by weight of sodium borohydride for reduction for 9 hours. After the reduction is completed, the mixture is concentrated under reduced pressure and washed with ether to obtain hydroxy-modified sulfaguanidine; (3) adding hydroxy-modified sulfaguanidine, intermediate 1, and p-toluenesulfonic acid catalyst into deionized water, wherein the mass ratio of hydroxy-modified sulfaguanidine, intermediate 1, and p-toluenesulfonic acid catalyst is 0.8:1:0.03-0.05, stirring and dispersing, and performing esterification reaction at 120° C. for 14 h. After the reaction, cooling, washing, and drying to obtain intermediate 2; (4) Add chitosan, chloromethylbenzoyl chloride and triethylamine to N,N-dimethylformamide, wherein the mass ratio of chitosan, chloromethylbenzoyl chloride and triethylamine is 7:1:0.03, heat to 73°C and stir to react for 14 hours, add distilled water to precipitate after the reaction, filter the solvent, wash and purify with distilled water and acetone to obtain benzyl chloride chitosan; (5) Add 10 parts by weight of benzyl chloride chitosan and 12 parts by weight of intermediate 2 to N,N-dimethylformamide solvent, stir and react at 120° C. for 14 h, add distilled water after the reaction to precipitate, filter, and wash with distilled water and acetone for purification to obtain sulfaguanidine modified quaternary ammonium chitosan; (6) Add 5 parts by weight of 3-chloro-2-hydroxypropyltrimethylammonium chloride and 8 parts by weight of sulfaguanidine-modified quaternized chitosan into a reactor, and stir at 400 rpm for 6 minutes to obtain a quaternary ammonium salt type cationic etherifying agent.

[0020] Comparative Example 1 10 parts by weight of 3-chloro-2-hydroxypropyltrimethylammonium chloride were added into the reactor and stirred at 450 rpm for 8 minutes to obtain a quaternary ammonium salt type cationic etherifying agent.

[0021] With Staphylococcus aureus, Escherichia coli, and Candida albicans as the test bacteria, a bacterial suspension with a concentration of 1×105 CFU / mL was prepared, 1.2 mL of the bacterial suspension was transferred to a sterilized culture dish containing MH broth medium, and then the quaternary ammonium salt type cationic etherifying agent sample was attached to the surface of the culture medium, and cultured at 42°C for 15 hours in a constant temperature incubator, and the diameter of the inhibition zone was measured after culture. The test results are shown in Table 1.

[0022] Table 1: Antimicrobial testing.

[0023]

[0024] It can be seen from Table 1 that Examples 1-5 of the present invention have better antibacterial effects than Comparative Example 1.

[0025] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A quaternary ammonium salt type cationic etherifying agent, characterized in that: The invention comprises the following components by weight: 5-12 parts by weight of 3-chloro-2-hydroxypropyltrimethylammonium chloride and 8-15 parts by weight of sulfaguanidine-modified quaternized chitosan.

2. The quaternary ammonium salt type cationic etherifying agent according to claim 1, characterized in that The preparation method of the sulfaguanidine modified quaternary ammonium chitosan is: (1) In a nitrogen atmosphere, 1,2,4-trimellitic anhydride chloride and 4-((dimethylamino)methyl)phenol were added to an acetonitrile solvent, and ultrasonic dispersion was performed uniformly. Pyridine catalyst was then added thereto to carry out a substitution reaction. The reaction was carried out at 75-90°C for 6-9h. After the reaction was completed, the reaction was cooled to room temperature, the solvent was removed by rotary evaporation, and the reaction was washed and dried to obtain an intermediate 1; (2) adding 5-12 parts by weight of sulfaguanidine to a reactor filled with anhydrous ethanol, and then heating to 70-80° C., and after it is completely dissolved, adding 6-10 parts by weight of 2,4-dihydroxybenzaldehyde, and continuing to stir and react for 8-10 hours, and then continuing to dropwise add 4-6 parts by weight of sodium borohydride for reduction for 5-9 hours. After the reduction is completed, the mixture is concentrated under reduced pressure and washed with ether to obtain hydroxy-modified sulfaguanidine; (3) Add hydroxy-modified sulfaguanidine, intermediate 1, and p-toluenesulfonic acid catalyst into deionized water, stir and disperse, and carry out esterification reaction at 110-130° C. for 12-16 hours. After the reaction, cool, wash, and dry to obtain intermediate 2; (4) adding 10-18 parts by weight of benzyl chloride chitosan and 12-15 parts by weight of intermediate 2 to N,N-dimethylformamide solvent, stirring and reacting at 120-135° C. for 14-18 hours, adding distilled water to precipitate after the reaction, filtering, washing and purifying with distilled water and acetone to obtain sulfaguanidine modified quaternary ammonium chitosan; The preparation method of the benzyl chloride chitosan in (4) is as follows: chitosan, chloromethylbenzoyl chloride and triethylamine are added to N,N-dimethylformamide, the temperature is raised to 60-85°C and stirred for reaction for 10-15h, distilled water is added after the reaction to precipitate, the solvent is filtered, and the benzyl chloride chitosan is washed and purified with distilled water and acetone to obtain the benzyl chloride chitosan.

3. The quaternary ammonium salt type cationic etherifying agent according to claim 2, characterized in that: The mass ratio of 1,2,4-trimellitic anhydride chloride, 4-((dimethylamino)methyl)phenol and pyridine catalyst in (1) is 1:1.1-1.3:0.01-0.

02.

4. The quaternary ammonium salt type cationic etherifying agent according to claim 2, characterized in that: The mass ratio of the hydroxy-modified sulfaguanidine, the intermediate 1, and the p-toluenesulfonic acid catalyst in (3) is 0.6-0.9:1:0.03-0.

05.

5. The quaternary ammonium salt type cationic etherifying agent according to claim 2, characterized in that: The mass ratio of the chitosan, chloromethylbenzoyl chloride and triethylamine is 4-10:1:0.01-0.

04.

6. A method for preparing a quaternary ammonium salt type cationic etherifying agent as claimed in any one of claims 1 to 5, characterized in that: The preparation method of the quaternary ammonium salt type cationic etherifying agent comprises: adding 3-chloro-2-hydroxypropyltrimethylammonium chloride and sulfaguanidine modified quaternary ammonium chitosan into a reactor, stirring at a speed of 400-550 rpm for 6-10 minutes, and obtaining the quaternary ammonium salt type cationic etherifying agent.

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