Quaternary ammonium salt ionic liquid with antibacterial and biodegradable functions as well as preparation method and application of quaternary ammonium salt ionic liquid

Abstract

The invention discloses quaternary ammonium salt ionic liquid with antibacterial and biodegradable functions, a preparation method and application, and belongs to the field of ionic liquid organic compounds, and the preparation method comprises the following steps: adding small molecular carbohydrates and N, N-dimethylacetamide into a reaction kettle, stirring at 90 DEG C until the small molecular carbohydrates are completely dissolved, cooling to 0 DEG C, and adding an organic solvent; a first mixed solution is obtained; adding potassium carbonate, N, N-dimethylformamide and acyl chloride into the first mixed solution, uniformly mixing, and keeping the temperature at 0 DEG C to react for 12 hours to obtain a second mixed solution; adding potassium carbonate and an ammonia compound, and keeping the temperature at 80 DEG C to react for 24 hours to obtain first quaternary ammonium cation liquid; reducing the temperature to 0 DEG C, adding potassium carbonate and acyl chloride, uniformly stirring to obtain a third mixed solution, heating to 25-35 DEG C, preserving heat for 12 hours, heating to 65 DEG C, preserving heat for 4 hours, and drying in a vacuum drying oven to constant weight to prepare the glycosyl quaternary ammonium salt ionic liquid. The synthesis process is mild, and the synthesis steps are simple and environment-friendly.

Description

Technical Field

[0001] The invention belongs to the field of ionic liquid organic compounds, and in particular relates to a quaternary ammonium salt ionic liquid with antibacterial and biodegradable functions, a preparation method and application thereof. Background Art

[0002] With the rapid development of social economy, environmental pollution, energy depletion and other problems have become increasingly prominent, attracting widespread attention. In order to alleviate the above problems, scholars and technicians from various countries have been committed to the development and efficient utilization of environmentally friendly materials (such as various biodegradable polymer materials). Among them, crop straw, as a kind of agricultural and forestry waste, has the advantages of wide sources, low cost, biodegradability and renewability. Its main chemical components are highly crystalline cellulose, amorphous hemicellulose and lignin. There are a large number of hydroxyl groups in the molecular structure, which leads to strong hydrogen bonding between (and within) macromolecules. Therefore, it is impossible to prepare related products using traditional thermoplastic processing technology (such as extrusion or injection molding). On the other hand, as a major agricultural country, my country has rich crop resources. According to statistics, the annual crop straw resources that can be collected and utilized in the country reach 674 million tons, mainly wheat straw, corn straw, bagasse and rice straw. If these resources are effectively utilized (such as partially replacing synthetic polyethylene, polypropylene, polyvinyl chloride and other petroleum-based materials), it will bring huge social benefits and economic value. Therefore, how to achieve thermoplastic processing of straw-based polysaccharide fibers becomes the key to solving the above problems.

[0003] As we all know, ionic liquids are widely used in the fields of biomass dissolution, synthesis reaction catalysis, extraction separation, and electrochemistry due to their unique physical and chemical properties, such as low melting temperature, good thermal stability, excellent solubility, good conductivity and chemical stability, high reactivity and low toxicity, and biodegradability. In recent years, the use of ionic liquids to dissolve biomass materials and separate and extract cellulose / hemicellulose / lignin has become a research hotspot in related fields.

[0004] Specifically speaking, the preparation method of quaternary ammonium ion liquid mainly includes the process of reacting tertiary amine with halogenated hydrocarbon to generate quaternary ammonium salt. Tertiary amine is the core raw material for synthesizing quaternary ammonium ion liquid, and commonly used tertiary amines include trimethylamine, triethylamine, N-methylpyridine, etc. These tertiary amines provide nitrogen atoms at the quaternary ammonium center for the quaternization reaction. Halogenated hydrocarbons are usually used as the main raw materials for introducing alkyl or other functional groups, and commonly used ones are bromoalkanes (such as ethyl bromide, hexyl bromide), chloroalkanes, etc. The selection of halogenated hydrocarbons can change the properties of quaternary ammonium ion liquids, such as hydrophobicity, hydrophilicity and ionic conductivity.

[0005] However, the preparation method using tertiary amines and halogenated hydrocarbons as raw materials has the disadvantages of low reaction selectivity and many by-products. In the traditional quaternization reaction, unreacted tertiary amines and impurity salts are easily generated, resulting in low purity of the target product. Especially in the case of long-chain alkyl or complex functional groups, the selectivity problem of the reaction is more prominent. At the same time, the traditional quaternization reaction is usually carried out in organic solvents (such as acetonitrile and dichloromethane), which are often toxic and flammable. The problem of solvent residue is difficult to completely remove after the reaction, which in turn affects the safety and purity of the quaternary ammonium ion liquid. In addition, the use of these organic solvents does not meet the requirements of green chemistry and increases the risk of environmental pollution. The most important thing is that the reaction rate and energy consumption of the traditional quaternization reaction are high, and usually higher temperatures and longer reaction times are required to ensure that the reaction is fully carried out. High reaction temperatures and energy consumption are not conducive to large-scale industrial production, nor are they in line with the concept of energy saving in green chemistry. At the same time, some halogenated hydrocarbons (such as chlorinated and brominated alkanes) have certain toxicity and environmental risks, and have high requirements for process operation and waste treatment. In addition, some long-chain or specially functionalized halogenated hydrocarbons are relatively expensive, which increases the preparation cost of quaternary ammonium ion liquids. Summary of the invention

[0006] One of the purposes of the present invention is to provide a method for preparing a quaternary ammonium salt ionic liquid with antibacterial and biodegradable functions, so as to solve the shortcomings of the prior art that the preparation process of the quaternary ammonium ionic liquid is not environmentally friendly, the reaction selectivity of the main raw materials tertiary amine and halogenated hydrocarbon is low, and there are many by-products.

[0007] The present invention is achieved by the following technical scheme: a method for preparing a quaternary ammonium salt ionic liquid with antibacterial and biodegradable functions, comprising: S100, adding a dried and dehydrated small molecule sugar compound and N,N-dimethylacetamide to a reactor, heating the reactor to 90°C and stirring, stirring until the small molecule sugar compound is completely dissolved, and then cooling to 0°C to obtain a first mixed solution; S200, adding potassium carbonate (K 2 CO 3), N,N-dimethylformamide (DMF), and acyl chloride are added to the first mixed solution and mixed evenly, and the mixture is kept warm for 12 hours at 0°C to obtain a second mixed solution, wherein the second mixed solution is an acyl chloride monosubstituted sugar compound; S300, potassium carbonate and an ammonia compound are added to the second mixed solution, and stirred evenly, and the mixture is kept warm for 24 hours at 80°C to obtain a first quaternary ammonium cationic liquid; S400, the temperature of the first quaternary ammonium cationic liquid is lowered to 0°C, and potassium carbonate and acyl chloride are added, and stirred evenly to obtain a third mixed solution, and the third mixed solution is heated to 25°C~35°C and kept warm for 12 hours, and then heated to 65°C and kept warm for 4 hours to prepare a second quaternary ammonium cationic liquid; S500, the second quaternary ammonium cationic liquid is washed 5~8 times with anhydrous ethanol at a temperature of 0°C~8°C, and the washed second quaternary ammonium cationic liquid is placed in a vacuum drying oven and dried to constant weight, and the drying temperature is 80°C to prepare a glycosyl quaternary ammonium salt ionic liquid.

[0008] Furthermore, the small molecule sugar compounds include one or more combinations of glucose, fructose, sucrose, raffinose and maltose.

[0009] Furthermore, the molar ratio of the small molecule sugar compound, potassium carbonate and acyl chloride in S100 and S200 is 2:1:2-2.1, the amount of N,N-dimethylacetamide is 19.0-22.0 mL, and the amount of N,N-dimethylformamide is 0.5-2.0 mL.

[0010] Furthermore, in step S300, the molar ratio of potassium carbonate to ammonia compound is 1:0.8~1.

[0011] Furthermore, the ammonia compound is one or a combination of two of aqueous ammonia, methylamine and diethanolamine.

[0012] Furthermore, the molar ratio of potassium carbonate to acyl chloride in S400 is 1:2-3.

[0013] Furthermore, the acyl chloride is one of chloroacetyl chloride or thionyl chloride.

[0014] Another aspect of the present invention provides a quaternary ammonium salt ionic liquid having antibacterial and biodegradable functions, wherein the quaternary ammonium salt ionic liquid is prepared according to the quaternary ammonium salt ionic liquid preparation method as described above.

[0015] On the other hand, the present invention also provides an application of a quaternary ammonium salt ionic liquid with antibacterial and biodegradable functions. The quaternary ammonium salt ionic liquid as described above can have any of the following uses: (1) application in antibacterial agents and disinfectants; (2) application in dissolving biomass materials; (3) application in catalysis of synthetic reactions; (4) application in extraction and separation; (5) application in thermoplastic processing of straw-based polysaccharide fibers; and (6) application in processing crop straw.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0017] 1. The present invention uses small molecule sugar compounds such as glucose and raffinose as main raw materials to synthesize quaternary ammonium ion liquids, and obtains a quaternary ammonium salt ion liquid with antibacterial and biodegradable functions through substitution reaction and quaternization reaction. The whole preparation process is green, environmentally friendly, mild and efficient. At the same time, small molecule sugars are used as raw materials with wide sources and low prices, which can effectively reduce the cost of raw materials.

[0018] 2. The quaternary ammonium salt ionic liquid prepared by the present invention has obvious ionic liquid characteristics, not only has excellent thermal stability, but also can effectively reduce the hydrogen bonding effect between (and within) cellulose macromolecules through "supramolecular induction" (i.e., strong interaction between chlorine atoms and hydrogen atoms), thereby achieving the dissolution of cellulose polysaccharide molecules, promoting the plasticization and molding of cellulose, and improving its application range. It can be used for crop straw treatment to improve the utilization rate of crop straw.

[0019] 3. The quaternary ammonium salt ionic liquid prepared by the present invention has good solubility in cellulose, high thermal stability, non-toxicity, and excellent antibacterial property, and can be widely used in the fields of cellulose extraction, thermal plasticization modification of biomass fibers, etc., and the quaternary ammonium salt ionic liquid prepared by the steps of the present invention can give the corresponding products broad-spectrum antibacterial properties due to its excellent antibacterial property, and the antibacterial property of cellulose polysaccharide materials can be achieved without adding an external antibacterial agent. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0021] Figure 1 This is a molecular structure diagram of the glucose-based quaternary ammonium salt ionic liquid provided in Example 1 of the present invention.

[0022] Figure 2 This is a physical picture of the glucose-based quaternary ammonium salt ionic liquid provided in Example 1 of the present invention.

[0023] Figure 3 Provided in Example 1 of the present invention1 H-NMR spectrum.

[0024] Figure 4 This is a thermogravimetric curve of the glucose-based quaternary ammonium salt ionic liquid provided in the experimental example of the present invention.

[0025] Figure 5 Thermogravimetric curve of raw material glucose provided in the experimental example of the present invention.

[0026] Figure 6 This is a diagram of the Staphylococcus aureus sterilization experiment provided by the experimental example of the present invention.

[0027] Figure 7 This is a diagram of the sterilization experiment of the standard strain of Escherichia coli provided in the experimental example of the present invention.

[0028] Figure 8 This is a natural degradation mass loss curve provided for the experimental example of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, 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 in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0030] Unless otherwise specified, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art in the art to which the present invention relates. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail. Regarding the "comprising", "including", "having", "containing", etc. used herein, they are all open terms, that is, they mean including but not limited to. Unless the context clearly indicates otherwise, the expressions "a" and "one" used herein include plural references. It should be noted that "first", "second", etc. are only for the convenience of description and distinction, and cannot be understood as indicating or implying relative importance. The term "about" used herein means a range of ±20% of the value thereafter. In some embodiments, the term "about" means a range of ±10% of the value thereafter. In some embodiments, the term "about" means a range of ±5% of the value thereafter.

[0031] Embodiment 1,

[0032] In this embodiment, a method for preparing a quaternary ammonium salt ionic liquid having antibacterial and biodegradable functions is provided. Figure 1The molecular structure diagram of the glucose-based quaternary ammonium salt ionic liquid prepared by the preparation method in this embodiment is shown, Figure 2 The physical picture of the glucosyl quaternary ammonium salt ionic liquid prepared by the preparation method in this embodiment is shown. The preparation method in this embodiment specifically comprises the following steps:

[0033] Step 1: Add 3.96 g of dried and dehydrated glucose and 20 mL of rotary evaporated N,N-dimethylacetamide (DMAc) into the reactor, heat the reactor to 90°C and stir continuously until the glucose and DMAc are completely dissolved to form a homogeneous solution, then cool to 0°C.

[0034] Step 2: Add 1.38 g K 2 CO 3 , 1 mL DMF and 2.26 g chloroacetyl chloride were added to the formed homogeneous solution, and the reaction was kept at 0°C for 12 h to obtain a chloroacetyl chloride monosubstituted glucose solution.

[0035] Step 3: Add 1.38 g K 2 CO 3 , 1.05 g of diethanolamine, and react at 80°C for 24 h to obtain the first quaternary ammonium cationic liquid.

[0036] Step 4: Lower the temperature of the first quaternary ammonium cation liquid to 0°C and continue to add 6.90 g K 2 CO 3 , 11.29 g chloroacetyl chloride, react at 25°C for 12 h, then heat to 65°C and keep reacting for 4 h to obtain the second quaternary ammonium cationic liquid;

[0037] Step 5: Wash the second quaternary ammonium cationic liquid 5 times with anhydrous ethanol at a temperature of 0°C, and place the washed second quaternary ammonium cationic liquid in a vacuum drying oven to dry to constant weight at a drying temperature of 80°C to prepare a glycosyl quaternary ammonium salt ionic liquid with antibacterial and biodegradable functions.

[0038] The quaternary ammonium salt ionic liquid prepared in this example was subjected to hydrogen nuclear magnetic resonance detection to obtain the following Figure 3 shown 1H-NMR spectrum, as can be seen from the figure, in addition to the characteristic solvent peak of the deuterated reagent DMSO, 6 characteristic peaks are clearly observed within the chemical shift range of δ (ppm) 0-6.0. The specific data are as follows, δ (ppm) 1.10 (dt, J = 5.0 Hz, 5H), δ (ppm) 3.12 (m, 7H), δ (ppm) 3.43 (m, 15H), δ (ppm) 4.46 (m, 14H), δ (ppm) 4.62 (d, J = 5.0 Hz, 3H), δ (ppm) 6.20 (d, J = 5.0 Hz, 3H). From Figure 3 It can be seen that the number of characteristic hydrogens and chemical shifts of the glycosyl quaternary ammonium salt ionic liquid sample synthesized by this embodiment are consistent with the theoretical structure, indicating that the glycosyl quaternary ammonium salt ionic liquid can be successfully synthesized through the steps in this embodiment.

[0039] Embodiment 2,

[0040] In this embodiment, a method for preparing a quaternary ammonium salt ionic liquid having antibacterial and biodegradable functions is provided, which specifically comprises the following steps:

[0041] Step 1: Add 6.84 g of dried and dehydrated sucrose and 20 mL of rotary evaporated N,N-dimethylacetamide (DMAc) to the reactor, heat the reactor to 90°C and stir continuously until the sucrose and DMAc are completely dissolved to form a homogeneous solution, then cool to 0°C.

[0042] Step 2: Add 1.38 g K 2 CO 3 , 1 mL DMF and 2.26 g chloroacetyl chloride were added to the formed homogeneous solution, and the reaction was kept at 0°C for 12 h to obtain a chloroacetyl chloride monosubstituted sucrose solution.

[0043] Step 3: Add 1.38 g K 2 CO 3 , 1.05 g of diethanolamine, and react at 80°C for 24 h to obtain the first quaternary ammonium cationic liquid.

[0044] Step 4: Lower the temperature of the first quaternary ammonium cation liquid to 0°C and continue to add 6.90 g K 2 CO 3 , 11.29 g chloroacetyl chloride, react at 25°C for 12 h, then heat to 65°C and keep reacting for 4 h to obtain the second quaternary ammonium cationic liquid;

[0045] Step 5: Wash the second quaternary ammonium cationic liquid 7 times with anhydrous ethanol at a temperature of 4°C, and place the washed second quaternary ammonium cationic liquid in a vacuum drying oven to dry to constant weight at a drying temperature of 80°C to prepare a glycosyl quaternary ammonium salt ionic liquid with antibacterial and biodegradable functions.

[0046] Embodiment 3,

[0047] In this embodiment, a method for preparing a quaternary ammonium salt ionic liquid having antibacterial and biodegradable functions is provided, which specifically comprises the following steps:

[0048] Step 1: Add 5.04 g of dried and dehydrated raffinose and 20 mL of rotary evaporated N,N-dimethylacetamide (DMAc) to the reactor, heat the reactor to 90°C and stir continuously until the raffinose and DMAc are completely dissolved to form a homogeneous solution, then cool to 0°C.

[0049] Step 2: Add 0.69 g K 2 CO 3 , 0.5 mL DMF and 1.19 g thionyl chloride were added to the formed homogeneous solution, and the mixture was kept at 0°C for 12 h to obtain a chloroacetyl chloride monosubstituted raffinose solution.

[0050] Step 3: Add 0.69 g K 2 CO 3 , 0.53 g ammonia water (NH 3 ), and the first quaternary ammonium cationic liquid was obtained after the reaction was kept at 80 °C for 24 h.

[0051] Step 4: Lower the temperature of the first quaternary ammonium cation liquid to 0°C and continue to add 6.90 g K 2 CO 3 , 11.90 g of chloroacetyl chloride, react at 25°C for 12 hours, then heat to 65°C and keep reacting for 4 hours to obtain a second quaternary ammonium cationic liquid;

[0052] Step 5: Wash the second quaternary ammonium cationic liquid 8 times with anhydrous ethanol at a temperature of 6°C, and place the washed second quaternary ammonium cationic liquid in a vacuum drying oven to dry to constant weight at a drying temperature of 80°C to prepare a glycosyl quaternary ammonium salt ionic liquid with antibacterial and biodegradable functions.

[0053] Embodiment 4,

[0054] In this embodiment, a method for preparing a quaternary ammonium salt ionic liquid having antibacterial and biodegradable functions is provided, which specifically comprises the following steps:

[0055] Step 1: Add 7.21 g of dried maltose and 20 mL of rotary evaporated N,N-dimethylacetamide (DMAc) to the reactor, heat the reactor to 90°C and stir continuously until all the raffinose and DMAc are dissolved to form a homogeneous solution, then cool to 0°C.

[0056] Step 2: Add 1.38 g K 2 CO 3 , 1 mL DMF and 2.26 g chloroacetyl chloride were added to the formed homogeneous solution, and the reaction was kept at 0°C for 12 h to obtain a chloroacetyl chloride monosubstituted maltose solution.

[0057] Step 3: Add 1.38 g K 2 CO 3 , 0.68 g ammonia water (NH 3 ), and the first quaternary ammonium cationic liquid was obtained after the reaction was kept at 80 °C for 24 h.

[0058] Step 4: Lower the temperature of the first quaternary ammonium cation liquid to 0°C and continue to add 6.90 g K 2 CO 3 , 13.55 g of chloroacetyl chloride, react at 25°C for 12 hours, then heat to 65°C and keep reacting for 4 hours to obtain a second quaternary ammonium cationic liquid;

[0059] Step 5: Wash the second quaternary ammonium cationic liquid 7 times with anhydrous ethanol at a temperature of 8°C, and place the washed second quaternary ammonium cationic liquid in a vacuum drying oven to dry to constant weight at a drying temperature of 80°C to prepare a glycosyl quaternary ammonium salt ionic liquid with antibacterial and biodegradable functions.

[0060] Experimental example:

[0061] The glycosyl quaternary ammonium salt ionic liquid prepared in Example 1 was subjected to thermogravimetric analysis experiments, antibacterial test experiments and natural degradation experiments.

[0062] The thermogravimetric analysis experiment of the saccharide quaternary ammonium salt ionic liquid prepared in Example 1 was performed to obtain a thermogravimetric (TGA) curve as shown in the following figure: Figure 4 As shown, the thermogravimetric (TGA) curve of raw glucose is as follows Figure 5 shown.

[0063] from Figure 4 and Figure 5It can be seen that the decomposition temperature of glucose is 222.1°C, and there is a 5% weight loss before 200°C, which is mainly due to the volatilization of water adsorbed by sugar molecules and the initial dehydration reaction within and / or between sugar molecules. The initial decomposition temperature of the glycosyl quaternary ammonium salt ionic liquid prepared by the steps in Example 1 is 169.8°C, and it maintains good stability when the temperature does not exceed 180°C, indicating that the adsorption performance of the ionic liquid to water is weakened and it is relatively stable in the air. The initial decomposition temperature of the ionic liquid prepared in Example 1 is reduced, but it is still higher than 160°C, mainly because the decomposition temperature of the acyl chloride segment is slightly lower.

[0064] The antibacterial test experiment was conducted to verify the killing effect of the glycosyl quaternary ammonium salt ionic liquid of the present invention on Staphylococcus aureus and Escherichia coli. The glycosyl quaternary ammonium salt ionic liquid used in this experimental example was prepared according to the steps described in Example 1.

[0065] The Staphylococcus aureus used in this experimental example is the standard strain of Staphylococcus aureus (ATCC29213), and the Escherichia coli used is the standard strain of Escherichia coli (ATCC25922).

[0066] The Staphylococcus aureus standard strain (ATCC29213) and the Escherichia coli standard strain (ATCC25922) were cultured to the logarithmic growth phase, which means that the bacterial population increases rapidly.

[0067] The antibacterial activity of quaternary ammonium salt ionic liquid against Staphylococcus aureus and Escherichia coli was tested by the inhibition ring test. The preserved Staphylococcus aureus and Escherichia coli stock solutions were cultured into 5×10 5 cfu / mL concentration suspension, dip a sterile cotton swab in the bacterial solution and evenly smear it on the surface of the LB solid culture medium plate three times. Each time you smear it, the plate should be rotated 60°, and finally the cotton swab should be smeared around the edge of the plate for one week. Cover the plate, incubate for 24 hours, take 5mL of glycosyl quaternary ammonium salt ionic liquid sample, drop it on the center of the culture dish on the surface of the culture medium, and incubate it in a constant temperature incubator at 37°C for 24 hours. Then take out the culture dish and measure the diameter of the antibacterial ring to evaluate the antibacterial effect of the antisense nucleic acid antibacterial hydrogel. The final experimental results of the glycosyl quaternary ammonium salt ionic liquid described in this experiment are as follows. Figure 6 , 7 As shown in the figure, the red dotted circle in the figure is where 5 mL of the quaternary ammonium salt ionic liquid sample prepared in Example 1 is added dropwise. It can be seen from the figure that the quaternary ammonium salt ionic liquid of the present invention has good antibacterial properties against Staphylococcus aureus and Escherichia coli, especially has excellent resistance to Staphylococcus aureus.

[0068] The degradation performance of the glycosyl quaternary ammonium salt ionic liquid of the present invention in a natural environment was verified by a natural degradation test experiment in a soil environment. The glycosyl quaternary ammonium salt ionic liquid used in this experimental example was prepared according to the steps described in Example 1.

[0069] Let the mass be m 0 , place the sterilized gauze with the size of 15 mm × 15 mm × 4 mm (length × width × thickness) in a 100 mL small beaker, then add 20 g of the saccharide quaternary ammonium salt ionic liquid prepared in the steps described in Example 1 to the beaker, raise the system temperature to 80°C, and ensure that the sterilized gauze is completely covered by the ionic liquid. Keep warm for 2 hours to allow the sterilized gauze to fully absorb the saccharide quaternary ammonium salt ionic liquid. Take the sterilized gauze out of the beaker, place it on a polytetrafluoroethylene watch dish, and cool it to room temperature for use. Accurately weigh the sterilized gauze adsorbed with the saccharide ionic liquid, and record the mass as m 1 The sterilized gauze adsorbed with sugar-based ionic liquid was buried in the natural soil environment outside the Chemistry Building of Yunnan University in Chenggong District, Kunming City, with a burial depth of 200 mm, soil pH = 6.45 ± 0.1, and temperature and humidity as local environmental parameters. Then, the samples were taken out of the soil every other week, the dust attached to the surface was washed with anhydrous ethanol, and then dried in an oven at 50 ° C to constant weight. The total mass of the sample was recorded as m t The following formula is used to record the degradation rate (DR) of the sample in the natural soil environment:

[0070] ,

[0071] Figure 8 The natural degradation mass loss curve in this experimental example is shown. Figure 8 From the degradation rate test curve shown, the sugar-based ionic liquid of the present invention has excellent degradability in the natural soil environment, and the sample quality shows a phenomenon of decay as the degradation time increases. In particular, when the degradation time reaches 5 weeks, the degradation rate of the sample exceeds 92%, indicating that the sugar-based ionic liquid has excellent degradability in the natural soil environment.

[0072] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a quaternary ammonium salt ionic liquid having antibacterial and biodegradable functions, characterized in that: The preparation method comprises: S100, adding the dried and dehydrated small molecule sugar compound and N,N-dimethylacetamide to a reaction kettle, heating the reaction kettle to 90° C. and stirring until the small molecule sugar compound is completely dissolved, and then cooling to 0° C. to obtain a first mixed solution; S200, adding potassium carbonate, N,N-dimethylformamide and acyl chloride to the first mixed solution, mixing them evenly, and reacting them at 0° C. for 12 hours to obtain a second mixed solution, wherein the second mixed solution is an acyl chloride monosubstituted sugar compound; S300, adding potassium carbonate and ammonia compound to the second mixed solution, stirring evenly, and keeping the mixture at 80° C. for 24 hours to obtain a first quaternary ammonium cation liquid; S400, lowering the temperature of the first quaternary ammonium cationic liquid to 0°C, adding potassium carbonate and acyl chloride, stirring evenly to obtain a third mixed solution, heating the third mixed solution to 25°C-35°C for 12 hours, and then heating to 65°C for 4 hours to obtain a second quaternary ammonium cationic liquid; S500, washing the second quaternary ammonium cation liquid 5 to 8 times with anhydrous ethanol at a temperature of 0°C to 8°C, placing the washed second quaternary ammonium cation liquid in a vacuum drying oven and drying it to constant weight at a drying temperature of 80°C, to prepare a glycosyl quaternary ammonium salt ionic liquid.

2. The method for preparing a quaternary ammonium salt ionic liquid with antibacterial and biodegradable functions according to claim 1, characterized in that: The small molecule sugar compound includes one or more combinations of glucose, fructose, sucrose, raffinose and maltose.

3. The method for preparing a quaternary ammonium salt ionic liquid with antibacterial and biodegradable functions according to claim 1, characterized in that: The molar ratio of the small molecule sugar compound, potassium carbonate and acyl chloride in the S100 and S200 is 2:1:2-2.1, the amount of N,N-dimethylacetamide is 19.0-22.0 mL, and the amount of N,N-dimethylformamide is 0.5-2.0 mL.

4. The method for preparing the quaternary ammonium salt ionic liquid with antibacterial and biodegradable functions according to claim 1, characterized in that: In step S300, the molar ratio of potassium carbonate to ammonia compound is 1:0.8-1.

5. The method for preparing the quaternary ammonium salt ionic liquid with antibacterial and biodegradable functions according to claim 1, characterized in that: The ammonia compound is one or a combination of two of aqueous ammonia, methylamine and diethanolamine.

6. The method for preparing the quaternary ammonium salt ionic liquid with antibacterial and biodegradable functions according to claim 1, characterized in that: The molar ratio of potassium carbonate to acyl chloride in the S400 is 1:2-3.

7. The method for preparing the quaternary ammonium salt ionic liquid with antibacterial and biodegradable functions according to claim 1, characterized in that: The acyl chloride is one of chloroacetyl chloride or thionyl chloride.

8. A quaternary ammonium salt ionic liquid having antibacterial and biodegradable functions, characterized in that: The quaternary ammonium salt ionic liquid is prepared according to the preparation method as described in any one of claims 1 to 7.

9. An application of a quaternary ammonium salt ionic liquid having antibacterial and biodegradable functions, characterized in that: The quaternary ammonium salt ionic liquid prepared by the preparation method according to any one of claims 1 to 7 can have any of the following uses: (1) Application in antimicrobial agents and disinfectants; (2) Application in dissolving biomass materials; (3) Application in catalysis of synthetic reactions; (4) Application in extraction and separation; (5) Application in thermoplastic processing of straw-based polysaccharide fibers; (6) Application in crop straw processing.

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