Antibacterial cellulose modified polylactic acid and preparation method thereof

Abstract

The invention relates to the technical field of high polymer materials, and discloses antibacterial cellulose modified polylactic acid, triazole compounds have excellent activity in the antifungal aspect, and sulfanilamide groups can influence nucleic acid metabolism of thalli and synthesis of dihydrofolic acid so as to play a bacteriostatic role. Under the synergistic effect of a sulfanilamide group and a triazole group, the synthesized antibacterial cellulose has excellent antibacterial activity, the antibacterial group is introduced in a grafting manner, so that the long-acting antibacterial activity can be maintained, the polylactic acid is modified by using the cellulose, and due to the large length-diameter ratio of the cellulose and mutual overlapping of the cellulose, the antibacterial activity of the polylactic acid is improved. A good net structure is formed in a polylactic acid matrix through hydrogen bonds and Van der Waals force, so that a toughening effect on polylactic acid can be achieved, and the modified polylactic acid not only has excellent antibacterial activity, but also has better mechanical properties and thermal stability.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, in particular to an antibacterial cellulose-modified polylactic acid and a preparation method thereof. Background Art

[0002] As people's environmental awareness increases, more and more countries have begun to implement plastic bans. With the issuance of plastic bans, the application of ordinary non-degradable plastics has suffered a severe blow. In the wave of plastic bans, polylactic acid stands out. Because polylactic acid has the advantages of good biodegradability, moderate mechanical strength, and good processing performance, it has the possibility of replacing traditional non-degradable plastics. However, due to the greater brittleness of polylactic acid and relatively poor strength, barrier and other properties, it is still difficult to directly replace non-degradable plastics with polylactic acid. Therefore, it needs to be enhanced and modified. At the same time, introducing new antibacterial functions on the basis of toughening can also broaden its application range to replace non-degradable antibacterial plastics.

[0003] In the Chinese patent "CN105670252B A toughened polylactic acid composition and its preparation method", a toughened modified polylactic acid with bio-based vulcanized polyester rubber as toughening particles is disclosed. It has a good toughening effect on polylactic acid, good dispersibility, and can be fully degraded, but it does not have antibacterial properties. By introducing sulfonamide groups and triazole groups with excellent antibacterial properties on the cellulose surface, it can not only have a toughening and modification effect on polylactic acid, but also give polylactic acid good antibacterial properties, so that polylactic acid materials have a broader application prospect.

[0004] 1. Technical issues to be resolved In view of the deficiencies in the prior art, the present invention provides an antibacterial cellulose modified polylactic acid and a preparation method thereof, which solves the problem that ordinary polylactic acid materials have poor toughness and lack of antibacterial properties.

[0005] (II) Technical solution To achieve the above object, the present invention provides the following technical solution: A method for preparing antibacterial cellulose modified polylactic acid comprises the following steps: (1) Preparation of amino cellulose: Add nanocellulose and ethylenediamine into a reaction vessel, then add 40-60% sulfuric acid solution, stir and mix, and then add KMnO dropwise. 4 The aqueous solution is heated to 70-90°C and refluxed for 3-5 hours. After the reaction is completed, the solution is filtered, washed with deionized water and anhydrous ethanol, and vacuum dried to obtain the amino cellulose. (2) Preparation of alkynyl-modified cellulose: adding amino cellulose to a mixed solvent, stirring to dissolve, then adding propargyl acid, and then adding N-hydroxysuccinimide and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, stirring to react for 8-16 hours, after the reaction is completed, distilling off the solvent under reduced pressure, washing with anhydrous ethanol, and vacuum drying to obtain the alkynyl-modified cellulose; (3) Preparation of sulfonamide-triazole antibacterial modified cellulose: 9 H 11 C1N 2 O 3 S-2-chloro-N-(4-sulfamoylphenyl)acetamide was added to the mixed solvent and stirred to dissolve. Then sodium azide was added and stirred to react for 30-90 minutes. Then sodium ascorbate and CuSO 4 and alkynyl-modified cellulose, stirring and reacting for 8-16 hours, after the reaction is completed, adding ice water for precipitation, suction filtration, washing with anhydrous ethanol, and vacuum drying to obtain the sulfonamide-triazole antibacterial modified cellulose; (4) Preparation of antibacterial cellulose modified polylactic acid: Add polylactic acid and sulfonamide-triazole antibacterial modified cellulose into dichloromethane solvent, ultrasonically disperse for 10-20 minutes, stir at room temperature for 4-8 hours, cast the resulting dispersion into a film, and vacuum dry for 24-36 hours to obtain antibacterial cellulose modified polylactic acid.

[0006] Preferably, in step (1), nanocellulose, ethylenediamine, sulfuric acid solution and KMnO 4 The mass ratio is 100:1200-2800:60-140:2-6.

[0007] Preferably, the mixed solvent in step (2) is a mixed solvent of dichloromethane and N,N-dimethylacetamide in a mass ratio of 1:1.

[0008] Preferably, in step (2), the mass ratio of the aminated cellulose, the mixed solvent, propargyl acid, N-hydroxysuccinimide and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride is 100:450-1300:8-24:20-40:35-90.

[0009] Preferably, the mixed solvent in step (3) is a mixed solvent of N,N-dimethylacetamide and water in a volume ratio of 1:1.

[0010] Preferably, in step (3), 2-chloro-N-(4-sulfamoylphenyl)acetamide, mixed solvent, sodium azide, sodium ascorbate, CuSO 4 The mass ratio of cellulose to acetylenic modified cellulose is 10-30:1200-3600:3-9:2-4:1-3:100.

[0011] Preferably, in step (4), the mass ratio of polylactic acid, sulfonamide-triazole antibacterial modified cellulose and dichloromethane is 100:1-3.5:4000-8000.

[0012] 3. Beneficial technical effects Compared with the prior art, the present invention has the following experimental principles and beneficial technical effects: The antibacterial cellulose modified polylactic acid comprises the following steps: firstly, ethylenediamine is used to modify nanocellulose by aminoation, and then the amino groups on the amino cellulose react with the carboxyl groups of propargyl acid under the catalytic system of N-hydroxysuccinimide and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, so that the propargyl acid is grafted on the cellulose to obtain the alkynyl modified cellulose, and then 2-chloro-N-(4-aminosulfonylphenyl)acetamide is treated with sodium azide, and an azide-alkyne click reaction is carried out under the catalytic system of sodium ascorbate and copper sulfate to form a triazole group, so as to obtain the sulfonamide-triazole antibacterial modified fiber. The element is finally mixed with polylactic acid to form a film, and the antibacterial cellulose modified polylactic acid is obtained. The triazole compound has excellent antifungal activity and can inhibit the activity of some enzymes in fungal cells, thereby causing the overflow of intracellular fluid and achieving the antibacterial effect. The sulfonamide group can affect the nucleic acid metabolism of the bacteria and the synthesis of dihydrofolate, thereby playing an antibacterial role. Under the synergistic effect of the sulfonamide group and the triazole group, the synthesized antibacterial cellulose has excellent antibacterial activity, and because the antibacterial group is introduced by grafting, it can maintain long-lasting antibacterial activity, thereby giving the polylactic acid material excellent antibacterial properties.

[0013] The invention discloses an antimicrobial cellulose-modified polylactic acid, in which cellulose is used to modify the polylactic acid. Since the aspect ratio of cellulose is large, cellulose fibers overlap each other, and a good network structure is formed in the polylactic acid matrix through hydrogen bonds and van der Waals forces, thereby having a toughening effect on the polylactic acid. At the same time, since the surface of the polylactic acid contains oxygen atoms, hydrogen bonds can be formed with hydroxyl groups on the cellulose, and the polylactic acid has good compatibility, the cellulose can be evenly dispersed in the polylactic acid matrix. Furthermore, since the network formed by the cellulose hinders the movement of the polylactic acid molecular chain, the thermal stability of the polylactic acid can also be improved, so that the modified polylactic acid not only has excellent antimicrobial activity, but also has better mechanical properties and thermal stability, so that it has higher application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The reaction diagram for preparing amino cellulose; Figure 2 Reaction diagram for the preparation of acetylenic modified cellulose. DETAILED DESCRIPTION

[0015] A method for preparing antibacterial cellulose modified polylactic acid, characterized in that it comprises the following steps: (1) Preparation of amino cellulose: Add 1g of nanocellulose and 20-40ml of ethylenediamine into a reaction vessel, then add 0.6-1.4g of 40-60% sulfuric acid solution, stir and mix, then add 0.02-0.06g of KMnO dropwise. 4 The aqueous solution is heated to 70-90°C and refluxed for 3-5h. After the reaction is completed, it is filtered, washed with deionized water and anhydrous ethanol, and vacuum dried to obtain the amino cellulose; (2) Preparation of alkynyl-modified cellulose: 1 g of amino cellulose is added to 50-100 ml of a mixed solvent of dichloromethane and N,N-dimethylformamide in a mass ratio of 1:1, and stirred to dissolve. Then, 0.08-0.24 g of propargyl acid is added, and then 0.2-0.4 g of N-hydroxysuccinimide and 0.35-0.9 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride are added. The mixture is stirred to react for 8-16 hours. After the reaction is completed, the solvent is distilled off under reduced pressure, and the cellulose is washed with anhydrous ethanol and dried in a vacuum to obtain the alkynyl-modified cellulose. (3) Preparation of sulfonamide-triazole antibacterial modified cellulose: 0.1-0.3 g of the molecular formula C 9 H 11 C1N 2 O 3 Add 2-chloro-N-(4-sulfamoylphenyl)acetamide to 150-350 ml of a mixed solvent of N,N-dimethylacetamide and water in a volume ratio of 1:1, stir to dissolve, then add 0.03-0.09 g of sodium azide, stir to react for 30-90 min, then add 0.02-0.04 g of sodium ascorbate, 0.01-0.03 g of CuSO 4 and 1 g of alkynyl-modified cellulose, stirring for 8-16 hours, after the reaction is complete, adding ice water for precipitation, suction filtration, washing with anhydrous ethanol, and vacuum drying to obtain the sulfonamide-triazole antibacterial modified cellulose; (4) Preparation of antibacterial cellulose modified polylactic acid: Add 5 g of polylactic acid and 0.05-0.15 g of sulfonamide-triazole antibacterial modified cellulose into 200-400 ml of dichloromethane solvent, ultrasonically disperse for 10-20 min, stir at room temperature for 4-8 h, cast the resulting dispersion into a film, and vacuum dry for 24-36 h to obtain antibacterial cellulose modified polylactic acid.

[0016] Example 1

[0017] (1) Preparation of amino cellulose: 1 g of nanocellulose and 20 ml of ethylenediamine were added to a reaction vessel, followed by 0.6 g of 40% sulfuric acid solution. After stirring, 0.02 g of KMnO was added dropwise. 4 The aqueous solution is heated to 70°C and refluxed for reaction for 3 hours. After the reaction is completed, it is filtered, washed with deionized water and anhydrous ethanol, and vacuum dried to obtain the amino cellulose; (2) Preparation of alkynyl-modified cellulose: 1 g of amino cellulose was added to 50 ml of a mixed solvent of dichloromethane and N,N-dimethylformamide in a mass ratio of 1:1, and stirred to dissolve. Then, 0.08 g of propargyl acid was added, and then 0.2 g of N-hydroxysuccinimide and 0.35 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride were added. The mixture was stirred to react for 8 h. After the reaction was completed, the solvent was distilled off under reduced pressure, and the cellulose was washed with anhydrous ethanol and dried in vacuo to obtain the alkynyl-modified cellulose. (3) Preparation of sulfonamide-triazole antibacterial modified cellulose: 0.1 g of the molecular formula C 9 H 11 C1N 2 O 3 S-2-chloro-N-(4-sulfamoylphenyl)acetamide was added to 150 ml of a mixed solvent of N,N-dimethylacetamide and water in a volume ratio of 1:1, stirred to dissolve, and then 0.03 g of sodium azide was added, stirred to react for 30 min, and then 0.02 g of sodium ascorbate and 0.01 g of CuSO 4 and 1 g of alkynyl-modified cellulose, stirring and reacting for 8 h, after the reaction is completed, adding ice water for precipitation, suction filtration, washing with anhydrous ethanol, and vacuum drying to obtain the sulfonamide-triazole antibacterial modified cellulose; (4) Preparation of antibacterial cellulose modified polylactic acid: 5 g of polylactic acid and 0.05 g of sulfonamide-triazole antibacterial modified cellulose were added to 200 ml of dichloromethane solvent, ultrasonically dispersed for 10 min, stirred at room temperature for 4 h, the resulting dispersion was cast into a film, and vacuum dried for 24 h to obtain antibacterial cellulose modified polylactic acid.

[0018] Example 2

[0019] (1) Preparation of amino cellulose: 1 g of nanocellulose and 25 ml of ethylenediamine were added to a reaction vessel, followed by 0.8 g of 50% sulfuric acid solution. After stirring, 0.03 g of KMnO was added dropwise. 4 The aqueous solution is heated to 75°C and refluxed for reaction for 3 hours. After the reaction is completed, it is filtered, washed with deionized water and anhydrous ethanol, and vacuum dried to obtain the amino cellulose; (2) Preparation of alkynyl-modified cellulose: 1 g of amino cellulose was added to 60 ml of a mixed solvent of dichloromethane and N,N-dimethylformamide in a mass ratio of 1:1, and stirred to dissolve. Then, 0.12 g of propargyl acid was added, and then 0.25 g of N-hydroxysuccinimide and 0.55 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride were added. The mixture was stirred to react for 10 h. After the reaction was completed, the solvent was distilled off under reduced pressure, and the cellulose was washed with anhydrous ethanol and dried in vacuo to obtain the alkynyl-modified cellulose. (3) Preparation of sulfonamide-triazole antibacterial modified cellulose: 0.15 g of the molecular formula C 9 H 11 C1N 2 O 3 S 2-chloro-N-(4-sulfamoylphenyl)acetamide was added to 200 ml of a mixed solvent of N,N-dimethylacetamide and water in a volume ratio of 1:1, stirred to dissolve, and then 0.04 g of sodium azide was added, stirred to react for 40 min, and then 0.025 g of sodium ascorbate and 0.015 g of CuSO 4 and 1 g of alkynyl-modified cellulose, stirring and reacting for 12 h, after the reaction is completed, adding ice water for precipitation, suction filtration, washing with anhydrous ethanol, and vacuum drying to obtain the sulfonamide-triazole antibacterial modified cellulose; (4) Preparation of antibacterial cellulose modified polylactic acid: 5 g of polylactic acid and 0.07 g of sulfonamide-triazole antibacterial modified cellulose were added to 250 ml of dichloromethane solvent, ultrasonically dispersed for 10 min, stirred at room temperature for 5 h, the resulting dispersion was cast into a film, and vacuum dried for 27 h to obtain antibacterial cellulose modified polylactic acid.

[0020] Example 3

[0021] (1) Preparation of amino cellulose: 1 g of nanocellulose and 30 ml of ethylenediamine were added to a reaction vessel, followed by 1 g of 50% sulfuric acid solution. After stirring, 0.04 g of KMnO was added dropwise. 4 The aqueous solution is heated to 80°C and refluxed for 4 hours. After the reaction is completed, it is filtered, washed with deionized water and anhydrous ethanol, and vacuum dried to obtain the amino cellulose; (2) Preparation of alkynyl-modified cellulose: 1 g of amino cellulose was added to 70 ml of a mixed solvent of dichloromethane and N,N-dimethylformamide in a mass ratio of 1:1, and stirred to dissolve. Then, 0.16 g of propargyl acid was added, and then 0.3 g of N-hydroxysuccinimide and 0.65 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride were added. The reaction was stirred for 12 h. After the reaction was completed, the solvent was distilled off under reduced pressure, and the cellulose was washed with anhydrous ethanol and dried in vacuo to obtain the alkynyl-modified cellulose. (3) Preparation of sulfonamide-triazole antibacterial modified cellulose: 0.2 g of the molecular formula C 9 H 11 C1N 2 O 3 S 2-chloro-N-(4-sulfamoylphenyl)acetamide was added to 200 ml of a mixed solvent of N,N-dimethylacetamide and water in a volume ratio of 1:1, stirred to dissolve, and then 0.06 g of sodium azide was added, stirred to react for 50 min, and then 0.03 g of sodium ascorbate and 0.02 g of CuSO 4 and 1 g of alkynyl-modified cellulose, stirring and reacting for 12 h, after the reaction is completed, adding ice water for precipitation, suction filtration, washing with anhydrous ethanol, and vacuum drying to obtain the sulfonamide-triazole antibacterial modified cellulose; (4) Preparation of antibacterial cellulose modified polylactic acid: 5 g of polylactic acid and 0.1 g of sulfonamide-triazole antibacterial modified cellulose were added to 300 ml of dichloromethane solvent, ultrasonically dispersed for 15 min, stirred at room temperature for 6 h, and the resulting dispersion was cast into a film and vacuum dried for 30 h to obtain antibacterial cellulose modified polylactic acid.

[0022] Example 4

[0023] (1) Preparation of amino cellulose: 1 g of nanocellulose and 35 ml of ethylenediamine were added to a reaction vessel, followed by 1.2 g of 50% sulfuric acid solution. After stirring, 0.05 g of KMnO was added dropwise. 4 The aqueous solution is heated to 85°C for reflux reaction for 4 hours, and after the reaction is completed, it is filtered, washed with deionized water and anhydrous ethanol, and vacuum dried to obtain the amino cellulose; (2) Preparation of alkynyl-modified cellulose: 1 g of amino cellulose was added to 80 ml of a mixed solvent of dichloromethane and N,N-dimethylformamide in a mass ratio of 1:1, and stirred to dissolve. Then, 0.2 g of propargyl acid was added, and then 0.35 g of N-hydroxysuccinimide and 0.8 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride were added. The reaction was stirred for 14 h. After the reaction was completed, the solvent was distilled off under reduced pressure, and the cellulose was washed with anhydrous ethanol and dried in vacuo to obtain the alkynyl-modified cellulose. (3) Preparation of sulfonamide-triazole antibacterial modified cellulose: 0.25 g of the molecular formula C 9 H 11 C1N 2 O 3 The 2-chloro-N-(4-sulfamoylphenyl)acetamide of S was added to 300 ml of a mixed solvent of N,N-dimethylacetamide and water in a volume ratio of 1:1, stirred to dissolve, and then 0.08 g of sodium azide was added, stirred to react for 80 min, and then 0.035 g of sodium ascorbate and 0.025 g of CuSO4 and 1 g of alkynyl-modified cellulose, stirring and reacting for 14 h, after the reaction is completed, adding ice water for precipitation, suction filtration, washing with anhydrous ethanol, and vacuum drying to obtain the sulfonamide-triazole antibacterial modified cellulose; (4) Preparation of antibacterial cellulose modified polylactic acid: 5 g of polylactic acid and 0.12 g of sulfonamide-triazole antibacterial modified cellulose were added to 350 ml of dichloromethane solvent, ultrasonically dispersed for 18 min, stirred at room temperature for 7 h, and the resulting dispersion was cast into a film and vacuum dried for 33 h to obtain antibacterial cellulose modified polylactic acid.

[0024] Example 5

[0025] (1) Preparation of amino cellulose: 1 g of nanocellulose and 40 ml of ethylenediamine were added to a reaction vessel, followed by 1.4 g of 60% sulfuric acid solution. After stirring, 0.06 g of KMnO was added dropwise. 4 The aqueous solution is heated to 90°C and refluxed for reaction for 5 hours. After the reaction is completed, the solution is filtered, washed with deionized water and anhydrous ethanol, and dried in vacuo to obtain the amino cellulose. (2) Preparation of alkynyl-modified cellulose: 1 g of amino cellulose was added to 100 ml of a mixed solvent of dichloromethane and N,N-dimethylformamide in a mass ratio of 1:1, and stirred to dissolve. Then, 0.24 g of propargyl acid was added, and then 0.4 g of N-hydroxysuccinimide and 0.9 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride were added. The mixture was stirred for 16 h. After the reaction was completed, the solvent was distilled off under reduced pressure, and the mixture was washed with anhydrous ethanol and dried in vacuo to obtain the alkynyl-modified cellulose. (3) Preparation of sulfonamide-triazole antibacterial modified cellulose: 0.3 g of the molecular formula C 9 H 11 C1N 2 O 3 S-2-chloro-N-(4-sulfamoylphenyl)acetamide was added to 350 ml of a mixed solvent of N,N-dimethylacetamide and water in a volume ratio of 1:1, stirred to dissolve, and then 0.09 g of sodium azide was added, stirred to react for 90 min, and then 0.04 g of sodium ascorbate and 0.03 g of CuSO 4 and 1 g of alkynyl-modified cellulose, stirring and reacting for 16 h, after the reaction is completed, adding ice water for precipitation, suction filtration, washing with anhydrous ethanol, and vacuum drying to obtain the sulfonamide-triazole antibacterial modified cellulose; (4) Preparation of antibacterial cellulose modified polylactic acid: 5 g of polylactic acid and 0.15 g of sulfonamide-triazole antibacterial modified cellulose were added to 400 ml of dichloromethane solvent, ultrasonically dispersed for 20 min, stirred at room temperature for 8 h, and the resulting dispersion was cast into a film and vacuum dried for 36 h to obtain antibacterial cellulose modified polylactic acid.

[0026] Comparative Example 1 (1) Preparation of amino cellulose: 1 g of nanocellulose and 30 ml of ethylenediamine were added to a reaction vessel, followed by 1.2 g of 50% sulfuric acid solution. After stirring, 0.04 g of KMnO was added dropwise. 4 The aqueous solution is heated to 80°C and refluxed for 4 hours. After the reaction is completed, it is filtered, washed with deionized water and anhydrous ethanol, and vacuum dried to obtain the amino cellulose; (2) Preparation of alkynyl-modified cellulose: 1 g of amino cellulose was added to 80 ml of a mixed solvent of dichloromethane and N,N-dimethylformamide in a mass ratio of 1:1, and stirred to dissolve. Then, 0.2 g of propargyl acid was added, and then 0.3 g of N-hydroxysuccinimide and 0.7 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride were added. The reaction was stirred for 12 h. After the reaction was completed, the solvent was distilled off under reduced pressure, and the cellulose was washed with anhydrous ethanol and dried in vacuo to obtain the alkynyl-modified cellulose. (3) Preparation of cellulose-modified polylactic acid: 5 g of polylactic acid and 0.1 g of acetylenic-modified cellulose were added to 300 ml of dichloromethane solvent, ultrasonically dispersed for 15 min, stirred at room temperature for 6 h, and the resulting dispersion was cast into a film and vacuum dried for 30 h to obtain cellulose-modified polylactic acid.

[0027] The polylactic acid prepared in Examples 1-5 and Comparative Example 1 is compared as follows: The polylactic acid prepared in the embodiment and the comparative example were respectively made into standard tensile specimens, and the tensile strength was tested using a CMT-5 electronic universal testing machine, and the test standard was GB / T 528-2009.

[0028]

[0029] The polylactic acid prepared in the example and the comparative example was cut into small discs with a diameter of 5 mm, and the Escherichia coli suspension was smeared on the surface of the nutrient agar plate. After culturing at 37° C. for 18 h, the diameter of the inhibition zone was observed.

[0030]

Claims

1. An antibacterial cellulose-modified polylactic acid, characterized in that: The method for preparing an antibacterial cellulose-modified polylactic acid comprises the following steps: (1) Preparation of amino cellulose: Add nanocellulose and ethylenediamine into a reaction container, then add 40-60% sulfuric acid solution, stir and mix, then add KMnO4 aqueous solution dropwise, heat to 70-90°C and reflux for 3-5h, after the reaction is completed, filter, wash with deionized water and anhydrous ethanol, and vacuum dry to obtain the amino cellulose; (2) Preparation of alkynyl-modified cellulose: adding amino cellulose to a mixed solvent, stirring to dissolve, then adding propargyl acid, and then adding N-hydroxysuccinimide and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, stirring to react for 8-16 hours, after the reaction is completed, distilling off the solvent under reduced pressure, washing with anhydrous ethanol, and vacuum drying to obtain the alkynyl-modified cellulose; (3) Preparation of sulfonamide-triazole antibacterial modified cellulose: 11 2-chloro-N-(4-sulfamoylphenyl)acetamide of ClN2O3S is added to a mixed solvent, stirred to dissolve, and then sodium azide is added, stirred to react for 30-90 minutes, and then sodium ascorbate, CuSO4 and alkynyl-modified cellulose are added, stirred to react for 8-16 hours, and after the reaction is completed, ice water is added for precipitation, suction filtration, anhydrous ethanol washing, and vacuum drying to obtain the sulfonamide-triazole antibacterial modified cellulose; (4) Preparation of antibacterial cellulose modified polylactic acid: Add polylactic acid and sulfonamide-triazole antibacterial modified cellulose into dichloromethane solvent, ultrasonically disperse for 10-20 minutes, stir at room temperature for 4-8 hours, cast the resulting dispersion into a film, and vacuum dry for 24-36 hours to obtain antibacterial cellulose modified polylactic acid.

2. The antibacterial cellulose modified polylactic acid according to claim 1, characterized in that: In the step (1), the mass ratio of nanocellulose, ethylenediamine, sulfuric acid solution and KMnO4 is 100:1200-2800:60-140:2-6.

3. The antibacterial cellulose modified polylactic acid according to claim 1, characterized in that: The mixed solvent in step (2) is a mixed solvent of dichloromethane and N,N-dimethylacetamide in a mass ratio of 1:

1.

4. The antibacterial cellulose modified polylactic acid according to claim 1, characterized in that: In the step (2), the mass ratio of the aminated cellulose, the mixed solvent, the propargyl acid, the N-hydroxysuccinimide and the 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride is 100:450-1300:8-24:20-40:35-90.

5. The antibacterial cellulose modified polylactic acid according to claim 1, characterized in that: The mixed solvent in step (3) is a mixed solvent of N,N-dimethylacetamide and water in a volume ratio of 1:

1.

6. The antibacterial cellulose modified polylactic acid according to claim 1, characterized in that: In the step (3), the mass ratio of 2-chloro-N-(4-sulfamoylphenyl)acetamide, mixed solvent, sodium azide, sodium ascorbate, CuSO4 and alkynyl modified cellulose is 10-30:1200-3600:3-9:2-4:1-3:

100.

7. The antibacterial cellulose-modified polylactic acid according to claim 1, characterized in that: In the step (4), the mass ratio of polylactic acid, sulfonamide-triazole antibacterial modified cellulose and dichloromethane is 100:1-3.5:4000-8000.

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