A multifunctional polylactic acid film, its preparation method and application
By coating the surface of polylactic acid film with a composite material formed by the reaction of furfural and polyethyleneimine, the problems of poor barrier performance and flammability of bio-based biodegradable packaging materials have been solved, achieving efficient flame retardant and antibacterial effects and expanding its applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HEBEI ANTAI PLASTIC PACKAGING PROD LTD
- Filing Date
- 2026-05-20
- Publication Date
- 2026-06-30
AI Technical Summary
Existing bio-based biodegradable packaging materials have poor barrier properties, are flammable, and lack antibacterial properties, which limits their widespread application.
By coating a functional coating onto the surface of a polylactic acid (PLA) film, the coating is formed by mixing a solid product generated from the reaction of furfural and polyethyleneimine solution with tetramethyldivinyldisiloxane to form a composite material, which is then coated onto a PEI-treated PLA film to improve its barrier, flame retardant, and antibacterial properties.
It significantly improves the barrier, flame retardant and antibacterial properties of polylactic acid films, expanding their application range.
Smart Images
Figure CN122302346A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of bio-based thin film technology, specifically relating to a multifunctional polylactic acid thin film, its preparation method, and its application. Background Technology
[0002] With the rapid development of the new materials industry, especially the widespread use of packaging materials in daily life, most of these materials are not easily degradable. Therefore, it is crucial to develop bio-based biodegradable packaging materials.
[0003] Bio-based biodegradable packaging materials generally have poor barrier properties, lack antibacterial properties, and are highly flammable, limiting their wider application. To further expand the application range of these materials, it is crucial to endow them with barrier, flame-retardant, and antibacterial properties.
[0004] Polylactic acid (PLA) is an important member of bio-based polymer materials and has been widely used and researched in recent years. To overcome its poor barrier properties and flammability, surface coating technology has been used to improve the barrier, flame retardant, and antibacterial properties of PLA. This has significant practical implications for the further research and industrialization of modified PLA films in the field of plastic packaging. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to provide a multifunctional polylactic acid film, its preparation method and application, which significantly improves the barrier, flame retardant and antibacterial properties of polylactic acid film.
[0006] This invention provides a method for preparing a multifunctional polylactic acid film, comprising the following steps: 1) Furfural was added to a polyethyleneimine solution, heated to reflux, and then dried to obtain a solid product; 2) After dissolving the solid product, it is mixed with tetramethyldivinyldisiloxane and reacted to obtain a functional coating; 3) Apply the functional coating onto the PEI-treated PLA film and dry it to obtain a multifunctional polylactic acid film.
[0007] Preferably, in step 1), the solvent in the polyethyleneimine solution is water with a mass concentration of 5-6%.
[0008] Preferably, in step 1), the weight ratio of furfural to polyethyleneimine is 2-4:1.
[0009] Preferably, in step 1), the temperature of the heating reflux is 50-70°C.
[0010] Preferably, in step 1), the drying temperature is 60°C.
[0011] Preferably, in step 2), the solvent used to dissolve the solid product is water.
[0012] Preferably, in step 2), the weight ratio of the solid product to tetramethyldivinyldisiloxane is 7-9:1.
[0013] Preferably, in step 2), the reaction temperature is 80-100℃.
[0014] This invention provides a multifunctional polylactic acid film, which is prepared using the aforementioned preparation method.
[0015] This invention provides an application of the aforementioned multifunctional polylactic acid film, which is used to prepare packaging materials.
[0016] The beneficial effects of this invention are that the multifunctional polylactic acid film of this invention not only plays a flame-retardant role through the composite material of nitrogen and silicon elements introduced on the surface, but also has a film-forming function to achieve a barrier effect; the coating contains Schiff base, which has an antibacterial function, and the composite effect of multiple raw materials significantly improves the barrier, flame-retardant and antibacterial properties of the polylactic acid film. Attached Figure Description
[0017] Figure 1 The graph shows the change in oxygen permeability of PLA and multifunctional polylactic acid films over time.
[0018] Figure 2 The graph shows the change in heat release rate over time for PLA and multifunctional polylactic acid films. Detailed Implementation
[0019] The present invention will be further described below with reference to the embodiments to facilitate understanding of the technical solution of the present invention, but it should not be construed as the scope of the present invention being limited to the following implementation examples.
[0020] Example 1 A method for preparing a multifunctional polylactic acid film includes the following steps: 1) Place 5g of polyethyleneimine (PEI) in a flask and dissolve it in 100ml of water; 2) Add 15g of furfural to the above flask under magnetic stirring. After the addition is complete, reflux the mixture at 60°C for 8 hours. The reaction is completed and the liquid is a dark brown liquid. 3) After drying the above dark brown liquid in an oven at 60°C for 24 hours, and after the water has completely evaporated, a solid product can be obtained; 4) Take 4g of the solid product from step 3) and add it to a flask containing 10ml of water. Then add 0.5g of tetramethyldivinyldisiloxane and react at 90℃ for 6 hours. After the reaction is complete, it is a dark brown liquid, which is the functional coating.
[0021] 5) Take the PLA film treated with PEI (cut PLA films of different sizes according to test requirements) and place it on a flat plate. Apply the functional coating (2g) from step 4) to the surface by scraping process. After drying, a multifunctional polylactic acid film is obtained.
[0022] The method for preparing the PLA film treated with PEI is as follows: 1. Weigh 10g of polyethyleneimine (PEI) and add it to 100ml of water; stir magnetically at room temperature until the PEI is completely dissolved to form a homogeneous and transparent solution, i.e., PEI aqueous solution.
[0023] 2. Cut the PLA film to the appropriate size, and gently wipe the surface of the PLA film with anhydrous ethanol to remove oil, dust or release agent; let the cleaned film air dry at room temperature or blow dry with cool air.
[0024] 3. Completely immerse the dried PLA film in the prepared PEI aqueous solution for 20 minutes, then slowly lift the film and drain off the excess liquid.
[0025] 4. Place the film in a forced-air drying oven, set the temperature to 50℃, and dry for 3 hours until the moisture is completely evaporated. A very thin PEI modified layer is formed on the film surface, resulting in a PEI-treated PLA film.
[0026] Example 2 Compared with Example 1, Example 2 differs in that in step 5), the functional coating (3g) from step 4) is coated onto the surface, and after drying, a multifunctional polylactic acid film is obtained. Everything else is the same as in Example 1.
[0027] Example 3 Compared with Example 1, Example 3 differs in that in step 5), the functional coating (4g) from step 4) is coated onto the surface, and after drying, a multifunctional polylactic acid film is obtained. Everything else is the same as in Example 1.
[0028] Example 4 Oxygen barrier performance test: The test was conducted according to the test method published in GB / T1038-2000 "Test method for gas permeability of plastic films and sheets - differential pressure method"; Flame retardant performance test: The test was conducted using a cone calorimeter according to the ISO 5660 test method. Antimicrobial performance test: The test was conducted according to the test method published in GB / T31402-2015 / ISO22196:2007 "Plastics - Test method for antimicrobial properties of plastic surfaces".
[0029] The performance results of each product, as tested experimentally, are as follows: Figure 1 , Figure 2The overall performance is shown in Table 1.
[0030] Table 1. Antibacterial properties, oxygen permeability, and heat release rate of PLA and multifunctional polylactic acid films.
[0031] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this application as described above, which are not provided in detail for the sake of brevity.
[0032] One or more embodiments in this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this application should be included within the protection scope of this application.
Claims
1. A method for preparing a multifunctional polylactic acid film, characterized in that, Includes the following steps: 1) Furfural was added to a polyethyleneimine solution, heated to reflux, and then dried to obtain a solid product; 2) After dissolving the solid product, it is mixed with tetramethyldivinyldisiloxane and reacted to obtain a functional coating; 3) Apply the functional coating onto the PEI-treated PLA film and dry it to obtain a multifunctional polylactic acid film.
2. The preparation method according to claim 1, characterized in that, In step 1), the solvent in the polyethyleneimine solution is water, with a mass concentration of 5-6%.
3. The preparation method according to claim 1, characterized in that, In step 1), the weight ratio of furfural to polyethyleneimine is 2-4:
1.
4. The preparation method according to claim 1, characterized in that, In step 1), the temperature of the reflux heating is 50-70℃.
5. The preparation method according to claim 1, characterized in that, In step 1), the drying temperature is 60℃.
6. The preparation method according to claim 1, characterized in that, In step 2), the solvent used to dissolve the solid product is water.
7. The preparation method according to claim 1, characterized in that, In step 2), the weight ratio of the solid product to tetramethyldivinyldisiloxane is 7-9:
1.
8. The preparation method according to claim 1, characterized in that, In step 2), the reaction temperature is 80-100℃.
9. A multifunctional polylactic acid film, characterized in that, It is prepared by the preparation method described in any one of claims 1-8.
10. An application of the multifunctional polylactic acid film as described in claim 9, characterized in that, The multifunctional polylactic acid film is used to prepare packaging materials.