PBAT degradable agricultural mulching film with antibacterial function
By composite chitosan and cellulose nanofibers into a three-dimensional network structure on PBAT agricultural mulch film, the threat of soil pathogenic microorganisms to crops is solved, resulting in antibacterial PBAT mulch film that promotes crop growth and improves agricultural efficiency.
Patent Information
- Application Number
- CN202422872303.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-25
- Publication Date
- 2026-02-03
- Estimated Expiration
- 2034-11-25
AI Technical Summary
Soil pathogens pose a threat to crop health. Existing PBAT agricultural mulch films lack antibacterial properties, leading to frequent root diseases and affecting crop growth and yield.
An antibacterial functional layer is composited on the PBAT support layer. The three-dimensional network structure composed of cellulose nanofibers and chitosan inhibits the growth of pathogens by electrostatic adsorption, disrupting bacterial cell membranes, and affecting bacterial metabolic processes.
It effectively inhibits the growth of pathogens, reduces root diseases, extends the service life of mulch film, improves the crop growth environment, and increases agricultural production efficiency.
Smart Images
Figure CN223859846U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the field of agricultural mulching film, especially to a PBAT degradable agricultural mulching film with antibacterial function. BACKGROUND
[0002] Polybutylene adipate terephthalate (PBAT) is a thermoplastic biodegradable plastic, which is a copolymer of butylene adipate and butylene terephthalate. It has biodegradability and can be degraded by microorganisms into water, carbon dioxide and organic matter in the natural environment, reducing environmental pollution. PBAT is commonly used to manufacture biodegradable plastic products such as packaging materials, agricultural films, household items, medical devices, etc. Its characteristics include good processing performance, mechanical properties and replaceability, making it a popular environmentally friendly plastic material. PBAT exhibits good plasticity and heat insulation and moisture retention capacity, good air permeability and light transmittance, etc., providing a huge development space for its application in agricultural films.
[0003] Soil is the basis for crop growth, not only providing nutrients and water, but also a complex ecosystem. There is a delicate balance between the microbial populations in the soil, but when this balance is broken, pathogenic microorganisms can become a threat to crop growth. Pathogenic microorganisms mainly include fungi, bacteria, viruses and nematodes, which exist and reproduce in different ways in the soil. Some pathogenic microorganisms can directly contact the roots of crops through water and soil particles in the soil. They can invade the roots of plants, causing infection and triggering various root diseases such as root rot, damping-off, wilt, etc. These diseases not only affect the healthy growth of plants, reduce crop yield and quality, and in severe cases can even cause crop death. Pathogenic microorganisms have diverse transmission routes, which can be transmitted through soil, water, seeds, farm tools, insects and other means. In suitable environmental conditions, such as temperature, humidity, soil pH and nutrient conditions that meet the needs of pathogenic organisms, they will rapidly reproduce and exacerbate disease development.
[0004] In summary, the threat of soil pathogenic microorganisms to crop health is a problem that needs to be solved in the agricultural field. Changing the structure of PBAT degradable agricultural mulch to provide antibacterial function is also a new attempt. After careful research by the inventors of the present application, it was found that by improving the structure of PBAT mulch through a composite chitosan film layer, PBAT mulch can become an antibacterial mulch that can inhibit the growth and reproduction of crop pathogenic bacteria and reduce the occurrence of root diseases. SUMMARY
[0005] The utility model mainly aims at the problem that the soil pathogenic microorganism constitutes the threat to crop health, provides a PBAT composite degradable agricultural mulching film with antibacterial function, which can not only reduce the spread of pathogenic microorganisms, prolong the service life of the mulching film, improve the crop growth environment, but also reduce the use of pesticides and improve the agricultural production efficiency, and has important significance for realizing the sustainable development and environment-friendly of agricultural production.
[0006] In order to solve the above technical problems, the utility model adopts the following solution: a PBAT degradable agricultural mulching film with antibacterial function is provided, the mulching film comprises a PBAT supporting layer 1, characterized in that: the mulching film further comprises an antibacterial functional layer 2 stacked on the PBAT supporting layer, the antibacterial functional layer 2 comprises a structure composed of cellulose nanofiber and chitosan, the cellulose nanofiber has a diameter of 10-60 nm and an aspect ratio of 50-200, the cellulose nanofiber forms a continuous three-dimensional network in the antibacterial functional layer 2, and a uniform and dense chitosan layer is closely attached in the three-dimensional network.
[0007] The PBAT supporting layer is composed of a single PBAT film, and the antibacterial functional layer 2 is composed of a structure composed of cellulose nanofiber and chitosan in a certain proportion. In the mulching film of the utility model, the cellulose nanofiber has a high aspect ratio and forms a continuous three-dimensional network, and the dissolved chitosan molecules are closely attached to the fiber network to form a uniform and dense layered structure, so that the PBAT degradable agricultural mulching film of the utility model can obtain good antibacterial function.
[0008] As a preferred, the crystallization temperature of the above-mentioned PBAT is 105-110 DEG C, the melting point is 110-140 DEG C, the density is 1.0-1.3 g ml -1 , and the crystallinity is 30%-35%.
[0009] As a preferred, the molecular weight of the above-mentioned chitosan is 100-200 kDa, and the addition amount is 3%-8%.
[0010] As a preferred, the diameter of the above-mentioned cellulose nanofiber is 10-60 nm, the aspect ratio is 50-200, and the crystallinity is 80-95%.
[0011] As a preferred, the thickness of the above-mentioned PBAT supporting layer is 15-20 mu m, and the thickness of the antibacterial functional layer is 5-10 mu m.
[0012] As a preferred, the above-mentioned PBAT supporting layer and antibacterial functional layer are prepared by adopting a layer-by-layer assembly process, and are hot-pressed after preparation at 80-95 DEG C.
[0013] The utility model discloses a beneficial effect: compared with the ordinary PBAT agricultural mulching film on the market, the utility model has excellent degradable performance, heat and moisture retention performance, processability and flexibility, and has excellent antibacterial performance. The chitosan molecule surface has positive charge, can have electrostatic adsorption effect with the negative charge on the bacterial cell wall, thereby changing the permeability of bacterial cell wall, leading to cell material leakage, and then inhibiting bacterial growth. Secondly, chitosan can interact with the phospholipid molecules on the bacterial cell membrane, destroy the integrity of the cell membrane, cause the cell material to leak, and thus inhibit bacterial growth. Moreover, chitosan can also interact with some key enzymes in the bacterial body, such as protease, lipase, etc., thereby affecting the metabolic process of bacteria and inhibiting bacterial growth. In addition, chitosan interacts with DNA, RNA and other nucleic acid molecules of bacteria, affects the expression and transcription process of genes, and thus inhibits bacterial growth. In summary, the antibacterial PBAT degradable composite agricultural mulching film can effectively ensure the visible light transmittance and excellent mechanical properties, effectively inhibit the growth and reproduction of plant pathogenic bacteria, and reduce the occurrence of root diseases. Thus, the growth and development of crops are promoted, the yield and growth quality of crops are improved, and the efficiency of agricultural production can be significantly improved. BRIEF DESCRIPTION OF DRAWINGS
[0014] Figure 1 . It is a PBAT degradable agricultural mulching film with antibacterial function cross section structure schematic diagram, wherein 1 is PBAT support layer;2 is antibacterial function layer
[0015] Figure 2 . It is the surface scanning electron microscope photo of the composite agricultural mulching film according to the utility model, from the drawing, chitosan molecules are uniformly dispersed in the matrix of the whole mulching film.
[0016] Figure 3 . It shows the digital photo of antibacterial test of the agricultural mulching film and the contrast mulching film of the utility model, wherein A graph is the polylactic acid agricultural mulching film according to the utility model, B graph is the commercially available pure PBAT mulching film as a contrast. DETAILED DESCRIPTION
[0017] In order to have a more detailed and intuitive understanding of the utility model, the utility model will be further described below in combination with the drawings and specific embodiments, it is emphasized that the following only describes the preferred embodiments of the utility model, and is not limited to the utility model, and any simple transformation of the utility model belongs to the protection scope of the utility model.
[0018] For example Figure 1As shown, a PBAT degradable agricultural mulch film with antibacterial function comprises a PBAT supporting layer 1 and an antibacterial functional layer 2. The PBAT supporting layer is composed of a single PBAT film, the crystallization temperature of the PBAT is 105-110 DEG C, the melting point is 110-140 DEG C, the density is 1.0-1.3 g / ml -1 , and the crystallinity is 30%-35%.
[0019] The antibacterial functional layer is composed of cellulose nanofiber and antibacterial active substance in proportion. The antibacterial active substance is chitosan, the molecular weight of the chitosan is 100-200 kDa, the adding amount is 3%-8%, the diameter of the cellulose nanofiber is 10-60 nm, the aspect ratio is 50-200, the crystallinity is 80-95%, and the chitosan molecules are uniformly distributed in the cellulose nanofiber film by mechanical mixing assembly.
[0020] Due to the uniform compounding of the antibacterial active substance in the cellulose nanofiber, the layer has excellent antibacterial effect, and in combination with the PBAT supporting layer, the thickness of the overall PBAT supporting layer is 15-20 mu m, the thickness of the antibacterial functional layer is 5-10 mu m, and the two are hot-pressed at 80-95 DEG C.
[0021] Figure 3 The digital photos of the antibacterial test of the agricultural mulch film and the commercially available pure PBAT mulch film of the utility model are shown, wherein the steps of the antibacterial test are as follows: firstly, sterile peptone water of 0.1% is prepared. Then, the sterilized pure cellulose nanofiber mulch film and the chitosan modified composite antibacterial agricultural mulch film are immersed in the pre-prepared 10 mL 0.1% sterile peptone water. After being fully shaken and mixed, the obtained liquid is diluted to an appropriate concentration. Then, the two dispersions are uniformly poured on the corresponding plate surface agar medium. Finally, the culture is carried out at 37 DEG C under visible light for 24 h. The colony distribution of the pure cellulose nanofiber film and the chitosan modified composite antibacterial agricultural mulch film is observed, so that the antibacterial performance of the chitosan modified composite film is verified. The results show that the antibacterial agricultural mulch film modified by chitosan has excellent antibacterial effect.
[0022] In conclusion, the utility model provides a PBAT degradable agricultural mulch film with antibacterial function. By changing the composite layer structure of the PBAT degradable composite agricultural mulch film, and by controlling the fine structure of the composite antibacterial functional layer, the visible light transmittance, excellent mechanical properties and processability can be effectively guaranteed, and the agricultural mulch film also has excellent antibacterial performance, can effectively inhibit the growth and reproduction of plant pathogenic bacteria, and reduce the occurrence of root diseases. Thus, the growth and development of crops are promoted, the yield and growth quality of crops are improved, and the efficiency of agricultural production can be significantly improved.
Claims
1. A PBAT degradable agricultural mulching film with antibacterial function, the mulching film comprising a polybutylene adipate terephthalate (PBAT) support layer (1), characterized in that: The mulch film further comprises an antibacterial functional layer (2) laminated on the support layer (1), the antibacterial functional layer (2) comprising a continuous three-dimensional network formed by cellulose nanofibers with a diameter of 10-60 nm and an aspect ratio of 50-200, and a uniform and dense chitosan layer closely attached in the three-dimensional network.
2. The PBAT degradable agricultural mulching film with antibacterial function according to claim 1, characterized in that The chitosan layer wraps the three-dimensional network.
3. The PBAT degradable agricultural mulching film with antibacterial function according to claim 1, characterized in that The antibacterial functional layer (2) is directly laminated on the PBAT support layer (1).
4. The PBAT degradable agricultural mulching film with antibacterial function according to claim 3, characterized in that There is no adhesive layer between the PBAT support layer (1) and the antibacterial functional layer (2).
5. The PBAT degradable agricultural mulch film with antibacterial function according to claim 1, characterized in that The thickness of the PBAT support layer (1) is 15-20 μm, and the thickness of the antibacterial functional layer (2) is 5-10 μm.