Pbat-based fully biodegradable mulching film and preparation method and application thereof
By developing a method for preparing composite materials such as PBAT with ultrafine hemp fiber powder and PLA, the problems of high cost and insufficient performance of PBAT-based fully biodegradable mulch film have been solved, achieving controllable degradation and multifunctionality of the mulch film, and improving the effect of flue-cured tobacco planting.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- INST OF BAST FIBER CROPS CHINESE ACADEMY OF AGRI SCI
- Filing Date
- 2026-06-01
- Publication Date
- 2026-07-24
Smart Images
Figure CN122445147A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of mulch film processing technology, specifically to a PBAT-based fully biodegradable mulch film, its preparation method, and its application. Background Technology
[0002] Mulching technology is an indispensable key cultivation technique in flue-cured tobacco planting. This technology effectively optimizes the light, heat, water, and fertilizer conditions of tobacco field soil by covering it with mulch. Specifically, it achieves the effects of soil moisture retention, increased soil temperature, suppression of weed growth, and reduction of pests and diseases. It not only shifts the critical latitude of flue-cured tobacco planting areas northward and raises the altitude, enabling stable tobacco yields in heat-deficient regions such as Northeast China and the Yunnan-Guizhou Plateau, but also reduces field management inputs and significantly improves tobacco yield and quality. Statistics show that mulched tobacco fields can increase yield by more than 10% and output value by 20% compared to unmulched fields.
[0003] Currently, the mulch films used in flue-cured tobacco cultivation are mainly divided into two categories: traditional polyethylene (PE) mulch films and fully biodegradable mulch films. Among them, traditional polyethylene mulch films are still the most widely used type of mulch film in flue-cured tobacco cultivation due to their low cost, excellent mechanical properties, and stable covering effect. Its material is mainly polyethylene.
[0004] With the increasing demands for green agriculture and ecological environmental protection, fully biodegradable mulch films are gradually being used in tobacco-growing areas. The core requirement is compliance with the standard "Fully Biodegradable Agricultural Ground Cover Film" (GB / T 35795—2017). These films must be able to completely degrade through microbial action in the natural environment, ultimately decomposing into water and carbon dioxide, eliminating the need for manual recycling. After tobacco harvesting, they can be directly plowed into the soil, avoiding residual film pollution. Currently, commonly used fully biodegradable mulch film substrates mainly include polybutylene adipate / terephthalate (PBAT), polylactic acid (PLA), and polypropylene carbonate (PPC). Among these, PBAT, due to its excellent flexibility, extensibility, and biodegradability, has become one of the mainstream substrates for fully biodegradable mulch films and has been used in demonstration studies for crops such as chili peppers, garlic, tomatoes, and flue-cured tobacco.
[0005] Tobacco cultivation places specific requirements on the performance of mulch film: On the one hand, tobacco has a long growing season, and the mulching period is usually 45-60 days. The mulch film needs to maintain good mechanical properties during its service life to avoid premature damage and ensure the stable performance of moisture retention, temperature increase, and weed control. On the other hand, tobacco fields are often treated with deep plowing and fertilization, so the mulch film needs to have a certain degree of puncture resistance to adapt to debris such as gravel and crop residues in the soil. At the same time, it needs to match the tobacco growth cycle and be able to degrade quickly after the tobacco leaves are harvested to avoid residual film contamination of the soil, which would affect subsequent crop planting and soil physicochemical properties.
[0006] While existing PBAT-based fully biodegradable mulch films have solved the core problem of the non-degradability of traditional polyethylene mulch films, they still have significant shortcomings: First, the cost is high; currently, PBAT composite mulch films cost 30-50% more than polyethylene mulch films. Second, their functions are relatively limited, only achieving basic functions such as moisture retention, temperature increase, and weed control. They cannot utilize the advantages of natural biomass materials to improve soil physical and chemical properties, nor can they further enhance the quality of flue-cured tobacco. Third, their mechanical properties are still lacking; pure PBAT-based mulch films have limited puncture resistance and tensile strength, making them prone to damage in tobacco fields with gravel and crop residues, affecting the mulching effect. Fourth, the controllability of the degradation rate is poor; the degradation rate of a single PBAT substrate is greatly affected by environmental factors such as soil temperature and humidity, and microbial content, making it difficult to accurately match the growth cycle of flue-cured tobacco, and in some cases, the mulch film may degrade prematurely or incompletely.
[0007] How to reduce costs while ensuring mechanical performance is a technical problem that existing technologies need to solve. Summary of the Invention
[0008] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a PBAT-based fully biodegradable mulch film, its preparation method and application, thereby solving the technical problem of how to ensure mechanical performance while reducing costs in the prior art.
[0009] To achieve the above-mentioned technical objectives, the present invention provides a PBAT-based fully biodegradable mulch film, which is made from the following raw materials in parts by weight: 70-85 parts PBAT, 5-10 parts ultrafine hemp fiber powder, 5-10 parts PLA, 2-5 parts plasticizer, and 0.5-2 parts anti-aging agent.
[0010] In any embodiment, the particle size of the ultrafine hemp fiber powder is 1500 mesh or larger.
[0011] In any embodiment, the ultrafine hemp fiber powder is obtained by crushing hemp stalks into small particles of less than 0.5 cm and then pulverizing them using an air jet mill.
[0012] In any embodiment, the plasticizer is dibutyl phthalate.
[0013] In any embodiment, the anti-aging agent is a hindered phenol.
[0014] In any embodiment, the thickness of the PBAT-based fully biodegradable mulch film is 0.008-0.015 mm; and / or, the density of the PBAT-based fully biodegradable mulch film is 0.8~1.0 g / cm³. 3 .
[0015] In any embodiment, the PBAT-based fully biodegradable mulch film is transparent, black, or a black and white color scheme.
[0016] In any embodiment, it also includes 1-2 parts of carbon black and / or 5-10 parts of black masterbatch.
[0017] Furthermore, this invention also proposes a method for preparing the above-mentioned PBAT-based fully biodegradable mulch film, comprising the following steps:
[0018] The raw materials are mixed, then melt-blended and granulated at 150-170°C, and then blow-molded to obtain the final product.
[0019] In addition, the present invention also proposes an application of the above-mentioned PBAT-based fully biodegradable mulch film in flue-cured tobacco planting.
[0020] Compared with the prior art, the beneficial effects of the present invention include: The PBAT-based fully biodegradable mulch film proposed in this invention is made from the following raw materials by weight percentage: 70%-85% PBAT, 5%-10% ultrafine hemp fiber powder, 5%-10% PLA, 2%-5% plasticizer, and 0.5%-2% anti-aging agent. This PBAT-based fully biodegradable mulch film, through the combination of ultrafine hemp fiber powder and PBAT, and the coordination of other components, achieves a reduction in mulch film density while ensuring mulch film strength, reducing costs by 18%-25% compared to existing PBAT-based mulch films, thereby achieving both mulch film strength and cost reduction. Attached Figure Description
[0021] Figure 1 This is a photograph of the mulch film prepared in Example 1 of the present invention.
[0022] Figure 2 These are performance test results of the mulch films prepared in Embodiment 1, Comparative Example 1, and Comparative Example 2 of the present invention.
[0023] Figure 3 This is a photograph of the mulch film used for tobacco planting according to Embodiment 1 of the present invention. Detailed Implementation
[0024] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for a specific parameter, it is also expected that ranges of 60~110 and 80~120 are also included. Furthermore, if minimum range values of 1 and 2 are listed, and if maximum range values of 3, 4, and 5 are listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this application, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.
[0025] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.
[0026] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).
[0027] This specific embodiment provides a PBAT-based fully biodegradable mulch film, made from the following raw materials in parts by weight: 70-85 parts PBAT, 5-10 parts ultrafine bast fiber powder, 5-10 parts PLA, 2-5 parts plasticizer, and 0.5-2 parts anti-aging agent; the ultrafine bast fiber powder has a particle size of 1500 mesh or larger; the plasticizer is dibutyl phthalate; the anti-aging agent is hindered phenol; the thickness of the PBAT-based fully biodegradable mulch film is 0.008-0.015 mm; and the density of the PBAT-based fully biodegradable mulch film is 0.8-1.0 g / cm³. 3 .
[0028] In some embodiments, the ultrafine hemp fiber powder is obtained by pulverizing hemp stalks into particles smaller than 0.5 cm using an air jet mill. The hemp stalks are one or more of ramie, industrial hemp, Apocynum venetum, kenaf, and jute.
[0029] In some embodiments, the PBAT-based fully biodegradable mulch film is transparent, black, or black and white.
[0030] In some embodiments, it further includes 1-2 parts carbon black and / or 5-10 parts black masterbatch.
[0031] Furthermore, this specific embodiment also proposes a method for preparing the above-mentioned PBAT-based fully biodegradable mulch film, including the following steps:
[0032] The raw materials are mixed, then melt-blended and granulated at 150-170°C, and then blow-molded to obtain the final product.
[0033] Furthermore, this specific embodiment also proposes an application of the above-mentioned PBAT-based fully biodegradable mulch film in flue-cured tobacco planting.
[0034] The PBAT in this invention is a polybutylene adipate-butylene terephthalate copolymer, a biodegradable polymer material with good processing and degradation properties.
[0035] PLA: Polylactic acid, a biodegradable polymer material prepared from renewable plant resources, has high mechanical strength and thermal insulation properties.
[0036] Light transmittance: refers to the percentage of light that the mulch film allows to pass through, expressed as a percentage, and is a key indicator affecting weed control.
[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0038] In this invention, the terms "some embodiments," "this embodiment," and examples are used to describe a subset of all possible embodiments. However, it is understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with each other without conflict.
[0039] If the application documents contain similar descriptions such as "first / second", the following explanation shall be added: In the following description, the terms "first / second / third" are used only to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.
[0040] In this embodiment, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, object A and / or object B can represent three situations: object A exists alone, object A and object B exist simultaneously, and object B exists alone.
[0041] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.
[0042] In the following embodiments, the ultrafine hemp fiber powder is made by crushing ramie stalks into small particles of less than 0.5 cm, and then using an air jet mill to pulverize it to a fineness of more than 1500 mesh.
[0043] Example 1
[0044] This embodiment proposes a PBAT-based fully biodegradable mulch film (i.e., hemp-based mulch film), which is a black and white alternating structure. The black part of the mulch film is made from the following raw materials in parts by weight: 85 parts PBAT, 5 parts ultrafine hemp fiber powder, 5 parts PLA, 2 parts plasticizer, 1 part anti-aging agent, and 2 parts carbon black. The white part of the mulch film is made from the following raw materials in parts by weight: 85 parts PBAT, 5 parts ultrafine hemp fiber powder, 5 parts PLA, 2 parts plasticizer, and 1 part anti-aging agent. The particle size of the ultrafine hemp fiber powder is 1500 mesh or larger. The plasticizer is dibutyl phthalate. The anti-aging agent is Irganox 1010.
[0045] This embodiment also proposes a method for preparing the above-mentioned PBAT-based fully biodegradable mulch film, including the following steps:
[0046] The raw materials are mixed, then melt-blended and granulated at 160°C, and finally blow-molded according to existing technology to obtain the mulch film. Figure 1 The mulch film has a black and white alternating structure, with the white part in the middle being 25cm wide and the black parts on both sides being 27.5cm wide.
[0047] The thickness of the PBAT-based fully biodegradable mulch film obtained in this embodiment is 0.008-0.09 mm.
[0048] Example 2
[0049] This embodiment proposes a PBAT-based fully biodegradable mulch film with a black and white alternating structure. The black portion of the mulch film is made from the following raw materials in parts by weight: 78 parts PBAT, 8 parts ultrafine bast fiber powder, 8 parts PLA, 2 parts plasticizer, 1 part anti-aging agent, and 1 part black masterbatch. The white portion of the mulch film is made from the following raw materials in parts by weight: 78 parts PBAT, 8 parts ultrafine bast fiber powder, 8 parts PLA, 2 parts plasticizer, and 1 part anti-aging agent. The particle size of the ultrafine bast fiber powder is 1500 mesh or larger. The plasticizer is dibutyl phthalate. The anti-aging agent is hindered phenol.
[0050] This embodiment also proposes a method for preparing the above-mentioned PBAT-based fully biodegradable mulch film, including the following steps:
[0051] The raw materials are mixed, then melt-blended and granulated at 150°C, and then blow-molded according to existing technology to obtain a black and white alternating structure mulch film.
[0052] The thickness of the PBAT-based fully biodegradable mulch film obtained in this embodiment is 0.01-0.012 mm.
[0053] Example 3
[0054] This embodiment proposes a PBAT-based fully biodegradable mulch film with a black and white alternating structure. The black portion of the mulch film is made from the following raw materials in parts by weight: 75 parts PBAT, 10 parts ultrafine bast fiber powder, 10 parts PLA, 2 parts plasticizer, 2 parts anti-aging agent, and 1 part carbon black. The white portion of the mulch film is made from the following raw materials in parts by weight: 75 parts PBAT, 10 parts ultrafine bast fiber powder, 10 parts PLA, 2 parts plasticizer, and 2 parts anti-aging agent. The ultrafine bast fiber powder has a particle size of 1500 mesh or larger. The plasticizer is dibutyl phthalate. The anti-aging agent is Irganox 1076.
[0055] This embodiment also proposes a method for preparing the above-mentioned PBAT-based fully biodegradable mulch film, including the following steps:
[0056] The raw materials for the mulch film are mixed, then melt-blended and granulated at 170°C, and finally blow-molded according to existing technology to obtain a mulch film with a black and white alternating structure.
[0057] The thickness of the PBAT-based fully biodegradable mulch film obtained in this embodiment is 0.012-0.013 mm.
[0058] Comparative Example 1
[0059] The difference between the mulch film (i.e., bamboo base film) in this comparative example and Example 1 is that an equal amount of bamboo powder is used to replace the ultrafine hemp fiber powder in Example 1, and the particle size of the bamboo powder is above 1500 mesh.
[0060] The preparation method of the mulch film in this comparative example is the same as that in Example 1.
[0061] Comparative Example 2
[0062] The difference between the mulch film (i.e., PBAT mulch film) in this comparative example and Example 1 is that no ultrafine hemp fiber powder was added, and the ultrafine hemp fiber powder in Example 1 was replaced with an equal amount of PBAT.
[0063] The preparation method of the mulch film in this comparative example is the same as that in Example 1.
[0064] The density and strength data of each embodiment and comparative example are shown in Table 1.
[0065] Table 1
[0066]
[0067] From Table 1 and Figure 2 It can be seen that the mulch film proposed in this invention has a low density but high strength.
[0068] Application Example 1
[0069] Combination Figure 3 The plastic film used in Example 1, Comparative Example 1, and Comparative Example 2 was applied to tobacco cultivation, as follows:
[0070] ① Area selection: Select tobacco-growing areas with flat terrain, loose soil structure, good water source conditions, convenient irrigation and drainage, and few weeds;
[0071] ② Land preparation and ridging: Before laying the film, remove residual crops, large clods of soil and stones from the tobacco field, keep the soil fine and flat, the ridge surface clean, the ridges straight and the furrows flat, and the ridges full, to avoid premature damage to the film during the laying process;
[0072] ③ Fertilizer application: Organic fertilizers should be applied to the soil in advance to avoid direct contact with the mulch film, which could lead to premature degradation of the mulch film;
[0073] ④ Mulching: Use a conventional mulching machine to lay the film. Lay it flat naturally during mulching. Do not pull it forcefully. Make it fit the soil bed appropriately and avoid longitudinal tension. In areas with strong winds, cover the ridge surface with a small amount of soil every 2-3 meters.
[0074] ⑤ Water and fertilizer irrigation: In tobacco-growing areas with irrigation conditions, the irrigation frequency and amount can be increased appropriately. Try to avoid long-term contact between the mulch film and the drip irrigation tape, and bury the drip irrigation tape shallowly to a depth of 1-2 cm in the soil.
[0075] ⑥ Transplanting time: The time interval between mulching and transplanting should be controlled within 15 days, and ideally, mulching and transplanting should be synchronized.
[0076] ⑦ Field management: If the film surface is damaged prematurely during the planting process, cover it with soil in time to slow down the rate of damage;
[0077] ⑧ Degradation treatment: After the tobacco leaves are harvested, there is no need to recycle the mulch film. Instead, it is directly plowed into the soil, where soil microorganisms promote its degradation and eventually integrate it into the soil, increasing soil organic matter.
[0078] The nicotine and potassium content of the tobacco leaves obtained from the planting were tested, and the results are shown in Table 2.
[0079] Table 2
[0080]
[0081] As can be seen from Table 2, the mulch film of Example 1 of the present invention can significantly reduce the nicotine content and increase the potassium content.
[0082] The mulch film proposed in this invention, through adjusting the ratio of PBAT to PLA and adding ultrafine hemp fiber powder, controls the degradation cycle of the mulch film to about 60 days. It cracks approximately 30 days after mulching, gradually degrades after tobacco harvest, and completely decomposes within 6 months, leaving no residual film. This ensures that the mulch film fully performs its weed-control, heat-preserving, and moisture-retaining functions during the tobacco growing season. In contrast, the mulch film of Comparative Example 1 cracks approximately 40 days after mulching, gradually degrades after tobacco harvest, and completely decomposes within 6 months; the mulch film of Comparative Example 2 cracks approximately 25 days after mulching and completely decomposes within 6 months. It is evident that premature or delayed cracking of the mulch film is detrimental to reducing nicotine and increasing potassium content.
[0083] Other beneficial effects:
[0084] 1. Significantly reduced cost: The production cost of the mulch film of this invention is 18%-25% lower than that of the existing PBAT base film, and close to that of traditional PE mulch film, which can be promoted and applied on a large scale.
[0085] 2. Multifunctional integration: It has four functions at the same time: weed control, heat preservation and moisture retention, environmental degradation and tobacco quality optimization. It eliminates the need for additional herbicides, reduces chemical pollution, and meets the comprehensive needs of high-quality and green flue-cured tobacco production.
[0086] 3. Significant weed control effect: The light transmittance of the black part is less than 10%, which can effectively inhibit the photosynthesis of weeds, reduce the growth of weeds, reduce the competition of weeds for nutrients with flue-cured tobacco, and ensure the growing space of flue-cured tobacco;
[0087] 4. Excellent heat preservation performance: The white part can increase the soil temperature, promote early and rapid growth of flue-cured tobacco, and enhance the resistance of tobacco plants to adverse conditions;
[0088] 5. Improved tobacco quality: By adjusting the chemical composition of tobacco leaves, the nicotine content of C3F tobacco leaves is brought closer to the premium standard, and the potassium content is increased to 3.67%, thereby improving the intrinsic quality of tobacco leaves and enhancing the economic value of flue-cured tobacco.
[0089] 6. Reliable environmental performance: The degradation cycle is controllable, and the tobacco is completely degraded within 6 months after harvest, leaving no residual film pollution, which meets the requirements of sustainable agricultural development.
[0090] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.
Claims
1. A PBAT-based fully biodegradable mulch film, characterized in that, It is made from the following raw materials in parts by weight: 70-85 parts PBAT, 5-10 parts ultrafine hemp fiber powder, 5-10 parts PLA, 2-5 parts plasticizer and 0.5-2 parts anti-aging agent.
2. The PBAT-based fully biodegradable mulch film according to claim 1, characterized in that, The particle size of the ultrafine hemp fiber powder is above 1500 mesh.
3. The PBAT-based fully biodegradable mulch film according to claim 2, characterized in that, The ultrafine hemp fiber powder is obtained by crushing hemp stalks into small particles of less than 0.5 cm and then pulverizing them using an air jet mill.
4. The PBAT-based fully biodegradable mulch film according to claim 1, characterized in that, The plasticizer is dibutyl phthalate.
5. The PBAT-based fully biodegradable mulch film according to claim 1, characterized in that, The anti-aging agent is a hindered phenol.
6. The PBAT-based fully biodegradable mulch film according to claim 1, characterized in that, The thickness of the PBAT-based fully biodegradable mulch film is 0.008-0.015 mm; and / or, the density of the PBAT-based fully biodegradable mulch film is 0.8~1.0 g / cm³. 3 .
7. The PBAT-based fully biodegradable mulch film according to claim 1, characterized in that, The PBAT-based fully biodegradable mulch film is available in transparent, black, or black and white color schemes.
8. The PBAT-based fully biodegradable mulch film according to claim 1, characterized in that, It also includes 1-2 parts carbon black and / or 5-10 parts black masterbatch.
9. A method for preparing a PBAT-based fully biodegradable mulch film according to any one of claims 1-8, characterized in that, Includes the following steps: The raw materials are mixed, then melt-blended and granulated at 150-170°C, and then blow-molded to obtain the final product.
10. The application of the PBAT-based fully biodegradable mulch film according to any one of claims 1-8 in flue-cured tobacco cultivation.