Degradable mulching film for rice and preparation method thereof

Abstract

The invention relates to the field of degradable mulching films, and particularly discloses a degradable mulching film for rice and a preparation method of the degradable mulching film. The degradable mulching film for rice comprises the following substances in percentage by mass: 0-65% of PBAT (poly (butylene adipate-co-terephthalate)); 20-25% of PPC (polypropylene carbonate); 3-5% of black master batch; 1-2% of a hydrolysis-resistant auxiliary agent; the hydrolysis-resistant auxiliary agent comprises a haplotype carbodiimide hydrolysis-resistant agent or a polymeric carbodiimide hydrolysis-resistant agent. The preparation method comprises the following steps: S1, drying the raw materials; s2, preparing the mulching film. The mulching film can be used for paddy fields, and has the advantages of excellent hydrolysis resistance, excellent weather resistance, biodegradability, high water vapor barrier property and the like.

Description

Technical Field

[0001] The present application relates to the technical field of degradable mulch films, and more specifically, to a degradable mulch film for rice and a preparation method thereof. Background Art

[0002] After meeting the needs of crop growth, biodegradable mulch should be able to be decomposed by microorganisms in the environment and eventually become water and carbon dioxide, thereby solving the pollution of residual film in farmland. Biodegradable mulch is usually required to have the following properties: (1) It cannot degrade during the crop growth cycle (more than 120 days); (2) It can eventually be decomposed by microorganisms; (3) It has water vapor barrier properties and the ability to retain moisture and increase soil moisture.

[0003] At present, most biodegradable mulch films can be biodegraded, but when used in rice fields, due to the high water content in the rice fields, the degradable mulch films are more easily hydrolyzed, resulting in the film being unable to be used continuously during the rice growth cycle, that is, the mulch films are more easily hydrolyzed, resulting in poor weather resistance. Summary of the invention

[0004] In order to improve the defects of mulch films that are easily hydrolyzed and have poor weather resistance, the present application provides a degradable mulch film for rice and a preparation method thereof.

[0005] The present application provides a degradable rice mulch film, which adopts the following technical solution:

[0006] In a first aspect, the present application provides a degradable mulch film for rice, comprising the following substances in percentage by mass:

[0007] PBAT 60-65%;

[0008] PPC 20-25%;

[0009] Black masterbatch 3-5%;

[0010] Hydrolysis resistance additive 1-2%;

[0011] The anti-hydrolysis agent includes a monomeric carbodiimide anti-hydrolysis agent or a polymeric carbodiimide anti-hydrolysis agent.

[0012] By adopting the above technical scheme, PBAT (polybutylene adipate-terephthalate) has good ductility, heat resistance, processability, fast degradation rate, and less residue, which can make the ground film obtain better heat resistance. PPC (polypropylene carbonate) has good flexibility, barrier properties and biocompatibility. Therefore, in this application, PBAT and PPC are preferably used as the base material of the ground film. The addition of PPC forms an island phase in PBAT. During the film blowing process, a larger area of ​​PPC sheet is formed, thereby improving the water vapor barrier performance and weather resistance of the ground film. The ground film in this application has excellent moisture retention performance and water-saving effect, and can eventually be degraded into carbon dioxide and water in the natural environment. It is green and pollution-free and is not easy to affect the sowing of the next season, and it also saves the cost of ground film recycling.

[0013] The amount of PPC added is optimized. At an appropriate amount, the ground film can obtain excellent water vapor barrier properties and mechanical strength.

[0014] Adding black masterbatch to the mulch film makes it black, which effectively inhibits the growth of weeds in the rice field and promotes the growth of rice.

[0015] It is preferred to use a polymeric carbodiimide anti-hydrolysis agent or a polymeric carbodiimide anti-hydrolysis agent as the hydrolysis resistance aid. The organic carbodiimide compound can react the decomposed carboxyl group with the carbodiimide group, thereby preventing the mulch from further degradation and effectively improving the hydrolysis resistance and weather resistance of the mulch.

[0016] Optionally, fillers are also included, and the fillers include straw powder, layered montmorillonite and wool powder.

[0017] By adopting the above technical solution, straw powder is added to the mulch film, and the fiber structure of the straw powder can increase the density of the mulch film and improve the water vapor barrier effect of the mulch film. At the same time, as the straw powder degrades in the environment, it can effectively increase the content of alkaline nitrogen, available phosphorus and available potassium, increase the richness of soil bacteria and the content of Bacillus subtilis, improve soil vitality, reduce the occurrence of rice sheath blight, and is beneficial to the growth of rice.

[0018] The unique layered structure of layered montmorillonite can be firmly bonded to the ground film substrate, and can give the ground film an excellent water vapor barrier effect, hinder ultraviolet radiation, and thus improve the weather resistance of the ground film.

[0019] The addition of wool powder can introduce fiber structure into the mulch film, and can cooperate with straw powder to build a fiber network structure, effectively enhancing the density of the mulch film. In addition, wool powder contains amino acid groups, which can cross-link with other components in the mulch film and transform into nitrogen fertilizer during the degradation process, thereby improving soil vitality and saving fertilization costs.

[0020] Through the combination of straw powder, layered montmorillonite and wool powder, the layered montmorillonite can be loaded on the network formed by the fiber structure, increasing the bonding effect between the fiber structure and the ground film, effectively improving the density of the ground film and the water vapor barrier effect, and making the ground film have excellent weather resistance.

[0021] Optionally, the filler is a filler modified by a silane coupling agent.

[0022] By adopting the above technical scheme, the filler is modified by a silane coupling agent, and the silane coupling agent is used to react with the hydroxyl group on the filler to reduce the polarity between the fillers, thereby improving the dispersion effect of the filler and the compatibility between the filler and the ground film, so that the filler can be evenly dispersed in the ground film, and the mechanical properties and water vapor barrier effect of the ground film can be stably enhanced.

[0023] Optionally, the straw powder is straw powder that has been esterified with an esterifying agent.

[0024] By adopting the above technical solution, the straw micropowder is modified by an esterifying agent, and the esterifying agent can combine with the reducing sugar in the straw micropowder, introduce a benzene ring structure on the surface of the straw micropowder, so that the straw micropowder has better hydrophobicity, thereby improving the hydrolysis resistance of the mulch film. At the same time, the combination of the esterifying agent and the straw micropowder can increase the roughness of the surface of the straw micropowder, effectively improve the bonding effect between the straw micropowder and the mulch film, and reduce the possibility of the straw micropowder generating continuous pores in the mulch film, that is, improve the water vapor barrier effect of the mulch film.

[0025] Optionally, carbendazim is loaded on the layered montmorillonite.

[0026] By adopting the above technical scheme, the interlayer spaces of the layered montmorillonite are utilized to load the carbendazim. As the mulch film contacts the water in the rice field, the carbendazim loaded in the montmorillonite is slowly released to kill or inhibit pathogens, thereby improving the growth effect of rice.

[0027] Optionally, the layered montmorillonite is loaded with tea tree essential oil and glycerin.

[0028] By adopting the above technical scheme, tea tree essential oil has a better antibacterial effect. When added to the ground film, it can effectively improve the antibacterial effect of the ground film, and the tea tree essential oil can migrate to the surface of the ground film to obtain an oil layer on the surface of the ground film, further improving the antibacterial effect and hydrophobicity of the ground film. Glycerol can be used as a plasticizer to improve the combination effect of PBAT and PPC in the ground film, and glycerol and tea tree essential oil can migrate to the surface of the ground film over time, so that an oil layer is formed on the surface of the ground film, improving the hydrophobic effect of the ground film. At the same time, tea tree essential oil and glycerol can drive carbendazim to migrate to the surface of the ground film synchronously to form a hydrophobic antibacterial layer. After water contacts the surface of the ground film, it is difficult to adhere to the surface of the ground film. Carbendazim can also be transferred to the soil to inhibit or kill pathogens in the soil, which is beneficial to the growth of rice.

[0029] Optionally, the wool powder is surface-treated wool powder.

[0030] Optionally, the surface treatment includes the following steps: placing the wool powder in an ultraviolet irradiation device, subjecting the wool to ultraviolet irradiation treatment to obtain ultraviolet treated wool, placing the ultraviolet treated wool in a hydrogen peroxide solution, subjecting the wool to immersion treatment to obtain surface treated wool powder.

[0031] By adopting the above technical scheme, the wool micropowder is treated with ultraviolet radiation and hydrogen peroxide in turn. Ultraviolet radiation and hydrogen peroxide can remove the cell membrane and vesicles on the surface of the wool, increase the roughness of the surface of the wool micropowder, and improve the roughness of the fiber network, so that the fiber network can be firmly combined with the ground film, reduce the number of through pores, and improve the water vapor barrier effect and mechanical properties of the ground film.

[0032] Optionally, the surface treatment further comprises the following steps: immersing the wool micropowder treated with hydrogen peroxide in silica sol, filtering, and drying to obtain the surface-treated wool micropowder.

[0033] By adopting the above technical solution, the active sites on the surface of wool micropowder treated with ultraviolet radiation and hydrogen peroxide are increased, so that the silica sol can be firmly loaded on the surface of the wool micropowder, and then a micro-nano rough structure is constructed on the surface of the wool fiber, further improving the roughness of the wool fiber, improving the bonding effect between the wool micropowder and the ground film, and also improving the hydrophobicity of the wool micropowder, thereby further improving the hydrolysis resistance of the ground film, so that the ground film has better mechanical properties and weather resistance. In addition, the introduction of silicon dioxide can further increase the density of the ground film, improve the mechanical properties and water resistance of the ground film.

[0034] In a second aspect, the present application provides a method for preparing a degradable mulch film for rice, which adopts the following technical solution:

[0035] A method for preparing a degradable rice mulch film comprises the following steps:

[0036] S1. Raw material drying: PBAT and PPC are vacuum dried to obtain dry PBAT and dry PPC;

[0037] S2. Preparation of ground film: PBAT, PPC, black masterbatch and hydrolysis resistance additive are mixed, extruded at 110-170°C, granulated, dried, and blow-molded at 110-160°C to obtain ground film.

[0038] In summary, this application has the following beneficial effects:

[0039] 1. Since the present application adopts PBAT and PPC as the base material of the ground film, the addition of PPC forms an island phase in PBAT. During the film blowing process, a larger area of ​​PPC sheet is formed, thereby improving the water vapor barrier performance and weather resistance of the ground film, so that the ground film has excellent moisture retention and water-saving effects, and can eventually be degraded into carbon dioxide and water in a natural environment. It is green and pollution-free and is not easy to affect the sowing of the next season, and it also saves the cost of recycling the ground film. Adding black masterbatch to the ground film makes the ground film black in color, effectively inhibits the growth of weeds in rice fields, and promotes rice growth. The carbodiimide in the hydrolysis-resistant agent can react with the decomposed carboxyl group to hinder the further degradation of the ground film, thereby improving the hydrolysis resistance of the ground film.

[0040] 2. In the present application, it is preferred to add straw powder to the ground film. The fiber structure of the straw powder can increase the density of the ground film and improve the water vapor barrier effect of the ground film. At the same time, as the straw powder degrades in the environment, it can effectively increase the content of alkaline nitrogen, available phosphorus and available potassium, increase the richness of soil bacteria and increase the content of Bacillus subtilis, improve soil vitality, reduce the occurrence of rice sheath blight, and be beneficial to the growth of rice. Through the combination of straw powder, layered montmorillonite and wool powder, the layered montmorillonite can be loaded on the network formed by the fiber structure, increase the combination effect of the fiber structure and the ground film, effectively improve the density of the ground film and the water vapor barrier effect, so that the ground film obtains excellent weather resistance.

[0041] 3. In the present application, both glycerol and tea tree essential oil can migrate to the surface of the mulch film over time, thereby forming an oil layer on the surface of the mulch film and improving the hydrophobic effect of the mulch film. At the same time, tea tree essential oil and glycerol can drive carbendazim to migrate to the surface of the mulch film synchronously to form a hydrophobic antibacterial layer. After water contacts the surface of the mulch film, it is difficult to adhere to the surface of the mulch film, and carbendazim can be transferred to the soil to inhibit or kill pathogens in the soil, which is beneficial to the growth of rice. DETAILED DESCRIPTION

[0042] The present application is further described in detail below with reference to the embodiments.

[0043] Preparation Example

[0044] Preparation example of straw micro powder

[0045] Preparation Example 1

[0046] Weigh 30g of straw powder and dissolve it in the aqueous solution, then pour it into a container. Add sodium hydroxide solution to the container, so that the amount of sodium hydroxide added is 3.5%. Measure 5mL of benzoyl chloride and slowly add it dropwise to the container, and react at 25℃ for 1h. After the reaction is completed, naturally cool to room temperature and filter, and wash with anhydrous ethanol several times until the filtrate is transparent and the pH is neutral. Dry it in a vacuum at 60℃ and crush it to obtain modified straw micropowder.

[0047] Preparation example of layered montmorillonite

[0048] Preparation Example 2

[0049] The layered montmorillonite was immersed in a carbendazim solution with a concentration of 200 mg / mL, shaken at 25° C. for 24 hours, filtered, and dried to obtain the modified layered montmorillonite.

[0050] Preparation Example 3

[0051] The modified layered montmorillonite prepared in Preparation Example 2, tea tree essential oil and glycerin were mixed in a mass ratio of 5:0.5:2 to obtain a secondary modified layered montmorillonite.

[0052] Preparation example of wool micro powder

[0053] Preparation Example 4

[0054] The wool powder was placed in a container and placed in an ultraviolet irradiation instrument, irradiated at 100W for 10 minutes, stirred every 2 minutes, and ultraviolet irradiated wool was obtained. The ultraviolet irradiated wool was immersed in a 5% by mass hydrogen peroxide solution for 30 minutes to obtain modified wool powder.

[0055] Preparation Example 5

[0056] The modified wool micropowder and silica sol with a mass fraction of 10% are mixed at a solid-liquid ratio of 1:30, filtered, and dried to obtain the surface-treated wool micropowder.

[0057] Example

[0058] Examples 1-3

[0059] On the one hand, the present application provides a degradable mulch film for rice, including PBAT, PPC, black masterbatch, hydrolysis-resistant additives and additives, and the specific qualities are shown in the table below.

[0060] Among them, PBAT is PBAT of Xinjiang Blue Mountain Tunhe Chemical TH801T brand, and PPC is a melt flow rate of 12.7g (10min) -1，The black masterbatch is the biodegradable black masterbatch from Dongguan Jinsuyan Plastic Technology Co., Ltd., and the hydrolysis-resistant additive is 2,6-diisopropylbenzene carbodiimide from Shanghai Rhein Chemical Co., Ltd.; the additives include antioxidant B225 of equal quality and chain extender ADR4400 from BASF of Germany.

[0061] In another aspect, the present application provides a method for preparing a degradable rice mulch film, comprising the following steps:

[0062] S1. Raw material drying: PBAT is vacuum dried at 60°C and PPC is vacuum dried at 40°C to obtain dry PBAT and dry PPC;

[0063] S2. Preparation of ground film: PBAT, PPC, black masterbatch and hydrolysis resistance additive are mixed, extruded at 150°C, granulated, dried, and blow-molded at 145°C to obtain ground film.

[0064] Table 1 Composition of mulch films in Examples 1-3

[0065] Mass percentage / % Example 1 Example 2 Example 3 PBAT 60 62 65 PPC 20 22 25 Black Masterbatch 3 4 5 Hydrolysis resistance additives 1 1 2 Additives 2 2 3

[0066] Example 4

[0067] The difference from Example 1 is that this embodiment further includes a filler with a mass fraction of 5%, and the filler includes straw powder, layered montmorillonite and wool powder in a mass ratio of 2.5:2:0.5.

[0068] Example 5

[0069] The difference from Example 1 is that this example further includes a modified filler with a mass fraction of 5%, and the preparation of the modified filler is as follows:

[0070] Straw micropowder, layered montmorillonite and wool micropowder were stirred and mixed in a mass ratio of 2.5:2:0.5 to obtain a mixture, and the mixture was stirred with a silane coupling agent KH570 in a mass ratio of 50:1 at 120° C. for 4 minutes to obtain a modified filler.

[0071] Example 6

[0072] The difference from Example 1 is that this embodiment further includes a filler with a mass fraction of 5%, and the filler includes the straw powder, layered montmorillonite and wool powder prepared in Preparation Example 1 in a mass ratio of 2.5:2:0.5.

[0073] Example 7

[0074] The difference from Example 1 is that this embodiment further includes a filler with a mass fraction of 5%, and the filler includes the straw powder prepared in Preparation Example 1, the layered montmorillonite prepared in Preparation Example 2, and the wool powder in a mass ratio of 2.5:2:0.5.

[0075] Example 8

[0076] The difference from Example 1 is that this embodiment further includes a filler with a mass fraction of 5%, and the filler includes the straw powder prepared in Preparation Example 1, the layered montmorillonite prepared in Preparation Example 3, and the wool powder in a mass ratio of 2.5:2:0.5.

[0077] Example 9

[0078] The difference from Example 1 is that this embodiment also includes a filler with a mass fraction of 5%, and the filler includes the straw powder prepared in Preparation Example 1, the layered montmorillonite prepared in Preparation Example 3, and the wool powder prepared in Preparation Example 4 in a mass ratio of 2.5:2:0.5.

[0079] Example 10

[0080] The difference from Example 1 is that this embodiment also includes a filler with a mass fraction of 5%, and the filler includes the straw powder prepared in Preparation Example 1, the layered montmorillonite prepared in Preparation Example 3, and the wool powder prepared in Preparation Example 5 in a mass ratio of 2.5:2:0.5.

[0081] Embodiment 11

[0082] The difference from Example 1 is that this example further includes a modified filler with a mass fraction of 5%, and the preparation of the modified filler is as follows:

[0083] The straw powder prepared in Preparation Example 1, the layered montmorillonite prepared in Preparation Example 3 and the wool powder prepared in Preparation Example 5 were stirred and mixed in a mass ratio of 2.5:2:0.5 to obtain a mixture, and the mixture was stirred with silane coupling agent KH570 in a mass ratio of 50:1 at 120°C for 4 minutes to obtain a modified filler.

[0084] Comparative Example

[0085] Comparative Example 1

[0086] The difference between this comparative example and Example 1 is that in this comparative example, no PPC is added to prepare the ground film.

[0087] Comparative Example 2

[0088] The difference between this comparative example and Example 3 is that in this comparative example, no hydrolysis resistance aid is added to prepare the ground film.

[0089] Performance testing

[0090] (1) Tensile strength test: According to GB / T 1040.3-2006 Determination of tensile properties of plastics, the test conditions for films and sheets are: dumbbell-shaped specimens with a length of 150 mm and a narrow parallel width of 10 mm, a tensile speed of 50 mm / min, and a room temperature of 25°C.

[0091] (2) Hydrolysis resistance test: Refer to GB / T 26253-2010 and use a moisture permeability meter to test the water vapor permeability of the ground film.

[0092] (3) Hygrothermal performance test: The specimens were placed in a hygrothermal aging oven at 85°C and 85% relative humidity for 24 h. After aging, the tensile strength was tested.

[0093] Table 2 Performance test

[0094]

[0095] The mulch films in Example 1, Example 7 and Example 8 were tested by potted plant experiments, and the specific test steps are as follows:

[0096] Seed disinfection: The rice variety is Late Indica 98. The seeds are surface disinfected with 0.1% potassium permanganate solution, then soaked in clean water for 1-2 days and placed at 37°C for germination. The germinated seeds are sown in plastic buckets (30cm×20cm×40cm), and a small amount of nitrogen fertilizer and potassium fertilizer are applied as base fertilizer. The ground film is covered, and 4 seeds are sown in each plastic bucket. After the rice seedlings emerge, they are moved into the greenhouse and watered and fertilized regularly (1g of urea is applied to each pot during the tillering stage, and 3g of urea is applied to each pot during the booting stage).

[0097] Preparation of rice sheath blight pathogen WH-1 bacterial solution: Rice sheath blight pathogen WH-1 was cultured on a PDA plate for 72 hours until white sclerotia were formed.

[0098] Planting and post-management: Inoculate the sclerotia of rice sheath blight at the base of the rice plants, one sclerotium per plant, and move to a glass greenhouse at 28±2℃ and 85±10%RH for moist cultivation. After 7 days, refer to the "Measures for the Forecasting of Major Crop Diseases and Insects" to investigate the incidence and disease index of rice sheath blight and observe the lesion area of ​​rice leaves.

[0099] The lesion area of ​​the rice planted in Example 1 was 60.45±4.55 mm 2 The lesion area of ​​the rice planted in Example 7 was 22.37±1.63mm 2 The lesion area of ​​the rice planted in Example 8 was 20.35±1.65mm 2In summary, it can be seen that the interlayer gaps of layered montmorillonite are used to load carbendazim, and the carbendazim loaded in the montmorillonite is slowly released to kill or inhibit pathogens, thereby improving the growth of rice. Tea tree essential oil and glycerol can drive carbendazim to migrate to the surface of the mulch film synchronously, forming a hydrophobic antibacterial layer, further improving the mulch film's effect in eliminating pathogens.

[0100] Combining the performance test comparison in Table 2, we can find that:

[0101] 1. By comparing Examples 1-3 with Comparative Examples 1-2, it can be found that the tensile strength and heat aging effect of the mulch films prepared in Examples 1-3 are improved, and the water vapor permeability is reduced. This shows that PBAT and PPC are used as the base material of the mulch film in this application. The addition of PPC forms an island phase in PBAT. During the film blowing process, a larger area of ​​PPC sheet is formed, thereby improving the water vapor barrier performance and mechanical properties of the mulch film. The carbodiimide in the hydrolysis resistance agent can react with the decomposed carboxyl group to hinder the further degradation of the mulch film, thereby improving the hydrolysis resistance of the mulch film.

[0102] 2. By comparing Example 4 with Example 1, it can be found that the tensile strength, heat aging effect and water vapor permeability of the ground film prepared in Example 4 are all improved, which shows that in this application, through the combination of straw powder, layered montmorillonite and wool powder, the layered montmorillonite can be loaded on the network formed by the fiber structure, increasing the bonding effect between the fiber structure and the ground film, effectively improving the density of the ground film and the water vapor barrier effect, so that the ground film has excellent weather resistance. Due to the addition of a small amount of wool, the hydrophilic groups of the ground film are increased, which reduces the water vapor barrier effect of the ground film.

[0103] 3. By comparing Example 5, Example 11 and Example 1, it can be found that the tensile strength and heat aging effect of the ground film prepared in Example 5 are improved, and the water vapor permeability is reduced. This shows that in the present application, the filler is modified by a silane coupling agent, and the silane coupling agent is used to react with the hydroxyl group on the filler to reduce the polarity between the fillers, improve the dispersion effect of the filler and the compatibility between the filler and the ground film, so that the filler can be evenly dispersed in the ground film, and the mechanical properties and water vapor barrier effect of the ground film are stably enhanced.

[0104] 4. By comparing Example 6 with Example 1, it can be found that the tensile strength and thermal aging effect of the mulch film prepared in Example 6 are improved, and the water vapor permeability is reduced. This shows that the fiber structure of the straw powder in this application can improve the density of the mulch film, the degradation of the straw powder in the environment, and the content of alkaline nitrogen, available phosphorus and available potassium. It can also increase the richness of soil bacteria and the content of Bacillus subtilis, and improve soil vitality, which is beneficial to the growth of rice. The straw powder is esterified and modified, and a benzene ring structure is introduced on the surface of the straw powder to improve the hydrophobicity of the straw powder and improve the hydrolysis resistance of the mulch film. The surface roughness of the straw powder is increased to improve the bonding effect between the straw powder and the mulch film.

[0105] 5. By comparing Examples 7-8 with Example 1, it can be found that the tensile strength and heat aging effect of the mulch films prepared in Examples 7-8 are improved, and the water vapor permeability is reduced. This shows that in the present application, glycerol and tea tree essential oil can migrate to the surface of the mulch film over time, so that an oil layer is formed on the surface of the mulch film, improving the hydrophobic effect of the mulch film. At the same time, tea tree essential oil and glycerol can drive carbendazim to migrate to the surface of the mulch film synchronously to form a hydrophobic antibacterial layer. After water contacts the surface of the mulch film, it is difficult to adhere to the surface of the mulch film, and carbendazim can be transferred to the soil to inhibit or kill pathogens in the soil, which is beneficial to the growth of rice.

[0106] 6. By comparing Examples 9-10 with Example 1, it can be found that the tensile strength and thermal aging effect of the mulch film prepared in Examples 9-10 are improved, and the water vapor permeability is reduced. This shows that in the present application, the silica sol can be firmly loaded on the surface of the wool micropowder, and then a micro-nano rough structure is constructed on the surface of the wool fiber, further improving the roughness of the wool fiber, improving the bonding effect of the wool micropowder and the mulch film, and also improving the hydrophobicity of the wool micropowder, thereby further improving the hydrolysis resistance of the mulch film, so that the mulch film has better mechanical properties and weather resistance. In addition, the introduction of silicon dioxide can further increase the density of the mulch film, improve the mechanical properties and water resistance of the mulch film.

[0107] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A degradable mulch film for rice, characterized in that: Includes the following substances in mass percentage: PBAT 60-65%; PPC 20-25%; Black masterbatch 3-5%; Hydrolysis resistance additive 1-2%; The anti-hydrolysis agent includes a monomeric carbodiimide anti-hydrolysis agent or a polymeric carbodiimide anti-hydrolysis agent.

2. The degradable rice mulch film according to claim 1, characterized in that: The invention also comprises fillers, which include straw micropowder, layered montmorillonite and wool micropowder.

3. The degradable rice mulch film according to claim 2, characterized in that: The filler is a filler modified by a silane coupling agent.

4. The degradable mulch film for rice according to claim 3, characterized in that: The straw powder is straw powder modified by esterification with an esterifying agent.

5. The degradable mulch film for rice according to claim 4, characterized in that: Carbendazim is loaded on the layered montmorillonite.

6. The degradable mulch film for rice according to claim 5, characterized in that: Tea tree essential oil and glycerin are loaded on the layered montmorillonite.

7. The degradable mulch film for rice according to claim 2, characterized in that: The wool powder is surface treated wool powder.

8. The degradable mulch film for rice according to claim 7, characterized in that: The surface treatment comprises the following steps: placing the wool micropowder in an ultraviolet irradiation device, subjecting the wool to ultraviolet irradiation treatment to obtain ultraviolet treated wool, placing the ultraviolet treated wool in a hydrogen peroxide solution, subjecting the wool to immersion treatment to obtain modified wool micropowder.

9. The degradable rice mulch film according to claim 8, characterized in that: The surface treatment further comprises the following steps: immersing the wool micropowder treated with hydrogen peroxide in silica sol, filtering, and drying to obtain the surface treated wool micropowder.

10. The method for preparing a degradable rice mulch film according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Raw material drying: PBAT and PPC are vacuum dried to obtain dry PBAT and dry PPC; S2. Preparation of ground film: PBAT, PPC, black masterbatch and hydrolysis resistance additive are mixed, extruded at 110-170°C, granulated, dried, and blow-molded at 110-160°C to obtain ground film.

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