A low-carbon high-barrier biodegradable mulch film and its preparation method

Abstract

This invention belongs to the field of polymer membranes. This invention relates to a low-carbon, high-barrier biodegradable mulch film and its preparation method. The material comprises the following raw materials in parts by weight: 15-25 parts PPCP; 5-25 parts PLA; 50-80 parts PBAT; 3.0-5.0 parts modified barrier filler; 0.5-1.0 parts UV absorber; 0.2-0.5 parts light stabilizer; 0.2-0.5 parts antioxidant; 0.3-0.8 parts anti-hydrolysis agent; 2.0-4.0 parts plasticizer; 2.0-3.0 parts heat stabilizer; 0.2-0.5 parts lubricant; and 0.1-0.2 parts degradation promoter; wherein the total mass of PPCP, PLA, and PBAT is 100 parts. The above raw materials are blended, granulated, and blown into film. This method effectively solves the defects of existing PBAT films, such as poor water vapor and gas barrier properties, poor mechanical strength, and slow degradation. Furthermore, the main raw materials used are all biodegradable, indicating significant application potential.

Description

Technical Field

[0001] This invention relates to a low-carbon, high-barrier biodegradable mulch film and its preparation method. This invention belongs to the field of biodegradable polymer films. Background Technology

[0002] Mulch film plays a significant role in reducing soil moisture evaporation, improving soil water use efficiency, and promoting crop growth and development, greatly contributing to the development of my country's agricultural economy. However, the polyethylene component of ordinary mulch film is non-biodegradable, causing "white pollution" and requiring manual cleanup, increasing labor costs. Using biodegradable mulch film is a promising direction. This type of material is further divided into naturally biodegradable mulch film (such as starch, protein, cellulose, etc.) and synthetic biodegradable mulch film (such as polylactic acid, polypropylene carbonate, polybutylene terephthalate, etc.).

[0003] Most current biodegradable mulch films are made from biodegradable polyester PBAT (polybutylene terephthalate). While PBAT has excellent biodegradability, it also has good ductility, elongation at break, heat resistance, and impact resistance. However, its water vapor barrier properties are poor, and it cannot block excessive ultraviolet rays. When used as mulch film, it has high water vapor permeability and poor water retention, which limits its application as agricultural mulch film. Therefore, it is necessary to prepare a high-barrier biodegradable mulch film material that not only has good biodegradability but also excellent water vapor barrier properties and mechanical properties. In addition, since different crops have different growth cycles, the mulch film needs to degrade as soon as possible after the crop growth cycle ends to achieve a low-carbon effect.

[0004] Among biodegradable materials, polylactic acid (PLA) is an aliphatic polyester that naturally decomposes into CO2 and water under composting conditions, making it a green and environmentally friendly bio-based material. Moreover, it is the only transparent biodegradable polymer with excellent light transmittance, and it also possesses excellent tensile strength and stiffness. PPCP (polypropylene carbonate), on the other hand, is a biodegradable plastic copolymerized from carbon dioxide and propylene oxide, exhibiting good biodegradability, high water resistance, and high oxygen barrier properties. Blending and modifying PBAT, PLA, and PPCP appears to be a promising new direction. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing PBAT films, such as poor water vapor and gas barrier properties, low mechanical strength, and slow degradation, by providing a method for preparing a low-carbon, high-barrier biodegradable mulch film. The method involves formula design, using PBAT, PPCP, and PLA as the main resins, and employing self-made modified barrier fillers; the film is prepared through mixing, granulation, and blown film extrusion processes. The technical solution adopted by this invention to solve its technical problems is as follows:

[0006] This invention provides a method for preparing modified barrier fillers, comprising the following steps:

[0007] S11, the barrier filler and the silane coupling agent containing carbon-carbon double bonds are placed in an alcohol solvent to carry out a silanization coupling reaction to obtain intermediate product I;

[0008] S12, lactic acid is reacted with epoxy olefins in a ring-opening reaction to obtain intermediate product II;

[0009] S13, intermediate II is subjected to a nucleophilic substitution reaction with perfluoroacyl chloride to obtain intermediate III;

[0010] S14 involves free radical polymerization of intermediate product I, intermediate product III, aromatic acrylate, aliphatic epoxy olefin, ethylene carbonate, and unsaturated quaternary ammonium salt to obtain the target product, namely the modified barrier filler.

[0011] Furthermore,

[0012] The ratio of the barrier filler, the carbon-carbon double-bonded silane, and the alcohol solvent is 1g:0.8-1.5g:80mL; and

[0013] The barrier filler has a layered structure.

[0014] Furthermore, the lactic acid and epoxy olefins are added in a molar ratio of 1:1 between carboxyl groups and epoxy groups.

[0015] Furthermore,

[0016] The intermediate product II was added in a ratio of 1:1 to perfluoroacyl chloride, with the hydroxyl group being added at a molar ratio of 1:1 to the acyl chloride; and

[0017] The carbon atoms of the perfluoroacyl chloride are C5-C8.

[0018] Furthermore, the intermediate product I, intermediate product III, aromatic acrylate, aliphatic epoxy olefin, ethylene carbonate, and unsaturated quaternary ammonium salt are added in a carbon-carbon double bond molar ratio of 0.15-0.25: 0.05-0.15: 0.15-0.25: 0.2-0.3: 0.1-0.2: 0.05-0.15.

[0019] The present invention also provides a modified barrier filler, which is prepared by the above-described method for preparing modified barrier fillers.

[0020] Another object of the present invention is to provide a low-carbon, high-barrier biodegradable mulch film, comprising the following raw materials in parts by weight:

[0021] PPCP 15-25 copies;

[0022] PLA 5-25 copies;

[0023] 50-80 copies of PBAT;

[0024] 3.0-5.0 parts of modified barrier filler;

[0025] 0.5-1.0 parts of UV absorber;

[0026] Light stabilizer 0.2-0.5 parts;

[0027] Antioxidant 0.2-0.5 parts;

[0028] Anti-hydrolysis agent 0.3-0.8 parts;

[0029] Plasticizer 2.0-4.0 parts;

[0030] Heat stabilizer 2.0-3.0 parts;

[0031] Lubricant 0.2-0.5 parts;

[0032] Degradation accelerator 0.1-0.2 parts;

[0033] The total mass of PPCP, PLA, and PBAT is 100 units.

[0034] Furthermore, the degradation promoter is ferric stearate.

[0035] Another object of the present invention is to provide a method for preparing a low-carbon, high-barrier biodegradable mulch film, comprising the following steps:

[0036] S21, Mixing, i.e.

[0037] According to the formula, place all raw materials into a mixer and mix them evenly;

[0038] S22, granulation, i.e.

[0039] The pellets are fed into a pelletizing unit and extruded and pelletized at 160-200℃; and...

[0040] S23, blown film, i.e.

[0041] The granules are fed into a blown film machine for blowing and winding to obtain a low-carbon, high-barrier biodegradable mulch film.

[0042] The beneficial effects of this invention are:

[0043] (1) This invention provides a low-carbon, high-barrier biodegradable mulch film, with PBAT as the main component and PPCP and PLA as functional resins, all of which are biodegradable materials. PBAT, as the main resin, has excellent ductility, heat resistance, and impact resistance; PPCP has excellent transparency and water vapor and gas barrier properties; and PLA has excellent mechanical strength and stiffness. The three biodegradable materials complement each other, resulting in excellent mechanical strength, ductility, stiffness, and water vapor and gas barrier properties.

[0044] (2) The present invention provides a low-carbon, high-barrier biodegradable mulch film, the formulation of which contains a self-made modified barrier filler, which is a two-dimensional lamellar filler structure with a linear macromolecular chain modified with aromatic ring side groups, aliphatic structure side groups, ester groups, carbonates, F element, epoxy side groups and quaternary ammonium salt structure. First, through molecular design, the chemical structures (aromatic rings, aliphatic structures, ester groups, carbonate and lactate structures) of the modified barrier fillers exhibit excellent compatibility and dispersibility with the main resin, making them suitable as compatibilizers; their dispersibility is particularly superior in the PBAT phase. Second, the two-dimensional sheet-like or layered structure provides good barrier properties against water vapor and oxygen. Third, the fluorine element can guide the additives to accumulate on the surface, further enhancing barrier properties; and the hydrophobicity of fluorine has a positive effect on water vapor barrier properties. Fourth, the epoxy structure can react with the hydroxyl or carboxyl groups in PLA and PBAT, as well as with the plasticizer structure, exhibiting excellent chain extension effects and reducing the migration of small molecules, effectively improving the mechanical properties of the material. Fifth, the organic chain structure has a certain molecular chain length, which is beneficial for it to be oriented during blown film production, causing the filler to align and further enhancing barrier properties. Sixth, the quaternary ammonium salt structure has highly efficient broad-spectrum antibacterial properties, which is beneficial to plant growth.

[0045] (3) This invention provides a method for preparing a low-carbon, high-barrier biodegradable mulch film. With reasonable formulation design, while using UV absorbers, light stabilizers, antioxidants and other additives, degradation promoters are used to ensure that the performance of the mulch film decreases slowly during its normal service life and degrades rapidly after its service life, thereby reducing labor costs and having low-carbon characteristics.

[0046] (4) This invention provides a method for preparing a low-carbon, high-barrier biodegradable mulch film. It is prepared using conventional blown film technology, is simple to operate, and is suitable for large-scale promotion and use. Detailed Implementation

[0047] The present invention will be described in detail below with reference to embodiments. However, it should be understood that the following embodiments are merely illustrative examples of implementation of the present invention and are not intended to limit the scope of the present invention.

[0048] The purpose of this invention is to develop a low-carbon, high-barrier biodegradable mulch film to address the problems of poor water vapor barrier properties, unsatisfactory mechanical properties, and slow degradation after use associated with existing PBAT (Bioplasma Officinalis) films. The design concept is as follows: First, due to the dominant role of PBAT, blending it with PLA (Plastic Acid) and PPCP (Polypropylene Cemented Polymer) can partially solve the problems of poor barrier properties and mechanical properties, but it also presents the problem of poor compatibility with dispersants. Second, by balancing antioxidants, light stabilizers, and other additives in the formulation design and adding degradation promoters, the aim is to achieve good performance during the service life and rapid degradation after the service life. The solution to the poor dispersibility is as follows: First, a modified two-dimensional lamellar filler is prepared, which not only further improves barrier properties but also has compatibilizing and chain-extending effects. Simultaneously, after modification, the two-dimensional lamellar filler will exhibit some movement during blown film stretching and orientation, forming a better shielding layer and further improving barrier properties. The theoretical basis for this invention lies in the following: First, modifying the barrier filler with a silane coupling agent yields a barrier filler containing carbon-carbon double bonds. Then, lactic acid and epoxy olefins undergo carboxyl group opening, and the resulting hydroxyl groups are substituted with fluorinated acyl chlorides to obtain fluorinated olefins containing lactic acid. Next, acrylates or olefins with different side group structures are designed and subjected to free radical polymerization to obtain macromolecular modified barrier fillers. The self-made components are then added to the formulation system for mixing, granulation, and blown film processing. The components work synergistically to effectively improve barrier properties and mechanical properties. Examples of this invention are as follows:

[0049] This invention provides a method for preparing a modified barrier filler, comprising the following steps:

[0050] S11, add the barrier filler and the silane coupling agent containing carbon-carbon double bonds into the alcohol solvent, sonicate for 0.5 h, let stand at room temperature for 2 h, react at 50-70℃ for 4-10 h, filter, take the insoluble matter, dry at 60℃ for 12 h to obtain intermediate product I.

[0051] The ratio of the barrier filler, the silane coupling agent containing carbon-carbon double bonds, and the alcohol solvent is 1g:0.8-1.5g:80mL; and

[0052] The barrier filler has a layered structure; it can be graphene oxide, montmorillonite, mica flakes, talc, etc.; and preferably graphene oxide.

[0053] The graphene oxide is prepared by a modified Hummer's method; and the hydroxyl content of the graphene oxide is 3.0-8.0 mmol / g.

[0054] The silane coupling agent containing carbon-carbon double bonds can be a vinyl silane coupling agent or an acryloxy silane coupling agent.

[0055] The vinylsilane coupling agent may be KH151, KH171 or KH172, etc.; and KH151 is preferred.

[0056] The acryloyloxysilane coupling agent can be KH570, KH571, KH670 or GX572, etc.; and KH570 is preferred.

[0057] The alcohol solvent can be anhydrous methanol, anhydrous ethanol, anhydrous isopropanol, etc.; and preferably anhydrous ethanol.

[0058] S12, lactic acid, epoxy olefins, tetrabutylammonium bromide, and hydroquinone were added to tetrahydrofuran, heated under reflux for 24 h, cooled to room temperature, deionized water A was added, the mixture was shaken, ethyl acetate was added for extraction, the organic phase was collected, dried with anhydrous sodium sulfate A, filtered, the filtrate was collected, and the mixture was distilled under reduced pressure and dried under vacuum at 40 °C for 12 h to obtain intermediate product II.

[0059] The lactic acid and epoxy olefins are added in a molar ratio of 1:1 between carboxyl groups and epoxy groups.

[0060] The lactic acid, tetrabutylammonium bromide, tetrahydrofuran, deionized water A, ethyl acetate, and anhydrous sodium sulfate A were added in the following ratio: 1 mmol: 0.1 mmol: 5 mL: 10 mL: 20 mL: 1 g.

[0061] The epoxyenes can be glycidyl methacrylate, ethyl methacrylate (glycidyloxy) methacrylate, allyl glycidyl ether, 1,2-epoxy-7-octene, or 1,2-epoxy-9-decene, etc.

[0062] The amount of hydroquinone used is 0.1 wt% of the mass of the epoxy olefins.

[0063] S13, intermediate product II and triethylamine were dissolved in N,N-dimethylformamide A and placed in a reaction vessel. Perfluoroacyl chloride was dissolved in N,N-dimethylformamide B and placed in a constant pressure dropping funnel. The mixture was placed in an ice bath and stirred. After the addition was completed, stirring was continued at 0-5℃ for 8-14 hours. After the reaction was completed, the mixture was filtered and distilled under reduced pressure. The concentrate was dissolved in dichloromethane, washed three times with saturated sodium bicarbonate solution, and then washed three times with deionized water B. The mixture was separated, and the organic phase was dried with anhydrous sodium sulfate B. The mixture was filtered, and the filtrate was distilled under reduced pressure and dried under vacuum at 80℃ for 4 hours to obtain intermediate product III.

[0064] The intermediate product II and perfluoroacyl chloride were added in a molar ratio of hydroxyl to acyl chloride of 1:1.

[0065] The ratio of intermediate product II, triethylamine, N,N-dimethylformamide A, N,N-dimethylformamide B, dichloromethane, saturated sodium bicarbonate solution, deionized water B, and anhydrous sodium sulfate B is: 0.1 mol: 0.1 mol: 100 mL: 50 mL: 200 mL: 200 mL: 200 mL: 10 g.

[0066] The perfluoroacyl chloride has a carbon number of C5-C8. When the number of carbon atoms is less than 5, the surface migration and enrichment effect of the modified barrier filler is poor, affecting the barrier effect. When the number of carbon atoms is greater than 8, the modified barrier filler is enriched on the surface, resulting in excellent barrier effect, but lacking compatibilizing effect. Furthermore, the migration and enrichment of the modified barrier filler is also related to the proportion of intermediate product III monomer.

[0067] S14, intermediate product I, intermediate product III, aromatic acrylate, aliphatic epoxy olefin, ethylene carbonate, unsaturated quaternary ammonium salt, and initiator AIBN are added to N,N-dimethylformamide C, heated to 75-85℃ and stirred for 6-10h; after the reaction is completed, the mixture is cooled to room temperature, filtered, and the filtrate is collected, distilled under reduced pressure, and dried under vacuum at 60℃ for 6h to obtain the target product, i.e., the modified barrier filler.

[0068] The intermediate product I, intermediate product III, aromatic acrylate, aliphatic epoxy olefin, ethylene carbonate, and unsaturated quaternary ammonium salt are added in a carbon-carbon double bond molar ratio of 0.15-0.25: 0.05-0.15: 0.15-0.25: 0.2-0.3: 0.1-0.2: 0.05-0.15.

[0069] The aromatic acrylate may be phenyl methacrylate, 2-phenoxyethyl acrylate, benzyl methacrylate, 4-(6-(acryloyloxy)hexyloxy)benzoic acid, etc.; and preferably 2-phenoxyethyl acrylate.

[0070] The aliphatic epoxyenes may be glycidyl methacrylate, ethyl methacrylate (glycidyloxy), allyl glycidyl ether, 1,2-epoxy-7-octene, or 1,2-epoxy-9-decene, etc.; and preferably ethyl methacrylate (glycidyloxy).

[0071] The ethylene carbonate may be ethylene carbonate or allyl methyl carbonate, etc.; and, preferably, allyl methyl carbonate.

[0072] The unsaturated quaternary ammonium salt can be acryloyloxyethyltrimethylammonium chloride, etc.

[0073] The ratio of intermediate product I to N,N-dimethylformamide C is 1 mol: 500 mL.

[0074] The amount of the initiator AIBN is 1.0-1.5% of the total mass of the monomers.

[0075] An embodiment of the present invention provides a low-carbon, high-barrier biodegradable mulch film, comprising the following raw materials in parts by weight:

[0076] PPCP 15-25 copies;

[0077] PLA 5-25 copies;

[0078] 50-80 copies of PBAT;

[0079] 3.0-5.0 parts of modified barrier filler;

[0080] 0.5-1.0 parts of UV absorber;

[0081] Light stabilizer 0.2-0.5 parts;

[0082] Antioxidant 0.2-0.5 parts;

[0083] Anti-hydrolysis agent 0.3-0.8 parts;

[0084] Plasticizer 2.0-4.0 parts;

[0085] Heat stabilizer 2.0-3.0 parts;

[0086] Lubricant 0.2-0.5 parts;

[0087] Degradation accelerator 0.1-0.2 parts;

[0088] The total mass of PPCP, PLA, and PBAT is 100 units.

[0089] The PPCP, with a glass transition temperature (Tg) of 46 ℃, was purchased from Shandong Lianchuang Co., Ltd.

[0090] The PLA, model PT102, was purchased from Pulis Biotechnology Co., Ltd.

[0091] The PBAT, brand name TH801T, was purchased from Xinjiang Lanshan Tunhe Polyester Co., Ltd.

[0092] The UV absorber is a benzotriazole class, specifically UV-326, UV-327, UV-328, or UV-329; and in the following embodiments of the present invention, the UV absorber is UV-329.

[0093] The hindered amine light stabilizer can be UV-292, UV-770, or GW540, etc.; and preferably, UV-292. In the following embodiments of the present invention, the light stabilizer is UV-292.

[0094] The antioxidant is a hindered phenol; it can be antioxidant 1010, antioxidant 1076, antioxidant 264, antioxidant 2246, etc.; and, in the following embodiments of the present invention, the antioxidant is antioxidant 1010.

[0095] The anti-hydrolysis agent is a monomeric anti-hydrolysis agent, bis(2,6-diisopropylbenzene)carbodiimide, model HyMax1010, which was purchased from Shanghai Langyi Functional Materials Co., Ltd.

[0096] The plasticizer can be glycerol, trimethylolpropane, pentaerythritol, triethyl citrate, and low molecular weight polyester glycol, polyether glycol, etc.; small molecule plasticizers and plasticizers of a certain molecular weight are selected for compounding and use, which can achieve a certain plasticizing effect while also having low migration; and, in the following embodiments of the present invention, the plasticizer is a mixture of glycerol, triethyl citrate, and PCL400 in a mass ratio of 3:2:1.

[0097] The heat stabilizer is a calcium-zinc stabilizer, specifically a mixture of calcium stearate, zinc stearate, and hydrotalcite in a mass ratio of 2:2:1.

[0098] The lubricant is EBS, oleamide, or erucamide, and in the following embodiments of the present invention, the lubricant is EBS.

[0099] The degradation accelerator is ferric stearate; ferric stearate has high photosensitivity and also has auxiliary effects on thermal stability and lubricity. By controlling the dosage and using it in combination with UV absorbers and light stabilizers, the material can have light stability during its service life and rapid degradation in the later stages.

[0100] This invention provides a method for preparing a low-carbon, high-barrier biodegradable mulch film, comprising the following steps:

[0101] S21, Mixing, i.e.

[0102] According to the formula, place all raw materials into a high-speed mixer and stir at 200 rpm for 20-30 minutes until they are evenly mixed.

[0103] S22, granulation, i.e.

[0104] The pellets are fed into a granulator and extruded at 160-190℃, then water-cooled, pelletized, and dried at 50℃.

[0105] The twin-screw extruder in the pelletizing unit is a general-purpose screw with a length-to-diameter ratio of 36:1 and a screw speed of 150-250 rpm; the pelletizer speed is 230-270 rpm.

[0106] S23, blown film, i.e.

[0107] The granules are fed into a blown film machine for blowing and winding to obtain a low-carbon, high-barrier biodegradable mulch film with a thickness of 5-20 μm.

[0108] The blown film machine is equipped with a single-screw extruder with a temperature of 180-190℃, a rotation speed of 200-300rpm, a traction speed of 6m / min, and a blow-up ratio of 3-4.

[0109] To further understand the present invention, the following detailed description of a low-carbon, high-barrier biodegradable mulch film provided by the present invention is provided in conjunction with specific embodiments. The scope of protection of the present invention is not limited by the following embodiments.

[0110] A method for preparing a modified barrier filler includes the following steps:

[0111] S11, graphene oxide and silane coupling agent KH570 were added to anhydrous ethanol solvent, ultrasonically vibrated for 0.5 h, allowed to stand at room temperature for 2 h, reacted at 60 °C for 8 h, filtered, and the insoluble matter was dried at 60 °C for 12 h to obtain intermediate product I.

[0112] The ratio of graphene oxide, silane coupling agent KH570, and anhydrous ethanol solvent is 1g:1.0g:80mL;

[0113] The graphene oxide is prepared by a modified Hummer's method; and the hydroxyl content of the graphene oxide is 5.0 mmol / g.

[0114] Its infrared data is as follows: 3315 cm -1 1710cm -1 -COOH is present (weak peak); 2953 cm⁻¹ -1 -CH exists; 1248 cm -1 Epoxy groups present (weak peak); 1109 cm⁻¹ -1 801cm -1 -Si-O- exists; 1735cm -1 -C=O exists; 1609cm -1 811cm -1 -C=C-exists.

[0115] S12, lactic acid, glycidyl methacrylate, tetrabutylammonium bromide, and hydroquinone were added to tetrahydrofuran, heated under reflux for 24 h, cooled to room temperature, deionized water A was added, the mixture was shaken, ethyl acetate was added for extraction, the organic phase was collected, dried with anhydrous sodium sulfate A, filtered, the filtrate was collected, and the mixture was distilled under reduced pressure and dried under vacuum at 40 °C for 12 h to obtain intermediate product II.

[0116] The lactic acid and glycidyl methacrylate are added in a molar ratio of 1:1 between carboxyl groups and epoxy groups.

[0117] The lactic acid, tetrabutylammonium bromide, tetrahydrofuran, deionized water A, ethyl acetate, and anhydrous sodium sulfate A were added in the following ratio: 1 mmol: 0.1 mmol: 5 mL: 10 mL: 20 mL: 1 g.

[0118] The amount of hydroquinone used is 0.1 wt% of the mass of the epoxy olefins.

[0119] Its infrared data is as follows: 3394cm -1 -OH is present; 1710 cm -1 -C=O (carboxyl group) does not exist; 1735cm -1 -C=O (ester group) present; 1606 cm⁻¹ -1 811cm -1 -C=C- exists; 1265cm -1 938cm -1 825cm -1 Epoxy groups are not present.

[0120] S13, intermediate product II and triethylamine were dissolved in N,N-dimethylformamide A and placed in a reaction vessel. Perfluoroheptanoyl chloride was dissolved in N,N-dimethylformamide B and placed in a constant pressure dropping funnel. The mixture was placed in an ice bath and stirred. After the addition was completed, stirring was continued at 0°C for 14 hours. After the reaction was completed, the mixture was filtered and distilled under reduced pressure. The concentrate was dissolved in dichloromethane, washed three times with saturated sodium bicarbonate solution, and then washed three times with deionized water B. The mixture was separated, and the organic phase was dried with anhydrous sodium sulfate B. The mixture was filtered, and the filtrate was distilled under reduced pressure and dried under vacuum at 80°C for 4 hours to obtain intermediate product III.

[0121] The intermediate product II was added in a ratio of 1:1 to perfluoroheptanoyl chloride.

[0122] The ratio of intermediate product II, triethylamine, N,N-dimethylformamide A, N,N-dimethylformamide B, dichloromethane, saturated sodium bicarbonate solution, deionized water B, and anhydrous sodium sulfate B is: 0.1 mol: 0.1 mol: 100 mL: 50 mL: 200 mL: 200 mL: 200 mL: 10 g.

[0123] Its infrared data is as follows: 3394cm -1 -OH is not present; 1735cm -1 : -C=O (ester group) is present and enhances; 1606cm -1 811cm -1 -C=C- exists; 1311cm -1-CF exists.

[0124] S14, intermediates I and III, 2-phenoxyethyl acrylate, glycidyl methacrylate, allyl methyl carbonate, acryloyloxyethyl trimethylammonium chloride, and initiator AIBN were added to N,N-dimethylformamide C, heated to 80°C, and stirred for 8.5 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filtrate was collected, distilled under reduced pressure, and dried under vacuum at 60°C for 6 h to obtain the target product, i.e., the modified barrier filler.

[0125] The intermediate product I, intermediate product III, 2-phenoxyethyl acrylate, methyl methacrylate (glycidyl methacrylate), allyl methyl carbonate, and acryloyloxyethyl trimethylammonium chloride are added in a carbon-carbon double bond molar ratio of 0.2:0.1:0.2:0.25:0.15:0.1.

[0126] The ratio of intermediate product I to N,N-dimethylformamide C is 1 mol: 500 mL;

[0127] The amount of the initiator AIBN is 1.2% of the total mass of the monomers.

[0128] Its infrared data is as follows: 3315 cm -1 1710cm -1 -COOH is present (weak peak); 2953 cm⁻¹ -1 -CH exists; 1109 cm -1 801cm -1 -Si-O- exists; 1735cm -1 -C=O exists; 1623cm -1 1609 cm -1 811cm -1 : -C=C- does not exist; 3011cm -1 1595cm -1 1498cm -1 : Benzene ring present; 1311 cm -1 :-CF exists; 1260cm -1 938cm -1 825cm -1 Epoxy groups are present.

[0129] A low-carbon, high-barrier biodegradable mulch film comprises the following raw materials in parts by weight:

[0130] PPCP 20 copies;

[0131] PLA 15 copies;

[0132] 65 copies of PBAT;

[0133] 4.0 parts of modified barrier filler;

[0134] 0.8 parts UV absorber;

[0135] 0.4 parts light stabilizer;

[0136] Antioxidant 0.3 parts;

[0137] 0.5 parts of anti-hydrolysis agent;

[0138] 3.0 parts plasticizer;

[0139] 2.5 parts heat stabilizer;

[0140] 0.4 parts lubricant;

[0141] 0.15 parts of degradation accelerator;

[0142] The total mass of PPCP, PLA, and PBAT is 100 units.

[0143] A method for preparing a low-carbon, high-barrier biodegradable mulch film includes the following steps:

[0144] S21, Mixing, i.e.

[0145] According to the formula, place all raw materials in a high-speed mixer and stir at 200 rpm for 25 minutes until they are evenly mixed.

[0146] S22, granulation, i.e.

[0147] The pellets are fed into a pelletizing unit with zones 160°C, 270°C, 380°C, and a die temperature of 180°C. The pellets are then extruded, water-cooled, and cut into pellets, and dried at 50°C.

[0148] The twin-screw extruder in the pelletizing unit is a general-purpose screw with a length-to-diameter ratio of 36:1 and a screw speed of 200 rpm; the pelletizer speed is 250 rpm.

[0149] S23, blown film, i.e.

[0150] The granules are fed into a blown film machine for blowing and winding to obtain a low-carbon, high-barrier biodegradable mulch film with a thickness of 10μm.

[0151] The blown film machine is equipped with a single screw extruder with the following temperature settings: zone 1 180℃, zone 1 185℃, zone 1 188℃, die head 190℃, rotation speed 250rpm, traction speed 6m / min, and blow-up ratio 3.5.

[0152] Everything else is the same as in Example 1, except that:

[0153] S11, graphene oxide and silane coupling agent KH570 were added to anhydrous ethanol solvent, ultrasonically vibrated for 0.5 h, allowed to stand at room temperature for 2 h, reacted at 50 °C for 10 h, filtered, and the insoluble matter was dried at 60 °C for 12 h to obtain intermediate product I.

[0154] The ratio of graphene oxide, silane coupling agent KH570, and anhydrous ethanol solvent is 1g:0.8g:80mL;

[0155] The graphene oxide is prepared by a modified Hummer's method; and the hydroxyl content of the graphene oxide is 3.0 mmol / g.

[0156] Its infrared data is as follows: 3315 cm -1 1710cm -1 -COOH is present (weak peak); 2953 cm⁻¹ -1 -CH exists; 1248 cm -1 Epoxy groups present (weak peak); 1109 cm⁻¹ -1 801cm -1 -Si-O- exists; 1735cm -1 -C=O exists; 1609cm -1 811cm -1 -C=C-exists.

[0157] S12, lactic acid, glycidyl methacrylate, tetrabutylammonium bromide, and hydroquinone were added to tetrahydrofuran, heated under reflux for 24 h, cooled to room temperature, deionized water A was added, the mixture was shaken, ethyl acetate was added for extraction, the organic phase was collected, dried with anhydrous sodium sulfate A, filtered, the filtrate was collected, and the mixture was distilled under reduced pressure and dried under vacuum at 40 °C for 12 h to obtain intermediate product II.

[0158] The lactic acid and glycidyl methacrylate are added in a molar ratio of 1:1 between carboxyl groups and epoxy groups.

[0159] The lactic acid, tetrabutylammonium bromide, tetrahydrofuran, deionized water A, ethyl acetate, and anhydrous sodium sulfate A were added in the following ratio: 1 mmol: 0.1 mmol: 5 mL: 10 mL: 20 mL: 1 g.

[0160] The amount of hydroquinone used is 0.1 wt% of the mass of the epoxy olefins.

[0161] Its infrared data is as follows: 3394cm -1 -OH is present; 1710 cm -1 -C=O (carboxyl group) does not exist; 1735cm -1 -C=O (ester group) present; 1606 cm⁻¹-1 811cm -1 -C=C- exists; 1265cm -1 938cm -1 825cm -1 Epoxy groups are not present.

[0162] S13, intermediate product II and triethylamine were dissolved in N,N-dimethylformamide A and placed in a reaction vessel. Perfluoroheptanoyl chloride was dissolved in N,N-dimethylformamide B and placed in a constant pressure dropping funnel. The mixture was placed in an ice bath and stirred. After the addition was completed, stirring was continued at 5°C for 8 hours. After the reaction was completed, the mixture was filtered and distilled under reduced pressure. The concentrate was dissolved in dichloromethane, washed three times with saturated sodium bicarbonate solution, and then washed three times with deionized water B. The mixture was separated, and the organic phase was dried with anhydrous sodium sulfate B. The mixture was filtered, and the filtrate was distilled under reduced pressure and dried under vacuum at 80°C for 4 hours to obtain intermediate product III.

[0163] The intermediate product II was added in a ratio of 1:1 to perfluoroheptanoyl chloride.

[0164] The ratio of intermediate product II, triethylamine, N,N-dimethylformamide A, N,N-dimethylformamide B, dichloromethane, saturated sodium bicarbonate solution, deionized water B, and anhydrous sodium sulfate B is: 0.1 mol: 0.1 mol: 100 mL: 50 mL: 200 mL: 200 mL: 200 mL: 10 g.

[0165] Its infrared data is as follows: 3394cm -1 -OH is not present; 1735cm -1 : -C=O (ester group) is present and enhances; 1606cm -1 811cm -1 -C=C- exists; 1311cm -1 -CF exists.

[0166] S14, intermediates I and III, 2-phenoxyethyl acrylate, glycidyl methacrylate, allyl methyl carbonate, acryloyloxyethyl trimethylammonium chloride, and initiator AIBN were added to N,N-dimethylformamide C, heated to 75°C, and stirred for 10 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filtrate was collected, distilled under reduced pressure, and dried under vacuum at 60°C for 6 hours to obtain the target product, i.e., the modified barrier filler.

[0167] The intermediate product I, intermediate product III, 2-phenoxyethyl acrylate, methyl methacrylate (glycidyl methacrylate), allyl methyl carbonate, and acryloyloxyethyl trimethylammonium chloride are added in a carbon-carbon double bond molar ratio of 0.2:0.1:0.2:0.25:0.15:0.1.

[0168] The ratio of intermediate product I to N,N-dimethylformamide C is 1 mol: 500 mL;

[0169] The amount of the initiator AIBN is 1.5% of the total mass of the monomers.

[0170] Its infrared data is as follows: 3315 cm -1 1710cm -1 -COOH is present (weak peak); 2953 cm⁻¹ -1 -CH exists; 1109 cm -1 801cm -1 -Si-O- exists; 1735cm -1 -C=O exists; 1623cm -1 1609 cm -1 811cm -1 : -C=C- does not exist; 3011cm -1 1595cm -1 1498cm -1 : Benzene ring present; 1311 cm -1 :-CF exists; 1260cm -1 938cm -1 825cm -1 Epoxy groups are present.

[0171] Everything else is the same as in Example 1, except that:

[0172] S11, graphene oxide and silane coupling agent KH570 were added to anhydrous ethanol solvent, ultrasonically vibrated for 0.5 h, allowed to stand at room temperature for 2 h, reacted at 70 °C for 4 h, filtered, and the insoluble matter was dried at 60 °C for 12 h to obtain intermediate product I.

[0173] The ratio of graphene oxide, silane coupling agent KH570, and anhydrous ethanol solvent is 1g:1.5g:80mL.

[0174] The graphene oxide is prepared by a modified Hummer's method; and the hydroxyl content of the graphene oxide is 8.0 mmol / g.

[0175] Its infrared data is as follows: 3315 cm -1 1710cm-1 -COOH is present (weak peak); 2953 cm⁻¹ -1 -CH exists; 1248 cm -1 Epoxy groups present (weak peak); 1109 cm⁻¹ -1 801cm -1 -Si-O- exists; 1735cm -1 -C=O exists; 1609cm -1 811cm -1 -C=C-exists.

[0176] S12, lactic acid, glycidyl methacrylate, tetrabutylammonium bromide, and hydroquinone were added to tetrahydrofuran, heated under reflux for 24 h, cooled to room temperature, deionized water A was added, the mixture was shaken, ethyl acetate was added for extraction, the organic phase was collected, dried with anhydrous sodium sulfate A, filtered, the filtrate was collected, and the mixture was distilled under reduced pressure and dried under vacuum at 40 °C for 12 h to obtain intermediate product II.

[0177] The lactic acid and glycidyl methacrylate are added in a molar ratio of 1:1 between carboxyl groups and epoxy groups.

[0178] The lactic acid, tetrabutylammonium bromide, tetrahydrofuran, deionized water A, ethyl acetate, and anhydrous sodium sulfate A were added in the following ratio: 1 mmol: 0.1 mmol: 5 mL: 10 mL: 20 mL: 1 g.

[0179] The amount of hydroquinone used is 0.1 wt% of the mass of the epoxy olefins.

[0180] Its infrared data is as follows: 3394cm -1 -OH is present; 1710 cm -1 -C=O (carboxyl group) does not exist; 1735cm -1 -C=O (ester group) present; 1606 cm⁻¹ -1 811cm -1 -C=C- exists; 1265cm -1 938cm -1 825cm -1 Epoxy groups are not present.

[0181] S13, intermediate product II and triethylamine were dissolved in N,N-dimethylformamide A and placed in a reaction vessel. Perfluoroheptanoyl chloride was dissolved in N,N-dimethylformamide B and placed in a constant pressure dropping funnel. The mixture was placed in an ice bath and stirred. After the addition was completed, stirring was continued at 0°C for 10 hours. After the reaction was completed, the mixture was filtered and distilled under reduced pressure. The concentrate was dissolved in dichloromethane, washed three times with saturated sodium bicarbonate solution, and then washed three times with deionized water B. The mixture was separated, and the organic phase was dried with anhydrous sodium sulfate B. The mixture was filtered, and the filtrate was distilled under reduced pressure and dried under vacuum at 80°C for 4 hours to obtain intermediate product III.

[0182] The intermediate product II was added in a ratio of 1:1 to perfluoroheptanoyl chloride.

[0183] The ratio of intermediate product II, triethylamine, N,N-dimethylformamide A, N,N-dimethylformamide B, dichloromethane, saturated sodium bicarbonate solution, deionized water B, and anhydrous sodium sulfate B is: 0.1 mol: 0.1 mol: 100 mL: 50 mL: 200 mL: 200 mL: 200 mL: 10 g.

[0184] Its infrared data is as follows: 3394cm -1 -OH is not present; 1735cm -1 : -C=O (ester group) is present and enhances; 1606cm -1 811cm -1 -C=C- exists; 1311cm -1 -CF exists.

[0185] S14, intermediates I and III, 2-phenoxyethyl acrylate, glycidyl methacrylate, allyl methyl carbonate, acryloyloxyethyl trimethylammonium chloride, and initiator AIBN were added to N,N-dimethylformamide C, heated to 85°C, and stirred for 6 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filtrate was collected, distilled under reduced pressure, and dried under vacuum at 60°C for 6 hours to obtain the target product, i.e., the modified barrier filler.

[0186] The intermediate product I, intermediate product III, 2-phenoxyethyl acrylate, methyl methacrylate (glycidyl methacrylate), allyl methyl carbonate, and acryloyloxyethyl trimethylammonium chloride are added in a carbon-carbon double bond molar ratio of 0.2:0.1:0.2:0.25:0.15:0.1.

[0187] The ratio of intermediate product I to N,N-dimethylformamide C is 1 mol: 500 mL;

[0188] The amount of the initiator AIBN is 1.0% of the total mass of the monomers.

[0189] Its infrared data is as follows: 3315 cm -1 1710cm -1 -COOH is present (weak peak); 2953 cm⁻¹ -1 -CH exists; 1109 cm -1 801cm -1 -Si-O- exists; 1735cm -1 -C=O exists; 1623cm -1 1609 cm -1 811cm -1 : -C=C- does not exist; 3011cm -1 1595cm -1 1498cm -1 : Benzene ring present; 1311 cm -1 :-CF exists; 1260cm -1 938cm -1 825cm -1 Epoxy groups are present.

[0190] Everything else is the same as in Example 1, except that:

[0191] A method for preparing a modified barrier filler, in step S11,

[0192] Replace the silane coupling agent KH570 with KH151.

[0193] Everything else is the same as in Example 1, except that:

[0194] A method for preparing a modified barrier filler, in step S12,

[0195] The glycidyl methacrylate was replaced with allyl glycidyl ether.

[0196] Everything else is the same as in Example 1, except that:

[0197] A method for preparing a modified barrier filler, in step S13,

[0198] The perfluoroheptanoyl chloride was replaced with perfluoropentanoyl chloride.

[0199] Everything else is the same as in Example 1, except that:

[0200] A method for preparing a modified barrier filler, in step S13,

[0201] The perfluoroheptanoyl chloride is replaced with perfluorooctanoyl chloride.

[0202] Everything else is the same as in Example 1, except that:

[0203] A method for preparing a modified barrier filler, in step S14,

[0204] The intermediate product I, intermediate product III, 2-phenoxyethyl acrylate, methyl methacrylate (glycidyl methacrylate), allyl methyl carbonate, and acryloyloxyethyl trimethylammonium chloride are added in a carbon-carbon double bond molar ratio of 0.15:0.15:0.15:0.3:0.1:0.15.

[0205] Everything else is the same as in Example 1, except that:

[0206] A method for preparing a modified barrier filler, in step S14,

[0207] The intermediate product I, intermediate product III, 2-phenoxyethyl acrylate, methyl methacrylate (glycidyl methacrylate), allyl methyl carbonate, and acryloyloxyethyl trimethylammonium chloride are added in a carbon-carbon double bond molar ratio of 0.25:0.05:0.25:0.2:0.2:0.05.

[0208] Everything else is the same as in Example 1, except that:

[0209] A low-carbon, high-barrier biodegradable mulch film comprises the following raw materials in parts by weight:

[0210] 15 copies of PPCP;

[0211] PLA 5 copies;

[0212] 80 copies of PBAT;

[0213] 5.0 parts of modified barrier filler;

[0214] 1.0 part UV absorber;

[0215] 0.5 parts light stabilizer;

[0216] Antioxidant 0.2 parts;

[0217] 0.8 parts of anti-hydrolysis agent;

[0218] 2.0 parts plasticizer;

[0219] 3.0 parts heat stabilizer;

[0220] 0.5 parts lubricant;

[0221] 0.2 parts of degradation accelerator;

[0222] The total mass of PPCP, PLA, and PBAT is 100 units.

[0223] A method for preparing a low-carbon, high-barrier biodegradable mulch film includes the following steps:

[0224] S21, Mixing, i.e.

[0225] According to the formula, place all raw materials in a high-speed mixer and stir at 200 rpm for 20 minutes until they are evenly mixed.

[0226] S22, granulation, i.e.

[0227] The pellets are fed into a pelletizing unit with zones 160°C, 270°C, 375°C, and a die temperature of 178°C. The pellets are then extruded, water-cooled, and pelletized, and dried at 50°C.

[0228] The twin-screw extruder in the pelletizing unit is a general-purpose screw with a length-to-diameter ratio of 36:1 and a screw speed of 150 rpm; the pelletizer speed is 230 rpm.

[0229] S23, blown film, i.e.

[0230] The granules are fed into a blown film machine for blowing and winding to obtain a low-carbon, high-barrier biodegradable mulch film with a thickness of 5μm.

[0231] The blown film machine is equipped with a single screw extruder with the following temperature settings: zone 1 180℃, zone 1 183℃, zone 1 185℃, and die head 185℃; rotation speed 200 rpm; traction speed 6 m / min; and blow-up ratio 3.0.

[0232] Everything else is the same as in Example 1, except that:

[0233] A low-carbon, high-barrier biodegradable mulch film comprises the following raw materials in parts by weight:

[0234] PPCP 25 copies;

[0235] PLA 25 copies;

[0236] 50 copies of PBAT;

[0237] 3.0 parts of modified barrier filler;

[0238] 0.5 parts UV absorber;

[0239] 0.2 parts light stabilizer;

[0240] Antioxidant 0.5 parts;

[0241] 0.3 parts of anti-hydrolysis agent;

[0242] 4.0 parts plasticizer;

[0243] 2.0 parts heat stabilizer;

[0244] 0.2 parts lubricant;

[0245] 0.1 parts degradation accelerator;

[0246] The total mass of PPCP, PLA, and PBAT is 100 units.

[0247] A method for preparing a low-carbon, high-barrier biodegradable mulch film includes the following steps:

[0248] S21, Mixing, i.e.

[0249] According to the formula, place all raw materials in a high-speed mixer and stir at 200 rpm for 30 minutes until they are evenly mixed.

[0250] S22, granulation, i.e.

[0251] The pellets are fed into a pelletizing unit with zones 160°C, 270°C, 380°C, and a die temperature of 190°C. The pellets are then extruded, water-cooled, and cut into pellets, and dried at 50°C.

[0252] The twin-screw extruder in the pelletizing unit is a general-purpose screw with a length-to-diameter ratio of 36:1 and a screw speed of 250 rpm; the pelletizer speed is 270 rpm.

[0253] S23, blown film, i.e.

[0254] The granules are fed into a blown film machine for blowing and winding to obtain a low-carbon, high-barrier biodegradable mulch film with a thickness of 20μm.

[0255] The blown film machine has the following settings: single screw extruder temperature ranges: 180℃ in zone 1, 185℃ in zone 1, 192℃ in zone 1, and 190℃ at the die head; rotation speed: 300 rpm; traction speed: 6 m / min; and blow-up ratio: 4.0.

[0256] The following comparative examples are all compared with specific embodiment 1:

[0257] Comparative Example 1

[0258] Everything else is the same as in Example 1, except that:

[0259] The aforementioned low-carbon, high-barrier biodegradable mulch film raw material formulation does not contain PPCP.

[0260] Comparative Example 2

[0261] Everything else is the same as in Example 1, except that:

[0262] The aforementioned low-carbon, high-barrier biodegradable mulch film raw material formulation does not contain PLA.

[0263] Implement Comparative Example 3

[0264] Everything else is the same as in Example 1, except that:

[0265] No UV absorbers were added to the formulation of the low-carbon, high-barrier biodegradable mulch film.

[0266] Comparative Example 4

[0267] Everything else is the same as in Example 1, except that:

[0268] No light stabilizer was added to the formulation of the low-carbon, high-barrier biodegradable mulch film.

[0269] Comparative Example 5

[0270] Everything else is the same as in Example 1, except that:

[0271] No antioxidants were added to the formulation of the low-carbon, high-barrier biodegradable mulch film.

[0272] Comparative Example 6

[0273] Everything else is the same as in Example 1, except that:

[0274] No anti-hydrolysis agent was added to the formulation of the low-carbon, high-barrier biodegradable mulch film.

[0275] Comparative Example 7

[0276] Everything else is the same as in Example 1, except that:

[0277] No degradation promoters were added to the formulation of the low-carbon, high-barrier biodegradable mulch film.

[0278] Implemented Comparative Example 8

[0279] Everything else is the same as in Example 1, except that:

[0280] No modified barrier fillers were added to the formula of the low-carbon, high-barrier biodegradable mulch film.

[0281] Comparative Example 9

[0282] Everything else is the same as in Example 1, except that:

[0283] In a method for preparing a modified barrier filler,

[0284] The intermediate product I, intermediate product III, 2-phenoxyethyl acrylate, methyl methacrylate (glycidyl methacrylate), allyl methyl carbonate, and acryloyloxyethyl trimethylammonium chloride were added in a carbon-carbon double bond molar ratio of 0:0.1:0.2:0.25:0.15:0.1; that is, intermediate product I was not added.

[0285] Implement Comparative Example 10

[0286] Everything else is the same as in Example 1, except that:

[0287] In a method for preparing a modified barrier filler,

[0288] The intermediate product I, intermediate product III, 2-phenoxyethyl acrylate, methyl methacrylate (glycidyl methacrylate), allyl methyl carbonate, and acryloyloxyethyl trimethylammonium chloride were added in a carbon-carbon double bond molar ratio of 0.2:0:0.2:0.25:0.15:0.1; that is, intermediate product III was not added.

[0289] Comparative Example 11

[0290] Everything else is the same as in Example 1, except that:

[0291] In a method for preparing a modified barrier filler,

[0292] The intermediate product I, intermediate product III, 2-phenoxyethyl acrylate, methyl methacrylate (glycidyl methacrylate), allyl methyl carbonate, and acryloyloxyethyl trimethylammonium chloride were added in a carbon-carbon double bond molar ratio of 0.2:0.1:0:0.25:0.15:0.1; that is, 2-phenoxyethyl acrylate was not added.

[0293] Comparative Example 12

[0294] Everything else is the same as in Example 1, except that:

[0295] In a method for preparing a modified barrier filler,

[0296] The intermediate product I, intermediate product III, 2-phenoxyethyl acrylate, glycidyl methacrylate, allyl methyl carbonate, and acryloyloxyethyl trimethylammonium chloride were added in a carbon-carbon double bond molar ratio of 0.2:0.1:0.2:0:0.15:0.1; that is, no glycidyl methacrylate was added.

[0297] Comparative Example 13

[0298] Everything else is the same as in Example 1, except that:

[0299] In a method for preparing a modified barrier filler,

[0300] The intermediate product I, intermediate product III, 2-phenoxyethyl acrylate, methyl methacrylate (glycidyl methacrylate), allyl methyl carbonate, and acryloyloxyethyl trimethylammonium chloride were added in a carbon-carbon double bond molar ratio of 0.2:0.1:0.2:0.25:0:0.1; that is, allyl methyl carbonate was not added.

[0301] Comparative Example 14

[0302] Everything else is the same as in Example 1, except that:

[0303] In a method for preparing a modified barrier filler,

[0304] The intermediate product I, intermediate product III, 2-phenoxyethyl acrylate, methyl methacrylate (glycidyl methacrylate), allyl methyl carbonate, and acryloyloxyethyltrimethylammonium chloride were added in a carbon-carbon double bond molar ratio of 0.2:0.1:0.2:0.25:0.15:0; that is, no acryloyloxyethyltrimethylammonium chloride was added.

[0305] The physical properties of the low-carbon, high-barrier biodegradable mulch films used in the embodiments and comparative examples of this invention are shown in Tables 1 and 2.

[0306] Table 1 Physical performance tests of each embodiment

[0307]

[0308] Table 2. Degradation performance observation records for each embodiment.

[0309] Days 40d 80d 110d 130d 145d 160d Example 1 Induction period Induction period Induction period Induction period Large Rift Period No membrane period Example 2 Induction period Induction period Induction period Induction period Large Rift Period No membrane period Example 3 Induction period Induction period Induction period Induction period Large Rift Period No membrane period Example 4 Induction period Induction period Induction period Induction period Large Rift Period No membrane period Example 5 Induction period Induction period Induction period Induction period Large Rift Period No membrane period Example 6 Induction period Induction period Induction period Induction period Large Rift Period No membrane period Example 7 Induction period Induction period Induction period Induction period Large Rift Period No membrane period Example 8 Induction period Induction period Induction period Induction period Large Rift Period No membrane period Example 9 Induction period Induction period Induction period Induction period Large Rift Period No membrane period Example 10 Induction period Induction period Induction period Induction period Cracking period No membrane period Example 11 Induction period Induction period Cracking period Fragmentation period No membrane period No membrane period Comparative Example 1 Induction period Induction period Induction period Induction period Large Rift Period No membrane period Comparative Example 2 Induction period Induction period Induction period Induction period Large Rift Period Fragmentation period Implement Comparative Example 3 Induction period Cracking period Fragmentation period Large Rift Period No membrane period No membrane period Comparative Example 4 Induction period Cracking period Fragmentation period Large Rift Period No membrane period No membrane period Comparative Example 5 Induction period Induction period Cracking period Fragmentation period No membrane period No membrane period Comparative Example 6 Induction period Induction period Cracking period Fragmentation period No membrane period No membrane period Comparative Example 7 Induction period Induction period Induction period Induction period Cracking period Large Rift Period Implemented Comparative Example 8 Induction period Cracking period Fragmentation period No membrane period No membrane period No membrane period Comparative Example 9 Induction period Cracking period Fragmentation period No membrane period No membrane period No membrane period Implement Comparative Example 10 Induction period Induction period Induction period Induction period Large Rift Period No membrane period Comparative Example 11 Induction period Induction period Induction period Induction period Cracking period Fragmentation period Comparative Example 12 Induction period Induction period Induction period Induction period Large Rift Period No membrane period Comparative Example 13 Induction period Induction period Induction period Induction period Large Rift Period No membrane period Comparative Example 14 Induction period Induction period Induction period Induction period Large Rift Period No membrane period

[0310] First, as can be seen from Tables 1 and 2, Examples 1-11, the low-carbon, high-barrier biodegradable mulch film of the present invention has excellent mechanical properties, water vapor and oxygen barrier properties, and rapid degradation ability.

[0311] Secondly, as can be observed from Example 1 and Comparative Examples 1-8, the low-carbon, high-barrier biodegradable mulch film of the present invention, modified by blending PBAT, PLA, and PPCP, has complementary advantages and possesses excellent mechanical properties, water vapor and oxygen barrier properties, and biodegradability. UV absorbers, light stabilizers, antioxidants, anti-hydrolysis agents, and modified barrier fillers synergistically inhibit the degradation of the mulch film, ensuring its excellent performance during its service life. Degradation promoters enable rapid degradation of the material after its service life, reducing labor costs and exhibiting low-carbon properties.

[0312] As can be observed from Example 1 and Comparative Examples 8-14, the self-made modified barrier filler in the low-carbon, high-barrier biodegradable mulch film of the present invention has excellent barrier effects on both water vapor and oxygen; at the same time, it can be found that the modified filler has better compatibility, excellent chain extension effect and antibacterial properties.

[0313] In summary, the low-carbon, high-barrier biodegradable mulch film provided by this invention, on the one hand, utilizes molecular design to create a self-made modified barrier filler; on the other hand, through formulation, it possesses excellent comprehensive properties such as mechanical properties and barrier properties.

[0314] The testing method is as follows:

[0315] (1) Mechanical properties: tested according to the method described in GB / T 1040.3-2006.

[0316] (2) Water vapor transmission rate: Tested according to the method described in GB / T 1037-2021; the average thickness of the membrane to be tested is 50 μm.

[0317] (3) Oxygen permeability: The test was conducted according to the method described in GB / T 1038.1-2022, with a test condition of 1 atm and an average thickness of 50 μm for the membrane under test.

[0318] (4) Antibacterial rate: The test was conducted according to the method described in ASTM E2180-07(2012), and the test species was Staphylococcus aureus.

[0319] (5) Degradation status: According to the experimental design, the degradation status of the mulch film was observed and recorded at 40d, 80d, 110d, 130d, 145d and 160d after the mulch film was laid. The monitoring and recording were carried out according to the induction period, cracking period, large cracking period, fragmentation period and no film period to observe the degradation status of the mulch film.

[0320] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method for preparing a modified barrier filler, characterized in that, Includes the following steps: S11, graphene oxide and a silane coupling agent containing carbon-carbon double bonds are placed in an alcohol solvent to carry out a silanization coupling reaction to obtain intermediate product I; S12, lactic acid is reacted with glycidyl methacrylate in a ring-opening reaction to give intermediate product II; S13, intermediate II is subjected to a nucleophilic substitution reaction with perfluoroacyl chloride to obtain intermediate III; S14, intermediate product I, intermediate product III, 2-phenoxyethyl acrylate, methacrylate (glycidyl oxy) ethyl methacrylate, allyl methyl carbonate, and acryloyloxyethyl trimethylammonium chloride are subjected to free radical polymerization to obtain the target product, namely the modified barrier filler. The intermediate product II was added in a ratio of 1:1 to perfluoroacyl chloride, with the hydroxyl group being added at a molar ratio of 1:1 to the acyl chloride; and The carbon atoms of the perfluoroacyl chloride are C5-C8; The intermediate product I, intermediate product III, 2-phenoxyethyl acrylate, glycidyl methacrylate, allyl methyl carbonate, and acryloyloxyethyl trimethylammonium chloride are added in a carbon-carbon double bond molar ratio of 0.15-0.25: 0.05-0.15: 0.15-0.25: 0.2-0.3: 0.1-0.2: 0.05-0.

15.

2. The preparation method according to claim 1, characterized in that, The ratio of graphene oxide, carbon-carbon double-bonded silane, and alcohol solvent is 1g:0.8-1.5g:80mL; and The graphene oxide has a layered structure.

3. The preparation method according to claim 1, characterized in that, In step S12, the ratio of lactic acid to glycidyl methacrylate is 1:1, with the carboxyl group to epoxy group being added.

4. A modified barrier packing, characterized in that, Prepared by the method for preparing the modified barrier filler as described in any one of claims 1-3.

5. A low-carbon, high-barrier biodegradable mulch film, characterized in that, Including the following parts by weight of raw materials: PPCP 15-25 copies; PLA 5-25 copies; 50-80 copies of PBAT; 3.0-5.0 parts of the modified barrier filler as described in claim 4; 0.5-1.0 parts of UV absorber; Light stabilizer 0.2-0.5 parts; Antioxidant 0.2-0.5 parts; Anti-hydrolysis agent 0.3-0.8 parts; Plasticizer 2.0-4.0 parts; Heat stabilizer 2.0-3.0 parts; Lubricant 0.2-0.5 parts; Degradation accelerator 0.1-0.2 parts; The total mass of PPCP, PLA, and PBAT is 100 units.

6. The low-carbon, high-barrier biodegradable mulch film according to claim 5, characterized in that, The degradation accelerator is ferric stearate.

7. The method for preparing the low-carbon, high-barrier biodegradable mulch film according to claim 5, characterized in that, Includes the following steps: S21, Mixing, i.e. According to the formula, place all raw materials into a mixer and mix them evenly; S22, granulation, i.e. The pellets are fed into a pelletizing unit and extruded and pelletized at 160-200℃; and... S23, blown film, i.e. The granules are fed into a blown film machine for blowing and winding to obtain a low-carbon, high-barrier biodegradable mulch film.

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