Degradable nursery stock grafting wrapping film and preparation method thereof

Abstract

The invention provides a degradable nursery stock grafting wrapping film. The nursery stock grafting wrapping film prepared from the composition resin material provided by the invention has proper mechanical properties, good flexibility, proper self-adhesion performance and controllable degradation characteristics. In the using process of the wrapping film, the wrapping film has good tensile strength, high elongation at break and excellent flexibility, can be knotted during seedling grafting, does not slip, even can be used for irregular and wrinkled surfaces, and can be easily in good contact with the surfaces of grafted seedlings to form high binding power; meanwhile, permeation of water and oxygen can be promoted, the film can be affected by microorganisms and hydrolysis reaction in the external environment through the effects of moisture absorption, swelling and the like, biodegradation of the grafting film in the natural environment is promoted, and the grafting film has good environmental protection performance.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and particularly relates to a degradable seedling grafting wrapping film and a preparation method thereof. Background Art

[0002] Grafting is highly regarded in horticulture and agriculture, and the use of grafting wrap is crucial. Regarding the tightness of grafting wrap, it's important to understand that tighter wrap doesn't guarantee better results. Overly tight wrap can compress the plant, hindering its growth and even damaging the grafted area, reducing survival rates.

[0003] When choosing a wrapping film for seedling grafting, consider its material, thickness, color, adhesion, ease of use, and environmental considerations to ensure successful grafting and healthy seedling growth. Breathability: Ensure the film has good air permeability to prevent moisture accumulation and disease. Elasticity: A film with good elasticity can fit tightly to the joint, preventing loosening or falling off. Weather resistance: After its approximately two-month protective period, the film should be naturally degradable to reduce negative environmental impacts. Thickness: A film of moderate thickness provides adequate protection without hindering seedling growth. Too thick may affect air permeability, while too thin may provide insufficient protection. Color: Color affects light transmittance and temperature. Transparent films transmit light well and are suitable for grafting that requires sunlight, while black films block light and are suitable for grafting that requires shade. Adhesion: The film should have appropriate adhesion to ensure a secure fit, but not be too sticky to prevent removal or damage to the seedling. Ease of use: The film should be easy to handle, making wrapping and removal convenient and improving work efficiency. Environmental protection: Choose biodegradable or environmentally friendly materials to reduce negative environmental impacts.

[0004] The grafting stretch films currently available on the market are mainly the following polymer films: polyethylene film, which has good toughness and transparency, but average weather resistance, poor adhesion, poor air and water permeability, and is non-degradable; polypropylene film, which has high heat resistance and mechanical strength, but low surface energy, poor adhesion, poor air and water permeability, and is non-degradable; polyethylene terephthalate film, which has high rigidity, good wear resistance and chemical resistance, is suitable for reinforced grafting membrane, has poor adhesion, poor air and water permeability, and is non-degradable; polyvinyl chloride, which has strong plasticity and is widely used in high-adhesion membrane materials, has poor air and water permeability, but is non-degradable, and environmental issues are of great concern.

[0005] Therefore, providing a seedling grafting wrap film with suitable mechanical properties, good flexibility, appropriate self-adhesive properties and controllable degradation characteristics becomes a problem to be solved. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide a degradable seedling grafting wrap film and a preparation method thereof. The seedling grafting wrap film provided by the present invention has suitable mechanical properties, good flexibility, appropriate self-adhesive properties and controllable degradation characteristics.

[0007] The present invention provides a degradable seedling grafting wrap film, and the raw materials for preparing the film include, by weight:

[0008]

[0009] The polyisobutylene resin and the paraffin wax form a dual-continuous phase structure in terms of microscopic thermodynamic phase structure.

[0010] Preferably, the number average molecular weight of the polyisobutylene resin is 1500 to 1100000;

[0011] Preferably, the number average molecular weight of the polyisobutylene resin is at least one of 1,500 to 3,000, 400,000 to 600,000, and 800,000 to 1,200,000.

[0012] Preferably, the polyisobutylene resin is selected from a mixture of polyisobutylene resins having a number average molecular weight of 1,500 to 3,000, a number average molecular weight of 400,000 to 600,000, and a number average molecular weight of 800,000 to 1,200,000.

[0013] Preferably, the paraffin wax is at least one of flaky paraffin wax, refined paraffin wax, and palm wax;

[0014] Preferably, the melting point of the paraffin wax is 50-70°C.

[0015] Preferably, the degradation modifier is at least one of polylactic acid resin, chitosan, thermoplastic starch, and polyurethane.

[0016] Preferably, the molecular weight regulator is at least one of polyethylene wax, polypropylene wax, polyethylene glycol, and polyvinyl alcohol.

[0017] Preferably, the disintegration promoter is at least one of montmorillonite, wollastonite, diatomaceous earth and zeolite;

[0018] Preferably, the particle size of the disintegration promoter is 400 to 800 nanometers.

[0019] The present invention also provides a method for preparing the above-mentioned degradable seedling grafting wrap film, comprising the following steps:

[0020] A) blending a polyisobutylene resin, paraffin wax, a degradation modifier, a molecular weight regulator, and a disintegration accelerator to obtain a degradable seedling grafting wrapping film blend composition;

[0021] B) casting the degradable seedling grafting wrapping film blend composition into a film, and winding it up to obtain the degradable seedling grafting wrapping film.

[0022] Preferably, in step A), the blending time is 10 to 60 minutes.

[0023] Preferably, in step B), the temperature of the film casting is 60-120°C.

[0024] The present invention provides a degradable seedling grafting wrap film, which mainly solves the following technical performance requirements of the grafting wrap film: (1) lower tensile strength (0.05-0.06MPa) and higher elongation at break (≥240%), so that users can use less force to stretch the wrap film and wrap it around the grafting position of the seedlings to be covered; (2) the main body of the grafting wrap film after stretching is a continuous network structure, so that the wrap film can promote the penetration of water and oxygen through the network structure when in use, accelerate moisture absorption, swelling, etc., so that the film can be affected by microorganisms and hydrolysis reactions in the external environment, and promote the grafting film in nature. (3) Good hydrophilic effect (contact angle of pure water ≤ 82.0°) to ensure that the stretch film can promote water penetration, accelerate moisture absorption, swelling, etc. when in use, so that the film can be affected by microorganisms and hydrolysis reactions in the external environment, and promote the biodegradation of the grafted film in the natural environment to ensure good environmental performance; (4) Good windability and knotting performance to ensure that the stretch film can be tied in a knot when in use, and the knot will not slip off, so that the film has high durability and excellent flexibility, which can ensure the durability of the overall covering of the grafted part during the use of seedling grafting.

[0025] Compared to existing technologies, the present invention provides a degradable wrap for grafted seedlings. The raw materials, calculated by weight, include: 100 parts polyisobutylene resin; 60-80 parts paraffin wax; 3-15 parts degradation modifier; 20-40 parts molecular weight regulator; and 0.5-5 parts disintegration accelerator. The polyisobutylene resin and paraffin wax form a co-continuous phase structure in terms of microscopic thermodynamic phase structure. The wrap for grafted seedlings, made from the composite resin material provided by the present invention, exhibits suitable mechanical properties, good flexibility, moderate self-adhesive properties, and controllable degradation characteristics. During the use of the stretch film, it has good tensile strength, high elongation at break and excellent flexibility. When used for seedling grafting, it can be tied into knots without slipping, and can even be used on irregular and wrinkled surfaces. It can easily come into good contact with the surface of the grafted seedlings to form a strong adhesive force; at the same time, it can promote the penetration of water and oxygen, and through moisture absorption, swelling and other effects, the film can be affected by microorganisms and hydrolysis reactions in the external environment, promoting the biodegradation of the grafted film in the natural environment, and has good environmental performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The main network structure of the degradable seedling grafting wrap film provided in Examples 1 to 3 of the present invention after ultimate stretching at room temperature;

[0027] Figure 2 This is the main network structure of the comparative stretch films provided in Comparative Examples 1 to 8 of the present invention after ultimate stretching at room temperature;

[0028] Figure 3 This is the effect of the degradable seedling grafting wrap film provided by Examples 1 to 3 of the present invention after being tied with a knot and placed indoors for 14 days. DETAILED DESCRIPTION

[0029] The present invention provides a degradable seedling grafting wrap film, and the raw materials for preparing the film include, by weight:

[0030]

[0031] The polyisobutylene resin and the paraffin wax form a dual-continuous phase structure in terms of microscopic thermodynamic phase structure.

[0032] The present invention provides a seedling grafting wrap film comprising 100 parts by mass of a polyisobutylene resin. The polyisobutylene resin has a main chain structure primarily composed of saturated hydrocarbon chains. The main chain formed after polymerization has branched methyl side chains. The molecular chain is flexible and non-polar, resulting in excellent fluidity and sealing properties while also exhibiting good windability and knot-tying properties. This ensures that the wrap film can be knotted without slipping during use, ensuring the durability of the overall covering of the grafted portion during the seedling grafting process.

[0033] In the present invention, the number average molecular weight of the polyisobutylene resin is 1500-1100000; preferably, the number average molecular weight of the polyisobutylene resin is at least one of 1500-3000, 400000-600000, and 800000-1200000.

[0034] In a preferred embodiment of the present invention, the polyisobutylene resin is selected from a mixture of polyisobutylene resins having a number average molecular weight of 1500-3000, a number average molecular weight of 400,000-600,000, and a number average molecular weight of 800,000-1200,000. The mass ratio of the polyisobutylene resins having a number average molecular weight of 1500-3000, a number average molecular weight of 400,000-600,000, and a number average molecular weight of 800,000-1200,000 is (1-5):(40-60):(40-60), preferably 4:50:50, 4:56:44, or any value between (1-5):(40-60):(40-60).

[0035] In the present invention, polyisobutylene is prepared by blending high molecular weight (number average molecular weight of 800,000-1,200,000), medium molecular weight (number average molecular weight of 400,000-600,000), and low molecular weight (number average molecular weight of 1,500-3,000) polyisobutylene in an optimized ratio. The synergistic effect of the different molecular weight polyisobutylenes optimizes the adhesion, mechanical properties, and biodegradability of the membrane, enabling it to automatically degrade or peel after grafting, eliminating the need for manual removal. The specific analysis is as follows:

[0036] (1) The use of polyisobutylene with different molecular weights can improve the comprehensive performance of the stretch film: Among them, high molecular weight (number average molecular weight of 800,000-1,200,000) polyisobutylene resin provides higher mechanical strength and weather resistance, making the stretch film less likely to break during the grafting process, and can effectively seal the wound to prevent water loss and invasion of pathogens. Medium molecular weight (number average molecular weight of 400,000-600,000) polyisobutylene resin gives the film better flexibility and ductility, allowing it to fit closely to the grafting site, improving the convenience and adaptability of the grafting operation. Low molecular weight (number average molecular weight of 1,500-3,000) polyisobutylene resin reduces the viscosity of the system and improves the self-adhesion of the material, so that the stretch film can be stably attached without additional adhesives, while enhancing degradation performance.

[0037] (2) Imparting biodegradable properties to the grafted membrane, reducing environmental pollution: Traditional plastic grafted membranes (such as PE and PVC) are difficult to degrade, leading to agricultural waste pollution. The present invention utilizes the oxidative degradation properties of polyisobutylene, combined with degradation modifiers and disintegration promoters, to enable the membrane to gradually degrade in the natural outdoor environment without affecting soil and plant growth. Furthermore, by adjusting the content of low molecular weight (number average molecular weight of 1,500 to 3,000) polyisobutylene, the degradation process of the membrane can be further accelerated, allowing it to automatically peel off after grafting, avoiding the additional operation of manual removal.

[0038] (3) Optimize adhesion and operability to improve the success rate of grafting. Traditional grafting films may cause uneven winding or damage to young shoots due to insufficient or excessive adhesion. The present invention adjusts the ratio of high molecular weight (number average molecular weight of 800,000-1,200,000), medium molecular weight (number average molecular weight of 400,000-600,000) and low molecular weight (number average molecular weight of 1,500-3,000) polyisobutylene to ensure that the film has moderate adhesion, can be firmly wound but will not cause mechanical damage to the seedlings; the blended material can maintain a stable shape under different temperature and humidity conditions, and is suitable for a variety of climate environments and seedling types.

[0039] The grafted seedling wrapping film provided by the present invention further comprises 60 to 80 parts by weight of paraffin wax, which may be 60, 62, 64, 65, 66, 68, 70, 72, 74, 75, 76, 78, 80, or any value between 60 and 80 parts by weight. The paraffin wax is at least one of flaky paraffin, refined paraffin, and palm wax; preferably, the paraffin wax has a melting point of 50 to 70°C.

[0040] In the present invention, the paraffin wax has non-polarity, low molecular weight, low melting point, and excellent biodegradability. On the one hand, it can reduce the degree of entanglement of the molecular chains of polyisobutylene, improve the flexibility and plasticity of the film, and impart moderate stretchability to the film. At the same time, the low-melting-point paraffin wax can form a certain lubricating layer at room temperature, improving the surface wettability of the film, making it easier to wrap and adhere, and preventing the grafted film from being too hard or difficult to handle. On the other hand, the low molecular weight components of the paraffin wax are easily decomposed by photooxidation in the natural environment, forming smaller degradation products. Through contact with external microorganisms or oxygen, the biodegradability of the film is improved. At the same time, due to the high non-polarity of polyisobutylene, it has excellent compatibility with the long-chain alkane structure of the paraffin wax at the molecular level, forming a uniform blend system, ensuring that the winding is not easily broken or loosened during winding and use. In particular, under the optimized raw material ratio of polyisobutylene to paraffin wax adopted in the present invention, the paraffin phase can be allowed to penetrate the polyisobutylene phase, forming a specific bicontinuous phase structure, which can make the prepared grafted film more plastic.

[0041] The grafted seedling wrapping film provided by the present invention further comprises 10 to 15 parts by weight of a degradation modifier, which may be 10, 11, 12, 13, 14, 15, or any value between 10 and 15 parts by weight. The degradation modifier is at least one of polylactic acid resin, chitosan, thermoplastic starch, and polyurethane.

[0042] The present invention utilizes an optimized material ratio of polyisobutylene resins of varying molecular weights and a degradation modifier to achieve a grafting membrane with excellent mechanical strength, flexibility, self-adhesion, and controlled degradation properties, thereby improving graft survival rates and allowing for natural degradation after use, reducing environmental pollution. The present invention utilizes the uniformly dispersed phase formed by blending the hydrophobic molecular chains of polyisobutylene with the degradation modifier to provide a multiphase composite system. The high viscoelasticity of polyisobutylene ensures that the wrap film effectively covers the grafting site and maintains a tight seal. While imparting excellent mechanical strength, flexibility, and self-adhesion, the inclusion of the degradation modifier imparts an appropriate degradation rate to the wrap film, allowing it to degrade naturally after grafting, eliminating the need for manual removal and reducing environmental pollution. The polylactic acid resin used in the present invention interacts with the polyisobutylene resin to adjust its hydrophilicity and natural degradation properties, so that the film can be naturally degraded after use, reducing environmental pollution. The chitosan used in the present invention has strong polarity, amino groups and hydroxyl groups, which can give the blended system excellent biocompatibility, air permeability, hydrophilicity and antibacterial properties. Although there are compatibility issues between the chitosan and the polyisobutylene resin due to its hydrophobicity, thermoplastic starch or polyurethane is used as an interfacial compatibilizer to improve the binding force between the two and make the system uniform and stable. The thermoplastic starch used in the present invention is a thermoplastic network formed by starch particles and a plasticizer (such as glycerol). It contains a large number of hydroxyl groups and easily absorbs water to swell, reducing the pure water contact angle of the material (≤82.0°) and increasing the degradation rate of the material. At the same time, the thermoplastic starch can also be micro-crosslinked with the polyisobutylene resin, improving the uniform dispersion of the degradable material in the polyisobutylene resin matrix. The polyurethane used in the present invention has good flexibility and compatibility. It can be embedded in the molecular chain gaps of polyisobutylene (PIB), which can improve the mechanical properties and degradation stability of the material.

[0043] The grafted seedling wrapping film provided by the present invention further comprises 5 to 15 parts by weight of a molecular weight regulator, which may be 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or any value between 5 and 15 parts by weight. The molecular weight regulator is at least one of polyethylene wax, polypropylene wax, polyethylene glycol, and polyvinyl alcohol.

[0044] The invention optimizes the mechanical properties, flexibility, self-adhesion and controllable degradability of the prepared grafting stretch film by blending a molecular weight regulator with a polyisobutylene resin. The stretch film is endowed with the ability to gradually degrade after grafting, thereby avoiding agricultural plastic waste pollution and improving the grafting survival rate. The polyethylene wax and polypropylene wax used in the present invention can migrate to the film surface to form a moderate lubricating layer, reduce entanglement between polyisobutylene molecular chains, improve the film's flexibility, make the film easy to wrap but not sticky, and improve handleability. At the same time, due to the short molecular chains of the waxes, they are easily decomposed under ultraviolet light and oxidation, which can accelerate the natural degradation of the grafted wrap film. The polyethylene glycol and polyvinyl alcohol used in the present invention have the characteristics of hydrophilicity, low melting point, and easy oxidative degradation. While improving the ductility of the film, preventing the film from being too hard or brittle, and optimizing handleability, they also have low compatibility with the polyisobutylene resin due to their polar groups. In particular, the optimized raw material ratio of polyisobutylene and molecular weight regulators (polyethylene wax, polypropylene wax, polyethylene glycol, and polyvinyl alcohol) used in the present invention can form a specific micro-domain phase separation structure. This structure can form cracks during the degradation process, accelerate hydrolysis and oxidative degradation, and improve the degradability of the grafted film.

[0045] The seedling grafting wrap provided by the present invention also includes 1.5 to 2.5 parts by mass of a disintegration promoter, which can be 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, or any value between 1.5 and 2.5 parts by mass. The disintegration promoter is at least one of montmorillonite, wollastonite, diatomaceous earth, and zeolite; and the particle size of the disintegration promoter is 400 to 800 nanometers, which can be 400, 500, 600, 700, 800, or any value between 400 and 800 nanometers.

[0046] The disintegration promoter used in the present invention has a large amount of negative charge and a high specific surface area in its molecular structure. This structure enables it to form a layered structure in the membrane matrix and interact with the molecular chains of polyisobutylene through electrostatic interaction to form a multilayer phase interface, which facilitates the diffusion of water and oxygen and promotes the degradation of the grafted membrane. On the other hand, since polyisobutylene itself is a non-polar polymer, while the disintegration promoter used in the present invention has certain polar properties, there is a significant difference in compatibility between the two. Under the optimized raw material ratio of polyisobutylene to disintegration promoter used in the present invention, a microscopic phase separation structure may be formed during the blending process, which helps to accelerate the decomposition of the grafted membrane through microcracks, pores or layered structures after use.

[0047] The present invention also provides a method for preparing the above-mentioned degradable seedling grafting wrap film, comprising the following steps:

[0048] A) blending a polyisobutylene resin, paraffin wax, a degradation modifier, a molecular weight regulator, and a disintegration accelerator to obtain a degradable seedling grafting wrapping film blend composition;

[0049] B) casting the degradable seedling grafting wrapping film blend composition into a film, and winding it up to obtain the degradable seedling grafting wrapping film.

[0050] Specifically, the present invention firstly blends polyisobutylene resin, paraffin wax, a degradation modifier, a molecular weight regulator, and a disintegration accelerator to obtain a degradable seedling grafting wrapping film blend composition.

[0051] In some embodiments of the present invention, polyisobutylene resins of different molecular weight ranges are mixed to obtain a polyisobutylene resin compound, wherein the mixing temperature is preferably room temperature, which is defined as 25±5°C in the present invention.

[0052] Then, paraffin wax, a degradation modifier and a molecular weight regulator are mixed, and then mixed with a polyisobutylene resin rubber compound. Finally, a disintegration accelerator is added and mixed to obtain a degradable seedling grafting wrapping film blend composition.

[0053] Next, the degradable seedling grafting wrap film blend composition is placed in the feed port of a film casting machine, the molding temperature is set to 60-120°C, the film is cast, and the film is wound to obtain the degradable seedling grafting wrap film. The molding temperature can be 60, 70, 80, 90, 100, 110, 120, or any value between 60 and 120°C.

[0054] The present invention proposes a degradable seedling grafting wrap film. The film is prepared by a casting method using raw materials such as polyisobutylene resin (PIB), paraffin wax, a degradation modifier, a molecular weight regulator, and a disintegration promoter, which are mixed uniformly. By adding paraffin wax, a degradation modifier, a molecular weight regulator, and a disintegration promoter to a polyisobutylene matrix and utilizing the molecular structure complementarity, interaction, and microphase structure regulation of these components, the film achieves excellent mechanical properties, good flexibility, moderate self-adhesion, hydrophilicity, air and moisture permeability, and controllable degradation characteristics. These properties enable the film to gradually decompose through hydrolysis and microbial degradation after use, thereby reducing agricultural plastic waste pollution and achieving both environmental and economic benefits. In the present invention, by compounding a certain amount of high molecular weight (number average molecular weight of 800,000 to 1,200,000), medium molecular weight (number average molecular weight of 400,000 to 600,000) and low molecular weight (number average molecular weight of 1,500 to 3,000) polyisobutylene, and utilizing the high viscosity of the polyisobutylene resin itself, the seedling grafting wrap film can self-adhere when used and can easily contact with the surface to form a strong adhesive force; while paraffin wax is used to increase the flexibility of the grafting wrap film, improve the surface smoothness of the film, and thereby improve the appearance quality and performance of the wrap film, under the optimized raw material ratio of polyisobutylene to paraffin wax adopted in the present invention, the paraffin wax phase penetrates the polyisobutylene phase and forms a specific bicontinuous phase structure with it. , this structure can make the prepared grafted membrane more plastic; the degradation modifier used in the present invention includes natural degradable materials such as polylactic acid resin, chitosan, thermoplastic starch, polyurethane, etc., which have good biodegradability. During the use of the membrane, the biodegradation of the grafted membrane is promoted by moisture absorption, swelling and other effects; the molecular weight regulator used in the present invention mainly adjusts the processing performance and mechanical properties of the blend by changing the molecular chain structure and molecular weight distribution of the polymer, while improving the hydrophilicity of the membrane (pure water contact angle ≤82.0°) and accelerating the degradation process of the membrane; the disintegration promoter used in the present invention mainly physically intervenes in the membrane through its unique microstructure, accelerates the penetration of water and forms a cleavage channel, and ultimately promotes the disintegration and degradation of the membrane. In addition, in the microscopic phase structure of a prepared degradable seedling grafting wrap film, paraffin and polyisobutylene phases can form a specific bicontinuous phase structure to enhance the plasticity of the system; polyisobutylene and disintegration promoters (montmorillonite, wollastonite, diatomaceous earth, zeolite) can form layered or porous structures. These structures not only improve the mechanical properties of the film (such as tear resistance and flexibility), but also promote the permeation of water and oxygen, making the film susceptible to microorganisms and hydrolysis reactions in the external environment, and ultimately accelerating the degradation process.

[0055] The technical solution provided by the present invention, by adopting an optimized raw material ratio of polyisobutylene and paraffin, can make the paraffin phase penetrate the polyisobutylene phase, and can form a specific bicontinuous phase structure. This structure can make the prepared grafting film more plastic, so as to ensure that the seedling grafting wrap film prepared by the present invention has both low tensile strength and high elongation at break and excellent flexibility. When used for seedling grafting, it can be tied into a knot, the knot will not slip, and it can even be used on irregular and wrinkled surfaces. At the same time, the flexibility and weather resistance of the seedling grafting wrap film can enable it to adapt to different climatic conditions, including low temperature, high humidity and other environments, ensuring that it can work effectively under various external conditions. In addition, due to the poor compatibility between polyisobutylene resin and paraffin and disintegration promoters (such as montmorillonite, wollastonite, etc.), a phase separation structure may be formed. This structure is prone to form cracks or pores during the use of the seedling grafting wrap film, thereby accelerating the biodegradation of the seedling grafting wrap film.

[0056] In order to further understand the present invention, the degradable seedling grafting wrap film and the preparation method thereof provided by the present invention are described below in conjunction with the embodiments. The protection scope of the present invention is not limited by the following embodiments.

[0057] Example 1

[0058] 1) Weighing 2 parts by mass of a polyisobutylene resin (brand: N100, manufacturer: BASF China GmbH, Germany, the same below), 25 parts by mass of a polyisobutylene resin (brand: N50, manufacturer: BASF China GmbH, Germany, the same below), and 25 parts by mass of a polyisobutylene resin (brand: B12, manufacturer: BASF China GmbH, Germany, the same below), placing them in an open rubber mixer, mixing them at room temperature for 20 minutes, and then taking them out to prepare a polyisobutylene resin rubber mix;

[0059] 2) Weigh 40 parts by mass of flaky paraffin wax (melting point: 65°C to 70°C, manufacturer: Sinopharm Chemical Reagent Co., Ltd., the same below), 5 parts by mass of polyethylene wax (brand: LP0200P, manufacturer: Thailand Elephant Group Co., Ltd., the same below), and 6 parts by mass of thermoplastic starch (brand: NX-TPS-01, manufacturer: Changzhou Noxin Polymer Technology Co., Ltd., the same below), mix the three in a high-speed mixer, and place them together with the polyisobutylene resin compound prepared in step (1) in an open rubber mixer. After mixing at room temperature for 20 minutes, continue to add 1.0 parts by mass of diatomaceous earth (brand: 800, manufacturer: Jinan Century Tongda Chemical Co., Ltd., the same below), mix at room temperature for 10 minutes, and then take out to prepare a seedling grafting wrapping film blend composition;

[0060] 3) The seedling grafting wrapping film blend composition prepared in step (2) is placed in the feeding port of a film casting machine (brand: XH-432, manufacturer: Xihua Testing Instrument Co., Ltd., the same below), the screw speed of the film casting machine is set to 100 rpm, the screw temperature is set from the feeding hopper to the die mouth to 80 ° C, 100 ° C, 115 ° C, 120 ° C, 120 ° C, the traction speed is set to 50 rpm, the magnetic powder winding rate is set to 65 rpm, the temperature of the first roller is set to 50 ° C, the roller spacing between the first and second rollers is set to 0.04 mm, the temperature of the second roller is set to 30 ° C, the roller spacing between the second and third rollers is set to 0.03 mm, and the temperature of the third roller is set to 30 ° C. Extrusion, casting, and winding can prepare a degradable seedling grafting wrapping film according to the present invention. The test results of the seedling grafting wrapping film are shown in Table 1.

[0061] Example 2

[0062] 1) Weighing 2 parts by mass of a polyisobutylene resin (brand: N100), 28 parts by mass of a polyisobutylene resin (brand: N50), and 22 parts by mass of a polyisobutylene resin (brand: B12), placing them in an open rubber mixer, mixing them at room temperature for 20 minutes, and then removing them to prepare a polyisobutylene resin rubber mix;

[0063] 2) Weighing 40 parts by mass of refined paraffin wax (brand: No. 58, manufacturer: PetroChina Fushun Petrochemical Company Petroleum Plant No. 1, the same below), 7 parts by mass of polyethylene wax, and 5.5 parts by mass of thermoplastic starch, mixing the three in a high-speed mixer, placing them together with the polyisobutylene resin rubber mix prepared in step (1) in an open rubber mixer, mixing at room temperature for 20 minutes, and then adding 1.2 parts by mass of diatomaceous earth. After mixing at room temperature for 10 minutes, the mixture is taken out to prepare a seedling grafting wrapping film blend composition;

[0064] 3) The seedling grafting wrapping film blend composition prepared in step (2) is placed in the feed port of a film casting machine, the screw speed of the film casting machine is set to 100 rpm, the screw temperature is set from the feed hopper to the die mouth to 80 ° C, 100 ° C, 115 ° C, 120 ° C, 120 ° C, the traction speed is set to 50 rpm, the magnetic powder winding rate is set to 65 rpm, the temperature of the first roller is set to 50 ° C, the roller spacing between the first and second rollers is set to 0.04 mm, the temperature of the second roller is set to 30 ° C, the roller spacing between the second and third rollers is set to 0.03 mm, the temperature of the third roller is set to 30 ° C, extrusion, casting, winding, and a degradable seedling grafting wrapping film according to the present invention can be prepared. The test results of the seedling grafting wrapping film are shown in Table 1.

[0065] Example 3

[0066] 1) Weighing 2 parts by mass of a polyisobutylene resin (brand: N100), 22 parts by mass of a polyisobutylene resin (brand: N50), and 28 parts by mass of a polyisobutylene resin (brand: B12), placing them in an open rubber mixer, mixing them at room temperature for 20 minutes, and then removing them to prepare a polyisobutylene resin rubber mix;

[0067] 2) Weighing 40 parts by mass of refined paraffin wax (brand: No. 58, manufacturer: PetroChina Fushun Petrochemical Company Petroleum Plant No. 1, the same below), 6 parts by mass of polyethylene wax, and 7.5 parts by mass of thermoplastic starch, mixing the three in a high-speed mixer, placing them together with the polyisobutylene resin rubber mix prepared in step (1) in an open rubber mixer, mixing at room temperature for 20 minutes, and then adding 0.3 parts by mass of diatomaceous earth. After mixing at room temperature for 10 minutes, the mixture is taken out to prepare a seedling grafting wrapping film blend composition;

[0068] 3) The seedling grafting wrapping film blend composition prepared in step (2) is placed in the feed port of a film casting machine, the screw speed of the film casting machine is set to 100 rpm, the screw temperature is set from the feed hopper to the die mouth to 80 ° C, 100 ° C, 115 ° C, 120 ° C, 120 ° C, the traction speed is set to 50 rpm, the magnetic powder winding rate is set to 65 rpm, the temperature of the first roller is set to 50 ° C, the roller spacing between the first and second rollers is set to 0.04 mm, the temperature of the second roller is set to 30 ° C, the roller spacing between the second and third rollers is set to 0.03 mm, the temperature of the third roller is set to 30 ° C, extrusion, casting, winding, and a degradable seedling grafting wrapping film according to the present invention can be prepared. The test results of the seedling grafting wrapping film are shown in Table 1.

[0069] Comparative Example 1

[0070] 1) Weighing 27 parts by mass of a polyisobutylene resin (brand: N50) and 25 parts by mass of a polyisobutylene resin (brand: B12), placing them in an open rubber mixer, mixing them at room temperature for 20 minutes, and then removing them to prepare a polyisobutylene resin rubber mix;

[0071] 2) Weigh 40 parts by mass of flaky paraffin wax, 5 parts by mass of polyethylene wax, and 6 parts by mass of thermoplastic starch, mix the three together in a high-speed mixer, and place them together with the polyisobutylene resin mix prepared in step (1) in an open rubber mixer. After mixing at room temperature for 20 minutes, 1.0 part by mass of diatomaceous earth is added, and after mixing at room temperature for 10 minutes, the mixture is removed to prepare the comparative example 1 stretch film blend composition;

[0072] 3) The Comparative Example 1 stretch film blend composition prepared in step (2) was placed in the feed port of a film casting machine, the screw speed of the film casting machine was set to 100 rpm, the screw temperature from the feed hopper to the die was set to 80°C, 100°C, 115°C, 120°C, and 120°C, the pulling speed was set to 50 rpm, the magnetic powder winding rate was set to 65 rpm, the temperature of the first roller was set to 50°C, the roller gap between the first and second rollers was set to 0.04 mm, the temperature of the second roller was set to 30°C, the roller gap between the second and third rollers was set to 0.03 mm, and the temperature of the third roller was set to 30°C. The stretch film of Comparative Example 1 of the present invention was prepared by extrusion, casting, and winding. The test results of the stretch film of Comparative Example 1 are shown in Table 1.

[0073] Comparative Example 2

[0074] 1) Weighing 2 parts by mass of a polyisobutylene resin (brand: N100) and 50 parts by mass of a polyisobutylene resin (brand: B12), placing them in an open rubber mixer, mixing them at room temperature for 20 minutes, and then removing them to prepare a polyisobutylene resin rubber mix;

[0075] 2) Weigh 40 parts by mass of flaky paraffin wax, 5 parts by mass of polyethylene wax, and 6 parts by mass of thermoplastic starch, mix the three together in a high-speed mixer, and place them together with the polyisobutylene resin mix prepared in step (1) in an open rubber mixer. After mixing at room temperature for 20 minutes, 1.0 part by mass of diatomaceous earth is added, and the mixture is mixed at room temperature for 10 minutes before being removed to prepare the stretch film blend composition of Comparative Example 2;

[0076] 3) The comparative example 2 stretch film blend composition prepared in step (2) was placed in the feed port of a film casting machine, the screw speed of the film casting machine was set to 100 rpm, the screw temperature from the feed hopper to the die was set to 80°C, 100°C, 115°C, 120°C, and 120°C, the pulling speed was set to 50 rpm, the magnetic powder winding rate was set to 65 rpm, the temperature of the first roller was set to 50°C, the roller spacing between the first and second rollers was set to 0.04 mm, the temperature of the second roller was set to 30°C, the roller spacing between the second and third rollers was set to 0.03 mm, and the temperature of the third roller was set to 30°C. The stretch film of comparative example 2 of the present invention was prepared by extrusion, casting, and winding. The test results of the stretch film of comparative example 2 are shown in Table 1.

[0077] Comparative Example 3

[0078] 1) Weighing 2 parts by mass of a polyisobutylene resin (brand: N100) and 50 parts by mass of a polyisobutylene resin (brand: N50), placing them in an open rubber mixer, mixing them at room temperature for 20 minutes, and then removing them to prepare a polyisobutylene resin rubber mix;

[0079] 2) Weigh 40 parts by mass of flaky paraffin wax, 5 parts by mass of polyethylene wax, and 6 parts by mass of thermoplastic starch, mix the three together in a high-speed mixer, and place them together with the polyisobutylene resin mix prepared in step (1) in an open rubber mixer. After mixing at room temperature for 20 minutes, 1.0 part by mass of diatomaceous earth is added, and the mixture is mixed at room temperature for 10 minutes before being removed to prepare the stretch film blend composition of Comparative Example 3;

[0080] 3) The comparative example 3 stretch film blend composition prepared in step (2) was placed in the feed port of a film casting machine, the screw speed of the film casting machine was set to 100 rpm, the screw temperature from the feed hopper to the die was set to 80°C, 100°C, 115°C, 120°C, and 120°C, the pulling speed was set to 50 rpm, the magnetic powder winding rate was set to 65 rpm, the temperature of the first roller was set to 50°C, the roller gap between the first and second rollers was set to 0.04 mm, the temperature of the second roller was set to 30°C, the roller gap between the second and third rollers was set to 0.03 mm, and the temperature of the third roller was set to 30°C. The film was extruded, cast, and wound to prepare the comparative example 3 stretch film of the present invention. The test results of the comparative example 3 stretch film are shown in Table 1.

[0081] Comparative Example 4

[0082] 1) Weighing 2 parts by mass of a polyisobutylene resin (brand: N100), 25 parts by mass of a polyisobutylene resin (brand: N50), and 25 parts by mass of a polyisobutylene resin (brand: B12), placing them in an open rubber mixer, mixing them at room temperature for 20 minutes, and then removing them to prepare a polyisobutylene resin rubber mix;

[0083] 2) Weigh 20 parts by mass of flaky paraffin wax, 5 parts by mass of polyethylene wax, and 6 parts by mass of thermoplastic starch, mix the two together in a high-speed mixer, and place them together with the polyisobutylene resin mix prepared in step (1) in an open rubber mixer. After mixing at room temperature for 20 minutes, 1.0 part by mass of diatomaceous earth is added, and the mixture is mixed at room temperature for 10 minutes before being removed to prepare the stretch film blend composition of Comparative Example 4;

[0084] 3) The Comparative Example 4 stretch film blend composition prepared in step (2) was placed in the feed port of a film casting machine, the screw speed of the film casting machine was set to 100 rpm, the screw temperature from the feed hopper to the die was set to 80°C, 100°C, 115°C, 120°C, and 120°C, the pulling speed was set to 50 rpm, the magnetic powder winding rate was set to 65 rpm, the temperature of the first roller was set to 50°C, the roller gap between the first and second rollers was set to 0.04 mm, the temperature of the second roller was set to 30°C, the roller gap between the second and third rollers was set to 0.03 mm, and the temperature of the third roller was set to 30°C. The film was extruded, cast, and wound to prepare the Comparative Example 4 stretch film of the present invention. The test results of the Comparative Example 4 stretch film are shown in Table 1.

[0085] Comparative Example 5

[0086] 1) Weighing 2 parts by mass of a polyisobutylene resin (brand: N100), 25 parts by mass of a polyisobutylene resin (brand: N50), and 25 parts by mass of a polyisobutylene resin (brand: B12), placing them in an open rubber mixer, mixing them at room temperature for 20 minutes, and then removing them to prepare a polyisobutylene resin rubber mix;

[0087] 2) Weigh 40 parts by mass of flaky paraffin wax and 5 parts by mass of polyethylene wax, mix the two in a high-speed mixer, and place them together with the polyisobutylene resin mix prepared in step (1) in an open rubber mixer. After mixing at room temperature for 20 minutes, 1.0 part by mass of diatomaceous earth is added, and after mixing at room temperature for 10 minutes, the mixture is removed to prepare a stretch film blend composition of Comparative Example 5;

[0088] 3) The Comparative Example 5 stretch film blend composition prepared in step (2) was placed in the feed port of a film casting machine, the screw speed of the film casting machine was set to 100 rpm, the screw temperature from the feed hopper to the die was set to 80°C, 100°C, 115°C, 120°C, and 120°C, the pulling speed was set to 50 rpm, the magnetic powder winding rate was set to 65 rpm, the temperature of the first roller was set to 50°C, the roller gap between the first and second rollers was set to 0.04 mm, the temperature of the second roller was set to 30°C, the roller gap between the second and third rollers was set to 0.03 mm, and the temperature of the third roller was set to 30°C. The film was extruded, cast, and wound to produce the Comparative Example 5 stretch film of the present invention. The test results of the Comparative Example 5 stretch film are shown in Table 1.

[0089] Comparative Example 6

[0090] 1) Weighing 2 parts by mass of a polyisobutylene resin (brand: N100), 25 parts by mass of a polyisobutylene resin (brand: N50), and 25 parts by mass of a polyisobutylene resin (brand: B12), placing them in an open rubber mixer, mixing them at room temperature for 20 minutes, and then removing them to prepare a polyisobutylene resin rubber mix;

[0091] 2) Weigh 40 parts by mass of flaky paraffin wax and 6 parts by mass of thermoplastic starch, mix the two in a high-speed mixer, and place them together with the polyisobutylene resin mix prepared in step (1) in an open rubber mixer. After mixing at room temperature for 20 minutes, 1.0 part by mass of diatomaceous earth is added, and after mixing at room temperature for 10 minutes, the mixture is removed to prepare a wrapping film blend composition of Comparative Example 6;

[0092] 3) The Comparative Example 6 stretch film blend composition prepared in step (2) was placed in the feed port of a film casting machine, the screw speed of the film casting machine was set to 100 rpm, the screw temperature from the feed hopper to the die was set to 80°C, 100°C, 115°C, 120°C, and 120°C, the pulling speed was set to 50 rpm, the magnetic powder winding rate was set to 65 rpm, the temperature of the first roller was set to 50°C, the roller gap between the first and second rollers was set to 0.04 mm, the temperature of the second roller was set to 30°C, the roller gap between the second and third rollers was set to 0.03 mm, and the temperature of the third roller was set to 30°C. The film was extruded, cast, and wound to produce the Comparative Example 6 stretch film of the present invention. The test results of the Comparative Example 6 stretch film are shown in Table 1.

[0093] Comparative Example 7

[0094] 1) Weighing 2 parts by mass of a polyisobutylene resin (brand: N100), 25 parts by mass of a polyisobutylene resin (brand: N50), and 25 parts by mass of a polyisobutylene resin (brand: B12), placing them in an open rubber mixer, mixing them at room temperature for 20 minutes, and then removing them to prepare a polyisobutylene resin rubber mix;

[0095] 2) Weigh 40 parts by mass of flaky paraffin wax, 5 parts by mass of polyethylene wax, and 6 parts by mass of thermoplastic starch, mix the three together in a high-speed mixer, place them together with the polyisobutylene resin rubber mix prepared in step (1) in an open rubber mixer, mix at room temperature for 20 minutes, and then take them out to prepare the stretch film blend composition of Comparative Example 7;

[0096] 3) The Comparative Example 7 stretch film blend composition prepared in step (2) was placed in the feed port of a film casting machine, the screw speed of the film casting machine was set to 100 rpm, the screw temperature from the feed hopper to the die was set to 80°C, 100°C, 115°C, 120°C, and 120°C, the pulling speed was set to 50 rpm, the magnetic powder winding rate was set to 65 rpm, the temperature of the first roller was set to 50°C, the roller gap between the first and second rollers was set to 0.04 mm, the temperature of the second roller was set to 30°C, the roller gap between the second and third rollers was set to 0.03 mm, and the temperature of the third roller was set to 30°C. The film was extruded, cast, and wound to prepare the Comparative Example 7 stretch film of the present invention. The test results of the Comparative Example 7 stretch film are shown in Table 1.

[0097] Comparative Example 8

[0098] 100 parts by mass of a polyethylene resin (melt flow rate: 7 g / 10 min at 210°C, elongation at break: 500%, brand: 1F7B, origin: Beijing Yanshan Petrochemical Co., Ltd., Sinopec Group) was weighed and placed in the feed port of a film casting machine. The screw speed was set to 100 rpm, and the screw temperatures from the feed port to the die were set to 150°C, 170°C, 180°C, 185°C, and 185°C, respectively. The draw speed was set to 50 rpm, the magnetic powder winding rate was set to 65 rpm, the temperature of the first roller was set to 50°C, the gap between the first and second rollers was set to 0.04 mm, the temperature of the second roller was set to 30°C, the gap between the second and third rollers was set to 0.03 mm, and the temperature of the third roller was set to 30°C. The film was then extruded, cast, and wound to produce the stretch film of Comparative Example 8 of the present invention. The test results of the stretch film of Comparative Example 8 are shown in Table 1.

[0099] Performance Testing

[0100] The testing process and method of the film samples prepared in the above examples and comparative examples are as follows:

[0101] The tensile strength and elongation at break of film samples were tested in accordance with GBT1040-2006 "Determination of tensile properties of plastics". The tensile rate was 10 mm / min and the test temperature was 23-25°C.

[0102] To test the windability of film samples: Cut a film sample 100mm long, 10mm wide, and 0.03mm thick. Fold it repeatedly along its long sides to form a 100mm long, 2.5mm wide strip. Intersect one end of the strip with the rest of the strip to form a loop. Pass the end of the strip through the loop and gradually tighten it to form a knot. This knot is then tightened to form a single knot for the film sample windability test. The two ends of the strip are crossed and twisted together. Wrap it again above the intersection. Finally, hold the ends of the strip and gradually tighten it to form a flat knot for the film sample windability test. After the test sample is left to stand at room temperature for 14 days, observe the knot for slippage.

[0103] For the test of the durability of film sample wrapping and lamination: the film sample to be tested is prepared into a sample with a width × length × thickness of 10mm × 150mm × 1mm using a flat vulcanizer. After slight stretching, it is wrapped around a glass test tube with a diameter of 2cm. After being left naturally at room temperature for 14 days, the wrapped film sample is observed to see whether the end of the film sample is warped, whether the film sample has stress relaxation, slippage, etc.

[0104] For the test of the main network structure of the film sample after slow extreme stretching: the film sample to be tested is prepared into a sample with a width × length × thickness of 10mm × 150mm × 1mm using a flat vulcanizing machine. After fixing one side of the sample, the other three sides are slowly stretched 100% in the horizontal direction and outward at a speed of 10mm / min, and the surface morphology of the sample after stretching is photographed with a camera.

[0105] The pure water contact angle of a film sample was measured according to GB / T 30447-2013, "Nanofilm Contact Angle Measurement Method." At room temperature, the film sample was placed under the lens of a JD2000D contact angle meter and the contact angle of the film sample with pure water was measured.

[0106] For the accelerated aging test of film samples: the test is carried out in accordance with ASTM G154-2023 "Standard for Fluorescent Ultraviolet Lamp Exposure of Nonmetallic Materials". The film sample to be tested is prepared into a sample with a width × length × thickness of 10mm × 150mm × 1mm using a flat vulcanizer. The UV-A 340 lamp is set as the ultraviolet light source with a light intensity of 0.68W / m 2 The UV irradiation time was 4 hours, the temperature was 45°C, the spraying time was 15 minutes, the condensation temperature was 45°C, the duration was 7 hours 45 minutes, and the continuous testing time was 14 days. After the test, the samples were inspected for surface damage, color change, cracks, etc. to support the evaluation of the sample's biodegradability.

[0107] Figure 1The main network structure of a degradable seedling grafting wrap film provided in Examples 1 to 3 of the present invention after ultimate stretching at room temperature is shown. Figure 2 This is the main network structure of the comparative stretch film provided in Comparative Examples 1 to 8 of the present invention after ultimate stretching at room temperature. Figure 1 and Figure 2 As can be seen, the biodegradable seedling grafting wrap provided in Examples 1-3 of the present invention, after being stretched to 100%, exhibits a distinct network structure and good integrity, with no large, noticeable holes. This structure ensures the wrap's overall coverage of the grafted area during use while also increasing water and vapor permeability. This prevents moisture absorption and swelling during use, promoting biological and environmental degradation of the grafted area.

[0108] Figure 3 The degradable seedling grafting wrap provided in Examples 1 to 3 of the present invention shows the effect after being tied with a knot and placed indoors for 14 days. As can be seen from the figure, the degradable seedling grafting wrap provided in Examples 1, 2, and 3 of the present invention can be tied with a knot when in use, and the knot will not slip off. It has high durability and excellent flexibility, and can ensure the durability of the overall covering of the grafted part during the use of seedling grafting.

[0109] Table 1 Test results of film samples

[0110]

[0111]

[0112] It can be seen from Comparative Examples 1 to 3 that when only two of the polyisobutylene resins with a number average molecular weight of 1500 to 3000, a number average molecular weight of 400,000 to 600,000, and a number average molecular weight of 800,000 to 1200,000 are used as polybutene resins, the tensile strength and elongation at break of the prepared film samples are relatively low (the tensile strength is required to be 0.05 to 0.06 MPa, and the elongation at break is ≥240%), which cannot well meet the mechanical performance requirements of the seedling grafting wrap film during use; at the same time, the contact angle for pure water is high (the pure water contact angle is required to be ≤82.0°), which cannot well meet the hydrophilic properties of the seedling grafting wrap film during use.

[0113] It can be seen from Comparative Example 4 that after reducing the amount of paraffin wax, the tensile strength and elongation at break of the prepared film sample are relatively low (the tensile strength is required to be 0.05-0.06MPa, and the elongation at break is ≥240%), which cannot meet the mechanical performance requirements of the seedling grafting wrap film during use; at the same time, the contact angle for pure water is relatively high (the pure water contact angle is required to be ≤82.0°), which cannot meet the hydrophilic properties of the seedling grafting wrap film during use.

[0114] It can be seen from Comparative Example 5 that when no degradation modifier is added, the tensile strength and elongation at break of the prepared film sample are relatively low (the tensile strength is required to be 0.05-0.06 MPa, and the elongation at break is ≥240%), which cannot meet the mechanical performance requirements of the seedling grafting wrap film during use; at the same time, the contact angle for pure water is too high (the pure water contact angle is required to be ≤82.0°), which cannot meet the hydrophilic properties of the seedling grafting wrap film during use; at the same time, after the accelerated aging test, the sample is basically intact, with only a small amount of disintegration, which shows that the degradation performance of the film sample during use is poor.

[0115] It can be seen from Comparative Example 6 that when the molecular weight regulator is not added, the tensile strength and elongation at break of the prepared film sample are relatively low (the tensile strength is required to be 0.05-0.06 MPa, and the elongation at break is ≥240%), which cannot meet the mechanical performance requirements of the seedling grafted wrap film during use; at the same time, the contact angle for pure water is too high (the pure water contact angle is required to be ≤82.0°), which cannot meet the hydrophilic properties of the seedling grafted wrap film during use; at the same time, after the accelerated aging test, the sample is broken in a small area and only a small amount of disintegration occurs, which shows that the degradation performance of the film sample during use is poor, thereby indirectly affecting the degradation performance of the seedling grafted wrap film during use.

[0116] It can be seen from Comparative Example 7 that when no disintegration promoter is added, the contact angle of the prepared film sample for pure water is too high (the pure water contact angle is required to be ≤82.0°), which cannot meet the hydrophilic properties of the seedling grafted wrap film during use; at the same time, after the accelerated aging test, the sample is basically intact, with only a small amount of disintegration, which shows that the degradation performance of the film sample during use is poor, thereby indirectly affecting the degradation performance of the seedling grafted wrap film during use.

[0117] It can be seen from Comparative Example 8 that, compared with pure PE resin, although the prepared film sample of Example 1 has better elongation at break, the tensile strength is too high (tensile strength is required to be 0.05-0.06 MPa), which cannot meet the mechanical performance requirements of the seedling grafting wrap film during use; it is difficult to tie a knot, the knot is easy to slip, the durability after knotting is poor, and the end has warping and looseness, which affects the winding durability of the wrap film during use; the contact angle for pure water is too high (pure water contact angle is required to be ≤82.0°), which cannot meet the hydrophilic properties of the seedling grafting wrap film during use; at the same time, after the accelerated aging test, the sample is intact and there is no disintegration, which shows that the film sample does not have degradation performance during use.

[0118] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A degradable seedling grafting wrap film, characterized in that: The raw materials for preparation include, by mass: The polyisobutylene resin and the paraffin wax form a dual-continuous phase structure in terms of microscopic thermodynamic phase structure.

2. The seedling grafting wrapping film according to claim 1, characterized in that: The number average molecular weight of the polyisobutylene resin is 1500 to 1100000; Preferably, the number average molecular weight of the polyisobutylene resin is at least one of 1,500 to 3,000, 400,000 to 600,000, and 800,000 to 1,200,000.

3. The seedling grafting wrapping film according to claim 2, characterized in that: The polyisobutylene resin is selected from a mixture of polyisobutylene resins having a number average molecular weight of 1,500 to 3,000, a number average molecular weight of 400,000 to 600,000, and a number average molecular weight of 800,000 to 1,200,000.

4. The seedling grafting wrapping film according to claim 1, characterized in that The paraffin wax is at least one of flaky paraffin wax, refined paraffin wax, and palm wax; Preferably, the melting point of the paraffin wax is 50-70°C.

5. The seedling grafting wrapping film according to claim 1, characterized in that: The degradation modifier is at least one of polylactic acid resin, chitosan, thermoplastic starch and polyurethane.

6. The seedling grafting wrapping film according to claim 1, characterized in that: The molecular weight regulator is at least one of polyethylene wax, polypropylene wax, polyethylene glycol, and polyvinyl alcohol.

7. The seedling grafting wrapping film according to claim 1, characterized in that: The disintegration accelerator is at least one of montmorillonite, wollastonite, diatomaceous earth and zeolite; Preferably, the particle size of the disintegration promoter is 400 to 800 nanometers.

8. A method for preparing the degradable seedling grafting wrapping film according to any one of claims 1 to 7, characterized in that: The following steps are involved: A) blending a polyisobutylene resin, paraffin wax, a degradation modifier, a molecular weight regulator, and a disintegration accelerator to obtain a degradable seedling grafting wrapping film blend composition; B) casting the degradable seedling grafting wrap film blend composition into a film, and winding it to obtain a degradable seedling grafting wrap film.

9. The preparation method according to claim 8, characterized in that In step A), the blending time is 10 to 60 minutes.

10. The preparation method according to claim 8, characterized in that In step B), the temperature of the film casting is 60-120°C.

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