Environment-friendly full-biodegradable mulching film as well as preparation method and application thereof

Abstract

The invention discloses an environment-friendly full-biodegradable mulching film as well as a preparation method and application thereof. The mulching film is prepared from the following components: poly (butylene adipate-co-butylene adipate) (PBAT), polylactic acid (PLA), a compatilizer, a heat stabilizer, talcum powder, calcium carbonate, a light stabilizer, an ultraviolet light absorber, an antioxidant, an anti-blocking agent and a lubricant. The environment-friendly full-biodegradable mulching film provided by the invention has the characteristics of high initial mechanical strength, good flexibility, high strength, low water vapor transmission rate and the like, and the mulching film prepared by the component proportion and the method does not contain common plastics which cannot be biologically degraded and also does not contain starch, is good in quality performance and relatively low in cost, is beneficial to moisture preservation and heat preservation, and is suitable for popularization and application. The crop yield can be effectively improved. And on the basis of the characteristic of complete biodegradation, the environment is not polluted, and the damage of the mulching film to soil is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of environmentally friendly mulch film preparation technology, and more specifically to an environmentally friendly fully biodegradable mulch film, its preparation method, and its application. Background Technology

[0002] Plastic film mulching is an important agricultural production technology for increasing crop yields and changing production methods in water-scarce areas. In recent years, the area covered by plastic film mulching has reached 17.5 × 10⁻⁶. 6 hm 2 The application of plastic film mulching technology has expanded from arid areas to high-altitude and cold regions, effectively ensuring stable grain production and achieving poverty reduction goals in these areas. The types of crops covered have also expanded from vegetables and cash crops to major grain crops, resulting in an annual increase in income of over 120 billion yuan. The application of plastic film mulching is particularly prominent in the Northwest cotton-growing region, the Northeast corn-growing region, the peanut-growing region, and the Southwest tobacco-growing region, playing a vital role in ensuring the safety of agricultural production.

[0003] However, the long-term unscientific use and inadequate recycling mechanisms of traditional polyethylene mulch film, especially its fragility and low mechanical strength after crop harvest, make it difficult to recover mulch film residues, leading to increasingly prominent pollution problems. Mulch film residues not only cause "white pollution" in farmland but also damage soil structure, reduce the variety and activity of soil microorganisms, affect sowing quality, and consequently restrict crop yield and quality, posing a serious threat to sustainable agricultural development. Therefore, the research and use of fully biodegradable mulch film has become a potentially effective way to solve the problem of mulch film residue pollution. Summary of the Invention

[0004] In view of this, the present invention provides an environmentally friendly fully biodegradable mulch film and its preparation method, which has the advantages of being environmentally friendly and overcomes the shortcomings and defects of traditional polyethylene mulch films mentioned in the background art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: First, the present invention provides an environmentally friendly, fully biodegradable mulch film, comprising, by weight: 80-85 parts of polybutylene terephthalate (PET), 4-6 parts of polylactic acid (PLA), 0.5-1.0 parts of compatibilizer, 0.1-0.2 parts of heat stabilizer, 8-12 parts of talc, 0.5-1.0 parts of calcium carbonate, 0.5-1.0 parts of light stabilizer, 0.3-0.5 parts of ultraviolet absorber, 0.01-0.1 parts of antioxidant, 0.5-1.0 parts of opening agent, and 0.1-0.3 parts of lubricant.

[0006] Preferably, the environmentally friendly fully biodegradable mulch film comprises, by weight, 81.9 parts of polybutylene terephthalate (PBAT), 5 parts of polylactic acid (PLA), 0.8 parts of compatibilizer, 0.2 parts of heat stabilizer, 10 parts of talc, 0.5 parts of calcium carbonate, 0.7 parts of light stabilizer, 0.3 parts of ultraviolet absorber, 0.1 parts of antioxidant, 0.5 parts of opening agent, and 0.2 parts of lubricant.

[0007] Preferably, the number-average molecular weight of the polybutylene terephthalate (PET) is 50,000 to 150,000, and the number-average molecular weight of the polylactic acid is 20,000 to 100,000.

[0008] Preferably, the compatibilizer is an epoxy-block copolymer type reactive compatibilizer CS-01; the heat stabilizer is polycarbodiimide.

[0009] Preferably, the talc powder has a particle size of 2500-3500 mesh, more preferably 3000 mesh.

[0010] Preferably, the light stabilizer is a mixture of light stabilizer 944 and light stabilizer 770, with a mass ratio of light stabilizer 944:light stabilizer 770 = 3:4.

[0011] Preferably, the ultraviolet absorber is ultraviolet absorber UV-570; the antioxidant is antioxidant 1010; the opening agent is oxoamyl amide or pentaerythritol stearate; and the lubricant is white oil No. 15.

[0012] This invention also provides a method for preparing the environmentally friendly, fully biodegradable mulch film as described above, comprising the following steps: S1. Polybutylene terephthalate and polylactic acid are vacuum dried at 50°C until the moisture content drops to below 400 ppm; S2. The dried polybutylene terephthalate, polylactic acid, compatibilizer, heat stabilizer, talc, calcium carbonate, light stabilizer, ultraviolet absorber, antioxidant, opening agent and lubricant are placed in a high-speed mixer in proportion and mixed thoroughly until uniform to obtain a premix. S3. The premixed material is fed into a screw extruder, and after melt blending, extrusion, cooling and pelletizing, it is dried until the moisture content of the plastic particles is less than 300 ppm. Then the plastic particles are blown into a film to obtain an environmentally friendly fully biodegradable mulch film.

[0013] Preferably, in S2, the high-speed mixer speed is 800 rpm to 1100 rpm, and the mixing time is 60 min to 80 min; in S3, the screw extruder melt temperature is 190℃ to 240℃, the screw speed is 600 rpm to 1200 rpm, the drying temperature is 50℃ to 60℃, and the blown film temperature is 140℃ to 180℃.

[0014] The present invention also provides an application of the environmentally friendly fully biodegradable mulch film described above in agriculture, forestry and animal husbandry.

[0015] As can be seen from the above technical solution, compared with the prior art, the present invention discloses an environmentally friendly fully biodegradable mulch film, its preparation method and application, which has the following beneficial effects: The environmentally friendly, fully biodegradable mulch film provided in this application possesses characteristics such as high initial mechanical strength, good flexibility, high strength, and low water vapor permeability. Mulch film prepared using this formulation and method does not contain non-biodegradable ordinary plastics or starch, exhibits good quality performance, and is low in cost. It is beneficial for moisture retention and heat preservation, effectively increasing crop yields. Due to its fully biodegradable nature, it does not pollute the environment and significantly reduces the damage to the soil caused by mulch film.

[0016] The preparation method described in this application has the characteristics of simple process flow, easy control, good product quality consistency and high production efficiency, and is suitable for large-scale industrial promotion. Detailed Implementation

[0017] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] The components used in this application are sourced from: The polybutylene terephthalate (PBAT) used was selected from Yingkou Kanghui Petrochemical Co., Ltd., grade KHB21AP11B. The polylactic acid (PLA) used was selected from Anhui Fengyuan Biotechnology Co., Ltd., brand name FY801. The compatibilizer selected was CS-01 from the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences. The heat stabilizer selected is PCDI from the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences. The talc powder used is from Guangxi Longsheng Huamei Talc Development Co., Ltd., model LH-500A; The calcium carbonate used is from Guangxi Hezhou Kelong Powder Co., Ltd., model KL-800. The light stabilizers selected are BASF China Co., Ltd., with brand names Tinuvin 944 and Tinuvin 770; The ultraviolet absorber used is BASF (China) Co., Ltd., brand name UV-570; The antioxidant selected is BASF (China) Co., Ltd., brand name Irganox 1010; The opening agent used was selected from Pingxiang County Xinfeng Plastics Co., Ltd., brand name Xinfeng Erucic Acid Opening Agent 1010; The lubricant selected is Industrial White Oil (I) No. 15 from China Petroleum & Chemical Corporation. To further understand this application, the following detailed description is provided in conjunction with specific embodiments.

[0019] Example 1 The environmentally friendly, fully biodegradable mulch film comprises the following components by weight: The ingredients are: 80 parts polybutylene terephthalate (PBAT), 4 parts polylactic acid (PLA), 0.6 parts compatibilizer, 0.1 parts heat stabilizer, 8 parts talc, 0.5 parts calcium carbonate, 0.7 parts light stabilizer, 0.3 parts ultraviolet absorber, 0.05 parts antioxidant, 0.8 parts opening agent, and 0.1 parts lubricant.

[0020] Among them, the number-average molecular weight of polybutylene terephthalate (PBAT) is 80,000, and the number-average molecular weight of polylactic acid (PLA) is 50,000. The compatibilizer is an epoxy-block copolymer reactive compatibilizer, CS-01; the heat stabilizer is polycarbodiimide, PCDI; The particle size of talc is 3000 mesh; The light stabilizer is selected as a mixture of light stabilizer 944 and light stabilizer 770, wherein the mass ratio of light stabilizer 944 to light stabilizer 770 is 3:4; The ultraviolet absorber is UV-570; the antioxidant is hindered phenolic antioxidant 1010; the opening agent is erucamide; and the lubricant is white oil No. 15. The method for preparing the environmentally friendly, fully biodegradable mulch film includes the following steps: S1: Polybutylene terephthalate (PBAT) and polylactic acid (PLA) are vacuum dried at 50°C until the moisture content drops below 400 ppm. S2: The dried polybutylene terephthalate (PBAT), polylactic acid (PLA), compatibilizer, heat stabilizer, talc, calcium carbonate, light stabilizer, UV absorber, antioxidant, opening agent, and lubricant are placed in a high-speed mixer at a predetermined ratio and mixed at 1000 rpm for 80 minutes until homogeneous to obtain a premix. S3: The premixed material is fed into a screw extruder, melt-blended at 220°C, extruded at 1000rpm, cooled and pelletized, and then dried at 55°C to ensure that the moisture content of the plastic pellets is below 300ppm. The resulting plastic pellets are blow-molded into a film at 170°C to obtain an environmentally friendly, fully biodegradable mulch film.

[0021] Example 2 The difference from Example 1 is that the environmentally friendly fully biodegradable mulch film comprises the following components by weight: The composition includes 84.9 parts of polybutylene terephthalate (PBAT), 6 parts of polylactic acid (PLA), 1 part of compatibilizer, 0.2 parts of heat stabilizer, 10 parts of talc, 1.0 part of calcium carbonate, 0.8 parts of light stabilizer, 0.4 parts of ultraviolet absorber, 0.1 parts of antioxidant, 0.5 parts of opening agent, and 0.3 parts of lubricant.

[0022] Example 3 The difference from Example 1 is that the environmentally friendly fully biodegradable mulch film comprises the following components by weight: The composition includes 81.9 parts of polybutylene terephthalate (PBAT), 5 parts of polylactic acid (PLA), 0.8 parts of compatibilizer, 0.2 parts of heat stabilizer, 10 parts of talc, 1.0 part of calcium carbonate, 0.7 parts of light stabilizer, 0.3 parts of ultraviolet absorber, 0.1 parts of antioxidant, 0.7 parts of opening agent, and 0.2 parts of lubricant.

[0023] Comparative Example 1 The difference from Example 1 is that the environmentally friendly fully biodegradable mulch film comprises the following components by weight: The composition includes 85 parts of polybutylene terephthalate (PBAT), 2 parts of polylactic acid (PLA), 0.8 parts of compatibilizer, 0.2 parts of heat stabilizer, 10 parts of talc, 2.0 parts of calcium carbonate, 0.6 parts of light stabilizer, 0.4 parts of ultraviolet absorber, 0.1 parts of antioxidant, 0.5 parts of opening agent, and 0.2 parts of lubricant.

[0024] Comparative Example 2 The difference from Example 1 is that the environmentally friendly fully biodegradable mulch film comprises the following components by weight: The ingredients are: 80 parts polybutylene terephthalate (PBAT), 8 parts polylactic acid (PLA), 0.8 parts compatibilizer, 0.2 parts heat stabilizer, 10 parts talc, 2.0 parts calcium carbonate, 0.7 parts light stabilizer, 0.4 parts ultraviolet absorber, 0.1 parts antioxidant, 0.5 parts opening agent, and 0.2 parts lubricant.

[0025] Experimental Example The environmentally friendly, fully biodegradable mulch films produced in Examples 1-3 and Comparative Examples 1-2 were subjected to performance tests. The test methods were in accordance with GB / T 35795-2017. The test results are shown in the table below:

[0026] During the performance testing of the mulch film, it was found that the mulch film of this application has the characteristics of high initial mechanical strength, good flexibility, high strength, and low water vapor permeability. Based on its completely biodegradable characteristics, it will not cause pollution to the environment and is suitable for agricultural, forestry and animal husbandry planting mulch film fields, with high practicality.

[0027] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An environmentally friendly, fully biodegradable mulch film, characterized in that, By weight, it comprises: 80-85 parts of polybutylene terephthalate (PET), 4-6 parts of polylactic acid (PLA), 0.5-1.0 parts of compatibilizer, 0.1-0.2 parts of heat stabilizer, 8-12 parts of talc, 0.5-1.0 parts of calcium carbonate, 0.5-1.0 parts of light stabilizer, 0.3-0.5 parts of ultraviolet absorber, 0.01-0.1 parts of antioxidant, 0.5-1.0 parts of opening agent, and 0.1-0.3 parts of lubricant.

2. The environmentally friendly, fully biodegradable mulch film according to claim 1, characterized in that, By weight, it includes: 81.9 parts of polybutylene terephthalate (PBAT), 5 parts of polylactic acid (PLA), 0.8 parts of compatibilizer, 0.2 parts of heat stabilizer, 10 parts of talc, 0.5 parts of calcium carbonate, 0.7 parts of light stabilizer, 0.3 parts of ultraviolet absorber, 0.1 parts of antioxidant, 0.5 parts of opening agent, and 0.2 parts of lubricant.

3. An environmentally friendly, fully biodegradable mulch film according to claim 1 or 2, characterized in that, The polybutylene terephthalate (PET) has a number-average molecular weight of 50,000 to 150,000, and the polylactic acid has a number-average molecular weight of 20,000 to 100,000.

4. An environmentally friendly, fully biodegradable mulch film according to claim 1 or 2, characterized in that, The compatibilizer is an epoxy-block copolymer type reactive compatibilizer CS-01; the heat stabilizer is polycarbodiimide.

5. An environmentally friendly, fully biodegradable mulch film according to claim 1 or 2, characterized in that, The talc powder has a particle size of 2500-3500 mesh.

6. An environmentally friendly, fully biodegradable mulch film according to claim 1 or 2, characterized in that, The light stabilizer is a mixture of light stabilizer 944 and light stabilizer 770, with a mass ratio of 3:

4.

7. An environmentally friendly, fully biodegradable mulch film according to claim 1 or 2, characterized in that, The ultraviolet absorber is UV-570; the antioxidant is antioxidant 1010; the opening agent is ozonamide or pentaerythritol stearate; and the lubricant is white oil No.

15.

8. A method for preparing an environmentally friendly, fully biodegradable mulch film according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Polybutylene terephthalate and polylactic acid are vacuum dried at 50°C until the moisture content drops to below 400 ppm; S2. The dried polybutylene terephthalate, polylactic acid, compatibilizer, heat stabilizer, talc, calcium carbonate, light stabilizer, ultraviolet absorber, antioxidant, opening agent and lubricant are placed in a high-speed mixer in proportion and mixed thoroughly until uniform to obtain a premix. S3. The premixed material is fed into a screw extruder, and after melt blending, extrusion, cooling and pelletizing, it is dried until the moisture content of the plastic particles is less than 300 ppm. Then the plastic particles are blown into a film to obtain an environmentally friendly fully biodegradable mulch film.

9. The method for preparing an environmentally friendly, fully biodegradable mulch film according to claim 8, characterized in that, The speed of the high-speed mixer in S2 is 800 rpm to 1100 rpm, and the mixing time is 60 min to 80 min; the melt temperature of the screw extruder in S3 is 190℃ to 240℃, the screw speed is 600 rpm to 1200 rpm, the drying temperature is 50℃ to 60℃, and the blown film temperature is 140℃ to 180℃.

10. The application of an environmentally friendly, fully biodegradable mulch film as described in any one of claims 1-7 in agriculture, forestry, and animal husbandry.

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