Special material for broccoli mulching cultivation full-biodegradable mulching film and preparation method thereof

Abstract

This invention discloses a special material for fully biodegradable mulch film for broccoli cultivation and its preparation method. The material is prepared by melt blending and extrusion using polybutylene succinate, polycaprolactone, polylactic acid, compatibilizers, slip agents, photosensitizers, melt index regulators, and enhancing agents. Developed specifically for broccoli cultivation mulch film production based on the growth cycle and characteristics of broccoli, this material exhibits good film-forming properties and stable blown film processing. Application demonstrations show that mulch film produced using this material performs normally under mechanical mulching conditions for broccoli cultivation, and naturally ruptures after 60 days. Soil burial tests show complete biodegradation within one year. Comparative tests show that the performance of this material meets or exceeds that of polyethylene mulch film, making it a viable alternative to polyethylene for broccoli mulch film production.

Description

Technical Field

[0001] This invention belongs to the field of fully biodegradable polymer new materials technology, specifically relating to a special material for fully biodegradable mulch film for broccoli mulching cultivation and its preparation method. Background Technology

[0002] Despite groundbreaking progress in the field of biodegradable mulch film over the past 37 years, its industrialization and widespread application have been slow due to various reasons. There are two main technical reasons: First, insufficient mechanical strength makes large-scale operation difficult, which is one of the main reasons limiting the widespread use of biodegradable mulch film. The physicochemical properties of biodegradable mulch film materials themselves determine their poor tensile strength, making mechanized mulching impossible in agricultural areas where mechanized operations are prevalent. Therefore, improving and refining the mulch film formula to increase its tensile strength and meet the requirements of agricultural machinery operations is essential to creating conditions for large-scale application of biodegradable mulch film. Second, the poor rupture time and controllable degradation of biodegradable mulch film make it difficult to meet the needs of different climatic conditions and crop growth. Some existing biodegradable mulch film products rupture and degrade too early, with coverage time far below the safe period for crop mulch film coverage. This makes it difficult to guarantee the effective functioning of its main functions such as warming, moisture retention, and weed suppression, thus hindering the promotion of mulch film. Summary of the Invention

[0003] To address the aforementioned issues in the background technology, it is necessary to develop specialized fully biodegradable mulch film materials tailored to different climatic conditions and crop growth cycles.

[0004] In the north, it takes about 60 days from planting to harvesting broccoli, which requires not only good tensile strength of the mulch film but also a fast degradation rate.

[0005] The technical solution provided by this invention is as follows:

[0006] A biodegradable mulch film material specifically for broccoli cultivation, comprising the following components by weight:

[0007]

[0008] The preparation method of the enhanced and transparent masterbatch is as follows: Raw materials are prepared in the following mass ratio: polybutylene succinate: calcium sulfate whiskers: slip agent = 35-75: 20-50: 5-15. First, weigh the calcium sulfate whiskers and slip agent. Add the calcium sulfate whiskers to a kneading pot, start stirring, then evenly add the slip agent and continue stirring for 30-40 minutes. Set aside. Then, weigh the polybutylene succinate and add the kneaded calcium sulfate whiskers and polybutylene succinate sequentially to a high-speed mixer, stirring for 5-15 minutes. Set aside. Finally, send the high-speed stirred material into a twin-screw extruder for granulation, controlling the temperature at 90-175℃. After cooling, mixing, and packaging, the enhanced and transparent masterbatch is obtained.

[0009] As a further preferred embodiment of the above invention, polybutylene succinate, polycaprolactone, and polylactic acid are all selected from blown film grade synthetic resins. The polybutylene succinate is selected from Xinjiang Changji Lanshan Tunhe Chemical Co., Ltd. (brand name TH801), the polycaprolactone is selected from Shenzhen Guanghua Weiye Co., Ltd. (brand name 800C), and the polylactic acid is selected from Zhejiang Haizheng Biomaterials Co., Ltd. (brand name REVODE101).

[0010] As a further preferred embodiment of the invention, Bondryam 7107, manufactured by Polyram, Israel, is selected as the compatibilizer.

[0011] As a further preferred embodiment of the invention, the photosensitizer is ferric stearate produced by Hubei Yikangyuan Chemical Co., Ltd., with a fineness of 1-3 microns and a purity greater than 99%.

[0012] As a further preferred embodiment of the invention, the melt flow index regulator is YTW-2P produced by Beijing Yitaiwei Plastic Raw Materials Co., Ltd.

[0013] As a further preferred embodiment of the invention, the stirring rate of the enhanced permeability masterbatch is 60-800 rpm.

[0014] As a further preferred embodiment of the above invention, the calcium sulfate whiskers are selected from those produced by Jiangxi Fengzhu New Material Technology Co., Ltd., with product grade S04-L and aspect ratio of 5-40.

[0015] As a further preferred embodiment of the invention, the slip agent is erucamide produced by Jiangxi Dongyuan Technology Co., Ltd., with a total amide content of more than 98%.

[0016] The preparation method of the above-mentioned biodegradable mulch film material for broccoli mulching includes the following steps:

[0017] Step 1. Preparation of Enhanced Transparency Masterbatch

[0018] (1) According to the formula of the enhanced and transparent masterbatch, weigh the calcium sulfate whiskers and the slip agent. First, add the calcium sulfate whiskers to the kneading pot, start stirring, then add the slip agent evenly, and continue stirring for 30-40 minutes.

[0019] (2) According to the formula of the enhanced and transparent masterbatch, weigh polybutylene succinate, add the kneaded calcium sulfate whiskers and polybutylene succinate to the high-speed mixer in sequence, and stir for 5-15 minutes.

[0020] (3) The high-speed mixed material is fed into a twin-screw extruder for extrusion granulation. The temperature is controlled at 90-175℃. After cooling, mixing and packaging, the enhanced and transparent masterbatch is obtained.

[0021] Step 2. Preparation of Special Materials for Fully Biodegradable Mulch Film for Broccoli Mulching

[0022] (1) According to the formula of the special material for fully biodegradable mulch film for broccoli mulching cultivation, add all the components of the material into a high-speed mixer in sequence and mix for 5-10 minutes.

[0023] (2) The high-speed mixed material is fed into a twin-screw extruder for extrusion granulation. The temperature is controlled at 90-170℃. After cooling, mixing, testing and packaging, the special material for fully biodegradable mulch film for broccoli cultivation is obtained.

[0024] The present invention also provides the application of the aforementioned biodegradable mulch film material for broccoli mulching in broccoli cultivation.

[0025] Compared with existing technologies, this invention effectively solves the problems of tensile strength and degradation rate of mulch film materials, and its beneficial effects are:

[0026] 1) The preferred materials—polybutylene succinate, polycaprolactone, and polylactic acid—are all blown film grade, with polybutylene succinate as the main component and polycaprolactone and polylactic acid as secondary components. Polybutylene succinate degrades relatively quickly and has properties similar to polyethylene. Polycaprolactone has excellent extensibility and can be used for high-strength film molding. Polylactic acid has good tensile strength and good transparency. The combination of these three materials provides complementary properties.

[0027] 2) Calcium sulfate whiskers are preferably surface-treated and made into masterbatch. Adding an appropriate amount can increase the strength of the material and improve its transparency.

[0028] 3) Select a compatible toughening agent to effectively improve the compatibility of polybutylene succinate, polycaprolactone, polylactic acid and calcium sulfate whiskers, while increasing the toughness of the material.

[0029] 4) Select melt index regulators to control viscosity fluctuations of materials and improve their film-forming properties and processing stability.

[0030] 5) Selective use of mesoamide slip agent can not only improve the feel of the mulch film, but also reduce the volume resistivity and avoid safety accidents caused by static electricity.

[0031] 6) Promotion and application have proven that mulch film produced using this material performs normally under mechanical mulching operations for broccoli cultivation, and naturally ruptures and breaks after 60 days. Soil burial tests show that it is completely biodegradable within one year.

[0032] In summary, the material of this invention is specifically designed for the production of fully biodegradable mulch film for broccoli cultivation, exhibiting excellent film-forming properties and stable blown film processing. Extensive application has demonstrated that mulch film produced using this material performs normally under mechanical mulching conditions for broccoli cultivation, and naturally ruptures and becomes brittle within 60 days. Soil burial tests show complete biodegradation within one year. Comparative tests show that the performance of the material of this invention meets or exceeds that of polyethylene mulch film, making it a viable alternative to polyethylene for broccoli mulch film production. Attached Figure Description

[0033] Figure 1 Photos taken on-site of a broccoli cultivation experimental field and the embrittlement and cracking of the mulch film.

[0034] Figure 2 Photos taken on-site showing broccoli cultivated under polyethylene mulch. Detailed Implementation

[0035] Material:

[0036] Polybutylene succinate was selected from Xinjiang Changji Lanshan Tunhe Chemical Co., Ltd., brand name TH801.

[0037] Polycaprolactone was selected from Shenzhen Guanghua Weiye Co., Ltd., grade 800C.

[0038] Polylactic acid (PLA) was selected from Zhejiang Hisun Biomaterials Co., Ltd., brand name REVODE101.

[0039] The compatibilizer used is Bondryam 7107, manufactured by Polyram, Israel.

[0040] The photosensitizer used is ferric stearate produced by Hubei Yikangyuan Chemical Co., Ltd., with a fineness of 1-3 microns and a purity greater than 99%.

[0041] The melt flow index regulator used is YTW-2P produced by Beijing Yitaiwei Plastic Raw Materials Co., Ltd.

[0042] The calcium sulfate whiskers used are those produced by Jiangxi Fengzhu New Material Technology Co., Ltd., with product grade S04-L and aspect ratio of 5-40.

[0043] The slip agent used is erucamide produced by Jiangxi Dongyuan Technology Co., Ltd., with a total amide content of more than 98%.

[0044] Preparation of enhanced permeability masterbatch

[0045] 1) Formula

[0046] 40 parts of polybutylene succinate

[0047] 50 parts of calcium sulfate whiskers

[0048] 10 parts of slip

[0049] 2) Preparation of enhanced permeability masterbatch

[0050] (1) Weigh the calcium sulfate whiskers and the slip agent according to the formula. First, add the calcium sulfate whiskers to the kneading pot and start stirring at a speed of 60 rpm. Then, add the slip agent evenly and continue stirring at the same speed for 35 minutes.

[0051] (2) Weigh polybutylene succinate according to the formula, and add the kneaded calcium sulfate whiskers and polybutylene succinate to a high-speed mixer in sequence. The mixing speed is 800 rpm. Mix for 10 minutes and set aside.

[0052] (3) The material that has been mixed at high speed is fed into a twin-screw extruder for extrusion granulation. The temperature is controlled at 90-175℃. After cooling, mixing and packaging, the enhanced and transparent masterbatch is obtained.

[0053] Example 1

[0054] 1) Formula

[0055]

[0056] 2) Process

[0057] (1) Weigh all the ingredients according to the formula, add them to the high-speed mixer in sequence, and mix for 10 minutes.

[0058] (2) The high-speed mixed material is fed into a twin-screw extruder for extrusion granulation. The temperature is controlled at 90-170℃. After cooling, mixing, testing and packaging, the special material for fully biodegradable mulch film for broccoli cultivation is obtained.

[0059] Example 2

[0060] 1) Formula

[0061]

[0062] 2) Process

[0063] (1) Weigh all the ingredients according to the formula, add them to the high-speed mixer in sequence, and mix for 10 minutes.

[0064] (2) The high-speed mixed material is fed into a twin-screw extruder for extrusion granulation. The temperature is controlled at 90-170℃. After cooling, mixing, testing and packaging, the special material for fully biodegradable mulch film for broccoli cultivation is obtained.

[0065] Example 3

[0066] 1) Formula

[0067]

[0068] 2) Process

[0069] (1) Weigh all the ingredients according to the formula, add them to the high-speed mixer in sequence, and mix for 10 minutes.

[0070] (2) The high-speed mixed material is fed into a twin-screw extruder for extrusion granulation. The temperature is controlled at 90-170℃. After cooling, mixing, testing and packaging, the special material for fully biodegradable mulch film for broccoli cultivation is obtained.

[0071] Example 4

[0072] 1) Formula

[0073]

[0074]

[0075] 2) Process

[0076] (1) Weigh all the ingredients according to the formula, add them to the high-speed mixer in sequence, and mix for 10 minutes.

[0077] (2) The high-speed mixed material is fed into a twin-screw extruder for extrusion granulation. The temperature is controlled at 90-170℃. After cooling, mixing, testing and packaging, the special material for fully biodegradable mulch film for broccoli cultivation is obtained.

[0078] Example 5

[0079] 1) Formula

[0080]

[0081] 2) Process

[0082] (1) Weigh all the ingredients according to the formula, add them to the high-speed mixer in sequence, and mix for 10 minutes.

[0083] (2) The high-speed mixed material is fed into a twin-screw extruder for extrusion granulation. The temperature is controlled at 90-165℃. After cooling, mixing, testing and packaging, the special material for fully biodegradable mulch film for broccoli cultivation is obtained.

[0084] Comparative Example 1: Polybutylene succinate, grade TH801 from Xinjiang Changji Lanshan Tunhe Chemical Co., Ltd.

[0085] Comparative Example 2: Linear polyethylene 7042 resin, produced by Lanzhou Petrochemical.

[0086] The samples obtained in Examples 1-5 and Comparative Example 1 were subjected to performance tests, and the results are as follows:

[0087]

[0088] The samples obtained in Examples 1-5 and Comparative Example 2 were subjected to performance tests, and the results are as follows:

[0089]

[0090] The standard for testing tensile strength is GB / T1040.2-2006.

[0091] The test standard for fracture growth rate is GB / T1040.2-2006.

[0092] The test standard for flow rate is GB / T3682-2000B.

[0093] By comparing the product performance test results of Examples 1-5 with the test results of Comparative Example 1, it can be seen that the formulation of Example 3 has the best overall performance.

[0094] By comparing the product performance test results of Examples 1-5 with those of Comparative Example 2, it can be seen that the formulation in Example 3 has the best overall performance and can replace polyethylene 7042. Polyethylene degrades slowly, while the broccoli mulch film has better biodegradability.

[0095] like Figure 1 As shown, the mulch film of Example 3 was used in a broccoli experiment, which began in April 2023 in Helan County, Ningxia. The mulch film produced using this material was used for broccoli cultivation; mechanical mulching worked normally, but it naturally brittled and broke after 60 days. However, as... Figure 2 As shown, the polyethylene mulch film of Comparative Example 2 maintained good toughness and did not become brittle or cracked after 60 days.

[0096] Further soil burial tests showed complete biodegradation within one year. The soil burial test method involved burying both the fully biodegradable mulch film and polyethylene mulch film simultaneously in natural soil to a depth of 10 cm, watering once a month. After 6 months (180 days), the films were excavated to observe degradation. Burial continued for another 12 months (360 days), followed by another excavation to observe degradation.

[0097] The above description is merely a preferred embodiment of the present invention, and therefore should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the patent and the contents of the specification should still fall within the scope of the present invention.

Claims

1. A special biodegradable mulch film material for broccoli mulching cultivation, characterized in that: The material comprises the following components in parts by weight: 62.5 parts of polybutylene succinate 9 parts of polycaprolactone 10 parts of polylactic acid 3 parts compatibilizer 0.25 parts photosensitizer Melt index modifier 0.25 parts 15 parts of enhanced transparency masterbatch; Polybutylene succinate was selected from Xinjiang Changji Lanshan Tunhe Chemical Co., Ltd., brand name TH801; Polycaprolactone was selected from Shenzhen Guanghua Weiye Co., Ltd., grade 800C; Polylactic acid (PLA) was selected from Zhejiang Hisun Biomaterials Co., Ltd., brand name REVODE101; The compatibilizer used was Bondryam 7107, manufactured by Polyram, Israel. The photosensitizer used is ferric stearate produced by Hubei Yikangyuan Chemical Co., Ltd., with a fineness of 1-3 microns and a purity greater than 99%. The melt flow index regulator used is YTW-2P produced by Beijing Yitaiwei Plastic Raw Materials Co., Ltd. The calcium sulfate whiskers used are calcium sulfate whiskers produced by Jiangxi Fengzhu New Material Technology Co., Ltd., with product grade S04-L and aspect ratio of 5-40. The slip agent used is erucamide produced by Jiangxi Dongyuan Technology Co., Ltd., with a total amide content of more than 98%. The preparation method of the special biodegradable mulch film for broccoli cultivation is as follows: (1) Weigh all the ingredients according to the formula, add them to the high-speed mixer in sequence, and mix for 10 minutes. (2) The high-speed mixed material is fed into a twin-screw extruder for extrusion granulation. The temperature is controlled at 90-170℃. After cooling, mixing, testing and packaging, the special material for fully biodegradable mulch film for broccoli covering cultivation is obtained. The preparation method of the enhanced and transparent masterbatch is as follows: Raw materials are prepared in the following mass ratio: polybutylene succinate: calcium sulfate whiskers: slip agent = 40:50:

10. Weigh the calcium sulfate whiskers and slip agent. First, add the calcium sulfate whiskers to a kneading pot and start stirring at a speed of 60 rpm. Then, evenly add the slip agent and continue stirring at the same speed for 35 minutes. Set aside. Next, weigh the polybutylene succinate. Add the kneaded calcium sulfate whiskers and polybutylene succinate sequentially to a high-speed mixer at a speed of 800 rpm for 10 minutes. Set aside. Finally, feed the high-speed stirred material into a twin-screw extruder for granulation, controlling the temperature at 90-175℃. After cooling, mixing, and packaging, the enhanced and transparent masterbatch is obtained.

2. The application of the fully biodegradable mulch film material for broccoli mulching as described in claim 1 in broccoli cultivation.

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