Anaerobic biodegradation accelerant for plastic for cultivation and seedling raising, preparation method of anaerobic biodegradation accelerant, anaerobic biodegradation plastic and product of anaerobic biodegradation plastic

Abstract

The invention discloses a plastic anaerobic biodegradation accelerant for cultivation and seedling raising, a preparation method of the plastic anaerobic biodegradation accelerant, anaerobic biodegradation plastic and a product of the anaerobic biodegradation plastic, and the accelerant comprises the following components in percentage by mass: 0.5-3% of fenpropathrin, 0.1-0.8% of monopotassium phosphate, 1-6% of nitrite, 1-4% of ammonium molybdate, 5-10% of PLA, 5-10% of nano starch, 3-6% of nano calcium carbonate and the balance of water. 1-5% of carbamide and the balance of biodegradable resin carrier. The production method comprises the following steps: 1, dispersion treatment; 2, centralization processing; 3, carrying out structured treatment; 4, carrying out carrier implantation treatment; and 5, plasticizing and granulating. The plastic anaerobic biodegradation accelerant is added into plastic, the addition amount is 1-5%, anaerobic degradation plastic is formed, and anaerobic biodegradation plastic products such as mulching films, seedling raising trays and seedling raising trays are further prepared. According to the invention, anaerobic degradation can be regulated and controlled, and more importantly, anaerobic degradation also realizes that the degradable plastic disclosed by the invention is in a normal use condition, the plastic cannot be degraded quickly in light and oxygen environments, the aging property of the plastic is equivalent to that of a resin matrix of the plastic, and the physical and mechanical properties are ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of anaerobic biodegradable plastics, and in particular relates to an anaerobic biodegradation accelerator for anaerobic biodegradable plastic products for cultivating seedlings (such as mulch films, seedling trays and seedling trays, etc.). By adding the accelerator to the plastic, the microbial degradation environment of such plastic products in a natural anaerobic environment is changed, thereby achieving the full biodegradation of such plastic products with PP and PE as the main raw materials. Background Art

[0002] Mulch films made primarily of PP and PE, as well as plastic containers such as trays, basins, and cups used for raising rice seedlings, play a vital role in modern agriculture, forestry, and the floriculture industry, and are widely used. However, due to the difficulty of degrading PP and PE, the environmental hazards posed by these discarded plastics are increasing with their increasing use. Therefore, the development of degradable plastics or additives for plastic degradation has become a major technological development direction to address the environmental hazards of discarded plastics.

[0003] The development of biodegradable plastics has gone through three stages: the first generation of biodegradable plastics is starch-modified plastics, which are made by adding additives such as modified starch and cellulose during the polymerization of monomers. The biodegradable properties of these additives are used to break down the modified plastics into tiny plastic fragments in the environment. However, since high molecular polymers such as PE are still difficult to degrade, starch-modified plastics are also called "biodegradable plastics" (incompletely degradable). The second generation of biodegradable plastics is photo-oxidative degradable plastics, which are made by constructing photosensitive groups such as ethylene-CO copolymers and ethylene-ethylene ketone copolymers in the main chain of the plastic molecules. By absorbing light energy (mainly ultraviolet rays) and inducing photo-oxidative effects, the high molecular polymers are degraded into low molecular weight compounds. The disadvantage of this photo-oxidative degradable material is that under normal use conditions, it degrades due to the effects of sunlight and oxygen in the air, resulting in a decline in performance before the material is discarded.

[0004] Third-generation biodegradable plastics are fully biodegradable plastics. These plastics are formed by the dehydration polymerization of organic acids and alcohols. Their common characteristic is the introduction of ester groups into the molecular chain. Various enzymes released by microorganisms, such as esterases, depolymerases, and dehydratases, bind to specific receptors on the plastic surface and catalyze the hydrolysis or oxidation of the ester groups in the polymer, degrading the macromolecules into fatty acids or lipids with a molecular weight of less than 500. These oligomers or their degradation products enter the microbial body and are ultimately metabolized by the microorganisms into water and carbon dioxide. Currently, this type of fully biodegradable plastic includes polylactic acid (PLA), polyhydroxyalkanoates (PHA), poly-3-hydroxybutyrate (PHB), polysuccinate (PBS), and polybutylene terephthalate (PBAT). However, due to cost and performance limitations (e.g., poor water resistance), these biodegradable plastics account for only a small proportion of real-world applications. Furthermore, the biodegradation of these biodegradable plastics is primarily aerobic, requiring industrial composting equipment or environments with demanding conditions such as oxygen-rich and high temperatures, resulting in high degradation costs.

[0005] For existing degradable agricultural mulch films, as well as containers for degradable seedling and rice seedling raising, such as seedling trays, seedling pots, seedling cups, etc., it is hoped that the required mechanical properties can be maintained during the storage and transportation and use period before being discarded, and degradation is expected to occur after being discarded. In addition, users usually do not want to collect and transport them to landfills for centralized degradation treatment after use, because the economic issues of recycling are unrealistic for most users. Abandoning them in the fields not only affects farming operations and crop root growth, but also affects the environment. Therefore, deep plowing to turn over the used mulch films, seedling and rice seedling raising containers and bury them deep is a more feasible way for farmers and other users. This is how straw burning is prohibited and returned to the field. However, usually when the soil depth reaches 20 cm, it is basically an oxygen-deficient or anaerobic environment. Therefore, whether it is photo-oxidative degradation or aerobic biodegradable plastics, their actual degradation performance when deeply buried is significantly lower than the degradation performance measured by industrial compost and laboratory.

[0006] Anaerobic biodegradation can solve the problem of maintaining mechanical properties without significant degradation during normal storage, transportation and use conditions, and can also undergo complete anaerobically biodegradable conditions under anaerobic or low-oxygen conditions after deep plowing and burial of abandoned plastics, thereby not causing undesirable negative impacts on farming and yields. However, the current research results on anaerobic degradation of plastics are still relatively scarce. Currently retrieved is the "Anaerobic Biodegradation Accelerator for Polymer Materials, Preparation Method and Use thereof" disclosed in US2023 / 0151194A1. The anaerobic biodegradation accelerator is a biological component in which at least one bacteria, fungi and enzyme selected from strict anaerobic bacteria or facultative anaerobic bacteria is added to a carrier matrix, as well as a protective layer material surrounding the biological component. A sample containing 5% of the accelerator in a PE film showed a biodegradation rate of 25.99% on the 180th day and a biodegradation rate of 63.07% on the 480th day after ASTM D5511 testing. However, this anaerobic biodegradation accelerator requires the addition of a protective agent and coating treatment, considering the inactivation of added microorganisms under high temperatures and other conditions during the extrusion process. This not only complicates the process and is costly, but also inevitably leads to inactivation. This results in a low 480-day degradation rate when the addition level is controlled at 5% to maintain the material's mechanical strength. Its use as a mulch film still has negative impacts on farming and crop production. The applicant's patent application, number CN202311742118.7, is titled "An Anaerobic Degradation Composite Yeast Agent, Production Method, and Anaerobic Biodegradable Plastic." The application states that PE plastic containing 3% composite yeast can achieve a degradation rate of over 10% under anaerobic conditions in 150 days.

[0007] As a plastics processing company, the applicant has, over the past fifteen years, collaborated with institutions such as East China University of Science and Technology, China University of Petroleum, the Institute of Physics and Chemistry of the Chinese Academy of Sciences, and Nanyang Technological University, Singapore, to address the issue of white pollution. The applicant has been dedicated to researching the conditions and environment for anaerobic microbial degradation of polyethylene (PE) and polypropylene (PP) in soil environments, as well as the industrialization of such technologies and the drafting of industry standards, achieving considerable success. Based on CN202311742118.7, the applicant has further developed and upgraded the degradation technology used in the anaerobic biodegradable mulch film, achieving a 120-day anaerobic biodegradation rate exceeding 90%, leading to the present invention. Summary of the Invention

[0008] In order to solve the problems existing in the existing degradable mulch films and seedling raising containers, the object of the present invention is to provide an anaerobic biodegradation accelerator for plastics used in planting and raising seedlings.

[0009] To achieve the first object of the present invention, the present invention provides an anaerobic biodegradation accelerator for plastics for planting and seedling cultivation, which comprises the following components in a biodegradable resin carrier in the following mass percentages:

[0010]

[0011] The nitrite can be one of sodium nitrite, potassium nitrite, calcium nitrite, ammonium nitrite, etc., or a mixture of several of them.

[0012] The biodegradable resin carrier can be one or a mixture of existing biodegradable resins such as PBAT, PHA, PLA, PHB, etc.

[0013] The nanostarch is modified mung bean starch by soaking it in a weakly acidic or alkaline sodium chloride solution and then drying it. This modification is not the traditional hydrophobic or volume-enhancing modification. Specifically, the mung bean is soaked in a weakly acidic (pH 6-7) or alkaline (pH 7-8) sodium chloride solution (2-5% wt) for 3-5 days and then dried. This softens the properties of the mung bean and balances the development of anaerobic microorganisms.

[0014] The present invention also provides a method for producing the above-mentioned anaerobic biodegradation accelerator, which is a commercially available masterbatch product that can be professionally produced and sold as a masterbatch to facilitate use by manufacturers of mulch films and seedling and rice seedling raising containers, comprising the following steps:

[0015] (1) Dispersion treatment: Grind PLA into nano-scale powder, add nano starch and mix well, then add titanate and anhydrous ethanol for grinding;

[0016] (2) Centralization treatment: First, mix the carbonamide with the material dispersed in step (1), then add white oil and mix well to perform centralization protection;

[0017] (3) Structural treatment: cypermethrin, nitrite, ammonium molybdate, and potassium dihydrogen phosphate are ground into nano-scale powders respectively, and then biodegradable resin carrier powder is added and ground and mixed evenly; nano-calcium carbonate is then added and mixed evenly to construct the material structure;

[0018] (4) Carrier implantation: Add a biodegradable resin carrier with a particle size of less than 10 μm and a plastic additive to the materials subjected to the centralization treatment in step (2) and the structured treatment in step (3), and mix them evenly;

[0019] (5) Plasticizing and granulating: the mixed material of step (4) is extruded and granulated to obtain the anaerobic biodegradation accelerator masterbatch product.

[0020] Furthermore, the present invention also provides an anaerobic biodegradable plastic containing the above-mentioned anaerobic biodegradation accelerator, the main components of which are:

[0021] 90-95% PE and / or PP resin that provides mechanical strength and heat resistance

[0022] 2-5% of the aforementioned anaerobic biodegradation promoter that promotes resin degradation

[0023] Dispersant to improve the dispersibility of anaerobic biodegradation accelerator 0.3-2%

[0024] Compatibilizer to improve the binding property between anaerobic biodegradation accelerator and resin 0.8-2%

[0025] 0.1-0.2% antioxidant to prevent oxidation of anaerobic biodegradation promoter.

[0026] The dispersant is used to improve the dispersibility and lubricity of the accelerator in PE and PP synthetic resins. It can be a fatty acid or metal soap dispersant used in the existing plastics industry, preferably an erucamide dispersant. In addition to providing dispersing and lubricating properties, it can also enhance the thermoplasticity and heat resistance of the plastic.

[0027] In the present invention, the anaerobic biodegradation accelerator in the anaerobic biodegradable plastic can be in the form of a masterbatch, or can be present and used in the form of components that meet the component requirements and are added separately to the plastic raw material.

[0028] The compatibilizer is used to increase the compatibility between the accelerator and the PE and PP resins. The present invention includes but is not limited to chain extenders (such as modified styrene acrylic polymers, lactic acid, ethylene glycol, 1,4-butanediol), coupling agents (such as maleic anhydride, tung oil anhydride, epoxidized soybean oil, methylene-diphenyl diisocyanate, acrylic acid, citric acid), preferably maleic anhydride grafted compatibilizer.

[0029] Antioxidants are used to inhibit oxidation reactions to protect accelerators during thermal processing, including but not limited to phosphorus antioxidants (such as TNPP, 168 antioxidant), phenolic antioxidants (such as 1010 antioxidant, 1076 antioxidant), sulfur antioxidants (such as thiopropionates), and composite antioxidants composed of complexes of phosphites and thioesters. The present invention preferably uses antioxidant 1010 combined with antioxidant 626, antioxidant 1010 is a hindered phenolic antioxidant with a melting point of 110-125°C, and antioxidant 626 is a phosphite antioxidant with a melting point of 170-180°C, so as to exert antioxidant effects in different processing temperature ranges.

[0030] In this application, the hydrophilicity and high specific surface area of ​​nano-calcium carbonate are mainly utilized. The calcium ions produced by dissolution in soil and water environments provide essential elements for the life activities of microorganisms, promoting the growth and metabolism of microorganisms during the initial implantation and enrichment stages of microorganisms. However, due to the insolubility of calcium carbonate, and due to the control of dosage and the isolation effect of the resin, the ion release is slow and will not effectively inhibit anaerobic microorganisms.

[0031] The anaerobic biodegradation accelerator of the present invention is added to the anaerobic biodegradable plastics made in the synthetic resin base material, and is used to produce ground film, seedling tray (basin, cup), seedling tray (basin, cup), when plastic is abandoned in the environment, such as buried in the soil, deposited in the water body, the accelerator dispersed in the plastic product, absorbs moisture in the environment and adsorbs microorganisms, while providing the nutrition and energy required for microbial growth metabolism, an appropriate amount of cypermethrin, nitrite can inhibit the growth metabolism of miscellaneous bacteria, and promote the growth of degradable microorganisms such as pseudomonas and bacillus, especially ammonium molybdate has a promoting effect on the microorganisms in the acid production and gas production process, by forming an ecological environment that is conducive to anaerobic degradation microorganisms, improving anaerobic microbial degradation activity, and can achieve the complete biodegradation of difficult-to-degrade plastics such as PP and PE under natural conditions. Potassium dihydrogen phosphate is both a microbial nutrient and a composite fertilizer. While improving anaerobic biodegradability, it also promotes the growth of crops. The present invention constructs a composite degradation system by the functional complementarity, metabolic mutualism, biofilm synergy and stress resistance superposition of the various components of the accelerator, and completes the biodegradation of plastics such as PP and PE. Furthermore, by making the plastic anaerobic biodegradation accelerator into an additive masterbatch, the dosage can be easily controlled according to the required degradation cycle length, thus achieving regulated anaerobic degradation. More importantly, anaerobic degradation also ensures that the physical and mechanical properties of the degradable plastic remain stable under normal light and oxygen conditions. DETAILED DESCRIPTION

[0032] The present invention will be further described below with reference to specific embodiments to facilitate understanding of the present invention.

[0033] 1. Example of Plastic Anaerobic Biodegradation Accelerator Masterbatch

[0034] The components and their mass percentages of Examples 1-6 of the anaerobic biodegradation accelerator for plastics are shown in Table 1.

[0035] Table 1 Components and mass percentages of the anaerobic biodegradation accelerators for plastics in Examples 1-6

[0036]

[0037]

[0038] The preparation method of the above-mentioned Examples 1-6 is divided into five steps, namely: 1. dispersion treatment; 2. centralization treatment; 3. structuring treatment; 4. carrier implantation treatment; 5. plasticization granulation, which are as follows:

[0039] 1. Dispersive treatment

[0040] 1) Grinding PLA particles to nanometer size at -10 to -5°C; soaking nanomung bean starch in sodium chloride (2-5% wt) at pH 6.5 for 3-5 days, drying, adding the mixture to the nano PLA powder, and then uniformly mixing and grinding for 5 minutes to prepare a nano hybrid material;

[0041] 2) adding titanate with a particle size of no more than 5 microns to the above-mentioned nano-mixed material, and stirring and dispersing the mixture uniformly in a high-speed mixer at 800-1200 rpm;

[0042] 3) adding anhydrous ethanol and grinding at a low temperature of -10 to -5°C for three times at high speed, each time for 3 minutes, with an interval of 1 hour between each time, to perform a pretreatment chemical reaction; forming a dispersed treatment material.

[0043] 2. Centralized Processing

[0044] 1) Dehumidify the carbonamide with dry air at a temperature of 12-15°C for 2 hours;

[0045] 2) Mix the dehumidified carbonamide and the dispersed material at a low speed of 50-150 rpm for 25-30 minutes in a dry environment at 20-22°C; then add a small amount of white oil and mix for 5 minutes;

[0046] 3) Add fumed silica and mix at a medium speed of 400-600 rpm clockwise for 10 minutes in an environment of 18-20°C for centralized protection.

[0047] 3. Structured processing

[0048] 1) Accelerator protection treatment: fenpropathrin, nitrite, ammonium molybdate, potassium dihydrogen phosphate, etc. are ground into nano-scale powders at low temperature (-10 to -5°C); then, the mixture is evenly mixed in proportion and the PBAT resin base powder is added, and the mixture is ground and mixed at low temperature for 30 minutes;

[0049] 2) Add nano calcium carbonate and mix at high speed three times at room temperature for 2 minutes each time, with a time interval of 30 minutes between each mixing to construct the material structure;

[0050] 4. Vector implantation

[0051] 1) Add a small amount of PBAT carrier powder with a particle size of less than 10 microns and an appropriate amount of related plasticizers and other additives to the structured mixed material, and mix at high speed at low temperature for 10 minutes;

[0052] 2) Add filler and mix at low speed and room temperature for 30 minutes;

[0053] 3) Add the remaining PBAT powder and mix at low temperature and high speed for 15 minutes;

[0054] 5. Plasticizing and granulating

[0055] 1) Preheating the twin-screw extruder to a temperature of 190-230° C. and a rotation speed of 135-230 r / min, performing extrusion granulation to obtain a masterbatch of a plastic anaerobic biodegradation accelerator.

[0056] 2. Degradation Experiment

[0057] The components and contents of Comparative Examples 1-5 are shown in Table 2.

[0058] Table 2 Components and mass percentages of comparative examples 1-5

[0059]

[0060]

[0061] The preparation methods of Comparative Examples 1-5 refer to Examples 1-6, and the corresponding steps of the preparation methods for the components not included need to be omitted to obtain the comparative composite additives of Comparative Examples 1-5.

[0062] The plastic anaerobic biodegradation accelerators of Examples 1-6 were added to HDPE and blown into film to form a biodegradable plastic film containing 3% of the plastic anaerobic biodegradation accelerators. The composite additives of Comparative Examples 1-5 were also added to HDPE to form a plastic film containing 3% of the composite additives.

[0063] 1. Anaerobic degradation detection

[0064] The degradation rates of the degradable plastic films of Examples 1-6 and Comparative Examples 1-5 were tested according to the "Determination of the Ultimate Anaerobic Biodegradability of Plastics Under High-Solid Composting Conditions Using the Method for Analyzing and Determining the Release of Biogas" (GBT33797-2017 or ASTM D5511). This method is used to determine the degradation rate of anaerobic biodegradation, i.e., the carbon content in the test material and the percentage of carbon dioxide and methane converted after degradation are used as the degradation rate. The results are shown in Table 2 below:

[0065] Table 2 Anaerobic degradation rate of different materials (%)

[0066] Number of days 30 60 90 120 150 Example 1 20.26 48.33 74.09 92.12 99.54 Example 2 10.33 31.65 50.67 64.66 75.27 Example 3 7.22 20.18 35.98 51.67 67.55 Example 4 18.05 38.77 57.08 78.43 88.07 Example 5 15.01 34.89 52.33 70.99 80.66 Example 6 17.77 37.36 56.99 77.18 87.09 Comparative Example 1 3.21 7.44 13.55 20.33 37.11 Comparative Example 2 10.66 27.42 43.77 59.11 78.12 Comparative Example 3 9.33 19.78 38.67 51.06 68.88 Comparative Example 4 8.98 26.00 40.21 57.98 72.03 Comparative Example 5 8.88 18.99 37.01 50.02 67.15

[0067] As can be seen in Table 2, the degradation rate of Comparative Example 1, which lacks fenpropathrin, is significantly lower than that of Examples 1-6 and Comparative Examples 2-5, indicating that fenpropathrin plays a major role in promoting the anaerobic biodegradation of plastics. The degradation rates of Comparative Examples 3 and 5 are lower than those of Examples 1-6, Comparative Examples 2, and Comparative Example 4, but higher than those of Comparative Example 1, demonstrating the important role of nitrite and mung bean starch in anaerobic biodegradation. The role of potassium dihydrogen phosphate, carbonamide, and ammonium molybdate in promoting anaerobic biodegradation is also demonstrated in Comparative Examples 2 and 4. However, Example 3, which contains the highest fenpropathrin content, exhibits a lower degradation rate than Comparative Examples 2 and 4, indicating that while fenpropathrin plays a major role in promoting degradation, a higher fenpropathrin content does not necessarily guarantee a better effect.

[0068] 2. Aerobic degradation detection

[0069] The anaerobic degradable plastic film from Example 1 was tested for degradation under aerobic conditions according to GB / T 19277.1-2011, "Determination of the Ultimate Aerobic Biodegradability of Materials Under Controlled Composting Conditions Using the Method for Measuring Released Carbon Dioxide." The results clearly show a 90-day degradation rate of 2.33%, significantly lower than the anaerobic biodegradation rate. This suggests that under aerobic conditions, only PBAT and PLA, inherently biodegradable materials, degraded, while HDPE remained undegraded. This effect is beneficial for maintaining the durability of the degradable plastic's performance under normal use.

[0070] 3. Detection of the effect of different accelerator masterbatch addition amounts on the mechanical properties of plastic films

[0071] Increasing the amount of accelerator added increases the degradation rate of plastic products. This can also negatively impact the mechanical properties of plastic products, particularly plastic film products such as packaging bags. To determine the optimal accelerator dosage, the accelerator from Example 1 was added to HDPE and blown into plastic films at concentrations of 1%, 3%, 5%, and 7% by mass. The tensile strength of these films was measured according to GB / T1040.1-2018. The results are shown in Table 3.

[0072] Table 3 Mechanical properties of HDPE 60 μm membranes with different anaerobic degradation accelerator additions

[0073] Accelerator content 1％ 3％ 5％ 7％ Transverse tensile strength (MPa) 22.01 23.93 24.77 10.88 Longitudinal tensile strength (MPa) 24.77 25.66 26.00 11.34

[0074] As can be seen from Table 3, when the addition amount exceeds 5%, the mechanical properties of the plastic deteriorate significantly, so the present invention adopts 1-5%.

[0075] 3. Mulch Film and Its Field Trials

[0076] 1. Anaerobic biodegradable film samples

[0077]

[0078] The above raw materials are blended and melted through a screw extruder, filtered, discharged from a die, cooled by an air ring, blown, and rolled to form a ground film with a thickness of 0.008 mm.

[0079] 2. Field comparative test

[0080] (1) Sample

[0081] Field tests were conducted to compare the anaerobic biodegradable mulch film samples of the present invention with commercially available PE non-degradable ordinary mulch films and commercially available fully biodegradable mulch films, all with a thickness of 0.008 mm and a width of 1.2 m.

[0082] (2) Location and crops

[0083] Location: Wulian County, Shandong Province, with a semi-humid continental climate in the warm temperate monsoon zone, with an average annual temperature of 13.2°C, an average annual rainfall of 747.0 mm, and an average annual evaporation of 1649.0 mm.

[0084] Crops grown: Field peanuts.

[0085] Experimental design: A total of three plots were set up, using anaerobic biodegradable mulch, ordinary mulch, and commercially available fully biodegradable mulch respectively. The experiment was repeated three times in each plot, and two rows of peanuts were planted in each plot.

[0086] (3) Test indicators

[0087] Test indicators include:

[0088] ①. Film degradation characteristics: Using visual inspection, the film degradation process was divided into five stages: induction stage, cracking stage, major cracking stage, fragmentation stage, and film-free stage. The film degradation rate was determined using the soil burial method.

[0089] ②. Crop growth conditions: Determine the germination rate of crops and plant height during the growth period.

[0090] ③. Crop yield: Crop yield is measured during the harvest period.

[0091] ④. Soil nutrients: After the crop harvest, measure the soil pH value, EC value, soil organic matter content, nutrient content, etc.

[0092] (4) Result analysis

[0093] ① Degradation of ground film

[0094] The anaerobic biodegradable mulch film of the present invention maintained its toughness and showed no significant cracking during the entire crop growth period, compared to conventional mulch films. The fully biodegradable mulch film began to crack after 31 days and cracked significantly after 90 days. This early cracking led to faster weed growth, increasing weed control costs.

[0095] ②Crop growth

[0096] See the table below:

[0097] Germination rate (%) Plant height (cm) Ordinary mulch 60.2 43.2 Anaerobic biodegradable mulch 81.2 45.5 Fully biodegradable mulch film 80.1 44.7

[0098] The germination rate of peanuts covered with ordinary mulch films is 20 percentage points lower than that of the two degradable mulch films. The anaerobic biodegradable mulch film of the present invention can increase the germination rate and plant height of crops, indicating that it can promote the growth of crops.

[0099] ③Crop yield

[0100] The peanut yield in the ordinary mulch area is 377.52 kg per mu, the anaerobic biodegradable mulch area is 389.68 kg per mu, and the fully biodegradable mulch area is 368.23 kg per mu. The anaerobic biodegradable mulch has achieved growth.

[0101] ④Soil nutrients

[0102] The soil nutrient characteristics under different mulch coverings are shown in the table below.

[0103] Ordinary mulch Anaerobic biodegradable mulch Fully biodegradable mulch film pH 4.85 4.88 4.70 EC(us / cm) 98.7 57.4 162.1 Available nitrogen (mg / kg) 60.3 63.3 72.8 Available phosphorus (mg / kg) 55.5 38.7 44.5 Fast-acting potassium (mg / kg) 100 107 166 Organic matter (g / kg) 9.0 9.0 9.2

[0104] As can be seen from the table above, the anaerobic biodegradable mulch film of the present invention can slightly increase the pH value compared to conventional mulch films and fully biodegradable mulch films, and has a slight ameliorative effect on soils with high acidity. Covering with the anaerobic biodegradable mulch film of the present invention can significantly reduce the soil EC value and reduce the soil salinity. The anaerobic biodegradable mulch film of the present invention has a lower post-harvest available phosphorus content in crops than conventional mulch films and fully anaerobic biodegradable mulch films, indicating that it promotes the absorption of available phosphorus by crops. The available nitrogen, potassium, and organic matter content are comparable to those of conventional mulch films, which may be related to the presence of nitrogen and potassium in the anaerobic degradation promoter masterbatch of the present invention.

[0105] 4. Seedling raising container

[0106] Including seedling trays, seedling cups, seedling pots, etc.

[0107]

[0108] Injection molding: raw material drying → melt injection → cooling and demoulding → trimming and quality inspection.

[0109] Compression molding: Pressure: 50-100 tons.

[0110] Anaerobic biodegradable modified PP: can be reused for 3-4 years.

[0111] Those skilled in the art will understand that the foregoing descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will be able to modify the technical solutions described in the foregoing embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A plastic anaerobic biodegradation accelerator for planting seedlings, characterized in that The biodegradable resin carrier contains the following components in percentage by mass:

2. The anaerobic biodegradation accelerator for plastics according to claim 1, characterized in that: The nitrite is one or a mixture of sodium nitrite, potassium nitrite, calcium nitrite, ammonium nitrite, etc.

3. The anaerobic biodegradation accelerator for plastics according to claim 1, characterized in that: The biodegradable resin carrier is one or a mixture of PBAT, PHA, PLA, and PHB.

4. The anaerobic biodegradation accelerator for plastics according to claim 1, wherein: The nano starch is mung bean starch modified after being soaked in weak acid or weak alkaline sodium chloride solution and dried.

5. A method for producing the plastic anaerobic biodegradation accelerator according to any one of claims 1 to 4, comprising the following steps: (1) Dispersion treatment: Grind PLA into nano-scale powder, add nano starch and mix well, then add titanate and anhydrous ethanol for grinding; (2) Centralization treatment: First, mix the carbonamide with the material dispersed in step (1), then add white oil and mix well to perform centralization protection; (3) Structural treatment: cypermethrin, nitrite, ammonium molybdate, and potassium dihydrogen phosphate are ground into nano-scale powders respectively, and then biodegradable resin carrier powder is added and ground and mixed evenly; nano-calcium carbonate is then added and mixed evenly to construct the material structure; (4) Carrier implantation: Add a biodegradable resin carrier with a particle size of less than 10 μm and a plastic additive to the materials subjected to the centralization treatment in step (2) and the structured treatment in step (3), and mix them evenly; (5) Plasticizing and granulating: the mixed material of step (4) is extruded and granulated to form a masterbatch of the plastic anaerobic biodegradation promoter.

6. The production method according to claim 5, wherein: In step (1), PLA is ground at low temperature at -10 to -5°C.

7. The production method according to claim 5, wherein: In step (2), the carbonamide is first dehumidified with dry air at 12 to 15°C, and then mixed with the dispersed material in step (1) in a dry environment at 20 to 22°C.

8. An anaerobic biodegradable plastic, characterized in that Its main components are: PE and / or PP resin 90-95% 2-5% of the anaerobic biodegradation promoter according to claim 1 Dispersant 0.3-2% Compatibilizer 0.8-2% Antioxidant 0.1-0.2%.

9. The anaerobic biodegradable plastic according to claim 8, characterized in that The synthetic resin substrate is a mixture of one or more of PE, PP, PVC, PUR, PET, PLA, PHA, PHB, PBAT, PBS, PA, ABS, PS, and EPS resins.

10. The anaerobic biodegradable plastic according to claim 8, characterized in that The dispersant is erucamide dispersant.

11. The anaerobic biodegradable plastic according to claim 8, characterized in that The compatibilizer is a maleic anhydride grafted compatibilizer.

12. The anaerobic biodegradable plastic according to claim 8, characterized in that The antioxidant is antioxidant 1010 compounded with antioxidant 626.

13. An anaerobic biodegradable plastic product, a ground film, characterized in that The PP or PE ground film contains 1-5% of the plastic anaerobic biodegradation accelerator masterbatch or corresponding components according to any one of claims 1-4.

14. An anaerobic biodegradable plastic product, a container for raising seedlings or rice seedlings, characterized in that The seedling or rice seedling raising container contains 1-5% of the plastic anaerobic biodegradation accelerator masterbatch or corresponding components described in any one of claims 1-4.

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