Preparation method of bio-based degradable master batch and bio-based degradable plastic

Abstract

The invention discloses a preparation method of a bio-based degradable master batch. The preparation method comprises the following steps: (1) extracting flavonoid compounds of phoenix tree leaves; (2) the degradable plastic is recycled and treated, and degradable plastic particles are obtained; (3) high-speed mixing: uniformly mixing the flavonoid compound and the degradable plastic particles in a high-speed stirrer to obtain a modified high-speed mixture; (4) placing the modified highly mixed material in a heating device, gradually heating to 80-86 DEG C, continuously stirring the material, and uniformly heating and mixing to obtain a molten material; and (5) putting the molten material into a granulator, and granulating to obtain the bio-based degradable master batch. The invention also discloses a preparation method of the bio-based degradable plastic, which comprises the following steps: uniformly mixing the bio-based degradable master batch, the filler and the assistant, and extruding by a screw machine to obtain the bio-based degradable plastic.

Description

Technical Field

[0001] The invention belongs to the field of material science and engineering, and specifically relates to a method for preparing a bio-based degradable masterbatch and a bio-based degradable plastic. Background Art

[0003] In the current biodegradable plastic market, there are three types of plastics: (1) natural polymer biodegradable plastics, mainly starch-based plastics; (2) biodegradable plastics synthesized by microbial metabolism, mainly PHA; (3) chemically synthesized biodegradable plastics, including PLA (polylactic acid), PBAT (polybutylene adipate / terephthalate), PBS (polybutylene succinate), etc.

[0004] At present, PLA is the leader in the emerging bioplastics market and has great market potential. PBAT from fossil resources is one of the most attractive materials for toughening PLA. By adjusting the ratio of the two structural units, the morphology, mechanical properties and melting properties of the product can be easily adjusted.

[0005] Due to the good biodegradability of PLA and PBAT and their performance being close to that of ordinary daily consumer plastics, their market acceptance and production capacity have been greatly developed. According to a relevant report from iResearch Consulting, PBAT and PLA currently occupy more than 80% of the market share.

[0006] The decomposition rate of biodegradable plastics on the market is still slow under natural and controlled conditions. It takes a long time to degrade under natural conditions and it is difficult to achieve complete decomposition. Under controlled conditions, the degradation rate of most biodegradable plastics is still slow and requires 3 to 6 months in an industrial composting system to degrade.

[0007] At present, in my country's garbage classification and treatment process, degradable plastics can only be sorted out as ordinary plastics indiscriminately and sent to incineration or landfill facilities, entering the traditional plastic treatment process. Therefore, judging from the current terminal treatment of biodegradable plastics, most biodegradable plastics will eventually enter the incineration or pyrolysis and other disposal links along with traditional plastics. Data show that 55.21% of biodegradable plastics are incinerated after being discarded. This data clearly shows that we need to re-understand the significance of using biodegradable plastics and the new environmental risks they bring during the incineration process.

[0008] Plane trees, especially French plane trees, are widely planted as a kind of urban roadside trees in some cities in China. At present, the treatment of dead plane leaves is mainly to directly sweep them away as garbage, which does not get any benefit and causes considerable energy consumption and waste. Summary of the invention

[0009] Purpose of the invention: The present invention aims to improve the problems existing in the above-mentioned prior art, that is, the present invention discloses a method for preparing a bio-based degradable masterbatch and a bio-based degradable plastic.

[0010] Technical solution: A method for preparing a bio-based degradable masterbatch, the steps are as follows:

[0011] (1) Extracting flavonoids from sycamore leaves;

[0012] (2) Recycling and processing degradable plastics to obtain degradable plastic particles;

[0013] (3) High-mixing: The flavonoid compound obtained in step (1) and the degradable plastic particles obtained in step (2) are mixed evenly in a high-grade agitator to obtain a modified high-mix material, wherein:

[0014] The mass ratio of the flavonoid compound obtained in step (1) to the degradable plastic particles obtained in step (2) is 100:30;

[0015] (4) Heating and melting: placing the modified high-mix material obtained in step (3) in a heating device, gradually heating it to 80-86° C., and continuously stirring the material to uniformly heat and mix it to obtain a molten material;

[0016] (5) Granulation: The molten material obtained in step (4) is placed in a granulator for granulation to obtain a bio-based degradable masterbatch.

[0017] Furthermore, step (1) comprises the following steps:

[0018] (11) washing, drying and crushing the sycamore leaves in sequence, and then passing through a 500-mesh sieve to obtain sycamore leaf powder;

[0019] (12) Add the sycamore leaf powder to an appropriate amount of entrainer and mix evenly to obtain a mixed solution, wherein:

[0020] The amount of the entrainer is 25-30 mL / g based on the weight of the sycamore leaf powder;

[0021] The entrainer is a mixture of ethanol and water in a volume ratio of (50-95):(50-5);

[0022] (13), placing the mixed solution obtained in step (12) in a high-pressure extractor, and then introducing supercritical CO2 fluid into the high-pressure extractor for extraction, and after completion, proceeding to step (14), wherein:

[0023] The flow rate of supercritical CO2 fluid is 460-550cm 3 / s;

[0024] The extraction time is 8-10min;

[0025] During extraction, the pressure in the high-pressure extractor is controlled at 380-420 MPa, and the temperature in the high-pressure extractor is controlled at 86°C;

[0026] (14) reducing the pressure in the high-pressure extractor to 300 MPa, so that the supercritical CO2 fluid introduced into the high-pressure extractor is transformed from a supercritical state to a gaseous state, and nitrogen is continuously passed into the high-pressure extractor at the same time, heating and activating the extract, and collecting the extract using a separator, and drying to obtain the flavonoid compounds in the leaves of the Chinese parasol tree, wherein:

[0027] During heating activation, the temperature in the high-pressure extractor was controlled at 86°C and the activation time was controlled at 9 minutes.

[0028] Furthermore, the method further comprises step (15) solvent recovery: the supercritical CO2 fluid and entrainer in step (14) are recovered and recycled.

[0029] Furthermore, step (2) comprises the following steps:

[0030] (21) Collecting discarded degradable plastics, wherein the degradable plastics are one or more of the following plastics:

[0031] Polylactic acid, polybutylene adipate / terephthalate, polybutylene succinate;

[0032] (22) removing dirt, labels and other non-plastic substances from the degradable plastic, and then cleaning the degradable plastic with a cleaning agent to remove attachments and contaminants thereon, wherein:

[0033] The amount of the cleaning agent used is 50-80 mL / g based on the mass of the degradable plastic;

[0034] (23) Flotation: Different types of biodegradable plastics are separated by flotation using the density differences of the different types of biodegradable plastics;

[0035] (24) drying and crushing the washed degradable plastics of the same type in sequence to obtain degradable plastic fragments;

[0036] (25) Melting and granulation: The degradable plastic fragments are re-melted and granulated to obtain degradable plastic particles.

[0037] Furthermore, the cleaning agent in step (22) is composed of the following components by mass:

[0038] 15-20 parts of dimethyl sulfoxide, 5-10 parts of ethanol, 4-8 parts of benzyl alcohol, 4-8 parts of ethylene glycol butyl ether, 0.5-1 parts of potassium hydroxide, 1-2 parts of methyl cellulose, 1-2 parts of alkyl benzene sulfonate, and 50-70 parts of water.

[0039] Furthermore, during the melting process of step (25), a filtration system is used to filter the degradable plastic particle melt.

[0040] A bio-based degradable masterbatch is prepared by any one of the preparation methods described above.

[0041] A method for preparing a bio-based degradable plastic, comprising the following steps:

[0042] The bio-based degradable masterbatch, filler and additives described in any one of the above are uniformly mixed and extruded by a screw machine to obtain a bio-based degradable plastic, wherein:

[0043] The mass ratio of bio-based degradable masterbatch, filler and additive is 10:(2-4):(1-3);

[0044] The filler is a wood fiber filler

[0045] The auxiliary agent is a bio-based coloring agent.

[0046] By adding flavonoids extracted from sycamore leaves as additives to recycled biodegradable plastics, the biodegradability of the material can be improved. The reason for improving biodegradability is that: 1. Flavonoids promote the growth and activity of certain microorganisms that have the ability to degrade plastics. Through the promotion of microbial enzymes, flavonoids accelerate the biochemical degradation process of plastics. 2. Certain functional groups in flavonoids react with chemical components in plastics, causing changes in the chemical structure of the plastics, thereby achieving degradation.

[0047] Beneficial effects: The method for preparing a bio-based degradable masterbatch and a bio-based degradable plastic disclosed in the present invention has the following beneficial effects:

[0048] 1. Greatly improve the biodegradation rate of degradable plastics;

[0049] 2. The discarded biodegradable plastics were recycled and compounded with flavonoids extracted from sycamore leaves to reduce environmental pollution. DETAILED DESCRIPTION

[0050] The specific embodiments of the present invention are described in detail below.

[0051] The "range" disclosed in the present invention is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 10 to 50 is listed for a specific parameter, it is understood that the range of 10 to 40 and 20 to 50 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In this application, unless otherwise specified, the range of values ​​"a to b" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the range of values ​​"0 to 5" means that all real numbers between "0 to 5" have been fully listed in this article, and "0 to 5" is only an abbreviation of these numerical combinations.

[0052] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0053] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0054] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0055] If there is no special explanation, the "include" and "comprising" mentioned in this application are open-ended or closed-ended. For example, the "include" and "comprising" may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0056] Unless otherwise specified, the reaction is carried out at room temperature and pressure.

[0057] Unless otherwise specified, all parts or percentages are by weight.

[0058] In the present invention, all substances used are known substances and can be purchased or synthesized by known methods.

[0059] In the present invention, the devices or equipment used are all conventional devices or equipment known in the art and are commercially available.

[0060] Example 1

[0061] A method for preparing a bio-based degradable masterbatch, comprising the following steps:

[0062] (1) Extracting flavonoids from sycamore leaves;

[0063] (2) Recycling and processing degradable plastics to obtain degradable plastic particles;

[0064] (3) High-mixing: The flavonoid compound obtained in step (1) and the degradable plastic particles obtained in step (2) are mixed evenly in a high-grade agitator to obtain a modified high-mix material, wherein:

[0065] The mass ratio of the flavonoid compound obtained in step (1) to the degradable plastic particles obtained in step (2) is 100:30;

[0066] (4) Heating and melting: placing the modified high-mix material obtained in step (3) in a heating device, gradually heating it to 80° C., and continuously stirring the material to uniformly heat and mix it to obtain a molten material;

[0067] (5) Granulation: The molten material obtained in step (4) is placed in a granulator for granulation to obtain a bio-based degradable masterbatch.

[0068] Furthermore, step (1) comprises the following steps:

[0069] (11) washing, drying and crushing the sycamore leaves in sequence, and then passing through a 500-mesh sieve to obtain sycamore leaf powder;

[0070] (12) Add the sycamore leaf powder to an appropriate amount of entrainer and mix evenly to obtain a mixed solution, wherein:

[0071] The amount of the entrainer is 25 mL / g based on the weight of the sycamore leaf powder;

[0072] The entrainer is a mixture of ethanol and water in a volume ratio of 50:50;

[0073] (13), placing the mixed solution obtained in step (12) in a high-pressure extractor, and then introducing supercritical CO2 fluid into the high-pressure extractor for extraction, and after completion, proceeding to step (14), wherein:

[0074] The flow rate of supercritical CO2 fluid is 460cm3 / s;

[0075] The extraction time was 8 min;

[0076] During extraction, the pressure in the high-pressure extractor was controlled at 380 MPa, and the temperature in the high-pressure extractor was controlled at 86°C;

[0077] (14) reducing the pressure in the high-pressure extractor to 300 MPa, so that the supercritical CO2 fluid introduced into the high-pressure extractor is transformed from a supercritical state to a gaseous state, and nitrogen is continuously passed into the high-pressure extractor at the same time, heating and activating the extract, and collecting the extract using a separator, and drying to obtain the flavonoid compounds in the leaves of the Chinese parasol tree, wherein:

[0078] During heating activation, the temperature in the high-pressure extractor was controlled at 86°C and the activation time was controlled at 9 minutes.

[0079] Furthermore, the method further comprises step (15) solvent recovery: the supercritical CO2 fluid and entrainer in step (14) are recovered and recycled.

[0080] Furthermore, step (2) comprises the following steps:

[0081] (21) Collecting discarded degradable plastics, wherein the degradable plastics are one or more of the following plastics:

[0082] Polylactic acid, polybutylene adipate / terephthalate, polybutylene succinate;

[0083] (22) removing dirt, labels and other non-plastic substances from the degradable plastic, and then cleaning the degradable plastic with a cleaning agent to remove attachments and contaminants thereon, wherein:

[0084] The amount of the cleaning agent used is 50 mL / g based on the mass of the degradable plastic;

[0085] (23) Flotation: Different types of biodegradable plastics are separated by flotation using the density differences of the different types of biodegradable plastics;

[0086] (24) drying and crushing the washed degradable plastics of the same type in sequence to obtain degradable plastic fragments;

[0087] (25) Melting and granulation: The degradable plastic fragments are re-melted and granulated to obtain degradable plastic particles.

[0088] Furthermore, the cleaning agent in step (22) is composed of the following components by mass:

[0089] 15 parts of dimethyl sulfoxide, 5 parts of ethanol, 4 parts of benzyl alcohol, 4 parts of ethylene glycol butyl ether, 0.5 parts of potassium hydroxide, 1 part of methyl cellulose, 1 part of alkylbenzene sulfonate, and 50 parts of water.

[0090] Furthermore, during the melting process of step (25), a filtering system is used to filter the degradable plastic particle melt to remove impurities and ensure the quality of the recycled plastic.

[0091] A bio-based degradable masterbatch is prepared by any one of the preparation methods described above.

[0092] A method for preparing a bio-based degradable plastic, comprising the following steps:

[0093] The bio-based degradable masterbatch, filler and additives described in any one of the above are uniformly mixed and extruded by a screw machine to obtain a bio-based degradable plastic, wherein:

[0094] The mass ratio of bio-based degradable masterbatch, filler and additive is 10:2:1;

[0095] The filler is a wood fiber filler

[0096] The auxiliary agent is a bio-based coloring agent.

[0097] Example 2

[0098] A method for preparing a bio-based degradable masterbatch, comprising the following steps:

[0099] (1) Extracting flavonoids from sycamore leaves;

[0100] (2) Recycling and processing degradable plastics to obtain degradable plastic particles;

[0101] (3) High-mixing: The flavonoid compound obtained in step (1) and the degradable plastic particles obtained in step (2) are mixed evenly in a high-grade agitator to obtain a modified high-mix material, wherein:

[0102] The mass ratio of the flavonoid compound obtained in step (1) to the degradable plastic particles obtained in step (2) is 100:30;

[0103] (4) Heating and melting: placing the modified high-mix material obtained in step (3) in a heating device, gradually heating it to 86° C., and continuously stirring the material to uniformly heat and mix it to obtain a molten material;

[0104] (5) Granulation: The molten material obtained in step (4) is placed in a granulator for granulation to obtain a bio-based degradable masterbatch.

[0105] Furthermore, step (1) comprises the following steps:

[0106] (11) washing, drying and crushing the sycamore leaves in sequence, and then passing through a 500-mesh sieve to obtain sycamore leaf powder;

[0107] (12) Add the sycamore leaf powder to an appropriate amount of entrainer and mix evenly to obtain a mixed solution, wherein:

[0108] The amount of the entrainer is 30 mL / g based on the weight of the sycamore leaf powder;

[0109] The entrainer is a mixture of ethanol and water, with a volume ratio of 95:5;

[0110] (13), placing the mixed solution obtained in step (12) in a high-pressure extractor, and then introducing supercritical CO2 fluid into the high-pressure extractor for extraction, and after completion, proceeding to step (14), wherein:

[0111] The flow rate of supercritical CO2 fluid is 550cm 3 / s;

[0112] The extraction time was 10 min;

[0113] During extraction, the pressure in the high-pressure extractor was controlled at 420 MPa, and the temperature in the high-pressure extractor was controlled at 86°C;

[0114] (14) reducing the pressure in the high-pressure extractor to 300 MPa, so that the supercritical CO2 fluid introduced into the high-pressure extractor is transformed from a supercritical state to a gaseous state, and nitrogen is continuously passed into the high-pressure extractor at the same time, heating and activating the extract, and collecting the extract using a separator, and drying to obtain the flavonoid compounds in the leaves of the Chinese parasol tree, wherein:

[0115] During heating activation, the temperature in the high-pressure extractor was controlled at 86°C and the activation time was controlled at 9 minutes.

[0116] Furthermore, the method further comprises step (15) solvent recovery: the supercritical CO2 fluid and entrainer in step (14) are recovered and recycled.

[0117] Furthermore, step (2) comprises the following steps:

[0118] (21) Collecting discarded degradable plastics, wherein the degradable plastics are one or more of the following plastics:

[0119] Polylactic acid, polybutylene adipate / terephthalate, polybutylene succinate;

[0120] (22) removing dirt, labels and other non-plastic substances from the degradable plastic, and then cleaning the degradable plastic with a cleaning agent to remove attachments and contaminants thereon, wherein:

[0121] The amount of the cleaning agent used is 80 mL / g based on the mass of the degradable plastic;

[0122] (23) Flotation: Different types of biodegradable plastics are separated by flotation using the density differences of the different types of biodegradable plastics;

[0123] (24) drying and crushing the washed degradable plastics of the same type in sequence to obtain degradable plastic fragments;

[0124] (25) Melting and granulation: The degradable plastic fragments are re-melted and granulated to obtain degradable plastic particles.

[0125] Furthermore, the cleaning agent in step (22) is composed of the following components by mass:

[0126] 20 parts of dimethyl sulfoxide, 10 parts of ethanol, 8 parts of benzyl alcohol, 8 parts of ethylene glycol butyl ether, 0.1 part of potassium hydroxide, 2 parts of methyl cellulose, 2 parts of alkylbenzene sulfonate, and 70 parts of water.

[0127] Furthermore, during the melting process of step (25), a filtering system is used to filter the degradable plastic particle melt to remove impurities and ensure the quality of the recycled plastic.

[0128] A bio-based degradable masterbatch is prepared by any one of the preparation methods described above.

[0129] A method for preparing a bio-based degradable plastic, comprising the following steps:

[0130] The bio-based degradable masterbatch, filler and additives described in any one of the above are uniformly mixed and extruded by a screw machine to obtain a bio-based degradable plastic, wherein:

[0131] The mass ratio of bio-based degradable masterbatch, filler and additive is 10:4:3;

[0132] The filler is a wood fiber filler

[0133] The auxiliary agent is a bio-based coloring agent.

[0134] Example 3

[0135] A method for preparing a bio-based degradable masterbatch, comprising the following steps:

[0136] (1) Extracting flavonoids from sycamore leaves;

[0137] (2) Recycling and processing degradable plastics to obtain degradable plastic particles;

[0138] (3) High-mixing: The flavonoid compound obtained in step (1) and the degradable plastic particles obtained in step (2) are mixed evenly in a high-grade agitator to obtain a modified high-mix material, wherein:

[0139] The mass ratio of the flavonoid compound obtained in step (1) to the degradable plastic particles obtained in step (2) is 100:30;

[0140] (4) Heating and melting: placing the modified high-mix material obtained in step (3) in a heating device, gradually heating it to 83° C., and continuously stirring the material to uniformly heat and mix it to obtain a molten material;

[0141] (5) Granulation: The molten material obtained in step (4) is placed in a granulator for granulation to obtain a bio-based degradable masterbatch.

[0142] Furthermore, step (1) comprises the following steps:

[0143] (11) washing, drying and crushing the sycamore leaves in sequence, and then passing through a 500-mesh sieve to obtain sycamore leaf powder;

[0144] (12) Add the sycamore leaf powder to an appropriate amount of entrainer and mix evenly to obtain a mixed solution, wherein:

[0145] The amount of the entrainer is 28 mL / g based on the weight of the sycamore leaf powder;

[0146] The entrainer is a mixture of ethanol and water, with a volume ratio of 60:40;

[0147] (13), placing the mixed solution obtained in step (12) in a high-pressure extractor, and then introducing supercritical CO2 fluid into the high-pressure extractor for extraction, and after completion, proceeding to step (14), wherein:

[0148] The flow rate of supercritical CO2 fluid is 500cm 3 / s;

[0149] The extraction time was 9 min;

[0150] During extraction, the pressure in the high-pressure extractor was controlled at 400 MPa, and the temperature in the high-pressure extractor was controlled at 86°C;

[0151] (14) reducing the pressure in the high-pressure extractor to 300 MPa, so that the supercritical CO2 fluid introduced into the high-pressure extractor is transformed from a supercritical state to a gaseous state, and nitrogen is continuously passed into the high-pressure extractor at the same time, heating and activating the extract, and collecting the extract using a separator, and drying to obtain the flavonoid compounds in the leaves of the Chinese parasol tree, wherein:

[0152] During heating activation, the temperature in the high-pressure extractor was controlled at 86°C and the activation time was controlled at 9 minutes.

[0153] Furthermore, the method further comprises step (15) solvent recovery: the supercritical CO2 fluid and entrainer in step (14) are recovered and recycled.

[0154] Furthermore, step (2) comprises the following steps:

[0155] (21) Collecting discarded degradable plastics, wherein the degradable plastics are one or more of the following plastics:

[0156] Polylactic acid, polybutylene adipate / terephthalate, polybutylene succinate;

[0157] (22) removing dirt, labels and other non-plastic substances from the degradable plastic, and then cleaning the degradable plastic with a cleaning agent to remove attachments and contaminants thereon, wherein:

[0158] The amount of the cleaning agent used is 60 mL / g based on the mass of the degradable plastic;

[0159] (23) Flotation: Different types of biodegradable plastics are separated by flotation using the density differences of the different types of biodegradable plastics;

[0160] (24) drying and crushing the washed degradable plastics of the same type in sequence to obtain degradable plastic fragments;

[0161] (25) Melting and granulation: The degradable plastic fragments are re-melted and granulated to obtain degradable plastic particles.

[0162] Furthermore, the cleaning agent in step (22) is composed of the following components by mass:

[0163] 18 parts of dimethyl sulfoxide, 8 parts of ethanol, 6 parts of benzyl alcohol, 6 parts of ethylene glycol butyl ether, 0.8 parts of potassium hydroxide, 1.6 parts of methyl cellulose, 1.6 parts of alkylbenzene sulfonate, and 60 parts of water.

[0164] Furthermore, during the melting process of step (25), a filtering system is used to filter the degradable plastic particle melt to remove impurities and ensure the quality of the recycled plastic.

[0165] A bio-based degradable masterbatch is prepared by any one of the preparation methods described above.

[0166] A method for preparing a bio-based degradable plastic, comprising the following steps:

[0167] The bio-based degradable masterbatch, filler and additives described in any one of the above are uniformly mixed and extruded by a screw machine to obtain a bio-based degradable plastic, wherein:

[0168] The mass ratio of bio-based degradable masterbatch, filler and additive is 10:3:2;

[0169] The filler is a wood fiber filler

[0170] The auxiliary agent is a bio-based coloring agent.

[0171] The above describes the embodiments of the present invention in detail. However, the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A method for preparing a bio-based degradable masterbatch, characterized in that: Here are the steps: (1) Extracting flavonoids from sycamore leaves; (2) Recycling and processing degradable plastics to obtain degradable plastic particles; (3) High-mixing: The flavonoid compound obtained in step (1) and the degradable plastic particles obtained in step (2) are mixed evenly in a high-grade agitator to obtain a modified high-mix material, wherein: The mass ratio of the flavonoid compound obtained in step (1) to the degradable plastic particles obtained in step (2) is 100:30; (4) Heating and melting: placing the modified high-mix material obtained in step (3) in a heating device, gradually heating it to 80-86° C., and continuously stirring the material to uniformly heat and mix it to obtain a molten material; (5) Granulation: The molten material obtained in step (4) is placed in a granulator for granulation to obtain a bio-based degradable masterbatch.

2. The method for preparing a bio-based degradable masterbatch according to claim 1, characterized in that: Step (1) comprises the following steps: (11) washing, drying and crushing the sycamore leaves in sequence, and then passing through a 500-mesh sieve to obtain sycamore leaf powder; (12) Add the sycamore leaf powder to an appropriate amount of entrainer and mix evenly to obtain a mixed solution, wherein: The amount of the entrainer is 25-30 mL / g based on the weight of the sycamore leaf powder; The entrainer is a mixture of ethanol and water in a volume ratio of (50-95):(50-5); (13), placing the mixed solution obtained in step (12) in a high-pressure extractor, and then introducing supercritical CO2 fluid into the high-pressure extractor for extraction, and after completion, proceeding to step (14), wherein: The flow rate of supercritical CO2 fluid is 460-550cm 3 / s; The extraction time is 8-10min; During extraction, the pressure in the high-pressure extractor is controlled at 380-420 MPa, and the temperature in the high-pressure extractor is controlled at 86°C; (14) reducing the pressure in the high-pressure extractor to 300 MPa, so that the supercritical CO2 fluid introduced into the high-pressure extractor is transformed from a supercritical state to a gaseous state, and nitrogen is continuously passed into the high-pressure extractor at the same time, heating and activating the extract, and collecting the extract using a separator, and drying to obtain the flavonoid compounds in the leaves of the Chinese parasol tree, wherein: During heating activation, the temperature in the high-pressure extractor was controlled at 86°C and the activation time was controlled at 9 minutes.

3. The method for preparing a bio-based degradable masterbatch according to claim 2, characterized in that: The method also includes step (15) solvent recovery: recovering the supercritical CO2 fluid and entrainer in step (14) and recycling them.

4. The method for preparing a bio-based degradable masterbatch according to claim 1, characterized in that: Step (2) comprises the following steps: (21) Collecting discarded degradable plastics, wherein the degradable plastics are one or more of the following plastics: Polylactic acid, polybutylene adipate / terephthalate, polybutylene succinate; (22) removing dirt, labels and other non-plastic substances from the degradable plastic, and then cleaning the degradable plastic with a cleaning agent to remove attachments and contaminants thereon, wherein: The amount of the cleaning agent used is 50-80 mL / g based on the mass of the degradable plastic; (23) Flotation: Different types of biodegradable plastics are separated by flotation using the density differences of the different types of biodegradable plastics; (24) drying and crushing the washed degradable plastics of the same type in sequence to obtain degradable plastic fragments; (25) Melting and granulation: The degradable plastic fragments are re-melted and granulated to obtain degradable plastic particles.

5. The method for preparing a bio-based degradable masterbatch according to claim 4, characterized in that: The cleaning agent in step (22) is composed of the following components by mass: 15-20 parts of dimethyl sulfoxide, 5-10 parts of ethanol, 4-8 parts of benzyl alcohol, 4-8 parts of ethylene glycol butyl ether, 0.5-1 parts of potassium hydroxide, 1-2 parts of methyl cellulose, 1-2 parts of alkyl benzene sulfonate, and 50-70 parts of water.

6. The method for preparing a bio-based degradable masterbatch according to claim 4, characterized in that: During the melting process of step (25), the degradable plastic particle melt is filtered using a filtering system.

7. A bio-based degradable masterbatch, characterized in that: It is prepared by the preparation method according to any one of claims 1 to 6.

8. A method for preparing a bio-based degradable plastic, characterized in that: Here are the steps: The bio-based degradable masterbatch, filler and additives described in claim 7 are uniformly mixed and extruded by a screw machine to obtain a bio-based degradable plastic, wherein: The mass ratio of bio-based degradable masterbatch, filler and additive is 10:(2-4):(1-3); The filler is a wood fiber filler The auxiliary agent is a bio-based coloring agent.