CN112063149A

CN112063149A - Degradable plastic with good stability and preparation method thereof

Info

Publication number: CN112063149A
Application number: CN202010988477.0A
Authority: CN
Inventors: 吴超雄
Original assignee: Shenzhen Baiao Degradable Materials Technology Co Ltd
Current assignee: Shenzhen Baiao Degradable Materials Technology Co Ltd
Priority date: 2020-09-18
Filing date: 2020-09-18
Publication date: 2020-12-11

Abstract

The invention belongs to the technical field of plastics, and particularly relates to a degradable plastic with good stability and a preparation method thereof; the degradable plastic comprises the following raw materials in parts by weight: 100-120 parts of matrix plastic resin, 10-20 parts of phenyl ester, 9-15 parts of inorganic filler, 10-50 parts of degradation agent and 0.8-1.5 parts of light stabilizer; the hardness and toughness of matrix plastic are effectively improved, the stability and the oxidation resistance of the plastic are improved, and the degradation rate of the plastic is also improved; the prepared plastic has good compatibility, is not easy to leave scratches, has good acid-base heat resistance, helps to improve the degradation speed, is convenient for further treatment of wastes, and is environment-friendly.

Description

Degradable plastic with good stability and preparation method thereof

Technical Field

The invention belongs to the technical field of plastics, and particularly relates to a degradable plastic with good stability and a preparation method thereof.

Background

The wide application of plastic products does bring great convenience to people, for example, plastics such as PC (polycarbonate), PA (polyamide), PVC (polyvinyl chloride), PPO (polyphenylene oxide), POM (polyformaldehyde), PBT (polybutylene terephthalate), PET (polyethylene terephthalate), PMMA (polymethyl methacrylate plastic), PF (phenolic plastics), PSF (polysulfone plastic), ER (epoxy plastic), AF (aminoplast), MF (melamine formaldehyde plastic) and the like are applied to the aspects of people's life, but because people lack sufficient attention and knowledge on the environmental pollution caused by the waste plastics, the used waste plastic products are discarded at will, because the synthetic plastics are high molecular polymers and are not easy to degrade, a large amount of plastic wastes are thrown and sprinkled in fields and roadside, and the self-cleaning capability of the environment on the plastic wastes is greatly exceeded, causing serious environmental pollution. If the fertilizer is buried, the fertilizer can affect crops to absorb oxygen and moisture, and the yield is reduced; compounds which release various chemical toxic gases such as dioxin when being incinerated are extremely toxic, even if the intake of the compounds is extremely small, the compounds can cause deformity or death of birds or fishes, cause ecological pollution and bring great harm to human beings, plastic products are one part of all domestic wastes which are most difficult to treat, and are also worldwide problems, and generally, three methods of sanitary landfill, high-temperature composting and incineration are adopted. However, in China, the situation is not optimistic, and at present, the garbage collection and treatment far reaches an ordered system.

The development of the degradable plastics can reduce the damage of the waste plastics to the environment, the degradation types include photodegradation, thermal degradation, biodegradation and the like, and the degradation is mostly complex, namely the photodegradation, the thermal degradation, the biodegradation and the like occur simultaneously. However, when the degradation performance of the plastic is vigorously developed, the usability of the plastic is often sacrificed, and further potential safety hazards are caused, so that the development of the plastic which has stable and safe performance in the use process and can be rapidly degraded after being discarded is of great significance.

Disclosure of Invention

In order to solve the above problems, a first aspect of the present invention provides a degradable plastic with good stability, which comprises the following raw materials in parts by weight: 100-120 parts of matrix plastic resin, 10-20 parts of phenyl ester, 9-15 parts of inorganic filler, 10-50 parts of degradation agent and 0.8-1.5 parts of light stabilizer.

As a preferable embodiment, the matrix plastic resin is at least one selected from the group consisting of polycarbonate resin, polyamide resin, polyvinyl chloride resin, polyphenylene ether resin, polyoxymethylene resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polymethyl methacrylate resin, phenol resin, polysulfone resin, epoxy resin, amino resin, and melamine formaldehyde resin.

As a preferred technical scheme, the inorganic filler is selected from one or a mixture of more of calcium carbonate, titanium dioxide, nano-alumina, carbon black, white carbon black, ceramic balls, silicon carbide, asbestos powder, cast stone powder, alumina powder, mica powder, fumed silica, montmorillonite and kaolin.

As a preferable technical scheme, the inorganic filler is mica powder and white carbon black, and the mass ratio of the mica powder to the white carbon black is (2-5): 2.

as a preferable technical scheme, the mica powder is modified by C14-C18 alkylamine.

As a preferable technical scheme, the particle size of the white carbon black is 2000-4000 meshes.

In a preferred embodiment, the degradation agent is at least one selected from the group consisting of poly-caprolactone, polylactic acid, polyglycolic acid, polyhydroxyalkanoate, polyhydroxybutyrate, polyvinyl alcohol, polybutylene succinate, polybutylene adipate-terephthalate copolymer, polymethylethylene phthalate, polyethylene terephthalate, ethylene-vinyl acetate copolymer, and polybutylene adipate-succinate copolymer.

As a preferable technical scheme, the degradation agent is polyhydroxyalkanoate and an ethylene-vinyl acetate copolymer, and the mass ratio of the polyhydroxyalkanoate to the ethylene-vinyl acetate copolymer is (2-4): 1.

as a preferable technical scheme, the mass content of the vinyl acetate in the ethylene-vinyl acetate copolymerized substance is 20-30%.

The second aspect of the invention provides a preparation method of degradable plastic with good stability, which comprises the following steps:

1) weighing matrix plastic resin, a plasticizer, a filler, a degrading agent and a light stabilizer, and uniformly mixing the raw materials to obtain a mixed material;

2) feeding the mixed material obtained in the step 1) into an internal mixer for internal mixing and kneading to obtain a rubber material;

3) feeding the rubber material obtained in the step 2) into a two-roll open mill for mixing to obtain a molten material;

4) feeding the molten material obtained in the step 3) into an extruder for plasticizing, and extruding and molding.

Has the advantages that: the invention provides a degradable plastic with good stability and a preparation method thereof, which effectively improve the hardness and toughness of matrix plastic, improve the stability and oxidation resistance of the plastic and simultaneously improve the degradation rate of the plastic by adding a specific amount of raw materials such as a degradation agent, a plasticizer, a filler and the like. The prepared plastic has good compatibility, is not easy to leave scratches, has good acid-base heat resistance, helps to improve the degradation speed, is convenient for further treatment of wastes, and is environment-friendly.

Detailed Description

The disclosure may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the examples included therein. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

The term "prepared from …" as used herein is synonymous with "comprising". The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

The conjunction "consisting of …" excludes any unspecified elements, steps or components. If used in a claim, the phrase is intended to claim as closed, meaning that it does not contain materials other than those described, except for the conventional impurities associated therewith. When the phrase "consisting of …" appears in a clause of the subject matter of the claims rather than immediately after the subject matter, it defines only the elements described in the clause; other elements are not excluded from the claims as a whole.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. "optional" or "any" means that the subsequently described event or events may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

Approximating language, as used herein throughout the specification and claims, is intended to modify a quantity, such that the invention is not limited to the specific quantity, but includes portions that are literally received for modification without substantial change in the basic function to which the invention is related. Accordingly, the use of "about" to modify a numerical value means that the invention is not limited to the precise value. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. In the present description and claims, range limitations may be combined and/or interchanged, including all sub-ranges contained therein if not otherwise stated.

In addition, the indefinite articles "a" and "an" preceding an element or component of the invention are not intended to limit the number requirement (i.e., the number of occurrences) of the element or component. Thus, "a" or "an" should be read to include one or at least one, and the singular form of an element or component also includes the plural unless the stated number clearly indicates that the singular form is intended.

In some embodiments, the matrix plastic resin is selected from at least one of polycarbonate resin, polyamide resin, polyvinyl chloride resin, polyphenylene oxide resin, polyoxymethylene resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polymethyl methacrylate resin, phenol resin, polysulfone resin, epoxy resin, amino resin, melamine formaldehyde resin.

In some preferred embodiments, the matrix plastic resin is selected from at least one of matrix plastics selected from polycarbonate resins, polyamide resins, polyethylene terephthalate resins, and polymethyl methacrylate resins.

In some more preferred embodiments, the matrix plastic resin is at least one selected from the group consisting of polycarbonate resin (CAS number: 24936-68-3), polyamide resin.

The polycarbonate resin described herein may be commercially available, for example, from Yingcang plastification, Inc., of Yuyao, trade name 1201 HP-08.

The polyamide resin described herein may be commercially available, for example, from Yingcang plastification, Inc., of Yuyao, under the designation A3K.

In some embodiments, the phenyl ester is selected from at least one of dioctyl phthalate, diisooctyl phthalate, dibutyl phthalate, diisobutyl phthalate, dimethyl phthalate, diethyl phthalate, dioctyl phthalate, triphenyl phosphate, tricresyl phosphate.

In some preferred embodiments, the phenyl ester is selected from at least one of dioctyl phthalate, diisooctyl phthalate, dibutyl phthalate, triphenyl phosphate, and tricresyl phosphate.

In some more preferred embodiments, the phenyl ester is selected from tricresyl phosphate (CAS number: 1330-78-5).

In some embodiments, the inorganic filler is selected from one or more of calcium carbonate, titanium dioxide, nano-alumina, carbon black, white carbon black, ceramic balls, silicon carbide, asbestos powder, cast stone powder, alumina powder, mica powder, fumed silica, montmorillonite, and kaolin.

In some preferred embodiments, the inorganic filler is selected from at least one of silicon carbide, silica, mica powder, montmorillonite, and kaolin.

In order to improve the hardness and scratch resistance of the degradable plastic, in some more preferred embodiments, the inorganic filler is white carbon black or mica powder. The applicant finds that when the mica powder and the white carbon black are selected as inorganic fillers, the plastic not only improves the hardness and the scratch resistance, but also has good thermal degradation stability, presumably because active groups on the surface of the mica powder are easily combined and entangled with molecular chains of matrix plastic, polyhydroxyalkanoate, ethylene-vinyl acetate copolymer and the like, so that the comprehensive mechanical property of the plastic is improved; after the white carbon black is added, the generation of ketone, lactone, vinyl compounds and the like after the plastic is aged is avoided, the degradation activity is prevented from being reduced after the plastic is aged, and the stabilization effect on the thermal degradation of the plastic is realized. In addition, the applicant unexpectedly finds that the mass ratio of the mica powder to the white carbon black is (2-5): 2, the plastic is best in mechanical properties and oxidation resistance, presumably because at this ratio, the synergistic effect of mica powder and white carbon black is best. The strong penetration of the white carbon black prevents the crosslinking generated by the mutual approach of macromolecular chains when the mica powder is modified by C14-C18 alkylamine, so that the comprehensive mechanical property of the mica powder is improved, and in addition, the white carbon black has the best effect of shielding and reflecting ultraviolet rays at the proportion, thereby playing a role in delaying oxidation.

In order to improve the overall mechanical properties and the permeation resistance of the plastic, in some preferred embodiments, the mica powder is modified by a C14-C18 alkylamine. The alkylamine modified mica powder forms protonated silicate, which is beneficial to improving the dispersibility of the inorganic filler in plastics and improving the compatibility. Particularly, when C14-C18 alkylamine is selected for modification, the compatibility is best, presumably because when the number of carbon chain carbon molecules is 14-18, alkylamine molecular chains are more easily combined and entangled with active groups on the surface of mica powder, and are arranged in parallel in the plastic and overlapped up and down, so that a dense layer network structure is formed inside a coating film, and the comprehensive mechanical property and the impermeability of the plastic are improved. In addition, the applicant unexpectedly finds that the mica powder modified by the C14-C18 alkylamine is beneficial to the acceleration of biodegradation of polyhydroxyalkanoate and an ethylene-vinyl acetate copolymer added into the plastic, particularly the biodegradation of the ethylene-vinyl acetate copolymer with the mass content of vinyl acetate of 20-30%, so that the biodegradation effect of the plastic is improved.

In order to improve the reinforcing effect of the plastic, in some preferred embodiments, the particle size of the white carbon black is 2000-4000 meshes. The applicant finds that when the particle size of the white carbon black is 2000-4000 meshes, the reinforcing effect of the plastic is optimal, a structural adsorption layer is formed on the surface of the white carbon black particles, and the macromolecular chains of the plastic are adsorbed on the surface of the white carbon black, so that the reinforcing effect with a sliding effect is generated. Generally, the smaller the carbon black particles, the better the reinforcing effect, but the applicant has unexpectedly found that in this plastic, the best effect is obtained when the silica particle size is 2000-4000 mesh, presumably because the weight ratio of mica powder to carbon black is (2-5): 2, the particle size of the white carbon black is too small, and the white carbon black and (C14-C18) alkylamine can also generate adsorption, so that the generation of gel is reduced, the compatibility of mica powder with plastics, polyhydroxyalkanoate and ethylene-vinyl acetate copolymer is also reduced, and the reinforcing effect is reduced.

The white carbon black can be commercially available, for example, from Jinsaijia chemical Co., Ltd, and is available under the brand name m-5.

In some embodiments, the degradation agent is selected from at least one of poly-caprolactone, polylactic acid, polyglycolic acid, polyhydroxyalkanoate, polyhydroxybutyrate, polyvinyl alcohol, polybutylene succinate, polybutylene adipate-terephthalate copolymer, polymethylethylene phthalate, polyethylene terephthalate, ethylene-vinyl acetate copolymer.

In some preferred embodiments, the degradation agent is selected from at least one of polyhydroxyalkanoate, polyhydroxybutyrate, polylactic acid, polyglycolic acid, ethylene-vinyl acetate copolymer, and polybutylene adipate-succinate copolymer.

In some more preferred embodiments, the degradation agent is polyhydroxyalkanoate and an ethylene-vinyl acetate copolymer, and the mass ratio of the polyhydroxyalkanoate to the ethylene-vinyl acetate copolymer is (2-4): 1. the applicant unexpectedly found that the degradation agent is polyhydroxyalkanoate and an ethylene-vinyl acetate copolymer, and the weight ratio is (2-4): 1, the plastic has the best degradation performance, and the flexibility of the plastic is improved. The polyhydroxy fatty acid ester is added to ensure that the plastic has good degradation performance and simultaneously the toughness of the plastic is increased, and the synergistic effect of the ethylene-vinyl acetate copolymer, the polyhydroxy fatty acid ester, the ethylene-vinyl acetate copolymer and the alkylamine is added to the plastic in which mica powder is modified by C14-C18 alkylamine, so that the improvement of the plastic degradation performance and the improvement of the flexibility of the plastic are facilitated.

In some preferred embodiments, the ethylene-vinyl acetate copolymer material has a vinyl acetate content of 20% to 30% by mass. The applicant has found that the content of vinyl acetate affects the degradation performance of the ethylene-vinyl acetate copolymer, and in the plastic, the degradation performance of the plastic is best when the mass content of the vinyl acetate is 20-30%, and the plastic is helpful for improving the stability of the plastic. The reason is presumed to be that vinyl acetate contributes to the generation of radicals and is thus more easily thermally decomposed, and when the vinyl acetate content is too high, the block structure formed in the molecular chain of the plastic is longer and the polyene structure is easily formed, thereby decreasing the stability. The vinyl acetate content is too low, and the degradation effect and the toughness are low.

In some preferred embodiments, the light stabilizer is selected from at least one of o-hydroxybenzophenones, benzotriazoles, salicylates, triazines, substituted acrylonitriles.

The ethylene vinyl acetate copolymer of the present invention is commercially available, for example, from Suzhou overfill engineering plastics under the designation 220.

The second aspect of the invention provides a preparation method of degradable plastic with good stability, which comprises the following steps: 1) weighing matrix plastic resin, a plasticizer, a filler, a degrading agent and a light stabilizer, and uniformly mixing the raw materials to obtain a mixed material;

Examples

The present invention will be further described with reference to the following examples, which should be construed as being exemplary in nature and not limiting the scope of the present invention. Unless otherwise specified, the starting materials in the present invention are all commercially available.

Example 1

The degradable plastic with good stability comprises the following raw materials in parts by weight: 110 parts of polycarbonate resin, 15 parts of tricresyl phosphate, 12 parts of inorganic filler, 30 parts of degradation agent and 1 part of ethyl salicylate (CAS number: 118-61-6).

Wherein the inorganic filler is mica powder and white carbon black, and the mass ratio of the mica powder to the white carbon black is 3: 2.

the mica powder is modified by N-methyl-N-hexadecylamine, and the modification method comprises the following steps: at room temperature, adding mica powder into absolute ethyl alcohol, continuously adding a small amount of distilled water, stirring for 10min, adding N-methyl-N-hexadecylamine (CAS number: 13417-08-8), continuously stirring for 1h, wherein the weight of the N-methyl-N-hexadecylamine is 5% of the weight of the mica powder, stirring for 1h, and then keeping the temperature at 50 ℃ for 3 h to obtain the modified mica powder.

The particle size of the white carbon black is 3000 meshes.

In the embodiment, the white carbon black is commercially available, and is sold under the brand name of m-5 by Jinan Seika chemical Co.

The polycarbonate resin in this example is commercially available from Yingcang plastification Co., Ltd, Yuyao, under the brand name of 1201 HP-08.

The degradation agent is polyhydroxy fatty acid ester and an ethylene-vinyl acetate copolymer, and the mass ratio of the polyhydroxy fatty acid ester to the ethylene-vinyl acetate copolymer is 3: 1.

the mass content of vinyl acetate in the ethylene-vinyl acetate copolymer is 30%.

The polyhydroxyalkanoate in this example is commercially available from Shanghai Plastic materials, Inc., Dongguan, under the trademark 74825.

The ethylene-vinyl acetate copolymer described in this example is commercially available and is available from Suzhou overflowing engineering plastic under the designation 220.

A preparation method of degradable plastic with good stability comprises the following steps:

2) feeding the mixed material obtained in the step 1) into an internal mixer for internal mixing and kneading, wherein the internal mixing temperature is 180 ℃, and the time is 5min, so as to obtain a rubber material;

3) feeding the rubber material obtained in the step 2) into a two-roll open mill for mixing at the mixing temperature of 200 ℃ for 30min to obtain molten material;

4) feeding the molten material obtained in the step 3) into an extruder for plasticizing, and extruding for molding, wherein the heating temperature is 220 ℃ during extrusion.

Example 2

The specific implementation mode of the degradable plastic with good stability is the same as that of the embodiment 1, and the degradable plastic is characterized by comprising the following raw materials in parts by weight: 110 parts of polyamide resin, 15 parts of tricresyl phosphate, 12 parts of inorganic filler, 30 parts of degradation agent and 1 part of ethyl salicylate.

The polyamide resin is commercially available in this example from Yingcang plastification, Inc., of Yuyao, under the designation A3K.

Example 3

The specific implementation mode of the degradable plastic with good stability is the same as that in example 1, and the inorganic filler is mica powder and white carbon black, and the mica powder is not subjected to improvement treatment.

Example 4

The specific implementation mode of the degradable plastic with good stability is the same as that of example 1, and the inorganic filler is mica powder.

Example 5

The specific implementation mode of the degradable plastic with good stability is the same as that of example 1, and the inorganic filler is white carbon black.

Example 6

The specific implementation mode of the degradable plastic with good stability is the same as that of example 1, and the particle size of the white carbon black is 1000 meshes.

In the present example, the white carbon black is commercially available and available from Shandong today's chemical Co.

Example 7

The specific implementation mode of the degradable plastic with good stability is the same as that of example 1, and the particle size of the white carbon black is 5000 meshes.

In this example, the white carbon black is commercially available and purchased from Guangzhou bright Sheng chemical Co., Ltd.

Example 8

The specific implementation mode of the degradable plastic with good stability is the same as that in example 1, and the mass content of vinyl acetate in the ethylene-vinyl acetate copolymer is 10%.

In this example, the ethylene vinyl acetate copolymer is commercially available from the Dow group of America under the trademark PRIMACOR 3004.

Example 9

The specific implementation mode of the degradable plastic with good stability is the same as that of example 1, and the degradation agent is ethylene-vinyl acetate copolymer.

Example 10

The specific implementation mode of the degradable plastic with good stability is the same as that of example 1, and the degradation agent is polyhydroxyalkanoate.

Evaluation of Performance

1. Biodegradation: with reference to GB/T19275-2003 evaluation of potential biological decomposition and disintegration capability of materials under the action of specific microorganisms, a soil landfill test method is used, the landfill time is 90 days, the biodegradation capability of the materials is evaluated by taking the average percentage (%) of mass change as an evaluation standard, and the higher the value is, the better the biodegradation capability is.

2. Thermal degradation: referring to GB/T7141-2008 plastic thermal aging test method, a gravity convection type thermal aging test box is used for testing, the exposure temperature is 55 ℃, the exposure period is 90 days, the evaluation standard refers to GB/T20197-2006 plastic degradation definition, classification, marking and degradation performance requirements, a high-temperature gel chromatograph is used for measuring the weight-average relative molecular mass, the result is expressed by the weight-average molecular mass reduction rate (%), and the higher the numerical value is, the better the thermal degradation capability is.

3. Photo-degradation: reference GB/T16422.2-2014 laboratory light source exposure test method part 2: xenon arc lamp, exposing the sample in an artificial accelerated aging box of the xenon lamp, exposing by using a sunlight filter, irradiating by using a broadband wavelength range of 300-400 nm, and setting the accumulated radiation energy to be 26MJ/m according to evaluation standard reference GB/T20197-²The blackboard temperature is 60 +/-5 ℃, the relative humidity is 60 +/-5%, the water spraying period is 20min +/-0.5 min for each water spraying time, the time between two water spraying times is 100min +/-0.5 min, a high-temperature gel chromatograph is used for measuring the weight-average relative molecular mass, the result is expressed by the weight-average molecular mass reduction rate (%), and the higher the value is, the better the photodegradation capability is.

TABLE 1

Through the examples 1-10, the invention provides the degradable plastic with good stability and the preparation method thereof, and the hardness and toughness of the matrix plastic are effectively improved, the stability and the oxidation resistance of the plastic are improved, and the degradation rate of the plastic is also improved by adding a specific amount of raw materials such as the degradation agent, the plasticizer, the filler and the like. The prepared plastic has good compatibility, is not easy to leave scratches, has good acid-base heat resistance, helps to improve the degradation speed, is convenient for further treatment of wastes, and is environment-friendly.

Finally, it should be understood that the above-described preferred embodiments are not intended to limit the present invention, and any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. The degradable plastic with good stability is characterized by comprising the following raw materials in parts by weight: 100-120 parts of matrix plastic resin, 10-20 parts of phenyl ester, 9-15 parts of inorganic filler, 10-50 parts of degradation agent and 0.8-1.5 parts of light stabilizer.

2. The degradable plastic with good stability as claimed in claim 1, wherein the matrix plastic resin is at least one selected from polycarbonate resin, polyamide resin, polyvinyl chloride resin, polyphenylene oxide resin, polyoxymethylene resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polymethyl methacrylate resin, phenol resin, polysulfone resin, epoxy resin, amino resin, and melamine formaldehyde resin.

3. The degradable plastic with good stability as claimed in claim 1, wherein the inorganic filler is selected from one or more of calcium carbonate, titanium dioxide, nano alumina, carbon black, white carbon black, ceramic balls, silicon carbide, asbestos powder, cast stone powder, alumina powder, mica powder, fumed silica, montmorillonite and kaolin.

4. The good-stability degradable plastic as claimed in claim 3, wherein the inorganic filler is mica powder and white carbon black, and the mass ratio of the mica powder to the white carbon black is (2-5): 2.

5. the degradable plastic with good stability of claim 4, wherein the mica powder is modified by C14-C18 alkylamine.

6. The degradable plastic with good stability as claimed in claim 4, wherein the particle size of said silica white is 2000-4000 mesh.

7. The degradable plastic with good stability as claimed in claim 1, wherein the degradation agent is at least one selected from the group consisting of poly-caprolactone, polylactic acid, polyglycolic acid, polyhydroxyalkanoate, polyhydroxybutyrate, polyvinyl alcohol, polybutylene succinate, polybutylene adipate-terephthalate copolymer, polymethylethylene terephthalate, polyethylene terephthalate, ethylene-vinyl acetate copolymer, and polybutylene adipate-succinate copolymer.

8. The degradable plastic with good stability as claimed in claim 7, wherein the degradation agent is polyhydroxyalkanoate and ethylene-vinyl acetate copolymer, and the mass ratio of the polyhydroxyalkanoate to the ethylene-vinyl acetate copolymer is (2-4): 1.

9. the degradable plastic with good stability as claimed in claim 8, wherein the mass content of vinyl acetate in the ethylene-vinyl acetate copolymer is 20% -30%.

10. The preparation method of the degradable plastic with good stability according to any one of claims 1 to 9, characterized by comprising the following steps:

1) weighing matrix plastic, a plasticizer, a filler, a degrading agent and a light stabilizer, and uniformly mixing the raw materials to obtain a mixed material;