A sand-containing degradable plastic masterbatch material and its preparation method

Abstract

The present invention relates to a sand-containing degradable plastic masterbatch material. Through the reasonable optimization and compatibility of each component, a degradable plastic material with excellent comprehensive properties is prepared by using sand as the main inorganic component and polyolefin as the resin component. The combination of glass fiber modified by a coupling agent and a terpolymer of vinyl acetate-acrylic acid-maleic anhydride improves the compatibility between the sand and the resin component, enhances the mechanical properties of the material, and both the tensile strength and the elongation at break of the material are increased, that is, the effects of reinforcement and toughening are achieved simultaneously. Ferrocene-modified glass fiber not only improves the material strength, but also does not require the additional addition of a photosensitizer or a catalyst. By loading ferrocene with promoting degradation activity on the chopped glass fiber, the mechanical strength of the material is ensured for a long period of time, and sufficient degradation performance is also imparted to the material.

Description

Technical Field

[0001] The present invention belongs to the technical field of environmental protection materials, and particularly relates to a sand-containing biodegradable plastic masterbatch material and a preparation method thereof. Background Art

[0002] Biodegradable plastics are important materials for solving environmental protection problems at present. Polylactic acid (PLA) materials are new polymer materials widely used in industrial applications at present. In China, great efforts are being made to promote the use of biodegradable plastics such as PLA and its improved products to complete the green transformation of various industries. The treatment of PLA products after use requires a large amount of energy when burned, and toxic and harmful gases will be generated during the combustion process. More seriously, the particles after combustion buried in the soil will pollute and poison the soil, causing irreversible effects, and it is not a qualified environmental protection material. In addition, the high manufacturing cost of PLA is several times that of other plastics.

[0003] PMU (Polymer-Metal Hybrid Unit) polymer materials can not only effectively reduce the dependence on traditional plastics, but also help to improve the mechanical strength and anti-aging properties of packaging materials. Compared with traditional plastics, PMU materials have better performance in terms of temperature resistance, water resistance, oil resistance, etc., making it better able to ensure the quality and safety of products when packaging liquid products such as synthetic gasoline. Biodegradability is a major highlight of PMU materials. According to relevant research, PMU materials can be completely degraded within several months under specific environmental conditions, which makes its application prospect in the packaging industry broad.

[0004] The prior patent CN110527191A of the inventor discloses an inorganic degradable plastic masterbatch, which contains the following components: 56 - 72% by mass of calcium carbonate ore powder; 3 - 10% by mass of polyethylene; 8 - 30% by mass of polypropylene; 2 - 5% by mass of glass fiber; and 3 - 5% by mass of additives; the proportion of calcium carbonate ore powder with different particle sizes in the above-mentioned 56 - 72% by mass of calcium carbonate ore powder is: 5 - 15% of 230 mesh, and the particle diameter is controlled at 65 - 60 microns; 5 - 15% of 250 mesh, and the particle diameter is controlled at 60 - 55 microns; 5 - 15% of 300 mesh, and the particle diameter is controlled at 55 - 50 microns; 20 - 40% of 400 mesh, and the particle diameter is controlled at 50 - 35 microns; 10 - 45% of 800 mesh, and the particle diameter is controlled at 20 - 10 microns; 10 - 45% of 1200 mesh, and the particle diameter is controlled at 10 - 5 microns; among them, the average particle diameter of the overall calcium carbonate ore powder must be between 20 microns and 45 microns. Its material has good mechanical properties and biodegradability. However, when using calcium carbonate ore powder, it is necessary to strictly control the particle size of the calcium carbonate ore powder to achieve suitable properties, and the manufacturing process is complicated and the cost is high. Sand and gravel are materials with a wide range of sources and low prices. If sand and gravel can be used in the preparation of plastic masterbatch without affecting mechanical properties and biodegradability, the manufacturing cost of PMU materials will be greatly reduced. However, sand has a low affinity with polymer matrix, and physical blending cannot solve its interfacial compatibility problem, resulting in defects such as poor aging resistance and toughness of the obtained material, and easy appearance of weak points in mechanical properties.

[0005] CN113603938A discloses a starch-based degradable, safe and environmentally friendly packaging box, which is composed of the following raw materials in parts by weight: 40 - 50 parts of starch-based material, 20 - 30 parts of polypropylene, 2 - 6 parts of polyolefin elastomer, 5 - 11 parts of glycerol, 25 - 35 parts of filler, 0.5 - 1.5 parts of antioxidant, 5 - 10 parts of lignocellulose aerogel, and 10 - 20 parts of biochar. Among them, sand and gravel powder can be used as the filler, but the starch-based material belongs to an incompletely biodegradable plastic. After the starch-based material decomposes, the whole material will become fragments, and these fragments are difficult to degrade, recycle and remove, which will cause damage to the soil environment. Moreover, such materials have poor high-temperature and high-humidity resistance and cannot be used as materials for long-term contact with hot water or in high-temperature and humid environments.

[0006] CN118480229A discloses a flame-retardant polypropylene plastic fresh-keeping box added with sand and calcined shell powder, which comprises the following raw materials in parts by mass: 80-100 parts of polypropylene, 40-60 parts of modified calcined shell powder, 41-49 parts of silica sol, 40-50 parts of expanded perlite, 10-20 parts of sand-based composite aerogel, 5-10 parts of coupling agent, 2-3 parts of dispersant, 3-5 parts of plasticizer, 0.01-0.03 parts of flame retardant; the modified calcined shell powder is prepared by mixing pretreated shell powder after high-temperature calcination with a cerium source and an organic intercalating agent, and then performing hydrothermal treatment; the pretreated shell powder is prepared by washing shell powder, grinding it into powder, sieving it, and treating it with an alkali treatment agent; the sand-based composite aerogel is prepared by mixing sand loaded with porous carbon with an antioxidant, adding it to cellulose nanofibers and melamine formaldehyde resin for crosslinking, and then performing freeze-drying; the sand loaded with porous carbon is prepared by washing and drying sand, then mixing it with a carbon precursor and a linker, and performing high-temperature carbonization. Although sand is used as a raw material for manufacturing the safe, the sand needs to go through a complicated preparation process to be the sand-based composite aerogel, and the manufacturing cost remains high, which is not suitable for large-scale industrial production.

[0007] CN102295793A discloses a highly filled oxidative degradation polymer packaging material, which is extruded by mixing the following components, and the components are in parts by weight: 70-90 parts of inorganic filler, 10-30 parts of polyolefin polymer, 0.01-0.2 parts of photo-functional additive, 0.01-0.2 parts of thermal-functional additive, 0.05-5 parts of coupling agent, 0.01-5 parts of lubricant. Through the photo-functional additive and the thermal-functional additive, the material is decomposed into fragments under the action of oxygen and sunlight, and further degraded into carbon dioxide and water. The content of the inorganic filler reaches more than 70%. However, the compatibility problem between sand and the polymer matrix has not been solved yet.

[0008] In addition, the balance between the degradation rate and the mechanical strength of such degradable materials is also a technical problem to be solved. If the degradation rate is too fast, the material will quickly lose its due mechanical strength; while increasing the mechanical strength often reduces the degradability of the material. Therefore, the balance between the degradability and the mechanical properties of such materials is also a problem to be solved. Summary of the Invention

[0009] To solve the above technical problems, the present invention provides a sand-based degradable plastic masterbatch material, which uses sand as the main inorganic component, polyolefins with different softening points as the polymer resin component, and is combined with modified glass fiber and vinyl acetate-acrylic acid-maleic anhydride terpolymer, solving the problem of poor compatibility between sand and polymer matrix. While not affecting the degradability of the material, it significantly improves the mechanical properties and weather resistance of the material. The preparation method of the present invention is simple, with low cost, and the raw materials are cheap and easily available. The obtained masterbatch has excellent mechanical properties, biodegradability, water resistance and anti-aging properties. It can be used to produce various environmentally friendly degradable products such as seedling pots, corrugated cardboard, and water pipes. Specifically, the present invention provides the following technical solutions to achieve the above objectives.

[0010] A sand-containing degradable plastic masterbatch material, comprising the following raw materials in parts by mass: 40-60 parts of sand powder, 6-10 parts of high-density polyethylene, 3-5 parts of low-density linear polyethylene, 22-28 parts of polypropylene, 5-8 parts of silica sol, 4-7 parts of coupling agent-modified glass fiber, 2-4 parts of ferrocene-modified glass fiber, 3-7 parts of vinyl acetate-acrylic acid-maleic anhydride terpolymer; the coupling agent-modified glass fiber is obtained by modifying glass fiber with a compound coupling agent, and the compound coupling agent includes coupling agent I and coupling agent II. Coupling agent I is selected from at least one of titanate coupling agent, aluminate coupling agent, and zirconate coupling agent, and coupling agent II is selected from at least one of amino silane coupling agent and epoxy silane coupling agent; the ferrocene-modified glass fiber is obtained by first coating glass fiber with dopamine and then surface-modifying it with ferrocene.

[0011] Further, the vinyl acetate-acrylic acid-maleic anhydride terpolymer is a terpolymer of monomer vinyl acetate, acrylic acid and maleic anhydride in a mass ratio of 30-50:20-30:7-12. Even further, the weight-average molecular weight of the vinyl acetate-acrylic acid-maleic anhydride terpolymer is 20,000-30,000.

[0012] Further, the vinyl acetate-acrylic acid-maleic anhydride terpolymer is prepared by a preparation method including the following steps: After mixing water and an emulsifier evenly to form an emulsion, add monomer vinyl acetate, acrylic acid, maleic anhydride and an initiator, and heat to the initiation temperature under an inert atmosphere for sufficient reaction. After the reaction is completed, the obtained mixture is post-treated to obtain the vinyl acetate-acrylic acid-maleic anhydride terpolymer.

[0013] Furthermore, the emulsifier is at least one of a nonionic surfactant and an anionic surfactant; preferably, it is a compound of a nonionic surfactant and an anionic surfactant in a mass ratio of 1-5:1-5. There are no particular limitations on the anionic surfactant and the nonionic surfactant, which are well known in the art. For example, the anionic surfactant is SDS and the nonionic surfactant is Tween 80; the emulsifier accounts for 6-10 wt% of the total mass of water and the emulsifier; the nitrogen atmosphere is at least one of nitrogen, argon, and helium; the initiator is selected from at least one of ammonium persulfate, sodium persulfate, and potassium persulfate, and the amount of the initiator is 0.5-1 wt% of the total mass of the monomers. The initiation temperature is determined by the initiator used. For example, for ammonium persulfate, the initiation temperature is 80-95 °C and the reaction time is 3-5 h; the post-treatment is to add calcium chloride for demulsification, and the flocculates are filtered by suction and washed repeatedly with deionized water 3-5 times, and then dried to a constant weight.

[0014] Furthermore, the size of the coupling agent-modified glass fiber is a single-filament diameter of 5-8 μm and a length of 7-12 mm, and the size of the ferrocene-modified glass fiber is a diameter of 2-4 μm and a length of 1-2 mm.

[0015] The coupling agent-modified glass fiber has a relatively long length and can better play the role of improving the compatibility between sand and polymer resin; the ferrocene-modified glass fiber uses short-cut fibers with a shorter length, and the ferrocene loaded on it as a degradation promoter can make the obtained material have a suitable degradation rate, so that the mechanical strength will not decrease due to initial degradation, but the material can still achieve the purpose of complete degradation.

[0016] Furthermore, the mass ratio of coupling agent I and coupling agent II is 1:2-3, and coupling agent II is preferably a compound of an amino-silane coupling agent and an epoxy-silane coupling agent in a mass ratio of 1-3:1-3.

[0017] Further, the titanate coupling agent is selected from at least one of isopropyl dioleoyl dioctylphosphate titanate, isopropyl tris(dioctylphosphate) titanate, isopropyl tri(4-dodecylbenzenesulfonyl) titanate, isopropyl triisostearate titanate, tetraisopropyl bis(dioctylphosphite) titanate, isopropyl tris(dioctylpyrophosphate) titanate, tetraisopropyl titanate bis(dilauryl phosphite), and tris(diphenylpropyl)-isopropyl titanate; the aluminate coupling agent is selected from at least one of distearoyl oxyisopropyl aluminate, isopropoxy dioleoyl oxyaluminate, triisopropoxy aluminum, and liquid aluminate coupling agent; the zirconate coupling agent is selected from at least one of tetrabutyl zirconate, tetraisopropyl zirconate, neoalkoxy tris(p-aminophenoxy) zirconate, tetra(triethanolamine) zirconate, and alkoxy tris(vinyl-ethoxy) zirconate; the amino silane coupling agent is selected from at least one of KH-540 and KH-550; the epoxy silane coupling agent is selected from at least one of KH-560, KH-561, and KH-563.

[0018] The coupling agent-modified glass fiber is prepared by a preparation method including the following steps: Dispersing the surface-cleaned glass fiber in an alcohol solvent, adding a compounded coupling agent, stirring and shaking the solution, heating it to 40-50 °C, and keeping it stirred and shaken for 1-3 h. After taking out the glass fiber, it is dried to obtain the coupling agent-modified glass fiber.

[0019] Further, the alcohol solvent is selected from at least one of methanol, ethanol, and isopropanol; the dosage of the compounded coupling agent is 5-10 wt% of the surface-cleaned glass fiber.

[0020] The ferrocene-modified glass fiber is prepared by a preparation method including the following steps:

[0021] (L1) Adding the surface-cleaned glass fiber into a dopamine buffer solution, stirring at room temperature for 20-30 h, filtering, washing, and drying to obtain dopamine-coated glass fiber;

[0022] (L2) Adding the dopamine-coated glass fiber into a dopamine buffer solution dispersed with ferrocene, stirring at room temperature for 20-30 h, filtering, washing, and drying to obtain the ferrocene-modified glass fiber.

[0023] Further, in step (L1), the dopamine concentration in the dopamine buffer solution is 3-6 g / L; the mass ratio of the surface-cleaned glass fiber to the volume of the dopamine buffer solution is 1 g:10-20 mL; in step (L2), the dopamine concentration in the dopamine buffer solution dispersed with ferrocene is 1-2 g / L, and the ferrocene concentration is 1-3 g / L; the mass ratio of the dopamine-coated glass fiber to the volume of the dopamine buffer solution dispersed with ferrocene is 1 g:10-20 mL.

[0024] The dopamine buffer solution is obtained by preparing dopamine into an aqueous dopamine solution with a concentration of 3 - 6 g / L, adjusting the pH to 8 - 9 with Tris-HCl, and dispersing it evenly.

[0025] The surface cleaning of glass fiber is well-known in the art. Since the commercially available glass fiber surface contains a sizing agent, this part of the sizing agent needs to be removed before modification. The specific method is to place the glass fiber in a muffle furnace and calcine it at 400 - 600 °C for 3 - 5 h.

[0026] Furthermore, the mass ratio of the sum of sand powder and polymer (i.e., the sum of high-density polyethylene, linear low-density polyethylene, and polypropylene) is 1.2 - 1.5:1.

[0027] Furthermore, the crystallinity of the high-density polyethylene is 81 - 88%, and the softening point is 125 - 135 °C; the softening point of the linear low-density polyethylene is 110 - 115 °C; the softening point of the polypropylene is 140 - 155 °C.

[0028] Furthermore, the sand powder is ground to 1000 - 1500 mesh. The present invention only needs to grind common sand and gravel to the specified particle size, without the need for complex grading, with low cost and wide sources.

[0029] Optionally, the sand-containing degradable plastic masterbatch material further includes the following parts by mass of auxiliary reagents: 0.5 - 1 part of lubricant, 0.1 - 0.3 part of antioxidant, and 0.3 - 0.5 part of plasticizer. The lubricant, antioxidant, and plasticizer are well-known in the art. For example, the antioxidant is selected from antioxidant 1010 and antioxidant 168; the lubricant is selected from at least one of paraffin wax, polypropylene wax, and stearate; the plasticizer is selected from at least one of tributyl citrate, polyethylene glycol, dioctyl phthalate, and methyl acetyl ricinoleate.

[0030] The present invention also provides a preparation method of the above-mentioned sand-containing degradable plastic masterbatch material, including the following steps:

[0031] (S1) Grind the sand to obtain sand powder with appropriate fineness, and add the sand powder, high-density polyethylene, linear low-density polyethylene, polypropylene, silica sol, coupling agent-modified glass fiber, ferrocene-modified glass fiber, and vinyl acetate-acrylic acid-maleic anhydride terpolymer into a mixer. Optionally, auxiliary materials are also added, and they are mixed evenly and degassed under ultrasonic vibration conditions to obtain a precursor;

[0032] (S2) Add the precursor into a kneading and melting device, extrude it into strips at a temperature of 240 - 250 °C, cut the strips into pellets after water cooling, and dehydrate them to obtain the sand-containing degradable plastic masterbatch material.

[0033] Further, in step (S1), the conditions for ultrasonic vibration are a vibration frequency of 50 - 100 kHz, and the kneading and melting equipment is a single-screw extruder, a twin-screw extruder, or a triple-screw extruder.

[0034] Through the reasonable optimization and compatibility of each component, the present invention realizes the preparation of a degradable plastic material with excellent comprehensive properties using sand as the main inorganic component and polyolefin as the resin component. The combination of glass fiber modified by a coupling agent and a terpolymer of vinyl acetate - acrylic acid - maleic anhydride improves the compatibility between the sand and the resin component, enhances the mechanical properties of the material, and both the tensile strength and elongation at break of the material are improved, achieving the effects of reinforcement and toughening simultaneously. Ferrocene-modified glass fiber not only improves the material strength but also does not require the additional addition of a photosensitizer or catalyst. Loading ferrocene with promoting degradation activity on the chopped glass fiber ensures the mechanical strength of the material for a long time and endows the material with sufficient degradation performance. Description of the Drawings

[0035] Figure 1 Optical microscope photograph of the sand-containing degradable plastic masterbatch material prepared in Example 1.

[0036] Figure 2 Physical photograph of the sand-containing degradable plastic masterbatch material prepared in Example 1. Detailed Description of the Invention

[0037] High-density polyethylene is purchased from Yanshan Petrochemical, with a crystallinity of 82% and a softening point of 131 °C; linear low-density polyethylene is purchased from Yanshan Petrochemical, with a softening point of 112 °C; polypropylene is purchased from Yanshan Petrochemical, with a softening point of 145 °C.

[0038] Preparation Example 1

[0039] Using SDS: Tween 80 as a compound emulsifier, stir to prepare an emulsion. The mass ratio of the compound emulsifier to water is 6:94. Add vinyl acetate, acrylic acid, and maleic anhydride as monomers in a mass ratio of 50:30:7, and then add ammonium persulfate at 1 wt% of the total mass of the monomers as an initiator. Heat to 85 °C under a nitrogen atmosphere, keep the temperature for 3 h, cool to room temperature, add CaCl2 for demulsification, wash the flocculants with deionized water by filtration 3 times, and dry to constant weight to obtain a terpolymer a of vinyl acetate - acrylic acid - maleic anhydride. After testing, the weight-average molecular weight of the terpolymer a is about 28,000.

[0040] Preparation Example 2

[0041] Other conditions were the same as those in Preparation Example 1, except that the mass ratio of vinyl acetate monomer, acrylic acid and maleic anhydride was 30:20:12, and a vinyl acetate-acrylic acid-maleic anhydride terpolymer b was obtained. After testing, the weight-average molecular weight of the terpolymer b was about 22,000.

[0042] Preparation Example 3

[0043] The long glass fibers (with a diameter of 5 μm and a length of 10 mm) were placed in a muffle furnace and heated to 500 °C for calcination for 3 h to complete surface cleaning. 10 g of the surface-cleaned long glass fibers were dispersed in ethanol, and 0.5 g of a complex coupling agent was added. The complex coupling agent was a compound of isopropyltris(dioctylphosphate) titanate, KH-540 and KH-560 in a mass ratio of 1:1:1. The dispersion was stirred and shaken, and the temperature was raised to 50 °C, and stirring and shaking were maintained for 3 h. Then the glass fibers were taken out and dried to obtain coupling agent-modified glass fiber a.

[0044] Preparation Example 4

[0045] Other conditions were the same as those in Preparation Example 3, except that the long glass fibers (with a diameter of 5 μm and a length of 10 mm) were replaced with short glass fibers (with a diameter of 3 μm and a length of 1 mm), and finally coupling agent-modified glass fiber b was obtained.

[0046] Preparation Example 5

[0047] Other conditions were the same as those in Preparation Example 3, except that the coupling agent was a compound of isopropyltris(dioctylphosphate) titanate and KH-540 in a mass ratio of 1:2, and coupling agent-modified glass fiber c was obtained.

[0048] Preparation Example 6

[0049] Other conditions were the same as those in Preparation Example 3, except that the coupling agent was a compound of isopropyltris(dioctylphosphate) titanate and KH-560 in a mass ratio of 1:2, and coupling agent-modified glass fiber d was obtained.

[0050] Preparation Example 7

[0051] (L1) The short glass fibers (with a diameter of 3 μm and a length of 1 mm) were placed in a muffle furnace and heated to 500 °C for calcination for 3 h to complete surface cleaning. 1 g of the surface-cleaned short glass fibers was added to 20 mL of a 5 g / L dopamine buffer solution (adjusted to pH 8.5 with tris-HCl), and stirred at room temperature for 24 h, filtered, washed, and dried to obtain dopamine-coated glass fibers;

[0052] (L2) Add 1 g of dopamine-coated glass fiber to the dopamine buffer solution (dopamine concentration 2 g / L, ferrocene concentration 2 g / L, pH = 8.5) in which ferrocene is dispersed, stir at room temperature for 24 h, filter, wash, and dry to obtain ferrocene-modified glass fiber a.

[0053] Preparation Example 8

[0054] Other conditions and operations are the same as those in Preparation Example 7, except that short glass fibers are replaced with long glass fibers (diameter 8 μm, length 6 mm), and finally ferrocene-modified glass fiber b is obtained.

[0055] Comparative Preparation Example 1

[0056] Other conditions are the same as those in Preparation Example 3, except that the coupling agent is only isopropyltris(dioctylphosphate)titanate. That is, coupling agent II is not added, and finally coupling agent-modified glass fiber e is prepared.

[0057] Comparative Preparation Example 2

[0058] Other conditions are the same as those in Preparation Example 3, except that the coupling agent is a compound of KH-540 and KH-560 in a mass ratio of 1:1. That is, coupling agent I is not added, and finally coupling agent-modified glass fiber f is prepared.

[0059] Comparative Preparation Example 3

[0060] Other conditions are the same as those in Preparation Example 7, except that in step (L2), ferrocene is replaced with an equal mass of nano-iron oxide (D50 = 20 nm), and the nano-iron oxide concentration is 2 g / L. Finally, iron oxide-modified glass fiber is prepared.

[0061] Example 1

[0062] (S1) Grind the sand into powder, sieve to obtain 1500-mesh sand powder, and add 50 parts by mass of sand powder, 7 parts by mass of high-density polyethylene, 5 parts by mass of low-density linear polyethylene, 25 parts of polypropylene, 5 parts of silica sol, 5 parts of coupling agent-modified glass fiber a prepared in Preparation Example 3, 2 parts of ferrocene-modified glass fiber a prepared in Preparation Example 7, vinyl acetate-acrylic acid-maleic anhydride terpolymer a prepared in Preparation Example 1, as well as 0.5 part of iron stearate, 0.1 part of antioxidant 1010, and 0.3 part of plasticizer tributyl citrate into a mixer, and mix evenly and exhaust under ultrasonic vibration conditions to obtain a precursor;

[0063] (S2) Add the precursor to a triple-screw extruder, extrude into strips at a temperature of 240 - 250 °C, cool with water, cut into pellets, and dehydrate to obtain a sand-containing biodegradable plastic masterbatch material.

[0064] Figure 1It is an optical microscope photo of the sand-containing degradable plastic masterbatch material prepared in Example 1. It can be seen that the sample contains fiber posts and massive substances. Figure 2 It is a physical photo of the sand-containing degradable plastic masterbatch material prepared in Example 1.

[0065] Example 2

[0066] Other conditions are the same as those in Example 1, and the difference is that the coupling agent-modified glass fiber a prepared in Preparation Example 3 is replaced by the coupling agent-modified glass fiber b prepared in Preparation Example 4.

[0067] Example 3

[0068] Other conditions are the same as those in Example 1, and the difference is that the coupling agent-modified glass fiber a prepared in Preparation Example 3 is replaced by the coupling agent-modified glass fiber c prepared in Preparation Example 5.

[0069] Example 4

[0070] Other conditions are the same as those in Example 1, and the difference is that the coupling agent-modified glass fiber a prepared in Preparation Example 3 is replaced by the coupling agent-modified glass fiber d prepared in Preparation Example 6.

[0071] Example 5

[0072] Other conditions are the same as those in Example 1, and the difference is that the ferrocene-modified glass fiber a prepared in Preparation Example 7 is replaced by the ferrocene-modified glass fiber b prepared in Preparation Example 8.

[0073] Example 6

[0074] Other conditions are the same as those in Example 1, and the difference is that the terpolymer a in Preparation Example 1 is replaced by the terpolymer b prepared in Preparation Example 2.

[0075] Comparative Example 1

[0076] Other conditions are the same as those in Example 1, and the difference is that the coupling agent-modified glass fiber a prepared in Preparation Example 3 is replaced by the coupling agent-modified glass fiber e prepared in Comparative Preparation Example 1.

[0077] Comparative Example 2

[0078] Other conditions are the same as those in Example 1, and the difference is that the coupling agent-modified glass fiber a prepared in Preparation Example 3 is replaced by the coupling agent-modified glass fiber f prepared in Comparative Preparation Example 2.

[0079] Comparative Example 3

[0080] Other conditions are the same as those in Example 1, and the difference is that the ferrocene-modified glass fiber a prepared in Preparation Example 7 is replaced by the iron oxide-modified glass fiber prepared in Comparative Preparation Example 3.

[0081] Application Example

[0082] The sand-containing degradable plastic masterbatch materials of the above examples and comparative examples were subjected to the following performance tests, and the results are shown in Table 1.

[0083] The tensile strength was tested according to the reference standard ASTM D638, the flexural strength was tested according to the reference standard ASTM D790, and the degradation performance was tested according to ASTM D5511. The accelerated degradation conditions were to apply a fluorescent lamp with a power of 30 W, an irradiation distance of 50 cm, and a temperature of 25 ± 3 °C.

[0084] Table 1 Masterbatch Performance Test

[0085]

Claims

1. A sand-containing degradable plastic masterbatch material, characterized in that It includes raw materials in the following parts by mass: 40 - 60 parts of sand powder, 6 - 10 parts of high-density polyethylene, 3 - 5 parts of linear low-density polyethylene, 22 - 28 parts of polypropylene, 5 - 8 parts of silica sol, 4 - 7 parts of coupling agent-modified glass fiber, 2 - 4 parts of ferrocene-modified glass fiber, and 3 - 7 parts of vinyl acetate-acrylic acid-maleic anhydride terpolymer; the coupling agent-modified glass fiber is obtained by modifying glass fiber with a compound coupling agent, and the compound coupling agent includes coupling agent I and coupling agent II. Coupling agent I is selected from at least one of titanate coupling agent, aluminate coupling agent, and zirconate coupling agent, and coupling agent II is a compound of amino-silane coupling agent and epoxy-silane coupling agent in a mass ratio of 1 - 3:1 - 3; the ferrocene-modified glass fiber is obtained by first coating glass fiber with dopamine and then modifying the surface with ferrocene; the vinyl acetate-acrylic acid-maleic anhydride terpolymer is a terpolymer of monomer vinyl acetate, acrylic acid, and maleic anhydride in a mass ratio of 30 - 50:20 - 30:7 - 12; the weight-average molecular weight of the vinyl acetate-acrylic acid-maleic anhydride terpolymer is 20,000 - 30,000; the size of the coupling agent-modified glass fiber is a single-filament diameter of 5 - 8 μm and a length of 7 - 12 mm; the size of the ferrocene-modified glass fiber is a diameter of 2 - 4 μm and a length of 1 - 2 mm; the crystallinity of the high-density polyethylene is 81 - 88%, and the softening point is 125 - 135 °C; the softening point of the linear low-density polyethylene is 110 - 115 °C; the softening point of the polypropylene is 140 - 155 °C.

2. The sand-containing degradable plastic masterbatch material according to claim 1, characterized in that, The vinyl acetate-acrylic acid-maleic anhydride terpolymer is prepared by a preparation method including the following steps: after mixing water and an emulsifier evenly to form an emulsion, adding monomer vinyl acetate, acrylic acid, maleic anhydride, and an initiator, heating to the initiation temperature under a nitrogen atmosphere for sufficient reaction, and after the reaction ends, subjecting the obtained mixture to post-treatment to obtain the vinyl acetate-acrylic acid-maleic anhydride terpolymer; The emulsifier is at least one of a non-ionic surfactant and an anionic surfactant, and the non-ionic surfactant and the anionic surfactant are compounded in a mass ratio of 1 - 5:1 - 5; the emulsifier accounts for 6 - 10 wt% of the total mass of water and the emulsifier; the initiator is selected from at least one of ammonium persulfate, sodium persulfate, and potassium persulfate, and the amount of the initiator used is 0.5 - 1 wt% of the total mass of the monomers; the initiation temperature is 80 - 95 °C, and the reaction time is 3 - 5 h; the post-treatment is to add calcium chloride for demulsification, and after the flocculates are filtered by suction, wash them repeatedly with deionized water 3 - 5 times and dry to constant weight.

3. The sand-containing degradable plastic masterbatch material according to claim 1, characterized in that, The mass ratio of coupling agent I to coupling agent II is 1:2 - 3.

4. The sand-containing degradable plastic masterbatch material according to claim 1, characterized in that, The titanate coupling agent is selected from at least one of isopropyl dioleoyl dioctyl phosphate titanate, isopropyl tris(dioctyl phosphate) titanate, isopropyl tri(4-dodecylbenzenesulfonyl) titanate, isopropyl triisostearate titanate, tetraisopropyl bis(dioctyl phosphite) titanate, isopropyl tris(dioctyl pyrophosphate) titanate, tetraisopropyl titanate bis(dilauryl phosphite), and tris(diphenylpropyl)-isopropyl titanate; the aluminate coupling agent is selected from at least one of distearoyl oxyisopropyl aluminate, isopropoxy dioleoyl oxyaluminate, triisopropoxy aluminum, and liquid aluminate coupling agent; the zirconate coupling agent is selected from at least one of tetrabutyl zirconate, tetraisopropyl zirconate, neopentoxy tris(p-aminophenoxy) zirconate, tetra(triethanolamine) zirconate, and alkoxy tris(vinyl-ethoxy) zirconate; the amino silane coupling agent is selected from at least one of KH-540 and KH-550; the epoxy silane coupling agent is selected from at least one of KH-560, KH-561, and KH-563.

5. The sand-containing degradable plastic masterbatch material according to claim 1, wherein The coupling agent-modified glass fiber is prepared by a preparation method including the following steps: dispersing surface-cleaned glass fiber in an alcohol solvent, adding a compounded coupling agent, stirring and shaking the solution, heating to 40-50 °C, and keeping stirring and shaking for 1-3 h, taking out the glass fiber and drying it to obtain the coupling agent-modified glass fiber; The alcohol solvent is selected from at least one of methanol, ethanol, and isopropanol; the dosage of the compounded coupling agent is 5-10 wt% of the surface-cleaned glass fiber.

6. The sand-containing degradable plastic masterbatch material according to claim 1, characterized in that, The ferrocene-modified glass fiber is prepared by a preparation method including the following steps: (L1) Adding surface-cleaned glass fiber to a dopamine buffer solution, stirring at room temperature for 20-30 h, filtering, washing, and drying to obtain dopamine-coated glass fiber; (L2) Adding the dopamine-coated glass fiber to a dopamine buffer solution in which ferrocene is dispersed, stirring at room temperature for 20-30 h, filtering, washing, and drying to obtain ferrocene-modified glass fiber; In step (L1), the dopamine concentration in the dopamine buffer solution is 3-6 g / L; the mass ratio of the surface-cleaned glass fiber to the volume of the dopamine buffer solution is 1 g:10-20 mL; in step (L2), the dopamine concentration in the dopamine buffer solution in which ferrocene is dispersed is 1-2 g / L, and the ferrocene concentration is 1-3 g / L; the mass ratio of the dopamine-coated glass fiber to the volume of the dopamine buffer solution in which ferrocene is dispersed is 1 g:10-20 mL; The dopamine buffer solution is obtained by preparing dopamine into a 3-6 g / L dopamine aqueous solution, adjusting the pH to 8-9 with Tris-HCl, and dispersing evenly.

7. The sand-containing degradable plastic masterbatch material according to claim 1, characterized in that, The mass ratio of the sum of the sand powder and the polymer is 1.2-1.5:1, and the sum of the polymers is the sum of high-density polyethylene, low-density linear polyethylene, and polypropylene; The sand powder is ground to 1000-1500 mesh.

8. The preparation method of the sand-containing degradable plastic masterbatch material according to any one of claims 1 to 7, characterized in that, Including the following steps: (S1) Grind the sand into powder to obtain sand powder. Add the sand powder, high-density polyethylene, linear low-density polyethylene, polypropylene, silica sol, coupling agent-modified glass fiber, ferrocene-modified glass fiber, and vinyl acetate-acrylic acid-maleic anhydride terpolymer into a mixer. Optionally, auxiliary materials can also be added. Mix evenly and exhaust under ultrasonic vibration conditions to obtain a precursor; (S2) Add the precursor into a kneading and melting device, extrude it into strips at a temperature of 240 - 250 °C, cut the strips into pellets after water cooling, and dehydrate to obtain a sand-containing degradable plastic masterbatch material.

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