Polyethylene composite material, preparation method thereof and plastic product

Abstract

The invention relates to the technical field of recycling of polyethylene materials and waste fan blade resources, and discloses a polyethylene composite material, a preparation method thereof and a plastic product. The method comprises the following steps: (1) carrying out mixed reaction on preheated waste fan blade powder, a silane coupling agent, glycidyl methacrylate and a liquid lubricant; (2) carrying out mixed reaction on the reaction mixture obtained in the step (1), polyethylene grafted maleic anhydride, a solid lubricant and polyethylene, and carrying out extrusion granulation on the obtained mixture to obtain granules; (3) carrying out injection molding on the granules; wherein the particle size of the waste fan blade powder is 150 to 500 meshes; relative to 100 parts by weight of the waste fan blade powder, the use amount of the polyethylene is 100-1000 parts by weight. The plastic product prepared by the method has the characteristics of low density, smooth surface, excellent mechanical property, low production cost, high environmental friendliness and recyclable resources.

Description

Technical Field

[0001] The present invention relates to the technical field of recycling and utilization of polyethylene materials and waste wind turbine blades, and particularly relates to a polyethylene composite material, a preparation method thereof, and a plastic product. Background Art

[0002] With the rapid development of the wind energy industry, wind turbine blades will face large-scale retirement. How to dispose of waste wind turbine blades has gradually become a major challenge that countries around the world urgently need to address. The main component of wind turbine blades, glass fiber, belongs to thermosetting materials. In traditional industrial production processes, the common methods for treating thermosetting materials are burial or incineration. Due to the stable chemical properties of glass fiber, burial not only occupies a large amount of land but also may pollute underground water sources, while the soot and toxic and harmful gases generated by incineration pollute the environment and endanger human health. Therefore, recycling and reusing waste wind turbine blades has become an effective means to solve this problem.

[0003] Polyethylene materials are widely used. Although traditional polyethylene materials have good processing performance and chemical stability, they are still insufficient in some special environments, which greatly affects the application scope of polyethylene materials. In the existing industrial production process, in order to enhance the strength, rigidity, and wear resistance of polyethylene materials, the polyethylene materials need to be modified. Currently, the main modification methods include: blending modification, filling modification, reinforcement and toughening modification, nano-composite modification, cross-linking modification, adding wear-resistant additives, etc. Among them, filling modification has a wide application in the field of polyethylene material modification due to its simple process and low production cost. In the prior art, the mechanical properties of polyethylene composite materials prepared by filling polyethylene materials with fillers do not always meet the production requirements and need to be further improved, which requires exploring efficient fillers to make up for it. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problems existing in the prior art, such as low efficiency of recycling and reusing waste wind turbine blades, high environmental pollution risk, large deformation of polyethylene plastic products, and high preparation cost. A polyethylene composite material, a preparation method thereof, and a plastic product are provided. The plastic products of the polyethylene composite material prepared according to the method of the present invention have the characteristics of low density, smooth surface, small deformation, high dimensional stability, excellent mechanical properties, low production cost, strong environmental friendliness, and resource recyclability, providing a more efficient and convenient solution for the modification of polyethylene materials and the recycling and utilization of waste wind turbine blades.

[0005] To achieve the above purpose, on the one hand, the present invention provides a preparation method of a polyethylene composite material, which comprises the following steps:

[0006] (1) Mix the preheated waste wind turbine blade powder with a silane coupling agent, glycidyl methacrylate, and a liquid lubricant for a reaction;

[0007] (2) Mix the reaction mixture obtained in step (1) with maleic anhydride grafted polyethylene, a solid lubricant, and polyethylene for a reaction, and extrude and pelletize the obtained mixture to obtain pellets;

[0008] (3) Injection mold the pellets;

[0009] Among them, the particle size of the waste wind turbine blade powder is 150 - 500 mesh;

[0010] Relative to 100 parts by weight of the waste wind turbine blade powder, the dosage of polyethylene is 100 - 1000 parts by weight.

[0011] Preferably, in step (1), the particle size of the waste wind turbine blade powder is 200 - 400 mesh.

[0012] Preferably, in step (1), relative to 100 parts by weight of the waste wind turbine blade powder, the dosage of the silane coupling agent is 2 - 20 parts by weight, the dosage of glycidyl methacrylate is 1.5 - 15 parts by weight, and the dosage of the liquid lubricant is 1.5 - 15 parts by weight.

[0013] Preferably, in step (1), the mass ratio of the silane coupling agent to glycidyl methacrylate is 1 - 2:1.

[0014] Preferably, in step (1), the silane coupling agent is at least one of γ-aminopropyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, and vinyltris(β-methoxyethoxy)silane.

[0015] Preferably, in step (1), the liquid lubricant is at least one of liquid paraffin, methyl silicone oil, chlorinated paraffin, and n-butyl stearate.

[0016] Preferably, relative to 100 parts by weight of the waste wind turbine blade powder, the dosage of maleic anhydride grafted polyethylene is 3 - 25 parts by weight, the dosage of the solid lubricant is 5 - 40 parts by weight, and the dosage of polyethylene is 120 - 900 parts by weight.

[0017] Preferably, the solid lubricant is at least one of calcium stearate, polyethylene wax, polyphthalamide, stearamide, and zinc stearate.

[0018] Preferably, the solid lubricant is a combination of calcium stearate, polyethylene wax, and polyphthalamide, and the mass ratio of calcium stearate, polyethylene wax, and polyphthalamide is 1 - 3:1 - 2:1.

[0019] Preferably, the polyethylene is at least one of low-density polyethylene, high-density polyethylene, and linear low-density polyethylene.

[0020] The second aspect of the present invention provides a polyethylene composite material prepared by the above method.

[0021] The third aspect of the present invention provides a plastic product, wherein the plastic product is made of the above polyethylene composite material.

[0022] When preparing the polyethylene composite material according to the method of the present invention, by adding a silane coupling agent to react with the hydroxyl groups on the surface of the glass fiber in the waste wind turbine blade powder, the surface of the glass fiber is modified. The organic groups of the silane coupling agent form hydrogen bonds or chemical bonds with the polyethylene. Adding polyethylene grafted maleic anhydride, whose polar groups combine with the silane coupling agent, enhances the binding force between the glass fiber and the polyethylene. Adding glycidyl methacrylate enhances the binding force between the epoxy resin in the waste wind turbine blade powder and the polyethylene. The three work together synergistically to ensure the uniform mixing and effective compounding of the waste wind turbine blade powder and the polyethylene matrix, improve the interfacial binding force between the two, make the compatibility better, and thus improve the mechanical properties of the plastic product of the polyethylene composite material. Then, the modified waste wind turbine blade powder is used to fill the polyethylene material. On the one hand, it reduces the deformation amount of the plastic product and improves the dimensional stability. On the other hand, due to the low density of the powder, the product becomes thinner and lighter, thus reducing the production cost. Finally, by optimizing the particle size of the waste wind turbine blade powder, the problems of surface fiber floating and roughness of the waste wind turbine blade filled polyethylene plastic product are solved, making the surface of the plastic product prepared from the polyethylene composite material smooth and not rough. Detailed Description of Specific Embodiments

[0023] The following provides a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only for the purpose of illustrating and explaining the present invention, and are not used to limit the present invention.

[0024] In the ranges disclosed herein, the endpoints and any values are not limited to the exact range or value. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0025] The preparation method of the polyethylene composite material of the present invention includes the following steps:

[0026] (1) Mix and react the preheated waste wind turbine blade powder with a silane coupling agent, glycidyl methacrylate, and a liquid lubricant;

[0027] (2) Mix the reaction mixture obtained in step (1) with polyethylene grafted maleic anhydride, solid lubricant and polyethylene for a mixing reaction, and extrude and pelletize the obtained mixture to obtain pellets.

[0028] (3) Injection mold the pellets.

[0029] In the method of the present invention, the particle size of the waste wind turbine blade powder can be 150 - 500 mesh, preferably 200 - 400 mesh, and more preferably 250 - 350 mesh. When the particle size of the waste wind turbine blade powder is within the above preferred range, the surface of the plastic product of the prepared polyethylene composite material is smooth and not rough.

[0030] In step (1), in order to modify the surface of the glass fiber in the waste wind turbine blade powder and enhance the bonding force between the glass fiber and polyethylene, relative to 100 parts by weight of the waste wind turbine blade powder, the dosage of the silane coupling agent is preferably 2 - 20 parts by weight, further preferably 3 - 17 parts by weight, and more preferably 3.5 - 15 parts by weight.

[0031] In the method of the present invention, the type of the silane coupling agent is not particularly limited, and various silane coupling agents commonly used in the art can be used. In a preferred case, the silane coupling agent is at least one of γ - aminopropyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane and vinyltris(β - methoxyethoxy)silane. In the most preferred embodiment, the silane coupling agent is γ - aminopropyltriethoxysilane.

[0032] In step (1), in order to enhance the bonding force between the epoxy resin and polyethylene in the waste wind turbine blade powder, relative to 100 parts by weight of the waste wind turbine blade powder, the dosage of glycidyl methacrylate is preferably 1.5 - 15 parts by weight, further preferably 2 - 12 parts by weight, and more preferably 2.5 - 10 parts by weight.

[0033] In the method of the present invention, glycidyl methacrylate can be a commercially available product or prepared by a conventional method in the art.

[0034] In a preferred case, in step (1), the mass ratio of the silane coupling agent to glycidyl methacrylate is 1 - 2:1, and more preferably 1.25 - 1.75:1.

[0035] In step (1), relative to 100 parts by weight of the waste wind turbine blade powder, the dosage of the liquid lubricant can be 1.5 - 15 parts by weight, preferably 2 - 12 parts by weight, and more preferably 2.5 - 10 parts by weight.

[0036] In the method of the present invention, the type of the liquid lubricant is not particularly limited, and various liquid lubricants commonly used in the art can be used. In a preferred case, the liquid lubricant is at least one of liquid paraffin, methyl silicone oil, chlorinated paraffin, and n-butyl stearate. In the most preferred embodiment, the liquid lubricant is liquid paraffin.

[0037] In step (1), the conditions for mixing and reacting the preheated waste wind turbine blade powder with the silane coupling agent, glycidyl methacrylate, and the liquid lubricant may include: a temperature of 80-120°C and a time of 5-20 min.

[0038] In step (2), in order to further enhance the bonding strength between the glass fibers and polyethylene in the waste wind turbine blade powder, with respect to 100 parts by weight of the waste wind turbine blade powder, the amount of polyethylene grafted maleic anhydride is preferably 3-25 parts by weight, more preferably 4-22 parts by weight, and even more preferably 4.5-20 parts by weight.

[0039] In the present invention, the grafting rate of polyethylene grafted maleic anhydride can be 0.5-2%, preferably 0.7-1.5%, and more preferably 0.8-1.2%. Polyethylene grafted maleic anhydride can be a commercially available product or prepared by a conventional method in the art.

[0040] In step (2), with respect to 100 parts by weight of the waste wind turbine blade powder, the amount of the solid lubricant can be 5-40 parts by weight, preferably 6-38 parts by weight, and further preferably 7-35 parts by weight.

[0041] In the method of the present invention, the type of the solid lubricant is not particularly limited, and various solid lubricants commonly used in the art can be used. In a preferred case, the solid lubricant is at least one of calcium stearate, polyethylene wax, polyphthalamide, stearamide, and zinc stearate. In the most preferred embodiment, the solid lubricant is a combination of calcium stearate, polyethylene wax, and polyphthalamide, and the mass ratio of calcium stearate, polyethylene wax, and polyphthalamide is 1-3:1-2:1, preferably 1.5-2.5:1.2-1.8:1.

[0042] In the method of the present invention, with respect to 100 parts by weight of the waste wind turbine blade powder, the amount of polyethylene can be 100-1000 parts by weight, preferably 120-900 parts by weight, and more preferably 125-800 parts by weight. When the amount of polyethylene is within the above preferred range, the plastic products of the prepared polyethylene composite material have good comprehensive properties.

[0043] In the present invention, there is no particular limitation on the type of the polyethylene, and various polyethylenes commonly used in the art can be used. Preferably, the polyethylene is at least one of low-density polyethylene, high-density polyethylene, and linear low-density polyethylene. In the most preferred embodiment, the polyethylene is linear low-density polyethylene.

[0044] In step (2), the conditions for the mixing reaction of the reaction mixture with polyethylene grafted maleic anhydride, solid lubricant, and polyethylene may include: the temperature is 150 - 180°C, and the time is 10 - 20 min.

[0045] In step (2), the process of extruding and pelletizing the mixture may include: adding the mixture to a twin-screw extruder, controlling the temperature of each section of the twin-screw extruder to be 150 - 180°C, the rotation speed to be 10 - 25 rpm, continuously extruding through extrusion and plasticization, then cooling and shaping with cold water, and then performing traction cutting.

[0046] In a more preferred embodiment, the method for preparing the polyethylene composite material includes:

[0047] (1) Preheating waste wind turbine blade powder with a particle size of 250 - 350 mesh and mixing it with γ-aminopropyltriethoxysilane, glycidyl methacrylate, and liquid paraffin, and reacting at a temperature of 80 - 120°C for 5 - 20 min; wherein, relative to 100 parts by weight of the waste wind turbine blade powder, the dosage of γ-aminopropyltriethoxysilane is 3.5 - 15 parts by weight, the dosage of glycidyl methacrylate is 2.5 - 10 parts by weight, the dosage of liquid paraffin is 2.5 - 10 parts by weight, and the mass ratio of γ-aminopropyltriethoxysilane to glycidyl methacrylate is 1.25 - 1.75:1;

[0048] (2) Mixing the reaction mixture obtained in step (1) with polyethylene grafted maleic anhydride, calcium stearate, polyethylene wax, polyphthalamide, and linear low-density polyethylene, reacting for 10 - 20 min, then adding the obtained mixture to a twin-screw extruder, controlling the temperature of each section of the twin-screw extruder to be 150 - 180°C, extruding continuously through extrusion and plasticization at a rotation speed of 10 - 25 pm, then cooling and shaping with cold water, and then performing traction cutting and pelletizing to obtain pellets; wherein, relative to 100 parts by weight of the waste wind turbine blade powder, the dosage of polyethylene grafted maleic anhydride is 4.5 - 20 parts by weight, the combined dosage of calcium stearate, polyethylene wax, and polyphthalamide is 7 - 35 parts by weight, the dosage of linear low-density polyethylene is 125 - 800 parts by weight, and the mass ratio of calcium stearate, polyethylene wax, and polyphthalamide is 1.5 - 2.5:1.2 - 1.8:1;

[0049] (3) Inject mold the pellets at 150 - 180 °C.

[0050] The present invention also provides a polyethylene composite material prepared by the above method.

[0051] The present invention also provides a plastic product made of the above polyethylene composite material. As an example, the polyethylene composite material is injection molded into a baffle of a hazardous chemical barrel at 150 - 180 °C. This product has the characteristics of low density, smooth surface, small deformation, high dimensional stability, excellent mechanical properties, low production cost, strong environmental friendliness, and recyclability of resources. In addition, the polyethylene composite material can also be injection molded into the base of a hazardous chemical barrel and building pipes, having broad application prospects.

[0052] The following examples are used to further illustrate the polyethylene composite material, its preparation method, and plastic products of the present invention. The examples are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given. However, the protection scope of the present invention is not limited to the following examples.

[0053] The experimental methods in the following examples are all conventional methods in the art unless otherwise specified. The experimental materials used in the following examples are all commercially available unless otherwise specified.

[0054] In the following examples and comparative examples, the waste wind turbine blade powder is sourced from Guoneng (Shandong) Energy Environment Co., Ltd., and the content of glass fiber is about 65 wt%.

[0055] Example 1

[0056] (1) Preheat the waste wind turbine blade powder with a particle size of 300 mesh and mix it with γ-aminopropyltriethoxysilane (purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., the same below), glycidyl methacrylate (purchased from China National Pharmaceutical Corporation, the same below), and liquid paraffin (purchased from China National Pharmaceutical Corporation, the same below), and react at 100 °C for 15 min. Among them, relative to 100 parts by weight of the waste wind turbine blade powder, the dosage of γ-aminopropyltriethoxysilane is 5 parts by weight, the dosage of glycidyl methacrylate is 3.5 parts by weight, and the dosage of liquid paraffin is 3.5 parts by weight.

[0057] (2) The reaction mixture obtained in step (1) is mixed with polyethylene grafted maleic anhydride (grafting rate: 1%, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., the same below), calcium stearate, polyethylene wax (purchased from Dongguan Dinghai Plastic Chemical Co., Ltd., the same below), polyphthalamide (purchased from Dongguan Dinghai Plastic Chemical Co., Ltd., the same below), and linear low-density polyethylene (purchased from China National Petroleum Corporation, grade: DFDA-7042, the same below) and subjected to a mixing reaction for 15 min. Then, the obtained mixture is added to a twin-screw extruder, and the temperatures of each section of the twin-screw extruder are controlled at 150 °C in zone 1, 160 °C in zone 2, 170 °C in zone 3, 180 °C in zones 4 - 10, and 170 °C in zones 11 - 16. At a rotation speed of 18 rpm, extrusion and plasticization are carried out for continuous extrusion, followed by cooling and shaping with cold water, and then traction cutting and pelletizing to obtain pellets. Among them, relative to 100 parts by weight of the waste wind turbine blade powder, the dosage of polyethylene grafted maleic anhydride is 6.5 parts by weight, the combined dosage of calcium stearate, polyethylene wax, and polyphthalamide is 11.5 parts by weight, the dosage of linear low-density polyethylene is 200 parts by weight, and the mass ratio of calcium stearate, polyethylene wax, and polyphthalamide is 2:1.5:1.

[0058] (3) The pellets are injection-molded at 160 °C to obtain a plastic product S1 of the polyethylene composite material.

[0059] Example 2

[0060] (1) The waste wind turbine blade powder with a particle size of 250 mesh is preheated and mixed with γ-aminopropyltriethoxysilane, glycidyl methacrylate, and liquid paraffin, and reacted at 80 °C for 20 min. Among them, relative to 100 parts by weight of the waste wind turbine blade powder, the dosage of γ-aminopropyltriethoxysilane is 15 parts by weight, the dosage of glycidyl methacrylate is 10 parts by weight, and the dosage of liquid paraffin is 10 parts by weight.

[0061] (2) Mix the reaction mixture obtained in step (1) with polyethylene grafted maleic anhydride, calcium stearate, polyethylene wax, polyphthalamide, and linear low-density polyethylene and carry out a mixing reaction for 10 min. Then add the obtained mixture to a twin-screw extruder, and control the temperatures of each section of the twin-screw extruder to be 150 °C in zone 1, 160 °C in zone 2, 170 °C in zone 3, 180 °C in zones 4 - 10, and 170 °C in zones 11 - 16. Extrude continuously by extrusion and plasticization at a rotational speed of 10 rpm, then cool and shape with cold water, and then carry out traction cutting and granulation to obtain pellets. Among them, relative to 100 parts by weight of the waste wind turbine blade powder, the dosage of polyethylene grafted maleic anhydride is 20 parts by weight, the dosage of the combination of calcium stearate, polyethylene wax, and polyphthalamide is 35 parts by weight, the dosage of linear low-density polyethylene is 800 parts by weight, and the mass ratio of calcium stearate, polyethylene wax, and polyphthalamide is 1.5:1.2:1.

[0062] (3) Carry out injection molding on the pellets at 150 °C to obtain a plastic product S2 of a polyethylene composite material.

[0063] Example 3

[0064] (1) Preheat the waste wind turbine blade powder with a particle size of 350 mesh and mix it with γ-aminopropyltriethoxysilane, glycidyl methacrylate, and liquid paraffin, and react at a temperature of 120 °C for 5 min. Among them, relative to 100 parts by weight of the waste wind turbine blade powder, the dosage of γ-aminopropyltriethoxysilane is 3.5 parts by weight, the dosage of glycidyl methacrylate is 2.5 parts by weight, and the dosage of liquid paraffin is 2.5 parts by weight.

[0065] (2) Mix the reaction mixture obtained in step (1) with polyethylene grafted maleic anhydride, calcium stearate, polyethylene wax, polyphthalamide, and linear low-density polyethylene and carry out a mixing reaction for 15 min. Then add the obtained mixture to a twin-screw extruder, and control the temperatures of each section of the twin-screw extruder to be 150 °C in zone 1, 160 °C in zone 2, 170 °C in zone 3, 180 °C in zones 4 - 10, and 170 °C in zones 11 - 16. Extrude continuously by extrusion and plasticization at a rotational speed of 25 rpm, then cool and shape with cold water, and then carry out traction cutting and granulation to obtain pellets. Among them, relative to 100 parts by weight of the waste wind turbine blade powder, the dosage of polyethylene grafted maleic anhydride is 4.5 parts by weight, the dosage of the combination of calcium stearate, polyethylene wax, and polyphthalamide is 7 parts by weight, the dosage of linear low-density polyethylene is 125 parts by weight, and the mass ratio of calcium stearate, polyethylene wax, and polyphthalamide is 2.5:1.8:1.

[0066] (3) Carry out injection molding on the pellets at 150 °C to obtain a plastic product S3 of a polyethylene composite material.

[0067] Example 4

[0068] Prepare a plastic product of a polyethylene composite material according to the method of Example 1, except that in step (1), the amount of γ-aminopropyltriethoxysilane is 20 parts by weight relative to 100 parts by weight of the waste wind turbine blade powder, to obtain a plastic product S4 of a polyethylene composite material.

[0069] Example 5

[0070] Prepare a plastic product of a polyethylene composite material according to the method of Example 1, except that in step (1), the amount of glycidyl methacrylate is 15 parts by weight relative to 100 parts by weight of the waste wind turbine blade powder, to obtain a plastic product S5 of a polyethylene composite material.

[0071] Example 6

[0072] Prepare a plastic product of a polyethylene composite material according to the method of Example 1, except that relative to 100 parts by weight of the waste wind turbine blade powder, in step (2), the amount of polyethylene grafted maleic anhydride is 25 parts by weight, to obtain a plastic product S6 of a polyethylene composite material.

[0073] Example 7

[0074] Prepare a plastic product of a polyethylene composite material according to the method of Example 1. Relative to 100 parts by weight of the waste wind turbine blade powder, in step (2), the amount of linear low density polyethylene is 100 parts by weight, to obtain a plastic product S7 of a polyethylene composite material.

[0075] Example 8

[0076] Prepare a plastic product of a polyethylene composite material according to the method of Example 1, except that in step (1), the particle size of the waste wind turbine blade powder is 500 mesh, to obtain a plastic product S8 of a polyethylene composite material.

[0077] Comparative Example 1

[0078] Prepare a plastic product of a polyethylene composite material according to the method of Example 1, except that in step (1), the particle size of the waste wind turbine blade powder is 100 mesh, to obtain a plastic product D1 of a polyethylene composite material.

[0079] Comparative Example 2

[0080] Prepare a plastic product of a polyethylene composite material according to the method of Example 1, except that in step (1), γ-aminopropyltriethoxysilane is not added, to obtain a plastic product D2 of a polyethylene composite material.

[0081] Comparative Example 3

[0082] Plastic products of the polyethylene composite material were prepared according to the method of Example 1, except that in step (1), glycidyl methacrylate was not added, and plastic products D3 of the polyethylene composite material were obtained.

[0083] Comparative Example 4

[0084] Plastic products of the polyethylene composite material were prepared according to the method of Example 1, except that in step (2), polyethylene grafted maleic anhydride was not added, and plastic products D4 of the polyethylene composite material were obtained.

[0085] Comparative Example 5

[0086] Plastic products of the polyethylene composite material were prepared according to the method of Example 1, except that in step (2), the amount of linear low density polyethylene was 80 parts by weight relative to 100 parts by weight of the waste wind turbine blade powder, and plastic products D5 of the polyethylene composite material were obtained.

[0087] Comparative Example 6

[0088] Plastic products of the polyethylene composite material were prepared according to the method of Example 1, except that in step (1), diisostearoyl aluminum isopropylate was used to replace γ-aminopropyltriethoxysilane, and plastic products D6 of the polyethylene composite material were obtained.

[0089] Comparative Example 7

[0090] Plastic products of the polyethylene composite material were prepared according to the method of Example 1, except that the waste wind turbine blade powder did not go through step (1), and directly proceeded to step (2) and step (3), and plastic products D7 of the polyethylene composite material were obtained. The specific implementation process is as follows:

[0091] (2) Mix the waste wind turbine blade powder with a particle size of 300 mesh with maleic anhydride grafted polyethylene, calcium stearate, polyethylene wax, polyphthalamide, and linear low-density polyethylene and react for 15 min. Then add the obtained mixture to a twin-screw extruder, and control the temperatures of each section of the twin-screw extruder to be 150 °C in zone 1, 160 °C in zone 2, 170 °C in zone 3, 180 °C in zones 4 - 10, 170 °C in zones 11 - 16, and continuously extrude by extrusion and plasticization at a rotational speed of 18 rpm. Then cool and shape it with cold water, and then perform traction cutting and granulation to obtain pellets. Among them, relative to 100 parts by weight of the waste wind turbine blade powder, the dosage of maleic anhydride grafted polyethylene is 6.5 parts by weight, the dosage of the combination of calcium stearate, polyethylene wax, and polyphthalamide is 11.5 parts by weight, the dosage of linear low-density polyethylene is 200 parts by weight, and the mass ratio of calcium stearate, polyethylene wax, and polyphthalamide is 2:1.5:1.

[0092] (3) Inject mold the pellets at 160 °C to obtain the plastic product D7 of the polyethylene composite material.

[0093] Comparative Example 8

[0094] Prepare the plastic product of the polyethylene composite material according to the method of Example 1, except that in step (1), calcium carbonate powder is used to replace the waste wind turbine blade powder to obtain the plastic product D8 of the polyethylene composite material.

[0095] Test Example

[0096] (1) The present invention measures the longitudinal shrinkage rate of the plastic products of the polyethylene composite materials prepared in the above examples and comparative examples according to the method given in GB / T 6671-2001.

[0097] (2) The present invention measures the tensile strength of the plastic products of the polyethylene composite materials prepared in the above examples and comparative examples according to the method given in GB / T 1040.

[0098] (3) The present invention measures the elongation at break of the plastic products of the polyethylene composite materials prepared in the above examples and comparative examples according to the method given in GB / T 1040.

[0099] (4) The present invention measures the impact strength of the plastic products of the polyethylene composite materials prepared in the above examples and comparative examples according to the method given in GB / T 1843-2008.

[0100] (5) The present invention measures the hardness of the plastic products of the polyethylene composite materials prepared in the above examples and comparative examples according to the method given in GB / T 2411-2008.

[0101] The measurement results are shown in Table 1.

[0102] Table 1

[0103]

[0104] As can be seen from the results in Table 1, the plastic products made of the polyethylene composite material prepared by the method of the present invention have the characteristics of low density, smooth surface, small deformation, high dimensional stability, excellent mechanical properties, low production cost, strong environmental friendliness and recyclability of resources. This method enables the efficient recycling and reuse of waste wind turbine blades, avoiding the potential environmental pollution problems brought by traditional recycling methods, and realizing the effective reuse of waste wind turbine blades. It has broad application prospects in the fields of polyethylene material modification and the recycling and utilization of waste wind turbine blades.

[0105] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A method for preparing a polyethylene composite material, characterized in that: The method comprises the following steps: (1) mixing the preheated waste fan blade powder with a silane coupling agent, glycidyl methacrylate and a liquid lubricant for reaction; (2) mixing the reaction mixture obtained in step (1) with polyethylene grafted maleic anhydride, a solid lubricant and polyethylene for reaction, and extruding and granulating the obtained mixture to obtain pellets; (3) injection molding the pellets; Wherein, the particle size of the waste fan blade powder is 150-500 mesh; Relative to 100 parts by weight of the waste fan blade powder, the amount of polyethylene used is 100-1000 parts by weight.

2. The method according to claim 1, characterized in that In step (1), the particle size of the waste fan blade powder is 200-400 mesh.

3. The method according to claim 1 or 2, characterized in that: In step (1), relative to 100 parts by weight of the waste fan blade powder, the amount of the silane coupling agent is 2-20 parts by weight, the amount of glycidyl methacrylate is 1.5-15 parts by weight, and the amount of the liquid lubricant is 1.5-15 parts by weight.

4. The method according to claim 1 or 3, characterized in that: In step (1), the mass ratio of the silane coupling agent to glycidyl methacrylate is 1-2:

1.

5. The method according to any one of claims 1, 3 and 4, characterized in that: In step (1), the silane coupling agent is at least one of γ-aminopropyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane and vinyltri(β-methoxyethoxy)silane.

6. The method according to claim 1 or 3, characterized in that: In step (1), the liquid lubricant is at least one of liquid paraffin, methyl silicone oil, chlorinated paraffin and n-butyl stearate.

7. The method according to claim 1, characterized in that Relative to 100 parts by weight of the waste fan blade powder, the amount of polyethylene grafted maleic anhydride is 3-25 parts by weight, the amount of the solid lubricant is 5-40 parts by weight, and the amount of polyethylene is 120-900 parts by weight.

8. The method according to claim 1 or 6, characterized in that: In step (2), the solid lubricant is at least one of calcium stearate, polyethylene wax, polyphthalamide, stearamide and zinc stearate; Preferably, the solid lubricant is a combination of calcium stearate, polyethylene wax and polyphthalamide, and the mass ratio of calcium stearate, polyethylene wax and polyphthalamide is 1-3:1-2:

1.

9. The method according to claim 1, characterized in that: In step (2), the polyethylene is at least one of low-density polyethylene, high-density polyethylene and linear low-density polyethylene.

10. A polyethylene composite material prepared by the method according to any one of claims 1 to 9.

11. A plastic product, characterized in that: The plastic product is made from the polyethylene composite material described in claim 10.

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