Kenaf powder modified plastic material, and preparation method and application thereof

Abstract

This invention belongs to the field of polymer materials technology, and particularly relates to a kenaf powder modified plastic material, its preparation method, and its application. The kenaf powder modified plastic material of this invention comprises the following raw materials in parts by weight: 60-70 parts polypropylene, 10-20 parts kenaf powder, 4-6 parts modified cellulose fiber, 5-8 parts compatibilizer, 1-2 parts dispersant, 0.3-0.5 parts antioxidant, 0.1-0.3 parts UV stabilizer, 5-7 parts toughening agent, and 1-3 parts lubricant. The kenaf powder modified plastic material provided by this invention uses polypropylene as the main matrix raw material, combined with kenaf powder, modified cellulose fiber, lubricant, etc., to prepare a kenaf powder modified plastic material with high mechanical properties and excellent flame retardant properties, meeting the requirements of various industrial products.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, and particularly relates to a sesame powder modified plastic material, its preparation method and application. Background Technology

[0002] Polypropylene (PP) is a thermoplastic synthetic resin polymerized from propylene monomers. It is currently the lightest polymer available and boasts advantages such as good transparency, heat resistance, water absorption, and low price. It has wide applications in electronics, automotive, and home appliances, and is consumed in large quantities. However, polypropylene also has certain drawbacks, such as poor impact resistance and flammability, which limit its application in some fields.

[0003] In recent years, with the increasing awareness of environmental protection, developing high-performance, biodegradable plastic materials using plant fibers as reinforcing materials has become a key research focus. High-end alternative plastic raw materials require large quantities of corn starch and sweet potato starch, resulting in extremely high costs, safety concerns, and low decomposition and degradation rates. Alternative plastic raw materials made from kenaf powder possess characteristics such as high transparency, good hardness, heat resistance, antibacterial properties, and safe use. Introducing kenaf powder into the plastic matrix can not only reduce dependence on petroleum-based raw materials but also solve the problem of white pollution (plastic waste) and improve the eco-friendliness of composite materials. However, the overall performance of existing polypropylene plastic materials, including notched impact strength, flexural modulus, flexural strength, and flame retardancy, still needs improvement.

[0004] Therefore, it is of great significance to develop biodegradable plastic composite materials that combine high performance and high flame retardancy. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the first objective of the present invention is to provide a sesame powder modified plastic material.

[0006] The second objective of this invention is to provide a method for preparing a sesame powder modified plastic material.

[0007] A third objective of this invention is to provide an application of sesame powder-modified plastic materials.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] A kenaf powder modified plastic material comprises the following raw materials in parts by weight: 60-70 parts polypropylene, 10-20 parts kenaf powder, 4-6 parts modified cellulose fiber, 5-8 parts compatibilizer, 1-2 parts dispersant, 0.3-0.5 parts antioxidant, 0.1-0.3 parts UV stabilizer, 5-7 parts toughening agent, and 1-3 parts lubricant;

[0010] The preparation process of the modified cellulose fiber is as follows:

[0011] (1) Add cellulose fibers to water containing surfactant, then add silane coupling agent, heat to react, filter, wash with water and dry to obtain cellulose fibers modified with silane coupling agent;

[0012] (2) Add the cellulose fiber modified by the silane coupling agent in step (1) to a solvent containing polyethylene glycol methacrylate phosphate, then add an initiator, heat to react, filter, wash and dry to obtain the product.

[0013] Further, in step (1), the mass ratio of the cellulose fiber, surfactant and silane coupling agent is 1:0.5-1.2:(0.1-0.3), the mass fraction of the surfactant in water is 0.5-1%; the surfactant is sodium dodecyl sulfate, and the silane coupling agent is γ-methacryloyloxypropyltrimethoxysilane.

[0014] Furthermore, in step (1), the heating reaction is carried out at a temperature of 50-60°C for 3-5 hours.

[0015] Further, in step (2), the mass ratio of the silane coupling agent-modified cellulose fiber, polyethylene glycol phosphate methacrylate, and initiator is 100:(10-15):(0.5-1.2); the initiator is azobisisobutyronitrile, and the mass fraction of polyethylene glycol phosphate methacrylate in the solvent is 1.5-3%; the solvent is DMF.

[0016] Furthermore, in step (2), the heating reaction is carried out at a temperature of 60-70°C for 3-5 hours.

[0017] Furthermore, the lubricant is prepared as follows: calcium stearate is added to silica sol, heated and stirred to obtain the lubricant.

[0018] Furthermore, the mass ratio of calcium stearate to silica sol is 1:(0.4-0.6); the heating and stirring temperature is 50-60℃, and the time is 2-3h.

[0019] Furthermore, the compatibilizer is maleic anhydride-grafted polypropylene, the dispersant is ethylene bis-stearamide, the antioxidant is antioxidant 1010 or antioxidant 168, the UV stabilizer is UV-531, and the toughening agent is POE.

[0020] The method for preparing the sesame powder modified plastic material of the present invention includes the following steps:

[0021] S1. Weigh each raw material according to the above weight proportions, stir and mix well, and dry to obtain a mixture; melt extrude the mixture through a twin-screw extruder to granulate it to obtain granules;

[0022] S2. Add the granules into the mold and hot press at 150℃~180℃ and 5~10 MPa for 30-50 minutes. After molding, demold; and the product is obtained.

[0023] The present invention relates to the application of sesame powder modified plastic material in the preparation of automotive accessories or plastic substitute granules.

[0024] The present invention has the following advantages over the prior art:

[0025] This invention provides a sesame powder modified plastic material, which uses polypropylene as the main matrix raw material and combines it with sesame powder, modified cellulose fiber, lubricant, etc. The prepared sesame powder modified plastic material has high mechanical properties and excellent flame retardant properties, and meets the usage requirements of various plastic products.

[0026] Furthermore, the modified cellulose fiber introduced in this invention is first modified with a silane coupling agent to introduce double bonds on its surface. Then, under the action of an initiator, the double bonds of the silane coupling agent react with polyethylene glycol methacrylate phosphate, achieving a coating of polyethylene glycol methacrylate phosphate on the surface of the cellulose fiber. On the one hand, this improves the compatibility of the cellulose fiber in the plastic matrix, allowing it to be better dispersed in the plastic material and increasing the flexural modulus of the plastic material. On the other hand, when heated, phosphorus decomposes to generate strong dehydrating agents such as phosphoric acid and polyphosphoric acid, catalyzing the dehydration of the polymer into carbon, forming a dense carbon layer that can isolate oxygen and heat, inhibit the release of combustible gases, significantly reduce the combustion rate, and has a good flame retardant effect.

[0027] Meanwhile, the present invention introduces modified calcium stearate as a lubricant. After being coated with silica, calcium stearate can improve the fluidity of the plastic melt and enhance its lubricity. On the other hand, it can improve the density of the plastic material and enhance its mechanical properties.

[0028] This invention provides a method for preparing a modified sesame powder plastic material. The preparation process is simple to operate, suitable for large-scale industrial production, and conducive to expanding the application of this plastic material in the preparation of automotive accessories and plastic substitute granules. Attached Figure Description

[0029] Figure 1 This is an electron microscope image of the modified cellulose fibers obtained in Example 1 of the present invention. Detailed Implementation

[0030] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field. Test methods in the following embodiments that do not specify specific experimental conditions are generally performed according to conventional experimental conditions or experimental conditions recommended by the manufacturer. Unless otherwise specified, the reagents and raw materials used in the present invention are commercially available.

[0031] The compatibilizer of this invention is maleic anhydride-grafted polypropylene with a maleic anhydride grafting rate of 1%; the dispersant is ethylene bis-stearamide (EBS); the antioxidant is antioxidant 1010 or antioxidant 168; the UV stabilizer is UV-531; and the toughening agent is POE.

[0032] The cellulose fibers of this invention have a diameter of 5-50µm and a fiber length of 1-3mm.

[0033] The preparation process of sesame powder is as follows: Cut the mature sesame bark and stalks into small sections of about 3cm, place them in an oven and bake at 100℃ for 4 hours. Then, crush the sesame bark and stalks separately with a pulverizer, pass them through a 100-mesh sieve, and then mix them evenly to obtain sesame powder.

[0034] Example 1

[0035] A kenaf powder modified plastic material comprises the following raw materials in parts by weight: 67.5 parts polypropylene, 10 parts kenaf powder, 5.5 parts modified cellulose fiber, 7 parts compatibilizer (maleic anhydride grafted polypropylene), 2 parts dispersant (EBS), 0.3 parts antioxidant (antioxidant 1010), 0.2 parts UV stabilizer (UV-531), 6 parts toughening agent (POE), and 1.5 parts lubricant;

[0036] The preparation process of modified cellulose fibers is as follows:

[0037] (1) Add cellulose fibers to water containing sodium dodecyl sulfate, and then add γ-methacryloxypropyltrimethoxysilane. The mass ratio of the cellulose fibers, sodium dodecyl sulfate and γ-methacryloxypropyltrimethoxysilane is 1:1:0.2, and the mass fraction of sodium dodecyl sulfate in water is 0.8%. The mixture is placed at 55°C for 4 hours, filtered, washed with water and dried to obtain cellulose fibers modified with silane coupling agent.

[0038] (2) The cellulose fibers modified by the silane coupling agent in step (1) are added to N,N-dimethylformamide (DMF) containing polyethylene glycol methacrylate, and then azobisisobutyronitrile is added. The mass ratio of the silane coupling agent-modified cellulose fibers, polyethylene glycol methacrylate and initiator is 100:12:1; the mass fraction of polyethylene glycol methacrylate in DMF is 2%; the reaction is carried out at 65°C for 4 hours. After the reaction is completed, the fibers are filtered, washed and dried to obtain modified cellulose fibers.

[0039] The lubricant is prepared as follows: calcium stearate is added to silica sol, the mass ratio of calcium stearate to silica sol is 1:0.5, heated and stirred at 55°C for 2.5 hours, dried at 60°C, and then ball-milled to 2000 mesh to obtain the lubricant.

[0040] This invention also provides a method for preparing the above-mentioned sesame powder modified plastic material, comprising the following steps:

[0041] S1. Weigh each raw material according to the above weight proportions, stir and mix well, and dry to obtain a mixture; melt extrude the mixture through a twin-screw extruder to granulate it to obtain granules;

[0042] S2. Add the granules into the mold and hot press at 160℃ and 7 MPa for 40 minutes. After molding, demold; the product is obtained.

[0043] Example 2

[0044] A kenaf powder modified plastic material comprises the following raw materials in parts by weight: 60 parts polypropylene, 15 parts kenaf powder, 5 parts modified cellulose fiber, 8 parts compatibilizer (maleic anhydride grafted polypropylene), 2 parts dispersant (EBS), 0.4 parts antioxidant (antioxidant 168), 0.2 parts UV stabilizer (UV-531), 7 parts toughening agent (POE), and 2.4 parts lubricant;

[0045] The preparation process of modified cellulose fibers is as follows:

[0046] (1) Add cellulose fibers to water containing sodium dodecyl sulfate, and then add γ-methacryloxypropyltrimethoxysilane. The mass ratio of the cellulose fibers, sodium dodecyl sulfate and γ-methacryloxypropyltrimethoxysilane is 1:1:0.2, and the mass fraction of sodium dodecyl sulfate in water is 0.75%. The mixture is placed at 55°C for 4 hours, filtered, washed with water and dried to obtain cellulose fibers modified with silane coupling agent.

[0047] (2) The cellulose fibers modified by the silane coupling agent in step (1) are added to DMF containing polyethylene glycol phosphate methacrylate, and then azobisisobutyronitrile is added. The mass ratio of the silane coupling agent-modified cellulose fibers, polyethylene glycol phosphate methacrylate and initiator is 100:14:1; the mass fraction of polyethylene glycol phosphate methacrylate in DMF is 2.5%; the reaction is carried out at 65°C for 4 hours. After the reaction is completed, the mixture is filtered, washed and dried to obtain modified cellulose fibers.

[0048] The lubricant is prepared as follows: calcium stearate is added to silica sol, the mass ratio of calcium stearate to silica sol is 1:0.5, heated and stirred at 50°C for 2.5 hours, dried at 60°C, and then ball-milled to 2000 mesh to obtain the lubricant.

[0049] This invention also provides a method for preparing the above-mentioned sesame powder modified plastic material, comprising the following steps:

[0050] S1. Weigh each raw material according to the above weight proportions, stir and mix well, and dry to obtain a mixture; melt extrude the mixture through a twin-screw extruder to granulate it to obtain granules;

[0051] S2. Add the granules into the mold and hot press at 170℃ and 9 MPa for 40 minutes. After molding, demold; the product is obtained.

[0052] Example 3

[0053] A kenaf powder modified plastic material comprises the following raw materials in parts by weight: 62 parts polypropylene, 20 parts kenaf powder, 4 parts modified cellulose fiber, 5 parts compatibilizer (maleic anhydride grafted polypropylene), 1.2 parts dispersant (EBS), 0.5 parts antioxidant (antioxidant 1010), 0.3 parts UV stabilizer (UV-531), 5 parts toughening agent (POE), and 2 parts lubricant;

[0054] The preparation process of modified cellulose fibers is as follows:

[0055] (1) Add cellulose fibers to water containing sodium dodecyl sulfate, and then add γ-methacryloxypropyltrimethoxysilane. The mass ratio of the cellulose fibers, sodium dodecyl sulfate and γ-methacryloxypropyltrimethoxysilane is 1:1.2:0.3, and the mass fraction of sodium dodecyl sulfate in water is 1%. The mixture is placed at 60°C and reacted for 3 hours. After filtration, the mixture is washed with water and dried to obtain cellulose fibers modified with silane coupling agent.

[0056] (2) The cellulose fibers modified by the silane coupling agent in step (1) are added to DMF containing polyethylene glycol methacrylate, and then azobisisobutyronitrile is added. The mass ratio of the silane coupling agent-modified cellulose fibers, polyethylene glycol methacrylate and initiator is 100:15:1.2. The mass fraction of polyethylene glycol methacrylate in DMF is 3%. The reaction is carried out at 70°C for 3 hours. After the reaction is completed, the mixture is filtered, washed and dried to obtain the modified cellulose fibers.

[0057] The lubricant is prepared as follows: calcium stearate is added to silica sol, the mass ratio of calcium stearate to silica sol is 1:0.6, heated and stirred at 60°C for 3 hours, dried at 60°C, and then ball-milled to 2000 mesh to obtain the lubricant.

[0058] This invention also provides a method for preparing the above-mentioned sesame powder modified plastic material, comprising the following steps:

[0059] S1. Weigh each raw material according to the above weight proportions, stir and mix well, and dry to obtain a mixture; melt extrude the mixture through a twin-screw extruder to granulate it to obtain granules;

[0060] S2. Add the granules into the mold and hot press at 180℃ and 5MPa for 30 minutes. After molding, demold; the product is obtained.

[0061] Comparative Example 1

[0062] Comparative Example 1 is basically the same as Example 1, except that the modified cellulose fiber is replaced with cellulose fiber.

[0063] Comparative Example 2

[0064] Comparative Example 2 is basically the same as Example 1, except that the modified cellulose fiber is replaced with cellulose fiber modified with silane coupling agent.

[0065] Comparative Example 3

[0066] Comparative Example 3 is basically the same as Example 1, except that the lubricant is replaced with calcium stearate.

[0067] Test case

[0068] To test the properties of the plastic materials obtained in Examples 1-3 and Comparative Examples 1-3 of the present invention, the following tests were conducted:

[0069] (1) Tensile strength and elongation at break: tested according to ASTM D-638.

[0070] (2) Flexural modulus: Tested according to ASTM D-790 standard.

[0071] (3) Bending strength: Tested according to ASTM D-790 standard.

[0072] (4) Notched impact strength: Tested according to ASTM D-256 standard.

[0073] (5) Limiting Oxygen Index (LOI) test: The test was conducted in accordance with the standard GB / T 2406.2-2009. The sample size was 130mm×10mm×3m.

[0074] The test results are shown in Table 1.

[0075] Table 1

[0076]

[0077] As can be seen from the data in Table 1, the plastic materials obtained in Examples 1-3 of the present invention have higher yield tensile strength, flexural modulus, flexural strength, and cantilever beam notched impact strength than those in Comparative Examples 1-3, and also have excellent flame retardant properties.

[0078] Compared to Example 1, Comparative Example 1 replaced the modified cellulose fiber with cellulose fiber, Comparative Example 2 replaced the modified cellulose fiber with cellulose fiber modified with a silane coupling agent, and Comparative Example 3 replaced the lubricant with calcium stearate. The mechanical properties of the resulting plastic materials were all inferior to those of Example 1, indicating that the modified cellulose fiber plays an important role in improving the flame retardant and mechanical properties of the material, and the lubricant can further improve the mechanical properties of the material.

[0079] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A red sesame powder modified plastic material, characterized in that, The raw materials include the following parts by weight: 60-70 parts polypropylene, 10-20 parts kenaf powder, 4-6 parts modified cellulose fiber, 5-8 parts compatibilizer, 1-2 parts dispersant, 0.3-0.5 parts antioxidant, 0.1-0.3 parts UV stabilizer, 5-7 parts toughening agent, and 1-3 parts lubricant. The preparation process of the modified cellulose fiber is as follows: (1) Add cellulose fibers to water containing surfactant, then add silane coupling agent, heat to react, filter, wash with water and dry to obtain cellulose fibers modified with silane coupling agent; (2) Add the cellulose fiber modified by the silane coupling agent in step (1) to a solvent containing polyethylene glycol methacrylate phosphate, then add an initiator, heat to react, filter, wash and dry to obtain the product; In step (1), the mass ratio of the cellulose fiber, surfactant and silane coupling agent is 1:0.5-1.2:(0.1-0.3), and the silane coupling agent is γ-methacryloyloxypropyltrimethoxysilane; In step (2), the mass ratio of the silane coupling agent-modified cellulose fiber, polyethylene glycol phosphate methacrylate, and initiator is 100:(10-15):(0.5-1.2).

2. The sesame powder modified plastic material according to claim 1, characterized in that, In step (1), the surfactant has a mass fraction of 0.5-1% in water; the surfactant is sodium dodecyl sulfate.

3. The sesame powder modified plastic material according to claim 1, characterized in that, In step (1), the heating reaction is carried out at a temperature of 50-60°C for 3-5 hours.

4. The sesame powder modified plastic material according to claim 1, characterized in that, In step (2), the initiator is azobisisobutyronitrile, and the mass fraction of polyethylene glycol methacrylate phosphate in the solvent is 1.5-3%; the solvent is DMF.

5. The sesame powder modified plastic material according to claim 1, characterized in that, In step (2), the heating reaction is carried out at a temperature of 60-70°C for 3-5 hours.

6. The sesame powder modified plastic material according to claim 1, characterized in that, The lubricant is prepared as follows: calcium stearate is added to silica sol, heated and stirred to obtain the lubricant.

7. The sesame powder modified plastic material according to claim 6, characterized in that, The mass ratio of calcium stearate to silica sol is 1:(0.4-0.6); the heating and stirring temperature is 50-60℃, and the time is 2-3h.

8. The sesame powder modified plastic material according to claim 1, characterized in that, The compatibilizer is maleic anhydride-grafted polypropylene, the dispersant is ethylene bis-stearamide, the antioxidant is antioxidant 1010 or antioxidant 168, the UV stabilizer is UV-531, and the toughening agent is POE.

9. The method for preparing the sesame powder modified plastic material according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Weigh each raw material according to the above weight proportions, stir and mix well, and dry to obtain a mixture; melt extrude the mixture through a twin-screw extruder to granulate it to obtain granules; S2. Add the granules into the mold and hot press at 150℃~180℃ and 5~10 MPa for 30-50 minutes. After molding, demold; and the product is obtained.

10. The use of the sesame powder modified plastic material according to any one of claims 1-8 in the preparation of automotive accessories or plastic substitute granules.

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