PP / PE-based high-barrier composite material for tableware and preparation method of PP / PE-based high-barrier composite material

Abstract

The invention provides a PP / PE-based high-barrier composite material for tableware and a preparation method of the PP / PE-based high-barrier composite material, and belongs to the technical field of food contact materials.The composite material is prepared from a PP / PE matrix, PDA-coated chlorine-grafted fibers, PP-g-MAH phosphorus / silicon cross-linked substances, nanometer layered filler and food-grade assistants.The preparation method comprises the three steps that firstly, the PDA-coated chlorine-grafted fibers are prepared to construct a hydrophobic foundation; then preparing a PP-g-MAH phosphorus / silicon cross-linked substance to reinforce interface bonding; and finally, carrying out melt blending and injection molding to obtain the tableware. Through the synergistic effect of PDA chlorine-connecting hydrophobic, phosphorus / silicon cross-linking reinforcement and nano layered barrier, the composite material has excellent water / oil penetration resistance and mechanical properties, is adaptive to the existing injection molding process, meets the food contact safety standard, can be widely applied to preparation of PP / PE tableware such as dinner plates and bowls, and has the advantages of high practicability and wide application prospect. The technical problem that a traditional PP / PE tableware is poor in barrier property is solved.

Description

Technical Field

[0001] This invention relates to the field of food contact materials technology, specifically to a high-barrier composite material for PP / PE-based tableware and its preparation method. Background Technology

[0002] Polypropylene (PP) and polyethylene (PE) are widely used in the manufacture of tableware due to their excellent processing performance, low cost, and good chemical stability. However, traditional PP / PE tableware has significant technical defects: poor barrier properties, insufficient ability to block water vapor, oxygen, and grease, leading to easy spoilage and cross-contamination of food, and shortening the shelf life of food; in addition, traditional PP / PE tableware is also prone to deformation and degradation of mechanical properties under high-temperature use or microwave heating conditions.

[0003] To address the aforementioned issues, existing technologies primarily employ the addition of inorganic fillers or surface coatings to modify PP / PE. For example, the former utilizes graphene oxide / layered double hydroxides to construct a layered barrier structure, balancing heat resistance and mechanical reinforcement. However, the nanofillers exhibit poor dispersion in the PP / PE matrix and are prone to aggregation, leading to unstable barrier performance. The latter, such as using fluoropolymers or silicone resins to construct hydrophobic coatings on the substrate surface, can improve both hydrophobicity and oleophobicity. However, the interfacial bonding between these coatings and the PP / PE matrix is ​​weak, resulting in insufficient material mechanical properties and failing to meet the molding and usage requirements of high-quality tableware.

[0004] Meanwhile, with increasingly stringent safety standards for food contact materials (such as GB 4806.7-2023), higher requirements have been placed on the component safety and migration control of materials used in tableware. Existing modification technologies commonly use fluorinated compounds, some of which belong to perfluorinated and polyfluoroalkyl substances (PFAS), and their use has been restricted in the EU, the US, and other regions. Therefore, developing a PP / PE-based composite material that combines high barrier properties with compliance with food contact safety standards has become an urgent need in the tableware industry. Summary of the Invention

[0005] The purpose of this invention is to provide a high-barrier composite material for PP / PE-based tableware and its preparation method, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A high-barrier composite material for PP / PE-based tableware, comprising the following components by weight: 40-60 parts of PP / PE matrix; 5-15 parts of PDA-coated chlorinated fiber; 20-35 parts of PP-g-MAH phosphorus / silicon crosslinking compound; 3-8 parts of nano-layered filler; Heat stabilizer 1-3 parts; 0.5-1.5 parts of lubricant.

[0007] Furthermore, the PP / PE matrix is ​​one or more of food-grade homopolymer polypropylene, copolymer polypropylene, or high-density polyethylene, wherein the melt index of polypropylene is 1-6 g / 10 min (230℃, 2.16 kg), and the melt index of polyethylene is 1-3 g / 10 min (190℃, 2.16 kg), ensuring that the material has good injection molding performance while meeting the mechanical strength requirements of tableware; the heat stabilizer is at least one of hindered phenols and phosphites, which can effectively inhibit the thermal oxidative degradation of the PP / PE matrix during processing; the lubricant is at least one of erucamide, stearate, and silicone masterbatch, which reduces frictional resistance during processing and improves the surface finish of the product.

[0008] Further, the preparation method of the PDA-coated chlorinated fiber includes: dispersing plant fibers in a Tris-HCl buffer solution with pH=8.0-8.5, adding dopamine monomer to make the dopamine concentration 1-5 g / L, stirring at room temperature for 12-24 h, so that dopamine self-polymerizes on the fiber surface to form a PDA coating layer; then immersing the PDA-coated fiber in a chlorinated silane ethanol solution with a volume fraction of 3-6% and reacting at 50-60℃ for 4-6 h, so that the chlorinated silane and the PDA layer undergo covalent grafting; after the reaction, taking the solid phase, washing it with ethanol and deionized water 3-5 times in sequence, and drying it at 60-80℃ for 4-6 h after washing to obtain PDA-coated chlorinated fiber, and the chlorine content of the PDA-coated chlorinated fiber is 1.5-3 wt%.

[0009] Furthermore, the plant fiber includes bamboo fiber or wood fiber with a diameter of 50-200 μm, which has the advantages of wide availability and biodegradability; the chlorosilane is methyltrichlorosilane or dimethyldichlorosilane, avoiding the use of restricted PFAS substances and giving the material excellent hydrophobic and oil-resistant properties; the volume fraction of chlorosilane in the chlorosilane ethanol solution is 3-6%.

[0010] During the preparation of PDA-coated chlorinated fibers, the polydopamine layer formed by the self-polymerization of dopamine under weakly alkaline conditions can not only firmly coat the fiber surface, but its rich amino and hydroxyl groups can also undergo covalent reactions with chlorinated silanes, thereby improving the binding stability of chlorinated groups and reducing the risk of migration.

[0011] Further, the PP-g-MAH phosphorus / silicon crosslinker is prepared by melting maleic anhydride-grafted polypropylene (PP-g-MAH) and a phosphorus-containing siloxane compound. The preparation method includes: weighing PP-g-MAH and the phosphorus-containing siloxane compound at a mass ratio of (8-10):1, adding 0.1-0.3% of dibutyltin dilaurate as a catalyst relative to the weight of PP-g-MAH, placing it in a high-speed mixer, and stirring at 1200-1500 rpm for 10-15 min until uniform; then transferring the mixture to a twin-screw extruder, melting and reacting at 180-200℃ for 5-10 min, extruding and granulating to obtain the PP-g-MAH phosphorus / silicon crosslinker; the temperature of each zone of the twin-screw extruder is set sequentially as follows: zone 1 180℃, zone 2 190℃, zone 3 200℃, and die head 200℃, and the screw speed is 200-300 rpm.

[0012] Furthermore, the maleic anhydride grafting rate of the PP-g-MAH is 1.0-1.5%, ensuring sufficient reactivity; the phosphorus-containing siloxane compound is a compound of γ-aminopropyltriethoxysilane and ammonium dihydrogen phosphate, with a mass ratio of (2-6):1. The anhydride groups on the PP-g-MAH molecular chain can undergo amidation and esterification reactions with the amino and hydroxyl groups in the phosphorus-containing siloxane compound to form a cross-linked network structure, which can not only strengthen the interfacial bonding force between the PDA-coated chlorinated fiber and the PP / PE matrix, but also improve the thermal stability and boiling resistance of the material.

[0013] Furthermore, the nanolayered filler is montmorillonite, hydrotalcite, or graphene oxide nanosheets with a diameter of 100-500 nm and a thickness of 1-5 nm. The nanolayered filler is used after surface modification with γ-aminopropyltriethoxysilane. The specific modification method is as follows: the nanolayered filler is dispersed in an ethanol-water mixed solvent, adjusted to a weakly acidic state, and γ-aminopropyltriethoxysilane (APTES) is added. Under heating conditions of 50-70℃, the silane hydrolyzes and undergoes a condensation reaction with the hydroxyl and carboxyl groups on the filler surface. Finally, the modified filler is obtained after washing and drying. The modified nanolayered filler exhibits good dispersibility in the PP / PE matrix and can be oriented to form a "brick wall structure," significantly extending the penetration path of water vapor, oxygen, and grease, and improving the barrier properties of the material. Simultaneously, the nanolayered filler also strengthens and toughens the surface, improving the mechanical strength and service life of tableware.

[0014] This solution also provides a method for preparing a high-barrier composite material for PP / PE-based tableware, using the aforementioned high-barrier composite material for PP / PE-based tableware, including the following steps: Weigh out the PP / PE matrix, PDA-coated chlorinated fiber, PP-g-MAH phosphorus / silicon crosslinker, nano-layered filler, food-grade heat stabilizer, and lubricant according to the weight parts, add them to a high-speed mixer, and stir at 1200-1500 rpm for 0.2-0.4 hours until homogeneous; then transfer the mixture to a twin-screw extruder for extrusion granulation. The temperature of each zone of the twin-screw extruder is set as follows: Zone 1 160-170℃, Zone 2 180-190℃, Zone 3 190-200℃, Zone 4 200-210℃, and the die head 210-220℃, with a screw speed of 300-500 rpm, to obtain composite granules.

[0015] This solution also provides an application of a high-barrier composite material for PP / PE-based tableware in PP / PE-based tableware, and the application method includes: The composite granules obtained above are added to an injection molding machine. The barrel temperature is set to 180-220℃ (zone 1 180-190℃, zone 2 190-200℃, zone 3 200-210℃, nozzle 210-220℃), the mold temperature to 60-80℃, the injection pressure to 1500-1800 bar, the injection speed to 50-100 mm / s, the holding pressure to 1200-1600 bar, the cooling time to 1-3 seconds, and the production cycle to 8-12 seconds. The injection molded product is a plate, bowl, or other tableware. After molding, the finished product is placed in a sample stage to cool down for 0.1-0.2 hours to obtain the final product.

[0016] The beneficial effects of the above-described technical solution of the present invention are as follows: (1) This invention significantly improves the barrier performance of the material through the synergistic effect of "PDA chlorination hydrophobicity + nano-layered barrier". The hydrophobic layer constructed by PDA-coated chlorination fibers can effectively block the wetting of water and oil. The "brick wall structure" formed by the directional arrangement of nano-layered fillers extends the penetration path, making the water vapor permeability of the composite material <1.0g / (m²·24h) and the heat oxygen permeability <5.0cm³ / (m²·24h·0.1MPa), which is far superior to traditional PP / PE tableware materials and can effectively extend the shelf life of food. (2) The present invention strengthens the interfacial bonding force between PDA-coated chlorinated fiber and PP / PE matrix through the cross-linking network formed by PP-g-MAH phosphorus / silicon cross-linking agent, avoiding the problem of filler agglomeration. At the same time, the nano-layered filler plays a role in strengthening and toughening, making the flexural strength of the composite material >30MPa and the elongation at break >20%, which can meet the strength requirements of tableware. (3) All components selected in this invention are food grade, and chlorosilanes are used to replace restricted PFAS substances. Heat stabilizers, lubricants and other additives meet the requirements of GB 4806.7-2023 standard. The material migration is low and it is safe to use. The preparation process adopts melt blending and injection molding process, which is fully compatible with existing tableware production equipment. No new equipment is required, which is convenient for industrial promotion. Detailed Implementation

[0017] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0018] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products. Example 1

[0019] A high-barrier composite material for PP / PE-based tableware, comprising the following components by weight: PP 57 copies; 10 parts of PDA-coated chlorinated fiber; 25 parts of PP-g-MAH phosphorus / silicon crosslinking compound; 5 parts of nano-layered filler; 2 parts heat stabilizer; 1 part lubricant.

[0020] A method for preparing and applying a high-barrier composite material for PP / PE-based tableware includes the following steps: S1, Preparation of PDA-coated chlorinated bamboo fiber: Bamboo fiber with a diameter of 100-150 μm was dispersed in Tris-HCl buffer solution at pH=8.5, and dopamine monomer was added to make the dopamine concentration 3 g / L. The mixture was stirred at room temperature for 18 h. Then, it was immersed in 4.5% (volume fraction) methyltrichlorosilane ethanol solution and reacted at 55 °C for 5 h. After the reaction, it was washed 4 times each with ethanol and deionized water, and dried at 70 °C for 5 h to obtain PDA-coated chlorinated bamboo fiber with a chlorine content of 2.2 wt% and a surface contact angle of 115°.

[0021] S2, Preparation of PP-g-MAH phosphorus / silicon crosslinker: Weigh PP-g-MAH (maleic anhydride grafting rate 1.0%) and phosphorus-containing siloxane compound (γ-aminopropyltriethoxysilane and ammonium dihydrogen phosphate compounded at a mass ratio of 4:1) at a mass ratio of 9:1. Add 0.2% by weight of dibutyltin dilaurate as a catalyst to PP-g-MAH and stir at 1400 rpm for 12 min in a high-speed mixer. Transfer to a twin-screw extruder and set the temperature as follows: Zone 1 180℃, Zone 2 190℃, Zone 3 200℃, and Die head 200℃. The screw speed is 250 rpm. Melt reaction is carried out for 8 min. Extrusion and granulation are performed to obtain PP-g-MAH phosphorus / silicon crosslinker.

[0022] S3, Preparation of composite material: Weigh the PP matrix, the PDA-coated chlorinated fiber prepared in step S1, the PP-g-MAH phosphorus / silicon crosslinker prepared in step S2, the nano-layered filler (hydrotalcite, surface modified with γ-aminopropyltriethoxysilane), the heat stabilizer (hindered phenol), and the lubricant (erucamide) according to the weight parts, add them to a high-speed mixer and stir at 1400 rpm for 0.3 h until uniform; transfer to a twin-screw extruder, extrude and granulate at 165℃ in zone 1, 185℃ in zone 2, 195℃ in zone 3, 205℃ in zone 4, and 215℃ at the die head, with a screw speed of 400 rpm, to obtain composite particles.

[0023] S4, Molding tableware: Add the composite particles prepared in step S3 to the injection molding machine. The barrel temperature is 185℃ in zone 1, 195℃ in zone 2, 205℃ in zone 3, and 215℃ in nozzle. The mold temperature is 70℃, the injection pressure is 1600 bar, the holding pressure is 1400 bar, the injection speed is 80 mm / s, the cooling time is 2s, the production cycle is 10s, and the tableware is molded into finished tableware. Example 2

[0024] A high-barrier composite material for PP / PE-based tableware, comprising the following components by weight: PE 56 copies; 8 parts of PDA-coated chlorinated fiber; 30 parts of PP-g-MAH phosphorus / silicon crosslinking compound; Four parts of nano-layered filler; 1.5 parts heat stabilizer; 0.5 parts lubricant.

[0025] A method for preparing and applying a high-barrier composite material for PP / PE-based tableware includes the following steps: S1, Preparation of PDA-coated chlorinated bamboo fiber: Wood fibers with a diameter of 80-120 μm were dispersed in Tris-HCl buffer solution at pH=8.2, and dopamine monomer was added to make the dopamine concentration 2 g / L. The mixture was stirred at room temperature for 20 h. Then, it was immersed in 3% (volume fraction) dimethyldichlorosilane ethanol solution and reacted at 52 °C for 4.5 h. After the reaction, the mixture was washed 3 times each with ethanol and deionized water, and dried at 65 °C for 4.5 h to obtain PDA-coated chlorinated bamboo fiber with a chlorine content of 1.8 wt% and a surface contact angle of 112°.

[0026] S2, Preparation of PP-g-MAH phosphorus / silicon crosslinker: Weigh PP-g-MAH (maleic anhydride grafting rate 1.3%) and phosphorus-containing siloxane compound (γ-aminopropyltriethoxysilane and ammonium dihydrogen phosphate compounded at a mass ratio of 3:1) at a mass ratio of 8:1. Add 0.15% by weight of dibutyltin dilaurate as a catalyst to PP-g-MAH and stir in a high-speed mixer at 1300 rpm for 15 min. Transfer to a twin-screw extruder and set the temperature as follows: Zone 1 180℃, Zone 2 190℃, Zone 3 200℃, Die head 200℃, screw speed 220 rpm. Melt reaction for 9 min, then extrude and granulate to obtain PP-g-MAH phosphorus / silicon crosslinker.

[0027] S3, Preparation of composite material: Weigh the PE matrix, the PDA-coated chlorinated fiber prepared in step S1, the PP-g-MAH phosphorus / silicon crosslinker prepared in step S2, the nano-layered filler (montmorillonite, surface modified with γ-aminopropyltriethoxysilane), the heat stabilizer (phosphite), and the lubricant (zinc stearate) according to the weight parts, add them to a high-speed mixer at 1300 rpm and stir for 0.35 h until uniform; transfer to a twin-screw extruder, extrude and granulate at 160℃ in zone 1, 180℃ in zone 2, 190℃ in zone 3, 200℃ in zone 4, and 210℃ at the die head, with a screw speed of 350 rpm, to obtain composite particles.

[0028] S4, Molding tableware: Add the composite particles prepared in step S3 to the injection molding machine. The barrel temperature is 180℃ in zone 1, 190℃ in zone 2, 200℃ in zone 3, and 210℃ in nozzle. The mold temperature is 65℃, the injection pressure is 1500 bar, the holding pressure is 1300 bar, the injection speed is 70 mm / s, the cooling time is 1.5s, the production cycle is 9s, and the tableware is injection molded into finished tableware. Example 3

[0029] A high-barrier composite material for PP / PE-based tableware, which differs from Example 1 in that it comprises the following components by weight: PP 28 copies; PE 20 copies; 12 parts of PDA-coated chlorinated fiber; 30 parts of PP-g-MAH phosphorus / silicon crosslinking compound; Six parts of nano-layered filler; 2.5 parts heat stabilizer; 1.5 parts lubricant. Comparative Example 1

[0030] A high-barrier composite material for PP / PE-based tableware, comprising the following components by weight: PP 58 copies; PE 20 copies; 12 parts of PDA-coated chlorinated fiber; Six parts of nano-layered filler; 2.5 parts heat stabilizer; 1.5 parts lubricant.

[0031] The specific preparation and method include the following steps: Weigh out PP, heat stabilizer (hindered phenol) and lubricant (erucamide) according to the weight parts, add them to a high-speed mixer and stir at 1400 rpm for 0.3 h; transfer to a twin-screw extruder, set the temperature to 165℃ in zone 1, 185℃ in zone 2, 195℃ in zone 3, 205℃ in zone 4, and 215℃ at the die head, and the screw speed to 400 rpm, and extrude and granulate to obtain granular material.

[0032] The main physical properties of the PP / PE-based high-barrier composite materials for tableware prepared in Examples 1-3 and the granular material prepared in Comparative Example 1 were tested according to relevant testing standards. These properties included tensile strength, elongation at break, flexural strength, flexural modulus, water vapor transmission rate, and oxygen transmission rate. The test conditions and dimensions of the test specimens are as follows: The size of the specimen used for the tensile strength test was 172*10*4mm, and the tensile rate was 50mm / min. The size of the specimen used for the bending strength test was 80*10*4mm, and the bending rate was 2mm / min. The size of the spline used for the bending modulus test was 80*10*4mm, and the bending rate was 2mm / min. The testing standards and results are shown in the table below:

[0033] Test results show that the overall physical properties of Examples 1-3 of this invention are significantly better than those of Comparative Example 1. Specifically, the tensile strength of Examples 2 and 3 is better than that of Comparative Example 1, while the tensile strength of Example 1, although slightly lower, is still significantly higher than that of Comparative Example 1. In other key performance indicators, the performance of Comparative Example 1 is significantly different from that of Examples 1-3. This invention significantly improves the barrier properties and mechanical properties of PP / PE tableware materials through the synergistic effect of PDA-coated chlorinated fibers, PP-g-MAH phosphorus / silicon crosslinking, and nanolayered fillers, demonstrating significant technical advantages.

[0034] This invention relates to a high-barrier, multifunctional PP / PE-based tableware composite material and its preparation method. All raw materials used are commercially available food-grade products. The preparation process employs melt blending and injection molding, which is fully compatible with existing tableware production equipment, resulting in high production efficiency and controllable costs. The resulting tableware products possess excellent barrier and mechanical properties, meeting the requirements of GB 4806.7-2023 food contact plastic materials and products standard. They can be widely used in the production of various PP / PE tableware such as plates, bowls, cups, and takeout boxes, demonstrating good industrial practicality and market promotion value.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention, as long as they do not depart from the spirit and scope of the technical solutions of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. A high-barrier composite material for PP / PE-based tableware, characterized in that, By weight, it comprises the following components: 40-60 parts of PP / PE matrix; 5-15 parts of PDA-coated chlorinated fiber; 20-35 parts of PP-g-MAH phosphorus / silicon crosslinking compound; 3-8 parts of nano-layered filler; Heat stabilizer 1-3 parts; 0.5-1.5 parts of lubricant.

2. The high-barrier composite material for PP / PE-based tableware according to claim 1, characterized in that, The PP / PE matrix is ​​one or more of food-grade homopolymer polypropylene, copolymer polypropylene, or high-density polyethylene, wherein the melt index of polypropylene is 1-6 g / 10 min (230℃, 2.16 kg), and the melt index of polyethylene is 1-3 g / 10 min (190℃, 2.16 kg); the heat stabilizer is at least one of hindered phenols and phosphites; and the lubricant is at least one of erucamide, stearate, and silicone masterbatch.

3. The high-barrier composite material for PP / PE-based tableware according to claim 1, characterized in that, The method for preparing the PDA-coated chlorinated fiber includes: Plant fibers were dispersed in Tris-HCl buffer solution with pH 8.0-8.5, and dopamine monomer was added to make the dopamine concentration 1-5 g / L. The mixture was stirred at room temperature for 12-24 h to form PDA-coated fibers. The PDA-coated fibers were then immersed in a chlorosilane-ethanol solution and reacted at 50-60 °C for 4-6 h. The solid phase was washed and dried at 60-80 °C for 4-6 h to obtain PDA-coated chlorinated fibers.

4. The high-barrier composite material for PP / PE-based tableware according to claim 3, characterized in that, The plant fiber includes bamboo fiber or wood fiber with a diameter of 50-200 μm; the chlorinated silane is methyltrichlorosilane or dimethyldichlorosilane; the volume fraction of chlorinated silane in the chlorinated silane ethanol solution is 3-6%; the chlorine content in the PDA-coated chlorinated fiber is 1.5-3 wt%.

5. The high-barrier composite material for PP / PE-based tableware according to claim 1, characterized in that, The preparation method of the PP-g-MAH phosphorus / silicon crosslinker includes: PP-g-MAH, phosphorus-containing siloxane compounds and catalysts are added to a high-speed mixer, stirred evenly and then transferred to a twin-screw extruder. The mixture is melt-reacted at 180-200℃ for 5-10 minutes, and then extruded and granulated to obtain PP-g-MAH phosphorus / silicon crosslinked material.

6. The high-barrier composite material for PP / PE-based tableware according to claim 5, characterized in that, The mass ratio of PP-g-MAH to phosphorus-containing siloxane compound is (8-10):1, and the amount of catalyst added is 0.1-0.3% of the mass of PP-g-MAH.

7. The high-barrier composite material for PP / PE-based tableware according to claim 6, characterized in that, The maleic anhydride grafting rate of the PP-g-MAH is 1.0-1.5%; the phosphorus-containing siloxane compound is a compound of γ-aminopropyltriethoxysilane and ammonium dihydrogen phosphate in a mass ratio of (2-6):1; the catalyst is dibutyltin dilaurate.

8. The high-barrier composite material for PP / PE-based tableware according to claim 1, characterized in that: The nanolayered filler is montmorillonite, hydrotalcite, or graphene oxide nanosheets with a diameter of 100-500 nm and a thickness of 1-5 nm. The nanolayered filler is used after surface modification with γ-aminopropyltriethoxysilane.

9. A method for preparing a high-barrier composite material for PP / PE-based tableware, comprising using the PP / PE-based high-barrier composite material for tableware as described in any one of claims 1-8, characterized in that, include: S1. Weigh out the PP / PE matrix, PDA-coated chlorinated fiber, PP-g-MAH phosphorus / silicon crosslinker, nano-layered filler, heat stabilizer and lubricant by weight, add them to a high-speed mixer, and stir at 1200-1500 rpm for 0.2-0.4 hours until uniform; then transfer to a twin-screw extruder for extrusion granulation at an extrusion temperature of 160-220℃ and a screw speed of 300-500 rpm. S2. Add the composite granules obtained in step S1 to the injection molding machine, set the barrel temperature to 180-220℃, the mold temperature to 60-80℃, the injection pressure to 1500-1800 bar, the holding pressure to 1200-1600 bar, and the cooling time to 1-3 seconds, and injection mold the finished tableware.

10. The method for preparing the high-barrier composite material for PP / PE-based tableware according to claim 9, characterized in that: In step S1, the temperatures of each zone of the twin-screw extruder are set as follows: Zone 1 160-170℃, Zone 2 180-190℃, Zone 3 190-200℃, Zone 4 200-210℃, and Die head 210-220℃.

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