Modifying additive and polyethylene modified material composition, polyethylene modified material, and preparation method therefor and use thereof

Abstract

The present invention relates to the technical field of preparation of polyethylene modified materials. Disclosed are a modifying additive and a polyethylene modified material composition, a polyethylene modified material, and a preparation method therefor and a use thereof. The modifying additive is an organic compound and / or an inorganic substance. The lengths of the modifying additive in the x, y, and z directions in three‑dimensional space do not exceed 200 μm, and the melting point of the modifying additive is greater than or equal to 139.0°C. The organic compound is selected from one or more of sorbitol benzylidene derivatives, aliphatic carboxylic acid metal compounds, aromatic carboxylic acid metal compounds, organic phosphates, lignic acids and derivatives thereof. The inorganic substance is selected from one or more of metals, non-metal solid oxides, and non-metal elemental substances. By using the modifying additive, the viscosity of the polyethylene modified material during flow-field processing can be reduced, and the molecular weight distribution thereof can be utilized to improve the degree of orientation, thereby enhancing the lateral impact resistance of a final product.

Description

Modifying additives and polyethylene modifier compositions, polyethylene modifiers, their preparation methods and applications

[0001] Cross-reference to related applications

[0002] This application claims the benefit of Chinese Patent Application No. 202411940165.7, filed on December 26, 2024, entitled “Modified Additives and Polyethylene Modified Material Compositions and Polyethylene Modified Materials, Preparation Methods and Applications Thereof”, the contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of polyethylene modified material preparation technology, specifically to a modifying agent and a polyethylene modified material composition, as well as the polyethylene modified material, its preparation method and application. Background Technology

[0004] Polyethylene (PE) is a commonly used thermoplastic with a very large annual production, accounting for about one-third of the world's total annual polymer production. It is widely used in many fields, such as automotive, pharmaceutical, aerospace, and electronics, due to its lightweight, flexibility, good hydrophobicity, chemical stability, low price, and ease of processing. However, the lack of polar functional groups, high crystallinity, and low surface energy of PE also limit its applications. To overcome these limitations and broaden the applications of PE, researchers have conducted a series of physical and chemical modifications.

[0005] Reinforcing additives are among the additives used to improve the properties of polyethylene. Additives for reinforcing polyethylene mainly include glass fibers, carbon fibers, whiskers, and organic fibers. These reinforcing materials can significantly improve the mechanical strength of polyethylene, such as tensile strength, hardness, rigidity, and impact strength. Furthermore, the mechanical strength of plastics can be further improved by using coupling agents, nano-inorganic oxides, and nano-metal compounds, such as silanes and titanates containing functional groups, as bridges between inorganic reinforcing materials and fillers and organic polymers.

[0006] CN118546485A discloses a heat-resistant fluoroelastomer processing aid for metallocene polyethylene pipe materials and its preparation method. The method involves adding fluorinated modified carbon nanotubes, hexafluoropropylene-hexafluoroethylene copolymer, and siloxane to a twin-screw extruder for extrusion. The extrudate is then pulverized, extracted, filtered, and dried to obtain the high-temperature resistant fluoroelastomer processing aid. Fluorides have low surface energy, reducing intermolecular friction in metallocene resins. The fluoropolymer migrates to the outside of the melt and forms a lubricating layer on the extrusion die surface, reducing melt viscosity and delaying sharkskin melt fracture, resulting in a smoother surface. Simultaneously, carbon nanotubes exhibit good high-temperature resistance, and their synergistic effect with fluorinated compounds reduces coking at the die orifice. The carbon nanotubes also entangle with the open-ring chains of ε-caprolactone, forming inorganic-organic particles, giving the metallocene polyethylene good tensile properties, and the carbon nanotubes themselves also possess good tensile strength.

[0007] CN111941723B discloses a high-toughness trash can and its preparation method. The high-toughness trash can, by weight, comprises the following plastic bucket formula: 50-60 parts polypropylene, 15-20 parts modified montmorillonite, 2-5 parts ultraviolet absorber, 3-5 parts filler, 1-3 parts lubricant, and 0.5-3 parts flame retardant. When the trash can is used outdoors, the ultraviolet absorber absorbs ultraviolet rays from sunlight without changing itself, reducing the exposure of the polypropylene to ultraviolet rays, thereby slowing down the aging of the trash can and extending its service life. Adding filler to the raw materials enhances the physical and mechanical properties of the trash can and reduces production costs. Adding lubricant reduces friction between raw materials and between raw materials and processing equipment, thereby reducing melt flow resistance, reducing melt viscosity, improving melt fluidity, preventing melt adhesion to equipment, and improving the surface finish of the product. However, it does not have a clear effect on improving the mechanical properties of the product.

[0008] CN108017821A discloses a multifunctional anti-scratch-whitening plastic additive. The components and weight ratios of this multifunctional anti-scratch-whitening plastic additive are as follows: 80-90 parts calcium carbonate, 8-10 parts stearic acid, 3-5 parts calcined kaolin, 1-3 parts lubricant, 0.8-1.5 parts methacrylate, 1-2 parts organotin, 0.5-1 part sodium carbonate, 1-2 parts polyethylene wax, 1-2 parts mica powder, and 0.5-1 part silicone oil. This invention significantly reduces particle surface energy and interfacial tension by mixing modified calcium carbonate with the additive, effectively preventing the self-aggregation of fine particles, increasing its compatibility in plastics, promoting polymer plasticization, improving the impact strength, rigidity, and heat resistance of the product, reducing melt viscosity, improving fluidity, and enhancing the processing performance of the plastic. The addition of calcined kaolin to the mixture increases the plasticity of the plastic additive. The pressure and constant pressure time for the finished product are shortened compared to normal, helping to prevent the plastic from easily scratching and whitening.

[0009] CN108794847A discloses a rotational molding polyolefin composition and its preparation method. The polyolefin composition comprises the following raw materials: polyethylene, hyperbranched polyethylene, nucleating agent, acid scavenger, ultraviolet absorber, and antioxidant; wherein the hyperbranched polyethylene, nucleating agent, antioxidant, and acid scavenger are used after pretreatment. The pretreatment involves mixing the hyperbranched polyethylene, nucleating agent, antioxidant, and acid scavenger, adding n-hexane, heating under reflux to remove the solvent, and then drying. This invention can significantly improve the physical and mechanical properties of rotational molding raw materials and reduce melt viscosity (low zero-shear viscosity); the produced rotational molding products have smooth inner and outer surfaces, good plasticization, no obvious bubbles in the product cross-section, short heating time, easy demolding, and excellent long-term ultraviolet aging performance.

[0010] CN115340714A discloses a method for producing oriented self-reinforced polyethylene pipes. The raw material formulation includes polyethylene resin and color masterbatch. The polyethylene resin is composed of HDPE, LLDPE, and UHMWPE in a mass ratio of (60-75):(15-30):(0-20); the mass ratio of polyethylene resin to color masterbatch is 100:(3-7). In this patent, LLDPE enables the polyethylene material to have a low natural tensile ratio and obvious uniform orientation, while UHMWPE can induce the orientation of general-purpose HDPE macromolecules, improving the reinforcement effect. The special compounding and orientation self-reinforcement processing technology can significantly improve the circumferential strength of polyethylene pipes, and improve the water supply pressure bearing performance and water supply capacity. However, the molecular weight of UHMWPE is in the range of 100×10⁻⁶. 4 Polyolefin blends with a viscosity above g / mol, significantly higher than HDPE or LLDPE, will have a lower melt index than HDPE or LLDPE, thus increasing the processing difficulty of the pipes. Therefore, developing self-reinforced polyolefin blends that can reduce melt viscosity is crucial.

[0011] In summary, reinforcing additives and other types of additives play a crucial role in improving the performance of polyethylene. Through various chemical and physical modification methods, the practicality and application range of polyethylene can be significantly enhanced. However, glass fiber (GF), carbon fiber, whiskers, and other reinforcing additives for polyethylene have several disadvantages in application. Their higher density may increase product weight, their poor long-term temperature resistance limits their application in high-temperature environments, their low interlaminar shear strength affects the overall mechanical properties of the material, and their lower elastic modulus may affect their performance in high-stress applications. Furthermore, the interfacial bonding between inorganic reinforcing materials and the polyethylene matrix may be weak, affecting the reinforcing effect and potentially leading to easier material failure under stress. The addition of inorganic materials may also increase melt viscosity, affecting processing performance, and may affect thermal stability, causing thermal degradation of the material. There are also potential adverse environmental impacts, such as the generation of harmful byproducts during production and processing.

[0012] Therefore, applying new toughening materials and developing corresponding modification methods to overcome the disadvantage of increased melt viscosity is the main research direction of current polyethylene toughening functional additives. Summary of the Invention

[0013] The purpose of this invention is to overcome the defects of excessive melt viscosity and insufficient impact toughness of polyethylene products in the processing of existing polyethylene modified materials. It provides a modifying agent, a polyethylene modified material composition, a polyethylene modified material, its preparation method and application. By using this modifying agent, the polyethylene modified material can have the functions of reducing viscosity and increasing toughness, which can reduce the viscosity of the polyethylene modified material, improve the orientation degree, and improve the lateral impact strength.

[0014] To achieve the above objectives, the first aspect of the present invention provides a modified additive, wherein the modified additive is an organic compound and / or an inorganic substance, and the length of the modified additive in the x, y, and z directions of three-dimensional space is the same or different, and the length of each does not exceed 200 μm; the melting point of the modified additive is ≥139.0℃;

[0015] The organic compound is selected from one or more of the following: sorbitol benzylidene derivatives, aliphatic carboxylic acid metal compounds, aromatic carboxylic acid metal compounds, organophosphates, lignin acids and their derivatives;

[0016] The inorganic material is selected from one or more of metals, non-metal solid oxides, and non-metallic elements.

[0017] A second aspect of the present invention provides a polyethylene modified material composition, wherein the polyethylene modified material composition contains polyethylene and a modifying agent, wherein the modifying agent is the aforementioned modifying agent.

[0018] A third aspect of the present invention provides a method for preparing a polyethylene modified material using the aforementioned polyethylene modified material composition, wherein the method comprises: processing polyethylene and a modifying agent to obtain a polyethylene modified material.

[0019] A fourth aspect of the present invention provides a modified polyethylene material prepared by the aforementioned method.

[0020] The fifth aspect of the present invention provides the application of the aforementioned modified polyethylene material in one or more of injection molded parts, pipes, films, fibers, sheets and profiles.

[0021] By applying the modified additives of the present invention to polyethylene through the above technical solution, the resulting modified polyethylene material can have the effects of reducing viscosity and increasing toughness. Attached Figure Description

[0022] Figure 1 is a schematic diagram showing the effect of the modified additives prepared in Examples 1-8 and Comparative Examples 1-2 on the reduction of complex viscosity of polyethylene at 628.0 rad / s and 0.0628 rad / s.

[0023] Figure 2 is a schematic diagram showing the effect of the modified additives prepared in Examples 1-8 and Comparative Examples 1-2 on the orientation degree and impact resistance of polyethylene. Detailed Implementation

[0024] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0025] As mentioned above, the first aspect of the present invention provides a modified additive, wherein the modified additive is an organic compound and / or an inorganic substance, and the length of the modified additive in the x, y, and z directions of three-dimensional space is the same or different, and the length of each does not exceed 200 μm; the melting point of the modified additive is ≥139.0℃;

[0026] The organic compound is selected from one or more of the following: sorbitol benzylidene derivatives, aliphatic carboxylic acid metal compounds, aromatic carboxylic acid metal compounds, organophosphates, lignin acids and their derivatives;

[0027] The inorganic material is selected from one or more of metals, non-metal solid oxides, and non-metallic elements.

[0028] In this invention, it should be noted that "length" refers to the diameter or side length along that direction.

[0029] The inventors of this invention discovered that a composition obtained by compounding organic and inorganic substances can be used as a modifying agent. This modifying agent has the function of reducing viscosity and increasing toughness. Furthermore, by processing organic and inorganic substances at temperatures above the processing temperature with polyethylene granules or polyethylene powder, a modified polyethylene material is obtained. The organic or inorganic substances act as heterogeneous nucleating agents, inducing rapid crystallization of polyethylene molecular chains and improving the crystallization regularity of polyethylene molecular chains in the aggregated structure. As a result, the viscosity of the modified polyethylene material can be reduced, the orientation degree can be improved, and the lateral impact strength can be increased.

[0030] Furthermore, the inventors of this invention blended a modifying agent, whose length in each of the x, y, and z directions in three-dimensional space does not exceed 200 μm, with polyethylene to obtain a modified polyethylene material. The modifying agent, as a toughening functional additive, retains its original shape because its melting point is much higher than the processing temperature. During flow field processing above its melting point, the modified polyethylene material tends to align with the flow field direction, forming a flow field environment similar to a "racetrack." This facilitates the flow of polyethylene molecular chains in the established "racetrack" as straight chains, thereby reducing melt viscosity and forming a highly oriented polyethylene swirl structure near the modifying agent. Furthermore, due to the steric hindrance effect of the modifying agent, the straight chains in the already formed polyethylene swirl structure do not move towards bent chains, thus maintaining the orientation formed during flow field processing and improving the lateral impact strength of the product.

[0031] According to the present invention, the length of the modified additive in the x, y, and z directions of three-dimensional space does not exceed 200 μm, and preferably does not exceed 80 μm.

[0032] According to the present invention, when the modified additive is spherical, its length in the x, y, and z directions of three-dimensional space is 1-20 nm; more preferably, when the modified additive is any one of rod, cuboid, sheet, and tubular shape, its length in the x, y, and z directions of three-dimensional space is 1 nm-50 μm, preferably 100 nm-50 μm.

[0033] According to the present invention, the length (diameter or side length) of the modified additive in at least one of the x and y directions in three-dimensional space is 1-500 nm; more preferably, the length (diameter or side length) in at least two directions is 1-200 nm, and more preferably 5-100 nm.

[0034] In this invention, preferably, the length in the x-direction is 5-100 nm, the length in the y-direction is 5-100 nm, and the length in the z-direction is 5-50 μm; more preferably, the length in the x-direction is 20-100 nm, the length in the y-direction is 15-100 nm, and the length in the z-direction is 2-30 μm.

[0035] According to the present invention, the length ratio in the x direction and the y direction is (1-5):1, preferably (1-2):1, more preferably (1-1.5):1, and even more preferably 1:1.

[0036] According to the present invention, the length ratio in the z direction and the x or y direction is (1-1200):1.

[0037] According to the present invention, the length ratio in the z direction to the x direction is (1nm-50μm):(1-100nm); preferably, the length ratio in the z direction to the x direction is (2-50μm):(5-100nm).

[0038] According to the present invention, the length ratio in the z direction and the y direction is (1nm-50μm):(1-100nm), preferably, the length ratio in the z direction and the y direction is (2-50μm):(5-100nm).

[0039] According to the present invention, the modified additive is in one or more of the following shapes: spherical, rod-shaped, cuboid, sheet-shaped, and tubular.

[0040] According to the present invention, the organic compound is selected from one or more of sorbitol benzylidene derivatives, aliphatic carboxylic acid metal compounds, and aromatic carboxylic acid metal compounds.

[0041] According to the present invention, the relative molecular weight of the organic compound is 5 × 10⁻⁶. 1 -2×10 3 Preferably, the value is 80-500, and more preferably 81.38-414.49.

[0042] According to the present invention, the inorganic material is selected from one or more of nano zinc oxide, carbon nanotubes, polyhedral oligomeric silsesquioxanes, and monolayer graphene.

[0043] A second aspect of the present invention provides a polyethylene modified material composition, wherein the polyethylene modified material composition contains polyethylene and a modifying agent, wherein the modifying agent is the aforementioned modifying agent.

[0044] According to the present invention, the content of the modifying agent is 0.1-5 wt%, preferably 0.1-2 wt%, and more preferably 0.1-0.6 wt%, based on the total weight of the composition.

[0045] According to the present invention, the weight-average molecular weight of the polyethylene is less than 100 × 10⁻⁶. 4 g / mol, of which the weight-average molecular weight is 6 × 10⁻⁶ g / mol. 3 The content of the polyethylene is ≤2.0wt%, preferably 0.1-1.5wt%, with a concentration of less than g / mol.

[0046] Furthermore, in this invention, if the weight-average molecular weight is 6 × 10⁻⁶... 3 For contents below g / mol but >2.0 wt%, separation can be achieved through methods such as heated elution fractionation, solvent Soxhlet extraction, high molecular weight polyethylene blending, gel permeation chromatography, size exclusion chromatography, or microbial enzymatic hydrolysis. This method can separate molecules with a weight-average molecular weight of 6 × 10⁻⁶. 3For components with a content of less than g / mol, the content is reduced from >2.0 wt% to ≤2.0 wt%. The preferred methods are solvent Soxhlet extraction elution and / or high molecular weight polyethylene blending.

[0047] In this invention, the solvent Soxhlet extraction elution method is specifically implemented as follows:

[0048] In a Soxhlet extractor, the weight-average molecular weight of 6 × 10⁻⁶ was adjusted using an organic solvent. 3 After eluting the polyethylene with a content of less than g / mol and greater than 2.0 wt% for 1-24 hours, it is dried in a vacuum oven at ≤60℃ and a vacuum degree of <-0.9 MPa for 12-48 hours to obtain a weight-average molecular weight of 6×10⁻⁶. 3 Polyethylene powder or granules with a content of less than 2.0 wt% and a g / mol content of less than 2.0 wt%.

[0049] In this invention, the solvent includes one or more of alkanes, benzene series, cyclic ether chloroalkanes, alkyl carboxylic acids, and aliphatic ketones. Preferably, the solvent is selected from one or more of n-hexane, benzene, toluene, xylene, dioxane, tetrahydrofuran, dichloromethane, trichloromethane, carbon tetrachloride, ethyl acetate, isopropyl acetate, and acetone. More preferably, the solvent is selected from one or more of n-hexane, xylene, tetrahydrofuran, dichloromethane, and acetone. All solvents used must be anhydrous. The solvent is one of the above preferred solvents, or a mixture of multiple miscible organic solvents selected above.

[0050] In this invention, the high molecular weight polyethylene blending method is specifically implemented as follows:

[0051] Density between 0.860-0.970 g / cm³ 3 High molecular weight polyethylene within the range, with a weight-average molecular weight of 20.0 × 10⁻⁶. 4 g / mol - 1000.0 × 10 4 Within the g / mol range, with a molecular weight distribution ranging from 2.00 to 20.00, and at a mass fraction of 1.0 to 90.0 wt%, it is compared with polyethylene (weight-average molecular weight of 6 × 10⁻⁶). 3 After mixing in a high-speed mixer, the contents of particles with a weight average molecular weight of less than g / mol and >2.0 wt% are melt-blended through a twin-screw extruder or a closed-loop mixer, and then pelletized or pulverized to obtain a product with a weight average molecular weight of 6 × 10⁻⁶. 3 Polyethylene powder or granules with a content ≤2.0wt% (g / mol or less). In this invention, it should be noted that the "high molecular weight polyethylene blending method" is a common and effective way to reduce the content of small molecules. It aims to introduce high molecular weight polyethylene without changing the small amount in the original polyethylene material, thereby diluting the proportion of small molecules in the original polyethylene material.

[0052] According to the present invention, the density of the polyethylene is 0.860 g / cm³. 3 -0.970g / cm 3 Preferably, the density of the polyethylene is 0.8619 g / cm³. 3 -0.9547g / cm 3 .

[0053] According to the present invention, the molecular weight distribution of the polyethylene is 1.1-200; preferably, the molecular weight distribution of the polyethylene is 3-10, more preferably 3.15-9.76.

[0054] A third aspect of the present invention provides a method for preparing a polyethylene modified material using the aforementioned polyethylene modified material composition, wherein the method comprises: processing polyethylene and a modifying agent to obtain a polyethylene modified material.

[0055] In this invention, the processing method includes one or more of extrusion, injection molding, casting, and blow molding.

[0056] In this invention, polyethylene powder is obtained by homopolymerization of ethylene monomers or copolymerization of ethylene monomers and α-olefins through polymerization reaction, and polyethylene granules are obtained by melt extrusion granulation of polyethylene powder.

[0057] According to the present invention, the complex viscosity of the modified polyethylene material is reduced by 5-60% at 628.0 rad / s and by 20-90% at 0.0628 rad / s.

[0058] According to the present invention, the orientation degree of the modified polyethylene material is increased by 4-25%.

[0059] According to the present invention, the impact resistance of the modified polyethylene material is improved by 3-300%.

[0060] In this invention, it should be noted that the difference between 628 and 0.0628 lies in their frequency, intended to highlight the difference in their effects on long and short polymer chains. Orientation degree can better reflect the arrangement of molecular chains during injection molding. Impact strength can provide feedback on the toughness of the plastic, and the toughening effect is expressed as the impact resistance improvement rate.

[0061] A fourth aspect of the present invention provides a modified polyethylene material prepared by the aforementioned method.

[0062] The fifth aspect of the present invention provides the application of the aforementioned modified polyethylene material in one or more of injection molded parts, pipes, films, fibers, sheets and profiles.

[0063] In this invention, it should be noted that the modified polyethylene material is used to produce polyethylene injection molding, pipes, films, fibers, sheets or profiles, but is not limited to the polyethylene products obtained in the above production application scenarios.

[0064] In this invention, the injection molding machine includes, but is not limited to, one or more of the following: vertical plunger injection molding machine, horizontal plunger injection molding machine, horizontal single-screw injection molding machine, horizontal twin-screw injection molding machine, angle plunger injection molding machine, angle single-screw injection molding machine, and angle twin-screw injection molding machine, preferably a vertical plunger injection molding machine or a horizontal single-screw injection molding machine.

[0065] The present invention will be described in detail below through embodiments.

[0066] In the following examples and comparative examples:

[0067] Evaluation methods for the effect of reducing melt viscosity:

[0068] 1. Modifying agents are blended with polyethylene powder or polyethylene granules to obtain modified polyethylene material. Circular parallel-plate stress-type rotational rheometer test specimens are then prepared using a flat-plate vulcanizing machine under specific temperature, pressure, and time conditions. The complex viscosity of the circular parallel-plate stress-type rotational rheometer test specimens is measured under varying temperature programs and different shear frequencies. Specifically, frequency scanning is performed from 628.0 rad / s to 0.0628 rad / s during a low-temperature-high-low temperature process, repeated 5-10 times, to obtain the complex viscosity of the modified polyethylene material.

[0069] 2. Evaluation methods for toughening effect:

[0070] (1) A polyethylene modified material test strip was obtained by mixing the modified additive with polyethylene powder or polyethylene granules through an injection molding machine at a certain extrusion temperature, a certain injection pressure, and a certain cooling temperature. The orientation degree of the polyethylene modified material was tested using wide-angle X-ray diffraction (WAXD). Specifically, orientation degree test strips were obtained by using an injection molding machine at an extrusion temperature of 190-230℃, an injection pressure of 5-100MPa, and a cooling temperature of -70℃ to 100℃. The orientation degree of the polyethylene modified material was tested. The intensity distribution of the diffraction peaks of the (110), (200), and (040) crystal planes was analyzed, and the orientation function F = [3(cos 2 θ)-1] / 2(cos 2 θ is the average value of the square of the cosine of the angle between the molecular chain and the injection direction, used to quantitatively characterize the degree of orientation.

[0071] (2) The modified additives are blended with polyethylene powder or polyethylene granules and then injected through an injection molding machine at a specific extrusion temperature, injection pressure, and cooling temperature to obtain polyethylene modified material test specimens. The impact strength of the polyethylene modified material is tested using a cantilever beam impact testing machine according to the national standard GB / T1843-2008 "Determination of Cantilever Beam Impact Strength of Plastics". Specifically, impact performance test specimens are obtained by using an injection molding machine at an extrusion temperature of 190-260℃, an injection pressure of 5-100MPa, and a cooling temperature of -70℃ to 100℃ to test the impact resistance of the polyethylene modified material.

[0072] Example 1

[0073] This embodiment illustrates the preparation of polyethylene modified materials using the polyethylene modified material composition of the present invention.

[0074] Polyethylene modified material composition:

[0075] Modifying agent: sorbitol benzylide derivative, wherein the sorbitol benzylide derivative is rod-shaped with a length of 100 nm in the x-direction, 100 nm in the y-direction, and 5 μm in the z-direction; the relative molecular weight is 386.44; and the melting point of the sorbitol benzylide derivative is 298.1 °C.

[0076] Polyethylene, wherein the density of the polyethylene is 0.9547 g / cm³. 3 Its weight-average molecular weight is 13.3 × 10⁻⁶. 4 g / mol, with a weight-average molecular weight of 6 × 10⁻⁶ g / mol. 3 The content of less than g / mol is 1.2wt%; the molecular weight distribution is 5.94.

[0077] Preparation of modified polyethylene materials:

[0078] Sorbitol benzyl derivative was added to polyethylene at a mass ratio of 0.2 wt%, and the mixture was blended in a molten state above the melting point of polyethylene to obtain modified polyethylene material No. 1 with reduced melt viscosity, which was used to manufacture polyethylene injection molded parts.

[0079] Evaluation method for reducing melt viscosity: Circular parallel plate stress-type rotational rheometer test samples were prepared using a flat vulcanizing machine at a melting temperature of 170℃, a molding pressure of 10MPa, and a molding time of 10min. Frequency scanning was performed 10 times from 628.0 rad / s to 0.0628 rad / s during a temperature variation process of 160℃-220℃-160℃ to obtain the complex viscosity of the blend. At the final temperature of 160℃ and 628.0 rad / s, the reduction in complex viscosity was 40%; at the final temperature of 160℃ and 0.0628 rad / s, the reduction in complex viscosity was 80%.

[0080] Evaluation method of toughening effect: The blend was injection molded at 190℃, 30MPa and 70℃ to obtain orientation test specimens. The orientation degree of the modified polyethylene material was tested using an X-ray diffractometer, and the orientation degree improvement rate reached 25%. Impact strength test specimens were obtained, and the impact resistance of the specimens was tested using a cantilever beam impact testing machine according to the national standard GB / T1843-2008 "Determination of Impact Strength of Plastic Cantilever Beams". The impact resistance improvement rate reached 204.1%.

[0081] Example 2

[0082] This embodiment illustrates the preparation of polyethylene modified materials using the polyethylene modified material composition of the present invention.

[0083] Polyethylene modified material composition:

[0084] Modifying agent: a fatty carboxylic acid metal compound, wherein the fatty carboxylic acid metal compound is in the shape of a cuboid with a side length of 20 nm in the x direction, a side length of 15 nm in the y direction, and a length of 2 μm in the z direction; the relative molecular weight is 414.49; and the melting point of the fatty carboxylic acid metal compound is 208.9 °C.

[0085] Polyethylene, wherein the density of the polyethylene is 0.9410 g / cm³. 3 Its weight-average molecular weight is 7.6 × 10⁻⁶. 4 g / mol, with a weight-average molecular weight of 6 × 10⁻⁶ g / mol. 3 The content of less than g / mol is 1.5wt%; the molecular weight distribution is 3.34.

[0086] Preparation of modified polyethylene materials:

[0087] A fatty carboxylic acid metal compound was added to polyethylene at a mass ratio of 0.5 wt%. The mixture was blended in a molten state above the melting point of polyethylene to obtain modified polyethylene material No. 2 with reduced melt viscosity, which was used to manufacture polyethylene pipes.

[0088] Evaluation method for reducing melt viscosity: Circular parallel plate stress-type rotational rheometer test samples were prepared using a flat vulcanizing machine at a melting temperature of 190℃, a molding pressure of 10MPa, and a molding time of 15min. Frequency scans were performed from 628.0 rad / s to 0.0628 rad / s during a temperature variation process of 150℃-210℃-150℃, for a total of 9 times, to obtain the complex viscosity of the blend. At the final temperature of 150℃ and 628.0 rad / s, the reduction in complex viscosity was 20%; at the final temperature of 150℃ and 0.0628 rad / s, the reduction in complex viscosity was 90%.

[0089] Evaluation method of toughening effect: The blend was injection molded at 170℃, 50MPa and 50℃ cooling temperature to obtain orientation test specimens. The orientation degree of the low melt viscosity modified polyethylene material was tested using an X-ray diffractometer, and the orientation degree improvement rate reached 10%. Impact strength test specimens were obtained, and the impact resistance of the specimens was tested using a cantilever beam impact testing machine according to the national standard GB / T1843-2008 "Determination of Cantilever Beam Impact Strength of Plastics". The impact resistance improvement rate reached 269.3%.

[0090] Example 3

[0091] This embodiment illustrates the preparation of polyethylene modified materials using the polyethylene modified material composition of the present invention.

[0092] Polyethylene modified material composition:

[0093] Modifying agent: Aromatic carboxylic acid metal compound, wherein the aromatic carboxylic acid metal compound is rod-shaped with a side length of 30 nm in the x-direction, a side length of 30 nm in the y-direction, and a length of 10 μm in the z-direction; the relative molecular weight is 146.11; and the melting point of the aromatic carboxylic acid metal compound is 231.1 °C.

[0094] Polyethylene, wherein the density of the polyethylene is 0.9492 g / cm³. 3 Its weight-average molecular weight is 5.9 × 10⁻⁶. 4 g / mol, with a weight-average molecular weight of 6 × 10⁻⁶ g / mol. 3 The content of less than g / mol is 0.2wt%; the molecular weight distribution is 3.15.

[0095] Preparation of modified polyethylene materials:

[0096] An aromatic carboxylic acid metal compound was added to polyethylene at a mass ratio of 1.0 wt%. The mixture was blended in a molten state above the melting point of polyethylene to obtain modified polyethylene material No. 3 with reduced melt viscosity, which was used to manufacture polyethylene film.

[0097] Evaluation method for reducing melt viscosity: Circular parallel plate stress-type rotational rheometer test samples were prepared using a flat vulcanizing machine at a melting temperature of 190℃, a molding pressure of 10MPa, and a molding time of 15min. Frequency scans were performed from 628.0 rad / s to 0.0628 rad / s during a temperature variation process of 150℃-240℃-150℃, for a total of 8 cycles, to obtain the complex viscosity of the blend. At the final temperature of 150℃ and 628.0 rad / s, the reduction in complex viscosity was 30%; at the final temperature of 150℃ and 0.0628 rad / s, the reduction in complex viscosity was 60%.

[0098] Evaluation method of toughening effect: The blend was injection molded at 170℃, 50MPa and 50℃ cooling temperature to obtain orientation test strips. The orientation degree of the low melt viscosity modified polyethylene material was tested using X-ray diffraction, and the orientation degree improvement rate reached 19%. Impact strength test strips were obtained, and the impact resistance of the strips was tested using a cantilever beam impact testing machine according to the national standard GB / T1843-2008 "Determination of Cantilever Beam Impact Strength of Plastics". The impact resistance improvement rate reached 539.6%.

[0099] Example 4

[0100] This embodiment illustrates the preparation of polyethylene modified materials using the polyethylene modified material composition of the present invention.

[0101] Polyethylene modified material composition:

[0102] Modifying agent: nano zinc oxide, wherein the nano zinc oxide is rod-shaped with a side length of 80 nm in the x-direction, a side length of 80 nm in the y-direction, and a length of 8 μm in the z-direction; the relative molecular weight is 81.38; and the melting point of the nano zinc oxide is 1099.7 °C.

[0103] Polyethylene, wherein the density of the polyethylene is 0.9530 g / cm³. 3 Its weight-average molecular weight is 12.7 × 10⁻⁶. 4 g / mol, with a weight-average molecular weight of 6 × 10⁻⁶ g / mol. 3 The content below g / mol was 3.0 wt%; the molecular weight distribution was 9.76. The polyethylene used in Example 4 had a weight-average molecular weight of 6 × 10⁻⁶. 3 For products with a content of less than g / mol and >2.0wt%, xylene is used as the solvent for elution and fractionation by heating to obtain products with a weight-average molecular weight of 6×10⁻⁶. 3 For components with a content of less than g / mol, the content was reduced from 3.0 wt% to 0.7 wt%.

[0104] Preparation of modified polyethylene materials:

[0105] Nano zinc oxide was added to polyethylene at a mass ratio of 2.0 wt% and blended in a molten state above the melting point of polyethylene to obtain modified polyethylene material No. 4 with reduced melt viscosity, which was used to manufacture polyethylene injection molded parts.

[0106] Evaluation method for reducing melt viscosity: Circular parallel plate stress-type rotational rheometer test samples were prepared using a flat vulcanizing machine at a melting temperature of 180℃, a molding pressure of 15MPa, and a molding time of 20min. Frequency scanning was performed five times during a temperature variation process from 160℃-230℃-160℃, ranging from 628.0 rad / s to 0.0628 rad / s, to obtain the complex viscosity of the blend. At the final temperature of 160℃ and 628.0 rad / s, the reduction in complex viscosity was 20%; at the final temperature of 160℃ and 0.0628 rad / s, the reduction in complex viscosity was 75%.

[0107] Evaluation method of toughening effect: The blend was injection molded at 170℃, 50MPa and 50℃ cooling temperature to obtain orientation test specimens. The orientation degree of the low melt viscosity modified polyethylene material was tested using an X-ray diffractometer, and the orientation degree improvement rate reached 24%. Impact strength test specimens were obtained, and the impact resistance of the specimens was tested using a cantilever beam impact testing machine according to the national standard GB / T1843-2008 "Determination of Cantilever Beam Impact Strength of Plastics". The impact resistance improvement rate reached 62.8%.

[0108] Example 5

[0109] This embodiment illustrates the preparation of polyethylene modified materials using the polyethylene modified material composition of the present invention.

[0110] Polyethylene modified material composition:

[0111] Modifying agent: carbon nanotubes, wherein the nano zinc oxide is tubular in shape, with a diameter of 50 nm in the x-direction, a diameter of 50 nm in the y-direction, and a length of 50 μm in the z-direction; the relative molecular weight is 81.38; the melting point of the carbon nanotubes is 3550.0℃.

[0112] Polyethylene, wherein the density of the polyethylene is 0.8749 g / cm³. 3 Its weight-average molecular weight is 91.4 × 10⁻⁶. 4 g / mol, weight-average molecular weight is 6×10 3 The content below g / mol was 6.1 wt%; the molecular weight distribution was 9.17. The polyethylene used in Example 5 had a weight-average molecular weight of 6 × 10⁻⁶. 3 Content of less than g / mol > 2.0 wt%, with a weight-average molecular weight of 400.0 × 10⁻⁶. 4 g / mol was blended with polyethylene at a ratio of 20.0 wt%, with a weight-average molecular weight of 6 × 10⁻⁶. 3 For components with a content of less than g / mol, the content was reduced from 6.1 wt% to 0.2 wt%.

[0113] Preparation of modified polyethylene materials:

[0114] Carbon nanotubes were added to polyethylene at a mass ratio of 1.0 wt% and blended in a molten state above the melting point of polyethylene to obtain modified polyethylene material No. 5 with reduced melt viscosity, which was used to manufacture polyethylene pipes.

[0115] Evaluation method for reducing melt viscosity: Circular parallel plate stress-type rotational rheometer test samples were prepared using a flat vulcanizing machine at a melting temperature of 200℃, a molding pressure of 10MPa, and a molding time of 30min. Frequency scanning was performed five times during a temperature variation process from 190℃-250℃-190℃, ranging from 628.0 rad / s to 0.0628 rad / s, to obtain the complex viscosity of the blend. At the final temperature of 190℃ and 628.0 rad / s, the reduction in complex viscosity was 5%; at the final temperature of 190℃ and 0.0628 rad / s, the reduction in complex viscosity was 20%.

[0116] Evaluation method of toughening effect: The blend was subjected to injection molding at 230℃, 100MPa and -70℃ to obtain orientation test specimens. The orientation degree of the low melt viscosity modified polyethylene was tested using X-ray diffraction, and the orientation degree improvement rate reached 4%. Impact strength test specimens were obtained, and the impact resistance of the specimens was tested using a cantilever beam impact testing machine according to the national standard GB / T1843-2008 "Determination of Cantilever Beam Impact Strength of Plastics". The impact resistance improvement rate reached 3.0%.

[0117] Example 6

[0118] This embodiment illustrates the preparation of polyethylene modified materials using the polyethylene modified material composition of the present invention.

[0119] Polyethylene modified material composition:

[0120] Modifying agent: monolayer graphene, wherein the monolayer graphene is sheet-like, with a side length of 5nm in the x-direction, a diameter of 5nm in the y-direction, and a length of 5μm in the z-direction; the relative molecular weight is 12.01; and the melting point of the monolayer graphene is 3652℃.

[0121] Polyethylene, wherein the density of the polyethylene is 0.8619 g / cm³. 3 Its weight-average molecular weight is 2.0 × 10⁻⁶. 4 g / mol, weight-average molecular weight is 6×10 3 The content below g / mol was 20.7 wt%, and the molecular weight distribution was 6.74. The polyethylene used in Example 6 had a weight-average molecular weight of 6 × 10⁻⁶. 3For content greater than 2.0 wt% and below g / mol, microbial enzymatic hydrolysis is used to remove substances with a weight-average molecular weight of 6 × 10⁻⁶ g / mol or less. 3 For components with a content of less than g / mol, the content was reduced from 20.7 wt% to 0.1 wt%.

[0122] Preparation of modified polyethylene materials:

[0123] Monolayer graphene was added to polyethylene at a mass ratio of 2.0 wt% and blended in a molten state above the melting point of polyethylene to obtain modified polyethylene material No. 6 with reduced melt viscosity, which was used to manufacture polyethylene film.

[0124] Evaluation method for reducing melt viscosity: Circular parallel plate stress-type rotational rheometer test samples were prepared using a flat vulcanizing machine at a melting temperature of 170℃, a molding pressure of 5MPa, and a molding time of 10min. Frequency scanning was performed five times during a temperature variation process from 170℃ to 250℃ and back to 170℃, ranging from 628.0 rad / s to 0.0628 rad / s, to obtain the complex viscosity of the blend. At the final temperature of 170℃ and 628.0 rad / s, the reduction in complex viscosity was 60%; at the final temperature of 170℃ and 0.0628 rad / s, the reduction in complex viscosity was 90%.

[0125] Evaluation method of toughening effect: The blend was injection molded at 190℃, 5MPa and -10℃ to obtain orientation test specimens. The orientation degree of the low melt viscosity modified polyethylene was tested using an X-ray diffractometer, and the orientation degree improvement rate reached 20%. Impact strength test specimens were obtained, and the impact resistance of the specimens was tested using a cantilever beam impact testing machine according to the national standard GB / T1843-2008 "Determination of Cantilever Beam Impact Strength of Plastics". The impact resistance improvement rate reached 300.4%.

[0126] Example 7

[0127] This embodiment illustrates the preparation of polyethylene modified materials using the polyethylene modified material composition of the present invention.

[0128] Polyethylene modified material composition:

[0129] Modifying agent: sorbitol benzylide derivative, wherein the sorbitol benzylide derivative is tubular in shape, with a diameter of 50 nm in the x-direction, a diameter of 50 nm in the y-direction, and a length of 50 μm in the z-direction; the relative molecular weight is 81.38; and the melting point of the sorbitol benzylide derivative is 1975.2 °C.

[0130] Polyethylene, wherein the density of the polyethylene is 0.9519 g / cm³. 3 Its weight-average molecular weight is 26.4 × 10⁻⁶.4 g / mol, weight-average molecular weight is 6×10 3 The content below g / mol is 0.4wt%, and the molecular weight distribution is 4.17.

[0131] Preparation of modified polyethylene materials:

[0132] Carbon nanotubes were added to polyethylene at a mass ratio of 0.1 wt% and blended in a molten state above the melting point of polyethylene to obtain modified polyethylene material No. 7 with reduced melt viscosity, which was used to manufacture polyethylene sheets.

[0133] Evaluation method for reducing melt viscosity: Circular parallel plate stress-type rotational rheometer test samples were prepared using a flat vulcanizing machine at a melting temperature of 200℃, a molding pressure of 10MPa, and a molding time of 30min. Frequency scanning was performed five times during a temperature variation process from 190℃-250℃-190℃, ranging from 628.0 rad / s to 0.0628 rad / s, to obtain the complex viscosity of the blend. At the final temperature of 190℃ and 628.0 rad / s, the reduction in complex viscosity was 10%; at the final temperature of 190℃ and 0.0628 rad / s, the reduction in complex viscosity was 60%.

[0134] Evaluation method of toughening effect: The blend was subjected to injection molding at 230℃, 100MPa and -70℃ to obtain orientation test specimens. The orientation degree of the low melt viscosity modified polyethylene was tested using X-ray diffraction, and the orientation degree improvement rate reached 6%. Impact strength test specimens were obtained, and the impact resistance of the specimens was tested using a cantilever beam impact testing machine according to the national standard GB / T1843-2008 "Determination of Cantilever Beam Impact Strength of Plastics". The impact resistance improvement rate reached 21.6%.

[0135] Example 8

[0136] This embodiment illustrates the preparation of polyethylene modified materials using the polyethylene modified material composition of the present invention.

[0137] Polyethylene modified material composition:

[0138] Modifying agent: sorbitol benzylide derivative, wherein the sorbitol benzylide derivative is tubular in shape, with a diameter of 50 nm in the x-direction, a diameter of 50 nm in the y-direction, and a length of 50 μm in the z-direction; the relative molecular weight is 81.38; and the melting point of the sorbitol benzylide derivative is 1975.2 °C.

[0139] Polyethylene, wherein the density of the polyethylene is 0.9319 g / cm³. 3 Its weight-average molecular weight is 39.4 × 10⁻⁶. 4g / mol, weight-average molecular weight is 6×10 3 The content of less than g / mol is 0.1wt%, and the molecular weight distribution is 3.72.

[0140] Preparation of modified polyethylene materials:

[0141] Polyhedral oligomeric silsesquioxanes were added to ethylene-homogene at a mass ratio of 0.5 wt% and blended in a molten state above the melting point of polyethylene to obtain modified polyethylene material No. 8 with reduced melt viscosity, which was used to manufacture polyethylene injection molding materials.

[0142] Evaluation method for reducing melt viscosity: Circular parallel plate stress-type rotational rheometer test samples were prepared using a flat vulcanizing machine at a melting temperature of 200℃, a molding pressure of 10MPa, and a molding time of 30min. Frequency scanning was performed five times during a temperature variation process from 190℃-250℃-190℃, ranging from 628.0 rad / s to 0.0628 rad / s, to obtain the complex viscosity of the blend. At the final temperature of 190℃ and 628.0 rad / s, the reduction in complex viscosity was 10%; at the final temperature of 190℃ and 0.0628 rad / s, the reduction in complex viscosity was 20%.

[0143] Evaluation method of toughening effect: The blend was subjected to injection molding at 230℃, 100MPa and -70℃ to obtain orientation test specimens. The orientation degree of the low melt viscosity modified polyethylene was tested using X-ray diffraction, and the orientation degree improvement rate reached 3%. Impact strength test specimens were obtained, and the impact resistance of the specimens was tested using a cantilever beam impact testing machine according to the national standard GB / T1843-2008 "Determination of Cantilever Beam Impact Strength of Plastics". The impact resistance improvement rate reached 9.2%.

[0144] Comparative Example 1

[0145] Polyethylene modified material composition:

[0146] Modifying agent: sorbitol benzylide derivative, wherein the sorbitol benzylide derivative is rod-shaped with a length of 0.5 nm in the x-direction, 0.5 nm in the y-direction, and 500 μm in the z-direction; the relative molecular weight is 358.39; and the melting point of the sorbitol benzylide derivative is 97.2 °C.

[0147] Polyethylene, wherein the density of the polyethylene is 0.9547 g / cm³. 3 Its weight-average molecular weight is 13.3 × 10⁻⁶. 4 g / mol, weight-average molecular weight is 6×10 3 The content of less than g / mol is 1.2wt%, and the molecular weight distribution is 5.94.

[0148] Preparation of modified polyethylene materials:

[0149] Sorbitol benzyl derivative was added to polyethylene at a mass ratio of 2.0 wt% and blended in a molten state above the melting point of polyethylene to obtain modified polyethylene comparative material No. 1, which was used to manufacture polyethylene injection molded parts.

[0150] Evaluation method for reducing melt viscosity: Circular parallel plate stress-type rotational rheometer test samples were prepared using a flat vulcanizing machine at a melting temperature of 170℃, a molding pressure of 10MPa, and a molding time of 10min. Frequency scanning was performed 10 times from 628.0 rad / s to 0.0628 rad / s during a temperature variation process of 160℃-220℃-160℃ to obtain the complex viscosity of the blend. At the final temperature of 160℃ and 628.0 rad / s, the reduction effect on complex viscosity decreased by 5%; at the final temperature of 160℃ and 0.0628 rad / s, the complex viscosity increased by 20%.

[0151] Evaluation method for the enhancement effect: The blend was injection molded at 190℃, 30MPa and 70℃ to obtain orientation test specimens. The orientation degree of the low melt viscosity modified polyethylene was tested using an X-ray diffractometer, and the orientation degree enhancement rate was 1%. Impact strength test specimens were obtained, and the impact resistance of the specimens was tested using a cantilever beam impact testing machine according to the national standard GB / T1843-2008 "Determination of Cantilever Beam Impact Strength of Plastics". The impact resistance decreased by 31.0%.

[0152] Comparative Example 2

[0153] Polyethylene modified material composition:

[0154] Modifying agent: monolayer graphene, wherein the monolayer graphene is in sheet shape, with a side length of 250 μm in the x direction, a diameter of 250 μm in the y direction, and a length of 250 μm in the z direction; the relative molecular weight is 12.01; and the melting point of the monolayer graphene is 3652.0℃.

[0155] Polyethylene, wherein the density of the polyethylene is 0.8619 g / cm³. 3 Its weight-average molecular weight is 2.0 × 10⁻⁶. 4 g / mol, molecular weight distribution is 6.74, weight-average molecular weight is 6×10 3 The content below g / mol was 20.7 wt%.

[0156] Preparation of modified polyethylene materials:

[0157] Monolayer graphene was added to polyethylene at a mass ratio of 2.0 wt% and blended in a molten state above the melting point of polyethylene to obtain modified polyethylene reference material No. 2, which was used to manufacture polyethylene film.

[0158] Evaluation method for reducing melt viscosity: Circular parallel plate stress-type rotational rheometer test samples were prepared using a flat vulcanizing machine at a melting temperature of 170℃, a molding pressure of 5MPa, and a molding time of 10min. Frequency scans were performed five times during a temperature variation process from 170℃ to 250℃ and back to 170℃, ranging from 628.0 rad / s to 0.0628 rad / s, to obtain the complex viscosity of the blend. At the final temperature of 170℃ and 628.0 rad / s, the reduction effect on complex viscosity increased by 50%; at the final temperature of 170℃ and 0.0628 rad / s, the reduction effect on complex viscosity increased by 10%.

[0159] Evaluation method for the enhancement effect: The blend was subjected to injection molding at 190℃, 5MPa, and -10℃ cooling temperatures to obtain orientation test specimens. The orientation degree of the low melt viscosity modified polyethylene material was tested using an X-ray diffractometer, and the orientation degree decreased by 4.6%. Impact strength test specimens were obtained, and the impact resistance of the specimens was tested using a cantilever beam impact testing machine according to the national standard GB / T1843-2008 "Determination of Cantilever Beam Impact Strength of Plastics". The impact resistance decreased by 20.1%.

[0160] In addition, Figure 1 is a schematic diagram showing the effect of the modified additives prepared in Examples 1-8 and Comparative Examples 1-2 on the reduction of complex viscosity of polyethylene at 628.0 rad / s and 0.0628 rad / s; Figure 2 is a schematic diagram showing the effect of the modified additives prepared in Examples 1-8 and Comparative Examples 1-2 on the orientation degree and impact resistance of polyethylene. As can be seen from Figures 1 and 2, Examples 1-8 of the present invention use a composition obtained by compounding organic and inorganic substances as a modified additive. This modified additive has the function of reducing viscosity and increasing toughness. Furthermore, organic and inorganic substances above the processing temperature are combined with polyethylene granules or polyethylene powder through a processing technology to obtain modified polyethylene material. The organic or inorganic substances act as heterogeneous nucleating agents, inducing rapid crystallization of polyethylene molecular chains and improving the crystallinity of polyethylene molecular chains in the aggregated structure. This results in a decrease in the viscosity of the modified polyethylene material, an increase in orientation degree, and a simultaneous increase in lateral impact resistance. Specifically, in Examples 1-8, at the temperature endpoint of 170°C and 628.0 rad / s, the complex viscosity can be reduced by 5-40%; at the temperature endpoint of 170°C and 0.0628 rad / s, the complex viscosity can be reduced by 20-90%. Impact performance evaluation specimens are obtained through injection molding to evaluate orientation degree and impact strength. The orientation degree improvement rate can reach 3-25%, and the impact resistance improvement rate can reach 3-539.6%.

[0161] 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 inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A modifying aid, characterized by The modifying agent is an organic compound and / or an inorganic substance, and the length of the modifying agent in the x, y, and z directions of three-dimensional space is the same or different, and the length of each does not exceed 200 μm; the melting point of the modifying agent is ≥139.0℃; The organic compound is selected from one or more of the following: sorbitol benzylidene derivatives, aliphatic carboxylic acid metal compounds, aromatic carboxylic acid metal compounds, organophosphates, lignin acids and their derivatives; The inorganic material is selected from one or more of metals, non-metal solid oxides, and non-metallic elements.

2. The modifying aid of claim 1, wherein, The modified additive may be in any one of the following shapes: spherical, rod-shaped, cuboid, flake-shaped, or tubular.

3. The modifying aid according to claim 1 or 2, wherein, The length of the modified additive in the x, y, and z directions of three-dimensional space does not exceed 100 μm, and preferably does not exceed 80 μm. More preferably, when the modified additive is spherical, its length in the x, y, and z directions in three-dimensional space is 1-20 nm. More preferably, when the shape of the modified additive is any one of rod, cuboid, sheet, and tubular, its length in the x, y, and z directions in three-dimensional space is 1 nm-50 μm.

4. The modifying aid according to any one of claims 1 to 3, wherein The length ratio in the x-direction to the y-direction is (1-5):1, preferably (1-2):1, and more preferably (1-1.5):1; Preferably, the length ratio in the z-direction to the x or y-direction is (1-1200):1; Preferably, the length ratio in the z-direction to the x-direction is (1nm-50μm):(1-100nm); Preferably, the length ratio in the z-direction to the y-direction is (1nm-50μm):(1-100nm).

5. The modified adjuvant of any one of claims 1-4, wherein, The organic compound is selected from one or more of sorbitol benzylidene derivatives, aliphatic carboxylic acid metal compounds, and aromatic carboxylic acid metal compounds; And / or, the relative molecular weight of the organic compound is 5 × 10⁻⁶. 1 -2×10 3 ; And / or, the inorganic material is selected from one or more of nano zinc oxide, carbon nanotubes, polyhedral oligomeric silsesquioxanes, and monolayer graphene.

6. A polyethylene modified compound composition, characterized by, The polyethylene modified material composition contains polyethylene and a modifying agent, wherein the modifying agent is the modifying agent according to any one of claims 1-5.

7. The composition of claim 6, wherein, Based on the total weight of the composition, the content of the modifying agent is 0.1-5 wt%, preferably 0.1-2 wt%, more preferably 0.1-0.6 wt%; And / or, based on the total content of the polyethylene, the weight-average molecular weight is 6 × 10⁻⁶. 3 The content of polyethylene at g / mol or less is ≤2wt%, preferably 0.1-1.5wt%; and / or the polyethylene has a density of 0.86 g / cm3 3 -0.97 g / cm3 3 ; And / or, the molecular weight distribution of the polyethylene is in the range of 1.1-200.

8. The composition according to claim 6 or 7, wherein, The polyethylene has a weight average molecular weight of less than 100 x 10 4 g / mol; Preferably, the content of said polyethylene having a weight average molecular weight below 6 x 10 3 g / mol is < 2.0 wt%, preferably 0.1 - 1.5 wt%.

9. The composition according to claim 7 or 8, wherein, The content of components having a weight average molecular weight below 6 x 10 3 g / mol is reduced from > 2.0 wt% to < 2.0 wt% by one or more of a temperature rising elution fractionation method, a solvent soxhlet extraction elution method, a high molecular weight polyethylene blending method, a gel permeation chromatography column chromatography separation method, a size exclusion chromatography elution separation method, and a microbial enzymatic hydrolysis method.

10. A method for producing a polyethylene modified material using the polyethylene modified material composition according to any one of claims 6 to 9, characterized by, The method includes: processing polyethylene and modifying agents to prepare a modified polyethylene material.

11. The method of claim 10, wherein, The modified polyethylene material exhibits a 5-60% reduction in complex viscosity at 628.0 rad / s and a 20-90% reduction in complex viscosity at 0.0628 rad / s. And / or, the orientation degree of the modified polyethylene material is increased by 4-25%; And / or, the impact resistance of the modified polyethylene material is improved by 3-300%.

12. A modified polyethylene material prepared by the method of claim 10 or 11.

13. The use of the polyethylene modified material of claim 12 in one or more of injection molded parts, pipes, films, fibers, sheets and profiles.

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