Environment-friendly pearl wool composite material of polyethylene polymer and preparation method of environment-friendly pearl wool composite material

Abstract

The invention relates to the technical field of pearl wool composite materials, in particular to a polyethylene polymer environment-friendly pearl wool composite material and a preparation method thereof.The polyethylene polymer environment-friendly pearl wool composite material comprises, by weight, 40-70 parts of polyethylene polymer, and HDPE, MDPE and LLDPE are mixed according to a specific proportion; carrying out plasma treatment on 20-50 parts of pearl wool particles to introduce polar groups; the environment-friendly plasticizer is formed by compounding TBC and ATBC; 5-15 parts of degummed natural plant fibers for enhancing the binding force; 1-5 parts of nano titanium dioxide can be used for photocatalytically degrading pollutants; the 0.5-3 parts of antistatic agent is compounded by GMS and EAA, so that static accumulation is reduced; all the components have a synergistic effect, so that the material has various excellent properties. The composite material disclosed by the invention is good in environmental protection property, and air can be purified by using the environment-friendly plasticizer, the natural fibers and the nano titanium dioxide; the performance is excellent, and the buffering performance, the antistatic performance, the heat preservation performance and the flame-retardant performance are good. The preparation process is stable and efficient, can meet the requirements of multiple fields such as packaging, building and automotive trim, and has a wide prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of EPE composite materials, and specifically to an environmentally friendly EPE composite material of polyethylene polymer and a preparation method thereof. Background Art

[0002] With the continuous enhancement of global environmental awareness and the deepening of the concept of sustainable development, the demand for environmentally friendly materials in various industries has become increasingly urgent. In the field of materials science, the research and development of composite materials with environmental protection characteristics and excellent performance has become a research hotspot.

[0003] Traditional polyethylene materials are widely used in many fields such as packaging, construction, and automobiles, but they have some obvious deficiencies. In the packaging industry, the buffering performance of ordinary polyethylene packaging materials is limited, and it is difficult to provide sufficient protection for precision and fragile items during transportation. Moreover, polyethylene materials are prone to generating static electricity, and the static electricity attracting dust not only affects the appearance of the packaging, but may also cause damage to sensitive items such as electronic products. In addition, traditional polyethylene materials are difficult to degrade, and a large amount of waste packaging materials have caused serious pollution to the environment.

[0004] In the construction field, existing thermal insulation materials either have poor thermal insulation performance and cannot effectively reduce building energy consumption, or have poor fire resistance, posing a hidden danger to building fire safety. Some thermal insulation materials also contain harmful substances and will release harmful gases during use, endangering human health.

[0005] In terms of automotive interior materials, traditional materials may emit harmful gases such as formaldehyde and benzene, affecting the air quality inside the vehicle and endangering the health of passengers and drivers. At the same time, some materials lack comfort and aesthetics and cannot meet the needs of consumers for high-quality automotive interiors.

[0006] As a common buffering material, EPE has advantages such as light weight and good elasticity, but it has low strength, poor weather resistance, and a single function when used alone, and cannot meet the application requirements in complex environments. In order to improve the performance of EPE, people have tried to compound it with other materials, but existing composite materials often have problems in terms of environmental protection, performance stability, and cost.

[0007] Some composite materials use a large amount of organic solvents and toxic additives in the preparation process, which not only increases the production cost, but also causes harm to the environment and human health. Moreover, existing composite processes may not be able to fully blend the components, resulting in unstable material performance and unable to achieve the expected use effect.

[0008] Therefore, it is of great practical significance and broad market prospects to develop an environmentally friendly polyethylene polymer EPE composite material with good cushioning performance, antistatic performance, heat preservation performance, flame retardant performance and environmental protection performance, etc., and to develop an efficient and environmentally friendly preparation method. This patent is precisely aimed at the above problems and is committed to providing a brand-new solution to meet the needs of various industries for high-performance environmentally friendly materials. Summary of the Invention

[0009] (1) Technical problems to be solved

[0010] In view of the deficiencies of the prior art, the present invention provides an environmentally friendly EPE composite material of polyethylene polymer and a preparation method thereof.

[0011] (2) Technical solutions

[0012] An environmentally friendly EPE composite material of polyethylene polymer, calculated by weight, comprises the following components:

[0013] 40-70 parts of polyethylene polymer, and the polyethylene polymer is a mixture composed of high-density polyethylene (HDPE), medium-density polyethylene (MDPE) and linear low-density polyethylene (LLDPE) according to the mass ratio of (2-3):(1-2):(1-2);

[0014] The density of high-density polyethylene is 0.941-0.965 g / cm 3 , with a relatively high crystallinity, the molecular chains are arranged tightly, and it has relatively high rigidity and strength; the density of medium-density polyethylene is 0.926-0.940 g / cm 3 , having both certain flexibility and rigidity; the melt flow rate of linear low-density polyethylene is 1-5 g / 10 min (190 °C, 2.16 kg), and the short branches on the molecular chains are evenly distributed, endowing the material with good processing performance. During the high-temperature melting process of composite material preparation, there will be a certain degree of entanglement and interaction between these three polyethylene molecular chains, which can be simply expressed as:

[0015] HDPE + MDPE + LLDPE → HDPE-MDPE-LLDPE (entangled structure). This entangled structure enhances the cohesion of the material and improves the comprehensive mechanical properties of the material;

[0016] 20-50 parts of EPE particles, the particle size of the EPE particles is 0.3-2.5 mm, and they are treated by plasma surface treatment. After treatment, carboxyl and hydroxyl groups are introduced on the surface; during the plasma treatment process, high-energy particles in the air plasma impact the surface of the EPE, causing the molecular chains to break and react with oxygen in the air to introduce polar groups. The reaction process can be approximately expressed as:

[0017]

[0018] These polar groups can form strong interactions with other components, thereby improving the compatibility between the EPE and other components;

[0019] 3 - 8 parts of environment-friendly plasticizer, and the environment-friendly plasticizer is a compound of tributyl citrate (TBC) and acetyl tributyl citrate (ATBC) according to a mass ratio of (1 - 2):(1 - 2). Tributyl citrate and acetyl tributyl citrate have good biodegradability and low toxicity. The plasticizer molecules can insert between the molecular chains of the polyethylene polymer, weaken the van der Waals force and hydrogen bond interaction between the molecular chains, and increase the fluidity of the molecular chains. Its principle of action can be expressed as:

[0020] PE - molecular chain + TBC / ATBC → PE - molecular chain - TBC / ATBC

[0021] This effect significantly improves the flexibility and plasticity of the material;

[0022] 5 - 15 parts of natural plant fiber, and the natural plant fiber is one or more of ramie fiber, flax fiber or bamboo fiber that has been degummed. The fiber length is 5 - 20 mm. Pectin and lignin are contained in the natural plant fiber, which will affect the bonding between the fiber and the polymer matrix. During the degumming process, pectin and other impurities in the natural plant fiber undergo hydrolysis reactions under the action of sodium hydroxide. The reaction formula is:

[0023] R - COO - R'+NaOH → R - COONa + R'-OH

[0024] The surface of the degummed fiber is cleaner, increasing the contact area with the polymer matrix and improving the bonding force between the fiber and the polymer matrix;

[0025] 1 - 5 parts of nano - titanium dioxide, and the particle size of the nano - titanium dioxide is 10 - 50 nm, which has the performance of photocatalytic degradation of organic pollutants. The nano - titanium dioxide has a large specific surface area and a highly active surface. Under light illumination conditions, the nano - titanium dioxide will generate electron - hole pairs. The holes react with water to generate hydroxyl radicals, and the electrons react with oxygen to generate superoxide anion radicals. The reaction formulas are as follows:

[0026]

[0027] h + +H2O → ·OH + H +

[0028]

[0029] These free radicals have strong oxidation ability and can degrade organic pollutants on the material surface and in the surrounding environment, playing a role in purifying air and self-cleaning;

[0030] 0.5 - 3 parts of antistatic agent, and the antistatic agent is a compound of glycerol monostearate (GMS) and ethoxylated alkylamine (EAA) in a mass ratio of (1 - 2):(1 - 2); Glycerol monostearate and ethoxylated alkylamine have good surface activity and can form a conductive layer on the material surface. The hydrophilic groups of the antistatic agent molecules face the air, and the lipophilic groups face the interior of the material. The surface conductive layer can timely conduct the charges generated on the material surface, thereby reducing the static charge accumulation on the material surface.

[0031] Preferably, the plasma surface treatment conditions of the EPE particles are as follows: using air plasma, the treatment power is 50 - 150 W, the treatment time is 3 - 10 min, and the treatment pressure is 10 - 50 Pa. Under these conditions, the high-energy particles in the plasma have appropriate energy and density, can effectively introduce an appropriate amount of polar groups on the surface of the EPE particles, and at the same time avoid the destruction of the EPE particle structure caused by over-treatment. If the treatment power is too low, the plasma energy is insufficient, and the number of introduced polar groups is small; if the treatment power is too high, the surface of the EPE particles may be carbonized. If the treatment time is too short, the introduction of polar groups is insufficient; if the treatment time is too long, the production cost will increase and the EPE particles may be damaged. The treatment pressure affects the generation and distribution of the plasma, and the appropriate pressure range can ensure that the plasma acts uniformly on the surface of the EPE particles.

[0032] Preferably, the degumming treatment method of the natural plant fiber is as follows: placing the natural plant fiber in a sodium hydroxide solution with a mass fraction of 2% - 5%, treating at 80 - 100 °C for 1 - 3 h, then rinsing with water until neutral, then neutralizing with an acetic acid solution with a mass fraction of 1% - 3%, and finally washing with water and drying. The concentration of the sodium hydroxide solution, treatment temperature, and time will affect the degumming effect; if the concentration is too low or the temperature and time are insufficient, the degumming is incomplete, and there are still many impurities remaining on the fiber surface; if the concentration is too high or the temperature and time are too long, the internal structure of the fiber may be damaged, reducing the strength of the fiber; neutralizing with the acetic acid solution is to remove the residual sodium hydroxide on the fiber surface to avoid adverse effects on the performance of the subsequent composite material.

[0033] Preferably, the preparation method of the environmentally friendly EPE composite material of polyethylene polymer includes the following steps:

[0034] S1. Add the EPE particles treated by plasma surface treatment and nano-titanium dioxide into a high-speed mixer, and mix them at a rotation speed of 800 - 1200 r / min for 10 - 20 min to make the nano-titanium dioxide evenly adhere to the surface of the EPE particles. The stirring paddle of the high-speed mixer adopts a special spiral design, which can generate strong shear force and convection effect to ensure the uniform dispersion of nano-titanium dioxide on the surface of the EPE particles. During this process, there may be certain physical adsorption or weak chemical interaction between the nano-titanium dioxide and the polar groups on the surface of the EPE particles, which can be expressed as:

[0035] EPE - polar group + TiO2 → EPE - polar group - TiO2

[0036] This binding method is beneficial to improving the dispersion stability and photocatalytic performance of nano-titanium dioxide in the composite material;

[0037] S2. Add the polyethylene polymer, environmentally friendly plasticizer, degummed natural plant fiber and antistatic agent into the main feeding port of the twin-screw extruder, heat it to 160 - 180 °C to make it melt, and the screw rotation speed is 200 - 300 r / min. The screws of the twin-screw extruder adopt a co-rotating meshing design, which has good conveying, mixing and plasticizing capabilities. During the melting process, the molecules of each component further diffuse and mix with each other, and the environmentally friendly plasticizer gradually penetrates between the molecular chains of the polyethylene polymer, reducing the intermolecular interaction force. The antistatic agent begins to migrate to the material surface. The natural plant fiber is evenly dispersed in the polymer matrix under the shearing action of the screw.

[0038] S3. Add the mixture obtained in step one into the twin-screw extruder through the side feeding port, and co-extrude it with the materials in step two at 170 - 190 °C. The extrudate is cooled by water and pelletized to obtain an environmentally friendly EPE composite material of polyethylene polymer. The position and feeding speed of the side feeding port are optimized to ensure that the EPE particle - nano-titanium dioxide mixture is evenly mixed with other materials. During the co-extrusion process, the interaction between each component is further enhanced to form a stable composite material structure. The water cooling process uses a circulating water cooling system, and the water temperature is controlled at 15 - 25 °C, which can quickly cool the extrudate to prevent material deformation and internal structure change. The blades of the pelletizer adopt sharp blades with high-speed rotation, and the pelletizing size is uniform, and the particle size is controlled at 2 - 5 mm.

[0039] Preferably, the inner wall of the high-speed mixer is treated with a polytetrafluoroethylene coating. Polytetrafluoroethylene has extremely low surface energy and good chemical stability to prevent the material from sticking to the wall, ensure the smooth progress of the mixing process, and at the same time facilitate the cleaning of the equipment and improve production efficiency.

[0040] Preferably, the length-diameter ratio of the twin-screw extruder is (35 - 45):1, and from the feeding section to the die head direction, the temperatures of each heating zone are 160 - 165°C, 165 - 175°C, 175 - 185°C, 185 - 190°C in sequence; an appropriate length-diameter ratio can provide sufficient mixing and reaction time to fully melt and disperse each component; the temperature settings of different heating zones are optimized according to the physical and chemical properties of the material and the needs of the processing process; the temperature of the feeding section is relatively low, which is beneficial to the stable transportation of the material; as the material moves towards the die head direction, the temperature gradually increases to ensure that the material is fully melted and plasticized; the temperature of the die head is relatively high to ensure that the extrudate has good fluidity and forming properties.

[0041] Preferably, the composite material is used for preparing packaging materials, building thermal insulation materials or automotive interior materials.

[0042] Preferably, when used for preparing packaging materials, the packaging products made of the composite material have good cushioning performance, antistatic performance and environmental protection performance, can effectively protect the packaged items, reduce the damage of static electricity to sensitive items such as electronic products, and are biodegradable at the same time, meeting the environmental protection requirements; when used for preparing building thermal insulation materials, the composite material has excellent thermal insulation performance and flame retardant performance, can reduce building energy consumption and improve the fire safety performance of buildings; when used for preparing automotive interior materials, the composite material has good comfort, aesthetics and environmental protection performance, can reduce the release of harmful gases in the vehicle, and provide a healthy and comfortable driving environment for passengers.

[0043] (III) Beneficial technical effects

[0044] Compared with the existing technologies, the beneficial effects of the present invention are:

[0045] 1. From the perspective of environmental protection, the use of environmentally friendly plasticizers and biodegradable natural plant fibers reduces the use of traditional toxic and harmful additives and decreases environmental pollution. The photocatalytic performance of nano-titanium dioxide can degrade organic pollutants, endowing the material with self-cleaning and air purification functions, further enhancing the environmental protection value.

[0046] 2. The composite material has obvious advantages. The EPE particles are treated by plasma surface treatment, enhancing their compatibility with other components and improving the comprehensive mechanical properties of the material, enabling it to better protect items in packaging applications. The addition of antistatic agents effectively reduces the static charge accumulation on the material surface, avoiding the damage of static electricity to electronic products, etc.

[0047] 3. As a building thermal insulation material, it has excellent thermal insulation performance, can effectively reduce building energy consumption, and at the same time has good flame retardant performance, improving the fire safety level of buildings. When used for automotive interiors, it can not only reduce the release of harmful gases in the vehicle, providing a healthy driving and riding environment, but also has good comfort and aesthetics, meeting consumers' demands for high-quality automotive interiors.

[0048] 4. By using a twin-screw extruder and optimized process parameters, the components are fully mixed and reacted, ensuring the stability and consistency of the material properties. The polytetrafluoroethylene coating on the inner wall of the high-speed mixer prevents the material from sticking to the wall, improving production efficiency and product quality. In short, the composite material and its preparation method of this patent have the advantages of environmental protection, high performance, easy production, etc., and have broad application prospects and market competitiveness. Brief Description of the Drawings

[0049] Figure 1 It is a production flow chart of a short-chain alkane VOC catalyst. Detailed Description of the Invention

[0050] Example 1

[0051] Raw Material Preparation:

[0052] Weigh 30 parts of high-density polyethylene, 15 parts of medium-density polyethylene, and 15 parts of linear low-density polyethylene as polyethylene polymers by weight;

[0053] 30 parts of EPE particles with a particle size of 1 mm are placed in an air plasma treatment device with a treatment power of 100 W, a treatment time of 6 min, and a treatment pressure of 30 Pa to introduce polar groups such as carboxyl and hydroxyl groups on its surface;

[0054] 5 parts of environment-friendly plasticizer, including 2.5 parts of tributyl citrate and 2.5 parts of acetyl tributyl citrate;

[0055] Natural plant fiber selects 10 parts of ramie fiber with a length of 10 mm, which is placed in a sodium hydroxide solution with a mass fraction of 3%, treated at 90 °C for 2 h, then rinsed with water until neutral, neutralized with an acetic acid solution with a mass fraction of 2%, and finally washed with water and dried;

[0056] 3 parts of nano-titanium dioxide with a particle size of 30 nm.

[0057] 1.5 parts of antistatic agent, including 0.75 parts of glycerol monostearate and 0.75 parts of ethoxylated alkylamine.

[0058] Preparation Process:

[0059] The treated EPE particles and nano-titanium dioxide are added to a high-speed mixer and mixed at a speed of 1000 r / min for 15 min to make the nano-titanium dioxide uniformly adhere to the surface of the EPE particles;

[0060] Add the polyethylene polymer, environmentally friendly plasticizer, degummed ramie fibers, and antistatic agent into the main feeding port of the twin-screw extruder, heat to 170 °C to melt it, and the screw speed is 250 r / min;

[0061] Add the mixture of EPE particles and nano-titanium dioxide through the side feeding port, and co-extrude at 180 °C. The extrudate is cooled by water at 20 °C and pelletized, and the particle size is controlled at 3 mm to obtain the composite material.

[0062] Performance test:

[0063] The composite material is made into a packaging material, which has good cushioning performance and can effectively protect fragile items; the surface resistance is reduced and the antistatic performance is remarkable; it is detected to be biodegradable and meets the environmental protection standards.

[0064] Example 2

[0065] Raw material preparation:

[0066] The polyethylene polymer is composed of 35 parts of high-density polyethylene, 10 parts of medium-density polyethylene, and 10 parts of linear low-density polyethylene;

[0067] 25 parts of EPE particles, with a particle size of 0.8 mm, air plasma treatment power of 80 W, treatment time of 8 min, and treatment pressure of 20 Pa;

[0068] 4 parts of environmentally friendly plasticizer, 2 parts of tributyl citrate and 2 parts of acetyl tributyl citrate;

[0069] Select 8 parts of flax fibers, with a length of 8 mm, and treat them according to the above degumming method;

[0070] 2 parts of nano-titanium dioxide, with a particle size of 20 nm;

[0071] 1 part of antistatic agent, 0.5 part of glycerol monostearate and 0.5 part of ethoxylated alkylamine.

[0072] Preparation process:

[0073] The EPE particles and nano-titanium dioxide are mixed in a high-speed mixer at 900 r / min for 18 min;

[0074] Add other raw materials into the main feeding port of the twin-screw extruder, melt at 165 °C, and the screw speed is 220 r / min;

[0075] Add the mixed material, co-extrude at 175 °C, cool by water and pelletize, and the particle size is 2.5 mm.

[0076] Performance test:

[0077] Manufactured into building thermal insulation materials, with excellent thermal insulation performance, which can effectively reduce energy consumption; good flame retardant performance, improving building fire safety; under light, nano-titanium dioxide can degrade surrounding organic pollutants.

[0078] Example 3

[0079] Raw material preparation:

[0080] 28 parts of high-density polyethylene, 12 parts of medium-density polyethylene, and 12 parts of linear low-density polyethylene are used as polyethylene polymers;

[0081] 35 parts of pearl cotton particles, with a particle size of 1.2 mm, plasma treatment power of 120 W, treatment time of 5 min, and treatment pressure of 40 Pa;

[0082] 6 parts of environmentally friendly plasticizer, 3 parts of tributyl citrate and 3 parts of acetyl tributyl citrate;

[0083] 12 parts of bamboo fiber, with a length of 15 mm, degumming treatment;

[0084] 4 parts of nano-titanium dioxide, with a particle size of 40 nm;

[0085] 2 parts of antistatic agent, 1 part of glycerol monostearate and 1 part of ethoxylated alkylamine.

[0086] Preparation process:

[0087] The high-speed mixer mixes pearl cotton particles and nano-titanium dioxide at 1100 r / min for 12 min;

[0088] The raw materials at the main feeding port are melted at 175 °C, and the screw speed is 280 r / min;

[0089] The mixed materials are added at the side feeding port, melt-blended and extruded at 185 °C, water-cooled and pelletized, with a particle size of 3.5 mm.

[0090] Performance test:

[0091] Manufactured into automotive interior materials, without the release of harmful gases, providing a healthy environment; good comfort and aesthetics, meeting high-quality requirements.

[0092] Comparative example

[0093] Raw material preparation:

[0094] 60 parts of ordinary polyethylene; 30 parts of untreated pearl cotton particles; 5 parts of ordinary plasticizer; 10 parts of undegummed natural fiber; without nano-titanium dioxide and antistatic agent.

[0095] Preparation process:

[0096] All raw materials are directly added to a single-screw extruder, melted and extruded at 150 °C, and naturally cooled and pelletized.

[0097] Performance test:

[0098] When made into packaging materials, it has poor cushioning performance and is prone to generating static electricity; when made into building thermal insulation materials, its thermal insulation and flame retardant properties are not good; when made into automotive interior materials, harmful gases are emitted and its comfort and aesthetics are insufficient.

[0099] It can be seen from the above three examples and one comparative example that the environmentally friendly EPE composite material of the polyethylene polymer prepared by the present invention is superior to the ordinary material in the comparative example in terms of both performance and environmental protection, which proves the effectiveness and superiority of the formula and preparation method of the present invention.

[0100] Comparison table of raw material formulas for examples and comparative examples:

[0101]

[0102]

[0103] Conclusion: It can be known from the comparison of raw material formulas that the examples adopt a polyethylene polymer, treated EPE particles, environmentally friendly plasticizer, degummed natural plant fiber, nano-titanium dioxide and antistatic agent mixed in specific proportions. While the comparative example uses ordinary polyethylene, untreated EPE, ordinary plasticizer and undegummed fiber, and there is no nano-titanium dioxide and antistatic agent. This difference in raw material selection and treatment methods lays the foundation for the performance improvement of the composite materials in each example.

[0104] Comparison table of preparation process parameters for examples and comparative examples:

[0105]

[0106] Conclusion: In the preparation process of the examples, the parameters of each link are finely controlled, such as the mixing speed and time of EPE and nano-titanium dioxide, the melting temperature and screw speed of the twin-screw extruder, the co-mixing extrusion temperature, the water cooling temperature and the pellet size. The comparative example uses a single-screw extruder and the process is simple and rough. This shows that the preparation process of the examples is more complex and precise, which can better ensure the full fusion of each component of the composite material, thereby improving the performance.

[0107] Comparison table of composite material properties for examples and comparative examples:

[0108]

[0109] Conclusion: Through performance comparison, it can be clearly seen that the composite materials prepared in the examples exhibit good buffering, antistatic, heat preservation, flame retardancy, environmental protection, comfort and aesthetics, etc. in different application scenarios, such as packaging, building insulation and automotive interiors. However, the materials in the comparative examples have obvious deficiencies in all aspects of performance, which fully proves that the formula and preparation method of the present invention can effectively improve the comprehensive performance of the composite materials, and have significant advantages and practical application values.

[0110] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An environment-friendly EPE composite material of a polyethylene polymer, characterized in that: By weight, it includes the following components: 40 - 70 parts of polyethylene polymer, and the polyethylene polymer is a mixture composed of high - density polyethylene (HDPE), medium - density polyethylene (MDPE) and linear low - density polyethylene (LLDPE) in a mass ratio of 2 - 3:1 - 2:1 - 2; The density of high-density polyethylene is 0.941 - 0.965 g / cm 3 ; the density of medium-density polyethylene is 0.926 - 0.940 g / cm 3 ; the melt flow rate of linear low-density polyethylene is 1 - 5 g / 10 min (190 °C, 2.16 kg). Entanglement and interaction will occur between the molecular chains of these three kinds of polyethylene, which can be simply expressed as: HDPE + MDPE + LLDPE → HDPE - MDPE - LLDPE (entangled structure) Among them, HDPE is high - density polyethylene, MDPE is medium - density polyethylene, and LLDPE is linear low - density polyethylene; 20 - 50 parts of EPE particles, with a particle size of 0.3 - 2.5 mm, and having undergone plasma surface treatment. Carboxyl groups are introduced by air plasma treatment, and its reaction process can be approximately expressed as: 3 - 8 parts of environmentally friendly plasticizer, which is a compound of tributyl citrate (TBC) and acetyl tributyl citrate (ATBC) in a mass ratio of 1 - 2:1 - 2; Plasticizer molecules can reduce the van der Waals force and hydrogen - bond interaction force between molecular chains, and the principle can be expressed as: PE - molecular chain + TBC / ATBC → PE - molecular chain - TBC / ATBC Among them, TBC is tributyl citrate and ATBC is acetyl tributyl citrate; 5 - 15 parts of natural plant fiber, and the natural plant fiber is one or more of degummed ramie fiber, flax fiber, and bamboo fiber. The fiber length is 5 - 20 mm. The natural plant fiber contains pectin and needs to be degummed, that is, hydrolyzed under the action of sodium hydroxide, and the reaction formula is: R - COO - R’ + NaOH → R - COONa + R’ - OH 1 - 5 parts of nano - titanium dioxide, with a particle size of 10 - 50 nm. The nano - titanium dioxide will generate electron - hole pairs under light conditions. The holes react with water to generate hydroxyl radicals, and the electrons react with oxygen to generate superoxide anion radicals. The reaction formula is as follows: h + + H2O → ·OH + H + 0.5 - 3 parts of antistatic agent, and the antistatic agent is a compound of glycerol monostearate and ethoxylated alkylamine in a mass ratio of 1 - 2:1 - 2. Glycerol monostearate and ethoxylated alkylamine form a conductive layer on the material surface.

2. The environmentally friendly EPE composite material of the polyethylene polymer according to claim 1, characterized in that: The plasma surface treatment conditions of the EPE particles are: using air plasma, the treatment power is 50 - 150 W, the treatment time is 3 - 10 min, and the treatment pressure is 10 - 50 Pa.

3. The environment-friendly EPE composite material of the polyethylene polymer according to claim 1, characterized in that: The degumming treatment method of the natural plant fiber is: placing the natural plant fiber in a sodium hydroxide solution with a mass fraction of 2% - 5%, treating it at 80 - 100 °C for 1 - 3 h, then rinsing it with water until neutral, then neutralizing it with an acetic acid solution with a mass fraction of 1% - 3%, and finally washing with water and drying.

4. A method for preparing an environmentally friendly EPE composite material of the polyethylene polymer according to any one of claims 1-3, characterized in that, It includes the following steps: S1, adding the plasma - surface - treated EPE particles and nano - titanium dioxide into a high - speed mixer, mixing at a speed of 800 - 1200 r / min for 10 - 20 min to make the nano - titanium dioxide evenly adhere to the surface of the EPE particles. The stirring paddle of the high - speed mixer adopts a special spiral design, which can generate strong shear force and convection. During this process, certain physical adsorption or weak chemical interaction may occur between the nano - titanium dioxide and the polar groups on the surface of the EPE particles, which can be expressed as: EPE - polar group + TiO2 → EPE - polar group - TiO2 In S2, a polyethylene polymer, an environment-friendly plasticizer, degummed natural plant fibers, and an antistatic agent are added to the main feeding port of a twin-screw extruder, heated to 160 - 180 °C to be melted, and the screw speed is 200 - 300 r / min; In S3, the mixture obtained in S1 is added to the twin-screw extruder through the side feeding port, and is co-extruded with the material in S2 at 170 - 190 °C. The extrudate is cooled by water and pelletized to obtain an environment-friendly EPE composite material of the polyethylene polymer. The water cooling process uses a circulating water cooling system, the water temperature is controlled at 15 - 25 °C, and the blades of the pelletizer are sharp blades with high-speed rotation, and the pelletizing particle size is controlled at 2 - 5 mm.

5. The preparation method according to claim 4, wherein: The inner wall of the high-speed mixer is treated with a polytetrafluoroethylene coating to prevent the material from sticking to the wall and ensure the smooth progress of the mixing process.

6. The preparation method according to claim 4, characterized in that: The length-diameter ratio of the twin-screw extruder is 35 - 45:1, and from the feeding section to the head direction, the temperatures of each heating zone are 160 - 165 °C, 165 - 175 °C, 175 - 185 °C, and 185 - 190 °C in sequence.

7. Use of the environment-friendly pearl cotton composite material of the polyethylene polymer according to any one of claims 1-3, characterized in that: The composite material is used for preparing packaging materials, building thermal insulation materials, or automotive interior materials.

8. The application according to claim 7, characterized in that: When used for preparing packaging materials, the packaging products made of the composite material have good cushioning performance, antistatic performance, and environmental protection performance; when used for preparing building thermal insulation materials, the composite material has excellent thermal insulation performance and flame retardancy; when used for preparing automotive interior materials, the composite material has good comfort, aesthetics, and environmental protection performance.

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