High-resistance polyethylene film and production process thereof

Abstract

The invention belongs to the technical field of polyethylene films, and particularly provides a high-resistance polyethylene film and a production process. The high-resistance polyethylene film is prepared from the following raw materials in parts by weight: 70-80 parts of linear low-density polyethylene, 3-6 parts of modified silicon dioxide gel and 2-4 parts of maleic anhydride grafted polyethylene. The modified silicon dioxide gel is prepared by compounding aminated cellulose and a silicon source to prepare aerogel and then modifying the aerogel by using stearoyl chloride. The high-resistance polyethylene film prepared by the invention has the advantages of good barrier property and good mechanical property.

Description

Technical Field

[0001] This application belongs to the field of polyethylene film technology, and in particular relates to a high-durability polyethylene film and its production process. Background Technology

[0002] Polyethylene (PE), a thermoplastic polymer synthesized from ethylene monomers, has a molecular chain structure dominated by carbon-carbon single bonds. This often results in good chemical stability, low-temperature resistance, and processing adaptability, making it one of the most widely produced and applied synthetic polymers. Polyethylene has relatively abundant raw material sources, mature production processes, and is lightweight and relatively inexpensive, making it important in packaging, construction, agriculture, and medical fields. The molecular structure of polyethylene plastics can be controlled by adjusting the polymerization method (such as high-pressure polymerization or low-pressure polymerization) to regulate its density and branching degree, forming different types such as low-density polyethylene (LDPE), high-density polyethylene (HDPE), and linear low-density polyethylene (LLDPE), providing a basis for the performance differentiation design of subsequent film products. Based on these characteristics, polyethylene film, as an important processing form of polyethylene plastic, occupies a significant position in the packaging industry due to its advantages such as good flexibility, controllable transparency, and easy heat sealing. In the food packaging sector, it is commonly used for preserving fresh food, sealing cooked food, and moisture-proofing snacks. In daily necessities and industrial packaging, it is frequently used for outer wrapping of detergents and cosmetics, as well as dustproof packaging for mechanical parts and electronic components. Furthermore, polyethylene film can expand its application scenarios through processes such as lamination and coating, for example, as greenhouse covering film in agriculture and disposable packaging materials in the medical field. The lightweight properties of polyethylene film also help reduce logistics and transportation costs, aligning with the potential demand for pollution reduction in modern packaging. However, despite its wide range of applications, the shortcomings in key performance aspects of polyethylene film may still limit its use in the packaging field. Ordinary polyethylene film typically exhibits low molecular chain regularity, making it prone to tearing under impact or edge stress. This tearing risk increases significantly, especially at low temperatures where flexibility decreases, potentially compromising packaging integrity. Furthermore, existing polyethylene films may be punctured by hard objects with sharp edges, leading to leakage or the intrusion of external contaminants. Moreover, pure polyethylene film often has limited barrier properties against small molecules such as oxygen, carbon dioxide, and water vapor. When used for food packaging, it may struggle to effectively delay oxidative deterioration or provide moisture protection, sometimes necessitating the use of composite barrier materials. Additionally, the mechanical properties and chemical stability of the film may degrade in complex environments, potentially failing to meet the packaging requirements for long-term storage or harsh conditions. Therefore, developing polyethylene films with both high toughness and good mechanical properties is crucial for improving packaging reliability and expanding application scenarios.

[0003] Patent application CN103739913A discloses a novel polyethylene film material and its preparation method. The polyethylene film material of this invention is composed of the following raw materials: polyethylene, modified layered nano-silicate, LDPE-g-MAH, and ultrafine titanium dioxide. While the modified layered nano-silicate added in this invention can construct a physical barrier through its layered stacking structure, effectively improving the barrier properties of the polyethylene film against gases and water vapor, its dispersibility within the polyethylene matrix remains significantly insufficient. Due to its high surface energy and strong van der Waals forces between the layers, the layered nano-silicate is prone to agglomeration, forming micron-sized aggregates. This agglomeration not only disrupts the continuity of the matrix, leading to stress concentration and a decrease in the mechanical properties of the film, but also affects the synergistic effect of other functional fillers such as ultrafine titanium dioxide, hindering their uniform distribution and weakening the overall performance of the composite material. Furthermore, agglomerated nanosilicates can interfere with the interfacial compatibility of LDPE-g-MAH, reducing its effect on improving the interfacial bonding between the matrix and filler, which in turn has an adverse effect on the processing stability of the film and limits the application of this film material in the field of high-performance packaging. Summary of the Invention

[0004] To address the aforementioned issues and further improve the barrier properties and mechanical properties of polyethylene film, this application provides a high-durability polyethylene film and its production process.

[0005] In a first aspect, this application provides a high-durability polyethylene film, made from raw materials comprising the following parts by weight: 70-80 parts linear low-density polyethylene, 3-6 parts modified silica gel, and 2-4 parts maleic anhydride-grafted polyethylene; the preparation method of the modified silica gel includes the following steps: 1) Mix alkoxysilane, deionized water and ethanol evenly, adjust with acid and alkali in sequence, then add amino cellulose, age, dry, pulverize and grind to obtain aerogel; 2) The aerogel was dispersed in cyclohexane, and then stearoyl chloride and organic base were added to carry out a grafting reaction to obtain modified silica gel.

[0006] In some embodiments of the present invention, in step 1), aminated cellulose is prepared by oxidizing microcrystalline cellulose and then reacting it with an active amine in a condensation reaction.

[0007] In some embodiments of the present invention, the process of microcrystalline cellulose oxidation is as follows: microcrystalline cellulose is dispersed in an alkaline solution for swelling, then the pH value is adjusted using hydrochloric acid, and finally reacted with periodate.

[0008] In some embodiments of the present invention, in step 1), the molar ratio of alkoxysilane, deionized water and ethanol is 1:(4-6):(8-10).

[0009] In some embodiments of the present invention, in step 1), the alkoxysilane is tetramethoxysilane or methyltrimethoxysilane.

[0010] In some embodiments of the present invention, in step 2), the mass ratio of aerogel to stearoyl chloride is 1:(0.5-1.2).

[0011] In some embodiments of the present invention, in step 2), the organic base is triethylamine or N,N-dimethylaniline.

[0012] In some embodiments of the present invention, the active amine is one of polyethyleneamine, polyallylamine, and polyethyleneimine.

[0013] Secondly, this application provides a production process for a high-durability polyethylene film, characterized by comprising the following steps: S1: Linear low-density polyethylene, modified silica gel, and maleic anhydride-grafted polyethylene are melt-blended and granulated to obtain composite particles. S2: The composite particles are processed into a film by blow molding to obtain a high-durability polyethylene film.

[0014] In some embodiments of the present invention, the blow-inflation ratio of the blow molding process is 2-2.5.

[0015] Compared with the prior art, this application has the following beneficial effects: 1. The porous structure of modified silica gel extends the path for external substances to enter the interior of high-durability polyethylene film, thus playing a certain role in isolation and improving the barrier performance of high-durability polyethylene film.

[0016] 2. Aminated cellulose plays a role in enhancing the toughness of modified silica gel, giving it a certain resistance to impact and puncture. At the same time, in the preparation of high-durability polyethylene film, the amino groups on the surface of aminated cellulose react with maleic anhydride grafted onto polyethylene, improving the compatibility and bonding force between modified silica gel and polyethylene, thereby enhancing the tear resistance of high-durability polyethylene film.

[0017] 3. The modified silica gel surface is grafted with stearoyl chloride, which improves the hydrophobicity of the modified silica gel and its dispersibility in polyethylene. The longer hydrophobic segments are entangled in the polyethylene matrix, further enhancing the bonding force between the modified silica gel and the polyethylene matrix, and improving the mechanical properties of the high-durability polyethylene film. Detailed Implementation

[0018] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0019] This application, based on extensive experimental research, provides a high-durability polyethylene film, made from raw materials comprising the following parts by weight: 70-80 parts linear low-density polyethylene, 3-6 parts modified silica gel, and 2-4 parts maleic anhydride-grafted polyethylene; the preparation method of the modified silica gel includes the following steps: 1) Mix alkoxysilane, deionized water and ethanol evenly, add acid to adjust pH to 3-4, stir at 200-300 rpm for 8-12 hours at room temperature, then add alkali to adjust pH, then add amino cellulose, age, dry, pulverize and grind to obtain aerogel. 2) Disperse the aerogel in cyclohexane, then add stearoyl chloride and organic base, and carry out the grafting reaction at room temperature for 4-8 hours to obtain modified silica gel.

[0020] Furthermore, in step 1), aminated cellulose is prepared by oxidizing microcrystalline cellulose and then reacting it with an active amine in a condensation reaction.

[0021] Furthermore, the process for oxidizing microcrystalline cellulose is as follows: dispersing microcrystalline cellulose in an alkaline solution for swelling, adjusting the pH value with hydrochloric acid, and finally reacting it with periodate.

[0022] Furthermore, the preparation method of aminated cellulose in step 1) includes the following steps: microcrystalline cellulose and sodium hydroxide aqueous solution are mixed and stirred for 3-5 hours. Hydrochloric acid is added to adjust the pH, the temperature is raised to 50-70°C, periodate is added, and the reaction is carried out for 2-4 hours. Then, active amine is added, and the reaction is continued for 2-3 hours. After centrifugation, washing and drying are performed to obtain aminated cellulose.

[0023] Furthermore, in step 1), the molar ratio of alkoxysilane, deionized water and ethanol is 1:(4-6):(8-10).

[0024] In some specific embodiments, the molar ratio of the alkoxysilane, deionized water, and ethanol can be 1:4:8, 1:4.5:8, 1:5:8, 1:5.5:8, 1:6:8, 1:4:8, 1:4.5:8.5, 1:5:8.5, 1:5.5:8.5, 1:6:8.5, 1:4:8, 1:4.5:9, 1:5:9, 1:5.5:9, 1:6:9, 1:4:8, 1:4.5:9.5, 1:5:9.5, 1:5.5:9.5, 1:6:9.5, 1:4:8, 1:4.5:10, 1:5:10, 1:5.5:10, or 1:6:10. Generally, a molar ratio of 1:5.5:9 for the alkoxysilane, deionized water, and ethanol yields better experimental results.

[0025] Furthermore, in step 1), the alkoxysilane is tetramethoxysilane or methyltrimethoxysilane.

[0026] Furthermore, in step 2), the mass ratio of aerogel to stearoyl chloride is 1:(0.5-1.2).

[0027] In some specific embodiments, the mass ratio of the aerogel to stearoyl chloride can be 1:0.5, 1:0.55, 1:0.6, 1:0.65, 1:0.7, 1:0.75, 1:0.8, 1:0.85, 1:0.9, 1:0.95, 1:1, 1:1.05, 1:1.1, 1:1.15, or 1:1.2. Generally, a mass ratio of 1:0.7 for the aerogel to stearoyl chloride yields better experimental results.

[0028] Furthermore, in step 2), the organic base is triethylamine or N,N-dimethylaniline.

[0029] In some specific embodiments, the experimental results are better when the organic base is triethylamine under normal circumstances.

[0030] Furthermore, the active amine is one of polyethyleneamine, polyallylamine, and polyethyleneimine.

[0031] In some specific embodiments, better experimental results can be obtained when the active amine is polyethyleneimine under normal circumstances.

[0032] Example 1 The high-durability polyethylene film of this embodiment is made from the following raw materials by weight: 140g linear low-density polyethylene, 6g modified silica gel, 4g maleic anhydride-grafted polyethylene, 2g dioctyl phthalate, and 2g KH-550 coupling agent.

[0033] The preparation method of the modified silica gel in this embodiment is as follows: 1) Weigh 15.2g of tetramethoxysilane, 10g of deionized water and 41.4g of ethanol into a 250mL beaker and mix well. Then add 1mol / L hydrochloric acid to adjust the pH to 3 and stir at 200rpm for 8h at room temperature. While stirring continuously, add 1mol / L ammonia to adjust the pH to 6. Then add 6.5g of aminocellulose, disperse evenly by ultrasonication, and let it stand to gel. After gelation, seal with ethanol and age at 50℃ for 32h. After the aging is complete, pour out the ethanol and add a mixed solution of 100g of n-hexane and 10g of trimethoxychlorosilane. Let it stand for 24h. Then pour out the mixed solution, wash with n-hexane, dry, crush and grind to obtain aerogel. 2) Weigh 10g of aerogel into a 250mL three-necked flask, add 100g of cyclohexane, stir for 10min, add 7g of stearoyl chloride and 0.8g of triethylamine in a nitrogen atmosphere, carry out the grafting reaction at room temperature for 4h, filter, wash, and dry in an oven at 60℃ for 12h to obtain modified silica gel.

[0034] The preparation method of aminated cellulose in this embodiment is as follows: Weigh 5g of microcrystalline cellulose into a 500mL three-necked flask, add 200g of sodium hydroxide aqueous solution with a mass percentage concentration of 10%, stir for 5h, adjust the pH to 4 with 2mol / L hydrochloric acid, adjust the temperature to 50℃, add 2.5g of sodium periodate, react for 4h, then add 3.8g of polyethyleneimine, continue to react for 3h, centrifuge after the reaction is completed, wash, and dry to obtain aminated cellulose.

[0035] The production process of the high-durability polyethylene film in this embodiment is as follows: S1: Take 140g of linear low-density polyethylene, 6g of modified silica gel, 4g of maleic anhydride-grafted polyethylene, 2g of dioctyl phthalate, and 2g of KH-550 coupling agent and add them to a high-speed mixer. Mix for 3 minutes to obtain a blend. Add the blend to a twin-screw extruder for melt blending. The set temperatures of the twin-screw extruder are: 160℃ for the first stage, 170℃ for the second stage, 180℃ for the third stage, 185℃ for the fourth stage, 180℃ for the fifth stage, and 170℃ for the die head. Then, use a granulator to granulate the mixture. Dry the resulting particles at 60℃ to obtain composite particles. S2: The composite particles are added to the blown film machine and blown into a film with a blow-up ratio of 2 to obtain a high-durability polyethylene film.

[0036] Example 2 The high-durability polyethylene film of this embodiment is made from the following raw materials by weight: 160g linear low-density polyethylene, 12g modified silica gel, 8g maleic anhydride-grafted polyethylene, 6g dioctyl phthalate, and 4g KH-550 coupling agent.

[0037] The preparation method of the modified silica gel in this embodiment is as follows: 1) Weigh 13.6g of methyltrimethoxysilane, 10g of deionized water and 41.4g of ethanol into a 250mL beaker and mix well. Then add 1mol / L hydrochloric acid to adjust the pH to 4 and stir at 300rpm for 12h at room temperature. While stirring continuously, add 1mol / L ammonia to adjust the pH to 8. Then add 6.5g of aminocellulose, disperse evenly by ultrasonication, and let it stand to gel. After gelation, seal with ethanol and age at 50℃ for 24h. After the aging is complete, pour out the ethanol and add a mixed solution of 100g of n-hexane and 10g of trimethoxychlorosilane. Let it stand for 24h. Then pour out the mixed solution, wash with n-hexane, dry, crush and grind to obtain aerogel. 2) Weigh 10g of aerogel into a 250mL three-necked flask, add 100g of cyclohexane, stir for 10min, add 5g of stearoyl chloride and 0.6g of triethylamine in a nitrogen atmosphere, carry out the grafting reaction at room temperature for 8h, filter, wash, and dry in an oven at 60℃ for 12h to obtain modified silica gel.

[0038] The preparation method of aminated cellulose in this embodiment is as follows: Weigh 5g of microcrystalline cellulose into a 500mL three-necked flask, add 200g of sodium hydroxide aqueous solution with a mass percentage concentration of 10%, stir for 5h, adjust the pH to 4 with 2mol / L hydrochloric acid, adjust the temperature to 70℃, add 3g of sodium periodate, react for 3h, then add 3.5g of polyethyleneimine, continue the reaction for 2.5h, centrifuge after the reaction is completed, wash, and dry to obtain aminated cellulose.

[0039] The production process of the high-durability polyethylene film in this embodiment is as follows: S1: Take 160g of linear low-density polyethylene, 12g of modified silica gel, 8g of maleic anhydride grafted polyethylene, 6g of dioctyl phthalate, and 4g of KH-550 coupling agent and add them to a high-speed mixer. Mix for 3 minutes to obtain a blend. Add the blend to a twin-screw extruder for melt blending. The set temperatures of the twin-screw extruder are: 170℃ for the first stage, 180℃ for the second stage, 190℃ for the third stage, 190℃ for the fourth stage, 180℃ for the fifth stage, and 170℃ for the die head. Then, use a granulator to granulate the mixture. Dry the resulting particles at 60℃ to obtain composite particles. S2: The composite particles are added to a blown film machine and blown into a film with a blow-up ratio of 2.5 to obtain a high-durability polyethylene film.

[0040] Example 3 The high-durability polyethylene film of this embodiment is made from the following raw materials by weight: 155g linear low-density polyethylene, 8g modified silica gel, 7g maleic anhydride-grafted polyethylene, 3g dioctyl phthalate, and 3g KH-550 coupling agent.

[0041] The preparation method of the modified silica gel in this embodiment is as follows: 1) Weigh 13.6g of methyltrimethoxysilane, 10g of deionized water and 41.4g of ethanol into a 250mL beaker and mix well. Then add 1mol / L hydrochloric acid to adjust the pH to 3.5 and stir at 280rpm for 9h at room temperature. While stirring continuously, add 1mol / L ammonia to adjust the pH to 7. Then add 6.5g of aminocellulose, disperse evenly by ultrasonication, and let it stand to gel. After gelation, seal with ethanol and age at 50℃ for 32h. After the aging is complete, pour out the ethanol and add a mixed solution of 100g of n-hexane and 10g of trimethoxychlorosilane. Let it stand for 24h. Then pour out the mixed solution, wash with n-hexane, dry, pulverize and grind to obtain aerogel. 2) Weigh 10g of aerogel into a 250mL three-necked flask, add 100g of cyclohexane, stir for 10min, add 7g of stearoyl chloride and 0.8g of triethylamine in a nitrogen atmosphere, carry out the grafting reaction at room temperature for 6h, filter, wash, and dry in an oven at 60℃ for 12h to obtain modified silica gel.

[0042] The preparation method of aminated cellulose in this embodiment is as follows: 5g of microcrystalline cellulose was weighed and put into a 500mL three-necked flask, and then 200g of sodium hydroxide aqueous solution with a mass percentage concentration of 10% was added. The mixture was stirred for 3.5h, and then the pH was adjusted to 4 with hydrochloric acid with a concentration of 2mol / L. The temperature was adjusted to 60℃, and 2.5g of sodium periodate was added. The reaction was carried out for 4h, and then 3.8g of polyethyleneimine was added. The reaction was continued for 2h. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain aminated cellulose.

[0043] The production process of the high-durability polyethylene film in this embodiment is as follows: S1: Take 155g of linear low-density polyethylene, 8g of modified silica gel, 7g of maleic anhydride grafted polyethylene, 3g of dioctyl phthalate, and 3g of KH-550 coupling agent and add them to a high-speed mixer. Mix for 3 minutes to obtain a blend. Add the blend to a twin-screw extruder for melt blending. The set temperatures of the twin-screw extruder are: 165℃ for the first stage, 170℃ for the second stage, 180℃ for the third stage, 180℃ for the fourth stage, 190℃ for the fifth stage, and 170℃ for the die head. Then, use a granulator to granulate the mixture. Dry the resulting particles at 60℃ to obtain composite particles. S2: The composite particles are added to a blown film machine and blown into a film with a blow-up ratio of 2.4 to obtain a high-durability polyethylene film.

[0044] Control group 1 The polyethylene film in this control group was made from the following raw materials by weight: 140g linear low-density polyethylene, 6g aerogel, 4g maleic anhydride-grafted polyethylene, 2g dioctyl phthalate, and 2g KH-550 coupling agent.

[0045] The preparation method of the aerogel in this control group is as follows: 15.2g of tetramethoxysilane, 10g of deionized water and 41.4g of ethanol were weighed and put into a 250mL beaker and mixed evenly. Then, 1mol / L hydrochloric acid was added to adjust the pH to 3. The mixture was stirred at 200rpm for 8h at room temperature. Under continuous stirring, 1mol / L ammonia was added dropwise to adjust the pH to 6. Then, 6.5g of microcrystalline cellulose was added and ultrasonically dispersed evenly. The mixture was allowed to stand and gel. After gelation, the mixture was sealed with ethanol and aged at 50℃ for 32h. After the aging was completed, the ethanol was poured out and a mixed solution of 100g of n-hexane and 10g of trimethoxychlorosilane was added. The mixture was allowed to stand for 24h. Then, the mixed solution was poured out, washed with n-hexane, dried, crushed and ground to obtain the aerogel.

[0046] The production process of the polyethylene film in this control group is as follows: S1: Take 140g of linear low-density polyethylene, 6g of aerogel, 4g of maleic anhydride-grafted polyethylene, 2g of dioctyl phthalate, and 2g of KH-550 coupling agent and add them to a high-speed mixer. Mix for 3 minutes to obtain a blend. Add the blend to a twin-screw extruder for melt blending. The set temperatures of the twin-screw extruder are: 160℃ for the first stage, 170℃ for the second stage, 180℃ for the third stage, 185℃ for the fourth stage, 180℃ for the fifth stage, and 170℃ for the die head. Then, use a granulator to granulate the mixture. Dry the resulting particles at 60℃ to obtain composite particles. S2: The composite particles are added to a blown film machine and blown into a film with a blow-up ratio of 2 to obtain a polyethylene film.

[0047] Control group 2 The polyethylene film in this control group was made from the following raw materials by weight: 140g linear low-density polyethylene, 6g aerogel, 4g maleic anhydride-grafted polyethylene, 2g dioctyl phthalate, and 2g KH-550 coupling agent.

[0048] The preparation method of the aerogel in this control group is as follows: 15.2g of tetramethoxysilane, 10g of deionized water and 41.4g of ethanol were weighed and put into a 250mL beaker and mixed evenly. Then, 1mol / L hydrochloric acid was added to adjust the pH to 3. The mixture was stirred at 200rpm for 8h at room temperature. While stirring continuously, 1mol / L ammonia was added dropwise to adjust the pH to 6. The mixture was allowed to stand and gel. After gelation, the mixture was sealed with ethanol and aged at 50℃ for 32h. After the aging was completed, the ethanol was poured out and a mixed solution of 100g of n-hexane and 10g of trimethoxychlorosilane was added. The mixture was allowed to stand for 24h. Then, the mixed solution was poured out, washed with n-hexane, dried, crushed and ground to obtain the aerogel.

[0049] The production process of the polyethylene film in this control group is as follows: S1: Take 140g of linear low-density polyethylene, 6g of aerogel, 4g of maleic anhydride-grafted polyethylene, 2g of dioctyl phthalate, and 2g of KH-550 coupling agent and add them to a high-speed mixer. Mix for 3 minutes to obtain a blend. Add the blend to a twin-screw extruder for melt blending. The set temperatures of the twin-screw extruder are: 160℃ for the first stage, 170℃ for the second stage, 180℃ for the third stage, 185℃ for the fourth stage, 180℃ for the fifth stage, and 170℃ for the die head. Then, use a granulator to granulate the mixture. Dry the resulting particles at 60℃ to obtain composite particles. S2: The composite particles are added to a blown film machine and blown into a film with a blow-up ratio of 2 to obtain a polyethylene film.

[0050] Performance testing 1. Tensile test: The longitudinal tensile strength and transverse tensile strength of the film are tested in accordance with the standard GB / T1040.3-2006.

[0051] 2. Tear test: The tear performance of the film was tested according to the standard QB / T1130-91. The test conditions were room temperature 20℃ and tear rate (200±20) mm / min.

[0052] 3. Puncture resistance test: The puncture strength of the film is tested according to the standard GB / T10004-2008. The thickness of the film tested is 25±2μm.

[0053] 4. Oxygen Barrier Performance Testing: The oxygen permeability was tested using a differential pressure gas permeation analyzer according to the national standard GB / T19789-2005. The formula for calculating the oxygen permeability is as follows: Where OP is the oxygen permeability, and its unit is cm. 3 ·cm / cm 2 ·s·MPa, Q is oxygen permeation rate, t is permeation time, A is permeation area, X is membrane thickness, and ΔP is the pressure difference across the membrane.

[0054] The performance test data for Examples 1, 2, and 3, Control Group 1, and Control Group 2 are shown in Table 1 below: Table 1 Test Data Analysis of Examples 1-3 and Control Groups 1-2, combined with Table 1, shows that in Examples 1-3, the addition of modified silica gel doped with aminated cellulose and grafted with stearoyl chloride during the preparation of high-durability polyethylene films has a good effect on improving the barrier properties and mechanical properties of the high-durability polyethylene films. The grafting of aminated cellulose and stearoyl chloride can improve the dispersibility of the modified silica gel in the polyethylene matrix and enhance the bonding force between the modified silica gel and the polyethylene matrix. The various properties of the polyethylene films prepared in Control Groups 1-2, which were not treated with aminated cellulose and stearoyl chloride, were lower than those of the Examples.

[0055] Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this invention.

Claims

1. A high-durability polyethylene film, characterized in that: It is made from raw materials comprising the following parts by weight: 70-80 parts linear low-density polyethylene, 3-6 parts modified silica gel, and 2-4 parts maleic anhydride-grafted polyethylene; the preparation method of the modified silica gel includes the following steps: 1) Mix alkoxysilane, deionized water and ethanol evenly, adjust with acid and alkali in sequence, then add amino cellulose, age, dry, pulverize and grind to obtain aerogel; 2) The aerogel was dispersed in cyclohexane, and then stearoyl chloride and organic base were added to carry out a grafting reaction to obtain modified silica gel.

2. The high-durability polyethylene film according to claim 1, characterized in that: In step 1), aminated cellulose is prepared by oxidizing microcrystalline cellulose and then reacting it with an active amine in a condensation reaction.

3. The high-durability polyethylene film according to claim 2, characterized in that: The process of microcrystalline cellulose oxidation is as follows: microcrystalline cellulose is dispersed in an alkaline solution for swelling, then the pH value is adjusted with hydrochloric acid, and finally it is reacted with periodate.

4. The high-durability polyethylene film according to claim 1, characterized in that: In step 1), the molar ratio of alkoxysilane, deionized water and ethanol is 1:(4-6):(8-10).

5. A high-durability polyethylene film according to claim 1, characterized in that: In step 1), the alkoxysilane is tetramethoxysilane or methyltrimethoxysilane.

6. The high-durability polyethylene film according to claim 1, characterized in that: In step 2), the mass ratio of aerogel to stearoyl chloride is 1:(0.5-1.2).

7. The high-durability polyethylene film according to claim 1, characterized in that: In step 2), the organic base is triethylamine or N,N-dimethylaniline.

8. A high-durability polyethylene film according to claim 2, characterized in that: The active amine is one of polyethyleneamine, polyallylamine, and polyethyleneimine.

9. A production process for a high-durability polyethylene film as described in claim 1, characterized in that: Includes the following steps: S1: Linear low-density polyethylene, modified silica gel, and maleic anhydride-grafted polyethylene are melt-blended and granulated to obtain composite particles. S2: The composite particles are processed into a film by blow molding to obtain a high-durability polyethylene film.

10. The production process of a high-durability polyethylene film according to claim 9, characterized in that: The blow-up ratio of the blow molding process is 2-2.5.

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