Low-temperature impact-resistant polyethylene material for cold regions and preparation method thereof

Abstract

The application belongs to the technical field of high polymer materials, and particularly relates to a low-temperature-impact-resistant polyethylene base material in cold regions and a preparation method thereof. The low-temperature-impact-resistant polyethylene base material in cold regions comprises the following raw material components in parts by weight: grafted polyethylene 70-85 parts, POE and EVA blend 15-30 parts, lubricant 2-4 parts, stabilizer 1-2 parts, and antioxidant 1-3 parts. The low-temperature-impact-resistant polyethylene base material in cold regions provided by the application has good low-temperature-impact strength, mechanical properties and processing properties, and has good application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high polymer materials, and particularly relates to a low-temperature-impact-resistant polyethylene-based material for cold regions and a preparation method thereof. BACKGROUND

[0002] Polyethylene (PE) is a kind of general-purpose high polymer material, which is widely used in packaging, building materials, automobiles and other fields due to its excellent chemical stability, processability and cost advantage, and has a certain application potential in the field of track building materials. However, in low-temperature, cold and other special environments, the performance of PE material is not satisfactory. The PE molecular chain structure lacks polar groups, and the intermolecular force is weak. The alpha relaxation temperature is around room temperature. In low-temperature environment, especially under extreme low-temperature conditions of about-50℃, the molecular chain movement ability decreases significantly, the chain segment rigidity increases, and the chain segment movement is difficult to occur, resulting in brittle material, and thus the impact resistance of the material is deteriorated sharply, which is difficult to meet the demand of low-temperature-impact-resistant pad materials for railway construction in cold regions.

[0003] CN109280245A discloses a modified ultra-high molecular weight polyethylene material for railway pad in cold regions, which comprises the following raw materials by weight: ultra-high molecular weight polyethylene: 97-99; sunscreen: 0.2-1.0; modifier: 0.0-2.5. A large amount of ultra-high molecular weight polyethylene is used, which has high cost and high processing difficulty, and the cold resistance effect is limited based on the toughness of the ultra-high molecular weight polyethylene itself.

[0004] In view of the above background, the inventors have researched polyethylene-based materials in order to obtain a low-temperature-impact-resistant polyethylene-based material for cold regions. SUMMARY

[0005] The application aims to provide a low-temperature-impact-resistant polyethylene-based material for cold regions and a preparation method thereof.

[0006] To solve the above problems, the technical scheme adopted by the application is as follows:

[0007] Technical subject one

[0008] A low-temperature-impact-resistant polyethylene-based material for cold regions, which is characterized by comprising the following raw material components in the following weight ratio: grafted polyethylene 70-85 parts, polyolefin elastomer (POE) and ethylene-vinyl acetate copolymer (EVA) blend 15-30 parts, lubricant 2-4 parts, stabilizer 1-2 parts, and antioxidant 1-3 parts.

[0009] As a further improvement of the present application, the grafting polyethylene is made from the following raw materials in parts by weight: linear low density polyethylene 55-65 parts; ultra high molecular weight polyethylene 35-45 parts; maleic anhydride 1.5-2 parts; dicumyl peroxide 0.1-0.3 parts; and zinc stearate 0.25-1 part.

[0010] As a further improvement of the present application, the grafting polyethylene is made from the following raw materials in parts by weight: linear low density polyethylene 55-65 parts; ultra high molecular weight polyethylene 35-45 parts; maleic anhydride 1.5-2 parts; dicumyl peroxide 0.1-0.3 parts; and zinc stearate 0.25-1 part.

[0011] Step (1) preliminary mixing:

[0012] The mixture of linear low density polyethylene, ultra high molecular weight polyethylene, dicumyl peroxide and zinc stearate is added into the mixer preheated to 175-185°C, and mixed at 165-175°C, 20-40 rpm for 2-4 min;

[0013] Step (2) mixing the raw materials with different gradients:

[0014] a. First gradient: 40-60% of maleic anhydride (MAH) is added, the speed is increased to 45-55 rpm, the temperature is 175-185°C, and the mixing is carried out for 2-4 min;

[0015] b. Middle gradient: 20-35% of MAH is added, the temperature is 185-195°C, the speed is 55-60 rpm, and the mixing is carried out for 3-5 min;

[0016] c. Final gradient: the remaining 5-40% of MAH is added, the speed is reduced to 35-50 rpm, the temperature is 165-175°C, and the mixing is carried out for 4-6 min, and then the grafting polyethylene is obtained after discharging.

[0017] As a further improvement of the present application, the linear low density polyethylene has a density of 0.91-0.93 g / cm³, a weight average molecular weight of 150000-200000, and a melt flow rate of 2-5 g / 10 min at 190°C and 2.16 kg; and the ultra high molecular weight polyethylene has a density of 0.940-0.96 g / cm³, a weight average molecular weight of 1500000-2000000, and a melt flow rate of 0.02-0.08 g / 10 min at 190°C and 2.16 kg.

[0018] As a further improvement of the present application, the POE and EVA blend comprises the following components by weight percentage: POE is 70-90wt% and EVA is 10-30wt%; the preparation method is: mixing POE and EVA, adding solvent, ultrasonic treatment at 38-42KHz for 20-30min, then blending at 45-55℃ for 40-60min at 1000-1300rpm, recovering the solvent to obtain the POE and EVA blend;

[0019] The recovered solvent is a normal pressure distillation recovered solvent;

[0020] The mass-volume ratio of the raw material to the solvent is 1g:5ml-15ml; the solvent is selected from one of ethyl acetate, acetone, butyl acetate.

[0021] As a further improvement of the present application, the density of the POE is 0.84-0.88g / cm³, the melt flow rate at 190℃ and 2.16kg is 2-8g / 10min, the density of the EVA is 0.92-0.94g / cm³, and the melt flow rate at 190℃ and 2.16kg is 1.8-3.1g / 10min.

[0022] As a further improvement of the present application, the recovered solvent is then crushed by a crusher to obtain granular material;

[0023] As a further improvement of the present application, the lubricant is polyethylene wax;

[0024] The stabilizer is a hindered amine or benzophenone;

[0025] The antioxidant is selected from antioxidant 1010, antioxidant 168 or a mixture of antioxidant 1010 and antioxidant 168.

[0026] Technical subject two

[0027] A preparation method of a low-temperature impact resistant polyethylene-based material in cold regions as described in technical subject one, the key of which lies in that it comprises the following steps:

[0028] Step 1: proportion the grafted polyethylene, POE and EVA blend, lubricant, stabilizer, and antioxidant, and use a double-screw blender to granulate;

[0029] Step 2: after the granulation and extrusion are completed, dry the granules at 30-40℃ to a water mass percentage of below 0.30% to obtain plastic granules;

[0030] Step 3: prepare a low-temperature impact resistant polyethylene-based material in cold regions by hot press molding, injection molding or single-screw extrusion molding.

[0031] As a further improvement of the present application, the screw rotation speed in step 1 is 300-500 rpm, and the temperature conditions in the granulation zone of the twin-screw granulator are as follows:

[0032]

[0033] As a further improvement of the present application, in the injection molding of step 3, the barrel temperature is set as follows: the feeding zone is 150-170 DEG C, the melting zone is 210-240 DEG C, the nozzle is 230-250 DEG C, the mold temperature is 40-60 DEG C, the injection pressure is 100-120 MPa, the holding pressure is 30-50 MPa, the holding time is 8-12 seconds, the screw rotation speed is 40-60 rpm, the cooling time is 28-45 seconds, the drying treatment at 30-40 DEG C is 0.8-1.5 h, and the product is obtained.

[0034] As a further improvement of the present application, the hot-pressing molding in step 3 is as follows: the plastic particles are pre-melted for 3-10 min using a vacuum hot-pressing machine, pressurized for 4-6 min at 8-12 MPa, relaxed for 0.5-2 min, and then cooled at room temperature to obtain the product.

[0035] As a further improvement of the present application, the extrusion molding in step 3 is as follows: single-screw extrusion molding, and the temperature of each temperature zone of the single-screw extruder is as follows:

[0036]

[0037] The extrusion speed is 0.8-1.2 m / min, and the temperature of the three-roller calender after extrusion is 60±5 DEG C-70±5 DEG C-60±5 DEG C, and then the sample is cooled at room temperature to obtain the product.

[0038] Technical subject three

[0039] The application of the low-temperature impact-resistant polyethylene-based material in the railway pad is disclosed.

[0040] The beneficial effects produced by the above technical solution are as follows:

[0041] The low-temperature impact-resistant polyethylene-based material provided by the present application is prepared by mixing grafted polyethylene, POE and EVA blends, lubricants, stabilizers and antioxidants, and has good low-temperature impact strength, mechanical properties and processing properties, and has good application prospects. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be described clearly and completely in combination with specific examples.

[0043] Linear low density polyethylene (LLDPE) used in this application meets density 0.91-0.93 g / cm3, Mw=150000-200000, melt flow rate 2-5 g / 10 min at 190°C and 2.16 kg, LLDPE L6301.06 purchased from ExxonMobil.

[0044] Ultra high molecular weight polyethylene (UHMWPE) meets density 0.940-0.96 g / cm3, Mw=1500000-2000000, melt flow rate 0.02-0.08 g / 10 min at 190°C and 2.16 kg, purchased from Mitsui Chemicals, Japan, Lot No. L5000.

[0045] Maleic anhydride purchased from Aldrich Chemical Company, Lot No. P434515.

[0046] Dicumyl peroxide purchased from Nanjing Chemical Reagent Co., Ltd.

[0047] Zinc stearate purchased from Shandong Chongcheng Energy Sources Technology Co., Ltd.

[0048] POE meets density 0.84-0.88 g / cm3, melt flow rate 2-8 g / 10 min at 190°C and 2.16 kg, 8200 purchased from Dow Chemical.

[0049] EVA meets density 0.92-0.94 g / cm3, melt flow rate 1.8-3.1 g / 10 min at 190°C and 2.16 kg, Lot No. 3182 purchased from Dow Chemical.

[0050] Polyethylene wax purchased from Dinghai Plastic Chemical Co., Ltd., Lot No. HD-95.

[0051] Hindered amine particles purchased from BASF, Lot No. 944 FDL.

[0052] Total resin mass in this application refers to the mass of polyethylene material.

[0053] Example 1

[0054] Linear low density polyethylene was mixed with ultra-high molecular weight polyethylene at a mass ratio of 6:4, and maleic anhydride (1.5 wt%), dicumyl peroxide (0.1 wt%), zinc stearate (0.5 wt%) were prepared based on the total resin mass. Then, using an intermeshing internal mixer equipped with an oval rotor, the rotor speed was 40 rpm, the mixing chamber was preheated to 180°C for 10 min, then the mixture of UHMWPE / LLDPE, dicumyl peroxide and zinc stearate was added, the mixing time was 3 min, the rotor speed was 40 rpm, the temperature was 170°C; at 4-6 min, 50% MAH was added, the rotor speed was increased to 50 rpm, the temperature was 180°C; at 7-10 min: 30% MAH was added, the temperature was 190°C, the rotor speed was 60 rpm; at 11-15 min: the remaining 20% MAH was added, the rotor speed was reduced to 50 rpm, the temperature was 170°C; discharge, named grafted polyethylene.

[0055] POE 80 wt%, EVA 20 wt% were prepared, ethyl acetate solvent was added, the mass volume ratio of raw materials to ethyl acetate was 1 g: 10 ml, ultrasonic treatment was carried out at 40 kHz for 30 min, then blending was carried out in a stirrer at 50°C with a rotor speed of 1200 rpm for 60 min, the solvent was removed by atmospheric distillation, and the resulting mixed sample was crushed to normal plastic particle size by a crusher to obtain a sample named POEcoEVA.

[0056] Double screw blending granulation was carried out, the proportions were as follows: grafted polyethylene 70 parts, POEcoEVA 30 parts, polyethylene wax 2 parts, hindered amine particles 1.5 parts, antioxidant 1.5 parts (the antioxidant was a compound of primary antioxidant (1010) and secondary antioxidant (168) at a mass ratio of 1:0.3), then double screw extrusion granulation was carried out, and the temperature of each zone of the double screw extruder was as follows:

[0057]

[0058] The screw speed was set to 450 rpm, and after granulation, drying was carried out, and after the completion of granulation and extrusion, the granules were dried at a temperature of 40°C, and the moisture content of the dried material was below 0.30%, obtaining plastic particles.

[0059] Example 2

[0060] Linear low density polyethylene was mixed with ultra-high molecular weight polyethylene at a mass ratio of 6:4, and maleic anhydride (1.5 wt%), dicumyl peroxide (0.2 wt%), zinc stearate (0.5 wt%) were prepared based on the total resin mass. Then, using an intermeshing internal mixer equipped with an oval rotor, the rotor speed was 40 rpm, the mixing chamber was preheated to 180°C for 10 min, then the UHMWPE / LLDPE mixture, dicumyl peroxide, zinc stearate were added, the mixing time was 3 minutes, the speed was 40 rpm, the temperature was 170°C; at 4-6 minutes, 50% MAH was added, the speed was increased to 50 rpm, the temperature was 180°C; at 7-10 minutes: 30% MAH was added, the temperature was 190°C, the speed was 60 rpm; at 11-15 minutes: the remaining 20% MAH was added, the speed was reduced to 50 rpm, the temperature was 170°C; discharge, named grafted polyethylene.

[0061] POE 80 wt%, EVA 20 wt% were prepared, ethyl acetate solvent was added, the mass volume ratio of raw materials to ethyl acetate was 1 g: 10 ml, ultrasonic treatment was carried out at 40 kHz for 30 min, then blending was carried out in a stirrer at 50°C with a rotor speed of 1200 rpm for 60 min, after distilling off the solvent at normal pressure, the mixed sample was crushed to normal plastic particle size by a crusher, and a sample named POEcoEVA was obtained.

[0062] Double screw blending granulation was carried out, and the proportions were as follows: grafted polyethylene 70 parts, POEcoEVA 30 parts, polyethylene wax 2 parts, hindered amine particles 1.5 parts, antioxidant 1.5 parts (the antioxidant was a compound of primary antioxidant (1010) and auxiliary antioxidant (168) at a mass ratio of 1:0.3), then double screw extrusion granulation was carried out, and the temperature of each zone of the double screw extruder was as follows:

[0063]

[0064] The screw speed was set to 400 rpm, and after granulation, drying was carried out, and after the completion of granulation and extrusion, the granules were dried at a temperature of 40°C, and the moisture content of the dried material was below 0.30%, and plastic particles were obtained.

[0065] Example 3

[0066] Linear low density polyethylene was mixed with ultra-high molecular weight polyethylene at a mass ratio of 6:4, and maleic anhydride (1.75 wt%), dicumyl peroxide (0.3 wt%), zinc stearate (0.5 wt%) were prepared based on the total resin mass. Then using an intermeshing internal mixer, equipped with an oval rotor, the rotor speed was 40 rpm, the mixing chamber was preheated to 180°C for 10 min, then the UHMWPE / LLDPE mixture, dicumyl peroxide, zinc stearate were added, the mixing time was 3 minutes, the rotor speed was 40 rpm, the temperature was 170°C; at 4-6 minutes, 50% MAH was added, the rotor speed was increased to 50 rpm, the temperature was 180°C; at 7-10 minutes: 30% MAH was added, the temperature was 190°C, the rotor speed was 60 rpm; at 11-15 minutes: the remaining 20% MAH was added, the rotor speed was reduced to 50 rpm, the temperature was 170°C; discharge, named grafted polyethylene.

[0067] POE 80 wt% and EVA 20 wt% were prepared, ethyl acetate solvent was added, the mass volume ratio of raw materials to ethyl acetate was 1 g: 10 ml, ultrasonic treatment was carried out at 40 kHz for 30 min, then the mixture was blended in a stirrer at 50°C for 60 min at a rotor speed of 1200 rpm, and the solvent was removed by atmospheric distillation. The resulting mixed sample was crushed to normal plastic particle size by a crusher, and the sample was named POEcoEVA.

[0068] Double screw blending granulation was carried out, and the proportions were as follows: grafted polyethylene 70 parts, POEcoEVA 30 parts, polyethylene wax 2 parts, hindered amine particles 1.5 parts, antioxidant 1.5 parts (the antioxidant was a compound of primary antioxidant (1010) and auxiliary antioxidant (168) at a mass ratio of 1:0.3), then double screw extrusion granulation was carried out, and the temperature of each zone of the double screw extruder was as follows:

[0069]

[0070] The screw speed was set to 400 rpm, and after granulation, drying was carried out. After the completion of granulation and extrusion, the granules were dried at a temperature of 40°C, and the moisture content of the dried material was below 0.30%, obtaining plastic particles.

[0071] Example 4

[0072] Linear low-density polyethylene (LLDPE) and ultra-high molecular weight polyethylene (UHMWPE) were mixed at a mass ratio of 6:4. Maleic anhydride (1.75 wt%), dicumyl peroxide (0.3 wt%), and zinc stearate (0.5 wt%) were prepared based on the total resin mass. A meshing internal mixer equipped with an elliptical rotor was then used. The rotor speed was 40 rpm. After preheating the mixing chamber to 180°C and holding for 10 minutes, the UHMWPE / LLDPE mixture, dicumyl peroxide, and zinc stearate were added. The mixing time was 3 minutes, the speed was 40 rpm, and the temperature was 170°C. From the 4th to 6th minute, 50% MAH was added, the speed was increased to 50 rpm, and the temperature was 180°C. From the 7th to 10th minute, 30% MAH was added, the temperature was 190°C, and the speed was 60 rpm. From the 11th to 15th minute, the remaining 20% ​​MAH was added, the speed was reduced to 50 rpm, and the temperature was 170°C. The resulting product was discharged and named grafted polyethylene.

[0073] Prepare 80wt% POE and 20wt% EVA, add ethyl acetate solvent, with a mass-to-volume ratio of raw material to ethyl acetate of 1g:10ml, sonicate at 40kHz for 30min, then mix in a stirrer at 50℃ with a rotor speed of 1200 rpm for 60min. After removing the solvent by atmospheric distillation, the resulting mixed sample is crushed to the size of normal plastic particles by a crusher, and the sample is named POEcoEVA.

[0074] Twin-screw compounding and granulation were carried out, with the following proportions by weight: 75 parts grafted polyethylene, 25 parts POEcoEVA, 2 parts polyethylene wax, 1.5 parts hindered amine particles, and 1.5 parts antioxidant (the antioxidant is a compound of the main antioxidant (1010) and the auxiliary antioxidant (168) at a mass ratio of 1:0.3). Twin-screw extrusion granulation was then performed, and the temperatures of each zone of the twin-screw extruder were as follows:

[0075]

[0076] The screw speed is set to 400 rpm. After granulation, the material is dried. After granulation and extrusion, the granules are dried at 40℃. The moisture content of the dried material is below 0.30%, thus obtaining plastic granules.

[0077] Example 5

[0078] Linear low density polyethylene was mixed with ultra-high molecular weight polyethylene at a mass ratio of 6:4, and maleic anhydride (1.75 wt%), dicumyl peroxide (0.3 wt%), zinc stearate (0.5 wt%) were prepared based on the total resin mass. Then using an intermeshing internal mixer, equipped with an oval rotor, the rotor speed was 40 rpm, the mixing chamber was preheated to 180°C for 10 min, then the UHMWPE / LLDPE mixture, dicumyl peroxide, zinc stearate were added, the mixing time was 3 minutes, the rotor speed was 40 rpm, the temperature was 170°C; at 4-6 minutes, 50% MAH was added, the rotor speed was increased to 50 rpm, the temperature was 180°C; at 7-10 minutes: 30% MAH was added, the temperature was 190°C, the rotor speed was 60 rpm; at 11-15 minutes: the remaining 20% MAH was added, the rotor speed was reduced to 50 rpm, the temperature was 170°C; discharge, named grafted polyethylene.

[0079] POE 80 wt%, EVA 20 wt% were prepared, ethyl acetate solvent was added, the mass volume ratio of raw materials to ethyl acetate was 1 g: 10 ml, ultrasonic treatment was carried out at 40 kHz for 30 min, then the mixture was blended in a stirrer at 50°C for 60 min at a rotor speed of 1200 rpm, the solvent was removed by atmospheric distillation, and the obtained mixed sample was crushed to normal plastic particle size by a crusher, and the sample was named POEcoEVA.

[0080] Double screw blending granulation was carried out, and the proportions were as follows: grafted polyethylene 85 parts, POEcoEVA 15 parts, polyethylene wax 2 parts, hindered amine particles 1.5 parts, antioxidant 1.5 parts (the antioxidant was a compound of primary antioxidant (1010) and auxiliary antioxidant (168) at a mass ratio of 1:0.3), then double screw extrusion granulation was carried out, and the temperature of each zone of the double screw extruder was as follows:

[0081]

[0082] The screw speed was set to 400 rpm, and after granulation, drying was carried out, and after the completion of granulation and extrusion, the granules were dried at a temperature of 40°C, and the moisture content of the dried material was below 0.30%, and plastic particles were obtained.

[0083] Example 6

[0084] Linear low density polyethylene was mixed with ultra high molecular weight polyethylene at a mass ratio of 6.5:3.5, and maleic anhydride (2 wt%), dicumyl peroxide (0.2 wt%), zinc stearate (0.25 wt%) were prepared based on the total resin mass. Then using an intermeshing internal mixer, equipped with an oval rotor, the rotor speed was 40 rpm, the mixing chamber was preheated to 180°C for 10 min, then the mixture of UHMWPE / LLDPE, dicumyl peroxide and zinc stearate was added, the mixing time was 3 minutes, the rotor speed was 40 rpm, the temperature was 170°C; at 4-6 minutes, 50% MAH was added, the rotor speed was increased to 50 rpm, the temperature was 180°C; at 7-10 minutes: 30% MAH was added, the temperature was 190°C, the rotor speed was 60 rpm; at 11-15 minutes: the remaining 20% MAH was added, the rotor speed was reduced to 50 rpm, the temperature was 170°C; discharge, named grafted polyethylene.

[0085] POE 70 wt% and EVA 30 wt% were prepared, ethyl acetate solvent was added, the mass volume ratio of raw materials to ethyl acetate was 1 g:5 ml, ultrasonic treatment was carried out at 40 kHz for 30 min, then the mixture was blended in a stirrer at 50°C for 60 min at a rotor speed of 1200 rpm, and the solvent was removed by atmospheric distillation. The resulting mixed sample was crushed to normal plastic particle size by a crusher, and the sample was named POEcoEVA.

[0086] Double screw blending granulation was carried out, and the proportions were as follows: grafted polyethylene 70 parts, POEcoEVA 30 parts, polyethylene wax 4 parts, hindered amine particles 2 parts, antioxidant 3 parts (the antioxidant was a main antioxidant (1010) and a secondary antioxidant (168) compounded at a mass ratio of 1:0.3), then double screw extrusion granulation was carried out, and the temperature of each zone of the double screw extruder was as follows:

[0087]

[0088] The screw speed was set to 450 rpm, and after granulation, drying was carried out. After the completion of granulation and extrusion, the granules were dried at a temperature of 40°C. The moisture content of the dried material was below 0.30%, and plastic particles were obtained.

[0089] Example 7

[0090] Linear low density polyethylene was mixed with ultra high molecular weight polyethylene at a mass ratio of 5.5:4.5, and maleic anhydride (1.5 wt%), dicumyl peroxide (0.2 wt%), zinc stearate (1 wt%) were prepared based on the total resin mass. Then using an intermeshing internal mixer, equipped with an oval rotor, the rotor speed was set at 40 rpm, the mixing chamber was preheated to 180 °C for 10 min, then the mixture of UHMWPE / LLDPE, dicumyl peroxide and zinc stearate was added, the mixing time was 3 minutes, the rotor speed was 40 rpm, the temperature was 170 °C; at 4-6 min, 50% MAH was added, the rotor speed was increased to 50 rpm, the temperature was 180 °C; at 7-10 min: 30% MAH was added, the temperature was 190 °C, the rotor speed was 60 rpm; at 11-15 min: the remaining 20% MAH was added, the rotor speed was reduced to 50 rpm, the temperature was 170 °C; the material was discharged and named as grafted polyethylene.

[0091] POE 90 wt% and EVA 10 wt% were prepared, ethyl acetate solvent was added, the mass volume ratio of raw materials to ethyl acetate was 1 g: 15 ml, ultrasonic treatment was carried out at 40 kHz for 30 min, then the mixture was blended in a stirrer at 50 °C for 60 min at a rotor speed of 1200 rpm, the solvent was removed by atmospheric distillation, and the obtained mixed sample was crushed to normal plastic particle size by a crusher, and a sample named POEcoEVA was obtained.

[0092] Double screw blending granulation was carried out, and the proportions of grafting polyethylene 70 parts, POEcoEVA 30 parts, polyethylene wax 2 parts, hindered amine particles 1 part, and antioxidant 1 part (the antioxidant was a main antioxidant (1010) and a secondary antioxidant (168) compounded at a mass ratio of 1:0.3) were prepared, then double screw extrusion granulation was carried out, and the temperature of each zone of the double screw extruder was as follows:

[0093]

[0094] The screw speed was set at 450 rpm, and after granulation, drying was carried out, and after the completion of granulation and extrusion, the granules were dried at a temperature of 40 °C, and the moisture content of the dried material was below 0.30%, and plastic particles were obtained.

[0095] Example 8

[0096] Linear low density polyethylene was mixed with ultra-high molecular weight polyethylene at a mass ratio of 6:4, and maleic anhydride (1.5 wt%), dicumyl peroxide (0.1 wt%), zinc stearate (0.5 wt%) were prepared based on the total resin mass. Then, using an intermeshing internal mixer equipped with an oval rotor, the rotor speed was 40 rpm, the mixing chamber was preheated to 175°C for 10 min, then the mixture of UHMWPE / LLDPE, dicumyl peroxide and zinc stearate was added, the mixing time was 2 min, the speed was 20 rpm, the temperature was 165°C; at 3-6 min, 40% MAH was added, the speed was increased to 45 rpm, the temperature was 175°C; at 7-9 min: 20% MAH was added, the temperature was 185°C, the speed was 55 rpm; at 10-15 min: the remaining 40% MAH was added, the speed was reduced to 35 rpm, the temperature was 165°C; discharge, named grafted polyethylene.

[0097] POE 80 wt% and EVA 20 wt% were prepared, ethyl acetate solvent was added, the mass volume ratio of raw materials to ethyl acetate was 1 g: 10 ml, ultrasonic treatment was carried out at 40 kHz for 30 min, then blending was carried out in a stirrer at 50°C with a rotor speed of 1200 rpm for 60 min, the solvent was removed by atmospheric distillation, and the resulting mixed sample was crushed to normal plastic particle size by a crusher to obtain a sample named POEcoEVA.

[0098] Double screw blending granulation was carried out, the proportions were as follows: grafted polyethylene 70 parts, POEcoEVA 30 parts, polyethylene wax 2 parts, hindered amine particles 1.5 parts, antioxidant 1.5 parts (the antioxidant was a compound of primary antioxidant (1010) and auxiliary antioxidant (168) at a mass ratio of 1:0.3), then double screw extrusion granulation was carried out, and the temperature of each zone of the double screw extruder was as follows:

[0099]

[0100] The screw speed was set to 450 rpm, and after granulation, drying was carried out, and after the completion of granulation and extrusion, the granules were dried at a temperature of 40°C, and the moisture content of the dried material was below 0.30%, obtaining plastic particles.

[0101] Example 9

[0102] Linear low density polyethylene was mixed with ultra-high molecular weight polyethylene at a mass ratio of 6:4, and maleic anhydride (1.5 wt%), dicumyl peroxide (0.1 wt%), zinc stearate (0.5 wt%) were prepared based on the total resin mass. Then, using an intermeshing internal mixer equipped with an oval rotor, the rotor speed was 40 rpm, the mixing chamber was preheated to 185°C for 10 min, then the mixture of UHMWPE / LLDPE, dicumyl peroxide and zinc stearate was added, the mixing time was 4 min, the speed was 40 rpm, the temperature was 175°C; at 5-6 min, 60% MAH was added, the speed was increased to 55 rpm, the temperature was 185°C; at 7-11 min: 35% MAH was added, the temperature was 195°C, the speed was 60 rpm; at 12-17 min: the remaining 5% MAH was added, the speed was reduced to 50 rpm, the temperature was 175°C; discharge, named grafted polyethylene.

[0103] POE 80 wt% and EVA 20 wt% were prepared, ethyl acetate solvent was added, the mass volume ratio of raw materials to ethyl acetate was 1 g: 10 ml, ultrasonic treatment was carried out at 40 kHz for 30 min, then blending was carried out in a stirrer at 50°C with a rotor speed of 1200 rpm for 60 min, the solvent was removed by atmospheric distillation, and the resulting mixed sample was crushed to normal plastic particle size by a crusher to obtain a sample named POEcoEVA.

[0104] Double screw blending granulation was carried out, the proportions were as follows: grafted polyethylene 70 parts, POEcoEVA 30 parts, polyethylene wax 2 parts, hindered amine particles 1.5 parts, antioxidant 1.5 parts (the antioxidant was a compound of primary antioxidant (1010) and auxiliary antioxidant (168) at a mass ratio of 1:0.3), then double screw extrusion granulation was carried out, and the temperature of each zone of the double screw extruder was as follows:

[0105]

[0106] The screw speed was set to 450 rpm, and after granulation, drying was carried out, and after the completion of granulation and extrusion, the granules were dried at a temperature of 40°C, and the moisture content of the dried material was below 0.30%, obtaining plastic particles.

[0107] Comparative Example 1

[0108] Linear low density polyethylene was mixed with ultra-high molecular weight polyethylene at a mass ratio of 6:4, and dicumyl peroxide (0.1 wt%) and zinc stearate (0.5 wt%) were prepared based on the total resin mass. Then, using an intermeshing internal mixer equipped with an oval rotor, the rotor speed was 40 rpm, the mixing chamber was preheated to 180°C for 10 min, and then the UHMWPE / LLDPE mixture, dicumyl peroxide, and zinc stearate were added. The mixing time was 3 min, the rotor speed was 40 rpm, and the temperature was 170°C. From the 4th to the 6th minute, the rotor speed was increased to 50 rpm and the temperature was 180°C. From the 7th to the 10th minute, the temperature was increased to 190°C and the rotor speed was increased to 60 rpm. From the 11th to the 15th minute, the rotor speed was reduced to 50 rpm and the temperature was reduced to 170°C. The material was discharged and named polyethylene material.

[0109] POE 80 wt% and EVA 20 wt% were prepared, and ethyl acetate solvent was added at a mass to volume ratio of 1 g:10 ml. The mixture was ultrasonically treated at 40 kHz for 30 min, and then blended in a stirrer at 50°C with a rotor speed of 1200 rpm for 60 min. After removing the solvent by atmospheric distillation, the resulting mixture was crushed to normal plastic particle size using a crusher, and the sample was named POE co EVA.

[0110] Double screw blending granulation was performed, and the following components were mixed in parts by weight: polyethylene material 70 parts, POE co EVA 30 parts, polyethylene wax 2 parts, hindered amine particles 1.5 parts, and antioxidant 1.5 parts (the antioxidant was a mixture of primary antioxidant (1010) and secondary antioxidant (168) at a mass ratio of 1:0.3). Then, double screw extrusion granulation was performed, and the temperature of each zone of the double screw extruder was as follows:

[0111]

[0112] The screw speed was set to 450 rpm, and after granulation, the granules were dried. After the completion of the granulation and extrusion, the granules were dried at a temperature of 40°C. The moisture content of the dried material was below 0.30%, and plastic particles were obtained.

[0113] Comparative Example 2

[0114] Prepare UHMWPE, and prepare maleic anhydride (1.5 wt%) based on the total resin mass; dicumyl peroxide (0.1 wt%); zinc stearate (0.5 wt%). Then use an intermeshing type internal mixer, equipped with an oval rotor, the rotor speed is 40 rpm, the mixing chamber is preheated to 180°C for 10 min, then UHMWPE, dicumyl peroxide, zinc stearate are added, the mixing time is 3 minutes, the speed is 40 rpm, the temperature is 170°C; at 4-6 minutes, add 50% MAH, the speed is increased to 50 rpm, the temperature is 180°C; at 7-10 minutes: add 30% MAH, the temperature is 190°C, the speed is 60 rpm; at 11-15 minutes: add the remaining 20% MAH, the speed is reduced to 50 rpm, the temperature is 170°C; discharge, named as grafted polyethylene.

[0115] Prepare POE 80 wt%, EVA 20 wt%, add ethyl acetate solvent, the mass-volume ratio of raw materials to ethyl acetate is 1 g: 10 ml, ultrasonic treatment at 40 kHz for 30 min, then blend in a stirrer at 50°C for 60 min at a rotor speed of 1200 rpm, after removing the solvent by atmospheric distillation, the obtained mixed sample is crushed to normal plastic particle size by a crusher, and a sample named POEcoEVA is obtained.

[0116] Carry out double screw blending granulation, according to weight parts: grafted polyethylene 70 parts, POEcoEVA 30 parts, polyethylene wax 2 parts, hindered amine particles 1.5 parts, antioxidant 1.5 parts (antioxidant is a main antioxidant (1010) and auxiliary antioxidant (168) compounded at a mass ratio of 1:0.3), then carry out double screw extrusion granulation, the temperature of each zone of the double screw extruder is as follows:

[0117]

[0118] The screw speed is set to 450 rpm, and after granulation, drying is carried out, and after the completion of granulation and extrusion, the granules are dried at a temperature of 40°C, and the moisture content of the dried material is below 0.30%, obtaining plastic particles.

[0119] Comparative Example 3

[0120] Prepare linear low density polyethylene, and prepare maleic anhydride (1.5 wt%) based on the total resin mass; dicumyl peroxide (0.1 wt%); zinc stearate (0.5 wt%). Then use an intermeshing type internal mixer, equipped with an oval rotor, the rotor speed is 40 rpm, the mixing chamber is preheated to 180°C for 10 min, then add LLDPE, dicumyl peroxide, zinc stearate, mixing time is 3 minutes, rotor speed is 40 rpm, temperature is 170°C; at 4-6 minutes, add 50% MAH, the speed is increased to 50 rpm, the temperature is 180°C; at 7-10 minutes: add 30% MAH, temperature 190°C, speed 60 rpm; at 11-15 minutes: add the remaining 20% MAH, speed down to 50 rpm, temperature 170°C; discharge, named as grafted polyethylene.

[0121] Prepare POE 80 wt%, EVA 20 wt%, add ethyl acetate solvent, the mass-volume ratio of raw materials to ethyl acetate is 1 g: 10 ml, ultrasonic treatment at 40 kHz for 30 min, then blend in a stirrer at 50°C with a rotor speed of 1200 rpm for 60 min, after removing the solvent by atmospheric distillation, the obtained mixed sample is crushed to normal plastic particle size by a crusher, and a sample named POEcoEVA is obtained.

[0122] Carry out double screw blending granulation, according to weight parts: grafted polyethylene 70 parts, POEcoEVA 30 parts, polyethylene wax 2 parts, hindered amine particles 1.5 parts, antioxidant 1.5 parts (antioxidant is a main antioxidant (1010) and a secondary antioxidant (168) compounded at a mass ratio of 1:0.3), then carry out double screw extrusion granulation, the temperature of each zone of the double screw extruder is as follows:

[0123]

[0124] The screw speed is set to 450 rpm, and after granulation, drying is carried out, and after the completion of granulation and extrusion, the granules are dried at a temperature of 40°C, and the moisture content of the dried material is below 0.30%, obtaining plastic particles.

[0125] Comparative Example 4

[0126] Linear low-density polyethylene (LLDPE) and ultra-high molecular weight polyethylene (UHMWPE) were mixed at a mass ratio of 6:4. Maleic anhydride (1.5 wt%), dicumyl peroxide (0.2 wt%), and zinc stearate (0.5 wt%) were prepared based on the total resin mass. A meshing internal mixer equipped with an elliptical rotor was then used. The rotor speed was 40 rpm. After preheating the mixing chamber to 180°C and holding for 10 minutes, the UHMWPE / LLDPE mixture, dicumyl peroxide, and zinc stearate were added. The mixing time was 3 minutes, the speed was 40 rpm, and the temperature was 170°C. From the 4th to 6th minute, 50% MAH was added, the speed was increased to 50 rpm, and the temperature was 180°C. From the 7th to 10th minute, 30% MAH was added, the temperature was 190°C, and the speed was 60 rpm. From the 11th to 15th minute, the remaining 20% ​​MAH was added, the speed was reduced to 50 rpm, and the temperature was 170°C. The resulting product was discharged and named grafted polyethylene.

[0127] Ethyl acetate solvent was added to POE at a mass-to-volume ratio of 1g:10ml. The mixture was ultrasonically treated at 40kHz for 30min, and then blended in a stirrer at 50℃ with a rotor speed of 1200 rpm for 60min. After removing the solvent by atmospheric distillation, the resulting solid sample was crushed to the size of normal plastic particles using a crusher. The sample was named treated POE.

[0128] Twin-screw compounding and granulation were carried out, with the following proportions by weight: 70 parts grafted polyethylene, 30 parts treated POE, 2 parts polyethylene wax, 1.5 parts hindered amine particles, and 1.5 parts antioxidant (the antioxidant is a compound of the main antioxidant (1010) and the auxiliary antioxidant (168) at a mass ratio of 1:0.3). Twin-screw extrusion granulation was then performed, and the temperatures of each zone of the twin-screw extruder were as follows:

[0129]

[0130] The screw speed is set to 400 rpm. After granulation, the material is dried. After granulation and extrusion, the granules are dried at 40℃. The moisture content of the dried material is below 0.30%, thus obtaining plastic granules.

[0131] Comparative Example 5

[0132] Linear low density polyethylene was mixed with ultra-high molecular weight polyethylene at a mass ratio of 6:4, and maleic anhydride (1.5 wt%), dicumyl peroxide (0.2 wt%), zinc stearate (0.5 wt%) were prepared based on the total resin mass. Then using an intermeshing mixer equipped with an oval rotor, the rotor speed was 40 rpm, the mixing chamber was preheated to 180°C for 10 min, then the UHMWPE / LLDPE mixture, dicumyl peroxide, zinc stearate were added, the mixing time was 3 minutes, the speed was 40 rpm, the temperature was 170°C; at 4-6 minutes, 50% MAH was added, the speed was increased to 50 rpm, the temperature was 180°C; at 7-10 minutes: 30% MAH was added, the temperature was 190°C, the speed was 60 rpm; at 11-15 minutes: the remaining 20% MAH was added, the speed was reduced to 50 rpm, the temperature was 170°C; discharge, named as grafted polyethylene.

[0133] Ethyl acetate solvent was added to EVA, the mass-volume ratio of raw material to ethyl acetate was 1g:10ml, ultrasonic treatment at 40kHz for 30min, then blending at 50°C in a stirrer at a rotor speed of 1200rpm for 60min, the solvent was removed by atmospheric distillation, and the resulting mixed sample was crushed to normal plastic particle size by a crusher, to obtain a sample named as treated EVA.

[0134] Double screw blending granulation was carried out, the ratio of grafting polyethylene 70 parts, treated EVA 30 parts, polyethylene wax 2 parts, hindered amine particles 1.5 parts, antioxidant 1.5 parts (antioxidant is the main antioxidant (1010) and auxiliary antioxidant (168) compounded at a mass ratio of 1:0.3) was prepared, then double screw extrusion granulation was carried out, the temperature of each zone of the double screw extruder was as follows:

[0135]

[0136] The screw speed was set to 400 rpm, and after granulation, drying was carried out, after the completion of granulation and extrusion, the granules were dried at a temperature of 40°C, the moisture content of the dried material was below 0.30%, and plastic particles were obtained.

[0137] Comparative Example 6

[0138] Linear low density polyethylene was mixed with ultra-high molecular weight polyethylene at a mass ratio of 6:4, and maleic anhydride (1.5 wt%), dicumyl peroxide (0.2 wt%), zinc stearate (0.5 wt%) were prepared based on the total resin mass. Then, using an intermeshing internal mixer equipped with an oval rotor, the rotor speed was set to 40 rpm, and the mixing chamber was preheated to 180°C for 10 min. After that, the UHMWPE / LLDPE mixture, dicumyl peroxide, and zinc stearate were added, and the mixing time was 3 min, the rotor speed was 40 rpm, and the temperature was 170°C. At the 4th-6th minute, 50% MAH was added, the rotor speed was increased to 50 rpm, and the temperature was 180°C. At the 7th-10th minute, 30% MAH was added, the temperature was 190°C, and the rotor speed was 60 rpm. At the 11th-15th minute, the remaining 20% MAH was added, the rotor speed was reduced to 50 rpm, and the temperature was 170°C. The material was discharged and named as grafted polyethylene.

[0139] POE 80 wt% and EVA 20 wt% were prepared and subjected to twin-screw extrusion blending with the following screw conditions:

[0140]

[0141] The screw speed was set to 200 rpm, and after granulation, drying was performed. After the completion of granulation extrusion, the granules were dried at a temperature of 40°C, and the moisture content of the dried material was below 0.30%. The sample was named as POE co EVA.

[0142] Twin-screw blending granulation was performed with the following proportions by weight: grafted polyethylene 70 parts, POE co EVA 30 parts, polyethylene wax 2 parts, hindered amine particles 1.5 parts, and antioxidant 1.5 parts (the antioxidant was a compound of primary antioxidant (1010) and secondary antioxidant (168) at a mass ratio of 1:0.3). Then, twin-screw extrusion granulation was performed, and the temperature of each zone of the twin-screw extruder was as follows:

[0143]

[0144] The screw speed was set to 400 rpm, and after granulation, drying was performed. After the completion of granulation extrusion, the granules were dried at a temperature of 40°C, and the moisture content of the dried material was below 0.30%. Plastic granules were obtained.

[0145] Comparative Example 7

[0146] Linear low density polyethylene was mixed with ultra high molecular weight polyethylene in a mass ratio of 6:4 and prepared based on the total resin mass maleic anhydride (1.75 wt%), dicumyl peroxide (0.3 wt%), zinc stearate (0.5 wt%). Then using an intermeshing internal mixer, equipped with an oval rotor, the rotor speed was 40 rpm, the mixing chamber was preheated to 180 °C for 10 min, then the UHMWPE / LLDPE mixture, dicumyl peroxide, zinc stearate were added, the mixing time was 3 minutes, the rotor speed was 40 rpm, the temperature was 170 °C; at 4-6 minutes, 50% MAH was added, the rotor speed was increased to 50 rpm, the temperature was 180 °C; at 7-10 minutes: 30% MAH was added, the temperature was 190 °C, the rotor speed was 60 rpm; at 11-15 minutes: the remaining 20% MAH was added, the rotor speed was reduced to 50 rpm, the temperature was 170 °C; discharge, named as grafted polyethylene.

[0147] POE 80 wt%, EVA 20 wt% was prepared, ethyl acetate solvent was added, the mass volume ratio of raw materials to ethyl acetate was 1 g: 10 ml, ultrasonic treatment was carried out at 40 kHz for 30 min, then the mixture was blended in a stirrer at 50 °C for 60 min at a rotor speed of 1200 rpm, and the solvent was removed by atmospheric distillation. The obtained mixed sample was crushed to normal plastic particle size by a crusher, and the sample was named as POEcoEVA.

[0148] Double screw blending granulation was carried out, according to weight parts: grafted polyethylene 70 parts, POEcoEVA 30 parts, polyethylene wax 2 parts, then double screw extrusion granulation was carried out, and the temperature of each zone of the double screw extruder was as follows:

[0149]

[0150] The screw speed was set to 400 rpm, and after granulation, drying was carried out. After the completion of the granulation extrusion, the granules were dried at a temperature of 40 °C, and the moisture content of the dried material was below 0.30%, obtaining plastic particles.

[0151] Comparative Example 8

[0152] Linear low density polyethylene was mixed with ultra-high molecular weight polyethylene at a mass ratio of 6:4, and maleic anhydride (1.5 wt%), dicumyl peroxide (0.1 wt%), zinc stearate (0.5 wt%) were prepared based on the total resin mass. Then, using an intermeshing internal mixer equipped with an oval rotor, the rotor speed was 40 rpm, the mixing chamber was preheated to 180°C for 10 min, then the mixture of UHMWPE / LLDPE, dicumyl peroxide and zinc stearate was added, the mixing time was 3 min, the speed was 40 rpm, the temperature was 170°C; at 4-6 min, 50% MAH was added, the speed was increased to 50 rpm, the temperature was 180°C; at 7-10 min: 30% MAH was added, the temperature was 190°C, the speed was 60 rpm; at 11-15 min: the remaining 20% MAH was added, the speed was reduced to 50 rpm, the temperature was 170°C; discharge, named grafted polyethylene.

[0153] POE 80 wt% and EVA 20 wt% were prepared, ethyl acetate solvent was added, the mass volume ratio of raw materials to ethyl acetate was 1 g: 10 ml, ultrasonic treatment was carried out at 40 kHz for 30 min, then blending was carried out in a stirrer at 50°C with a rotor speed of 1200 rpm for 60 min, the solvent was removed by atmospheric distillation, and the resulting mixed sample was crushed to normal plastic particle size by a crusher to obtain a sample named POEcoEVA.

[0154] Double screw blending granulation was carried out, the proportions were as follows: grafted polyethylene 70 parts, POEcoEVA 30 parts, zinc stearate 2 parts, hindered amine particles 1.5 parts, antioxidant 1.5 parts (the antioxidant was a compound of primary antioxidant (1010) and auxiliary antioxidant (168) at a mass ratio of 1:0.3), then double screw extrusion granulation was carried out, the temperature of each zone of the double screw extruder was as follows:

[0155]

[0156] The screw speed was set to 450 rpm, and after granulation, drying was carried out, after the completion of granulation and extrusion, the granules were dried, the temperature was 40°C, the moisture content of the dried material was below 0.30%, and plastic particles were obtained.

[0157] Effect Example 1

[0158] The plastic particles in Examples 1-2, Examples 6-7 and Comparative Examples 1-6, Comparative Example 8 were hot-pressed using a vacuum hot press, pre-melted for 5 min, pressurized for 5 min at 10 MPa, relaxed for 1 min, and then cooled at room temperature, and hot-pressed into standard samples with a thickness of 2 mm. Tensile tests were performed on different samples at room temperature to measure the room temperature breaking strength and room temperature breaking elongation (GB / T 1040.2-2022); -50°C impact strength tests (GB / T 1843-2008) were performed by pre-placing the samples at the test temperature for more than 2 h, and then quickly testing after removal; and bending modulus was measured by a bending performance test at room temperature (GB / T 9341-2008). Three parallel experiments were set for each test.

[0159] The results of Examples 1, Examples 6-7, Comparative Examples 1-3, and Comparative Example 8 are shown in Table 1.

[0160] Table 1

[0161]

[0162] The results of Examples 2 and Comparative Examples 4-6 are shown in Table 2.

[0163] Table 2

[0164]

[0165] Example 2

[0166] In this example, the thermal-oxidative aging test was performed in accordance with the standard GB / T 3512-2014.

[0167] The xenon lamp irradiation test was performed in accordance with the standard GB / T 16422.2-2014, with a wavelength of 340 nm and an irradiance of 0.51 W / m².

[0168] The particles in Example 3 and Comparative Example 7 were subjected to a single-screw extrusion experiment under the same conditions to form a plate, with a sample thickness of 2 mm and a width of 2 m. The temperature of each zone of the single-screw extruder was as follows:

[0169]

[0170] The extrusion speed was 1 m / min, and the temperature of the three-roll calender after extrusion was 60°C-70°C-60°C. The sample was then cooled at room temperature to obtain a standard sample with a thickness of 2 mm.

[0171] Afterwards, the different plastic plates were respectively subjected to tensile test at room temperature to determine the room temperature breaking strength and room temperature breaking elongation (GB / T 1040.2-2022), and after 70℃ thermal oxidation aging for 144h and xenon lamp irradiation for 250h, the aged tensile test was performed; after-50℃ drop hammer impact test (GB / T 14152-2001) and 70℃ thermal oxidation aging for 144h and xenon lamp irradiation for 250h, the aged-50℃ drop hammer impact test was performed. During low temperature test, the sample was placed at the test temperature for more than 2h, and then quickly taken out for test. Three parallel tests were set for the experiment, and the results are shown in Table 3:

[0172] Table 3

[0173]

[0174] Example 3

[0175] The particles of Examples 3-5 were subjected to injection molding test under the same conditions, and the injection molding sample size was 4mmx16cmx16cm. The barrel temperature was set as: feed zone 160℃-melt zone 220℃-nozzle 240℃, mold temperature 50℃, injection pressure 110MPa, holding pressure 40MPa, holding time 10s, screw speed 50rpm, cooling time 35s; 40℃ drying treatment for 1h, and a gasket product was obtained.

[0176] The different plastic plates were prepared into standard samples and subjected to tensile test at room temperature to determine the room temperature breaking strength and room temperature breaking elongation (GB / T 1040.2-2022);-50℃ impact strength test (according to GB / T1843-2008), and during low temperature test, the sample was placed at the test temperature for more than 2h, and then quickly taken out for test. Three parallel tests were set for the experiment, and the results are shown in Table 4:

[0177] Table 4

[0178]

[0179] Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and such modification or replacement does not make the essence of the corresponding technical solution deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A cold region low-temperature impact resistant polyethylene-based material, characterized by, It comprises the following raw material components in parts by weight: 70-85 parts of grafted polyethylene, 15-30 parts of POE and EVA blend, 2-4 parts of lubricant, 1-2 parts of stabilizer, 1-3 parts of antioxidant; The grafted polyethylene is made of the following raw materials in parts by weight: 55-65 parts of linear low density polyethylene, 35-45 parts of ultra-high molecular weight polyethylene, 1.5-2 parts of maleic anhydride, 0.1-0.3 parts of dicumyl peroxide and 0.25-1 parts of zinc stearate; The POE and EVA blend comprises the following components in weight percentage: 70-90wt% of POE and 10-30wt% of EVA.

2. The low-temperature impact resistant polyethylene-based material of claim 1, wherein, The preparation method of the grafted polyethylene is as follows: Step (1) preliminary mixing: The mixture of linear low density polyethylene, ultra-high molecular weight polyethylene, dicumyl peroxide and zinc stearate is added to the mixer preheated to 175-185℃, and mixed at 165-175℃, 20-40rpm for 2-4min; Step (2) mixing the raw materials with different gradients: a. First gradient: add 40-60% of maleic anhydride, increase the speed to 45-55rpm, temperature 175-185℃, mix for 2-4min; b. Middle gradient: add 20-35% of maleic anhydride, temperature 185-195℃, speed 55-60rpm, mix for 3-5min; c. Last gradient: add the remaining maleic anhydride, reduce the speed to 35-50rpm, temperature 165-175℃, mix for 4-6min, and then discharge to obtain the grafted polyethylene.

3. The low-temperature impact resistant polyethylene-based material of claim 1, wherein, The linear low density polyethylene has a density of 0.91-0.93g / cm³, a weight average molecular weight of 150000-200000, and a melt flow rate of 2-5g / 10min at 190℃ and 2.16kg; the ultra-high molecular weight polyethylene has a density of 0.940-0.96g / cm³, a weight average molecular weight of 1500000-2000000, and a melt flow rate of 0.02-0.08g / 10min at 190℃ and 2.16kg.

4. The low-temperature impact resistant polyethylene-based material of claim 1, wherein, The preparation method of the POE and EVA blend is as follows: mix POE and EVA, add solvent, ultrasonic treatment at 38-42KHz for 20-30min, then blend at 45-55℃, 1000-1300rpm for 40-60min, and recover the solvent to obtain the POE and EVA blend; The mass-volume ratio of the raw materials to the solvent is 1g:5ml-15ml; The solvent is selected from one of ethyl acetate, acetone and butyl acetate.

5. The low-temperature impact resistant polyethylene-based material of claim 1, wherein, The POE has a density of 0.84-0.88g / cm³ and a melt flow rate of 2-8g / 10min at 190℃ and 2.16kg; the EVA has a density of 0.92-0.94g / cm³ and a melt flow rate of 1.8-3.1g / 10min at 190℃ and 2.16kg.

6. The cold region low-temperature impact resistant polyethylene-based material of claim 1, wherein, The lubricant is polyethylene wax; The stabilizer is hindered amine or benzophenone; The antioxidant is selected from antioxidant 1010, antioxidant 168 or a mixture of antioxidant 1010 and antioxidant 168.

7. A process for the production of a cold-resistant, low-impact polyethylene-based material according to any one of claims 1 to 6, characterized in that, It comprises the following steps: Step 1: mixing grafted polyethylene, POE and EVA blend, lubricant, stabilizer, antioxidant, and using double screw blending granulation; Step 2: after the completion of granulation extrusion, drying the granules at 30-40 DEG C to obtain plastic particles; Step 3: preparing the cold region low-temperature impact resistant polyethylene-based material by hot press forming, injection molding or extrusion molding.

8. The method for preparing low-temperature impact-resistant polyethylene-based material for cold regions according to claim 7, characterized in that, The screw rotation speed in step 1 is 300-500 rpm, and the temperature interval of double screw granulation is as follows:

9. The cold region low-temperature impact resistant polyethylene-based material according to claim 1 is applied to railway pads.

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