CN112778598B - A kind of polyolefin composition and its preparation method and application - Google Patents

Abstract

The invention provides a polyolefin composition, which comprises polyalphaolefin, ultra-high molecular weight polyethylene, polyethylene wax and high-density polyethylene. Through the combined use of polyalphaolefin oil, ultra-high molecular weight polyethylene, polyethylene wax and high-density polyethylene, the mechanical properties and processability of the prepared polyolefin composition are greatly improved.

Description

A kind of polyolefin composition and its preparation method and application

technical field

The invention relates to the technical field of polymer materials, in particular to a polyolefin composition and its preparation method and application.

Background technique

High-density polyethylene is widely used in construction, industry, medicine, daily necessities manufacturing and other fields because of its good wear resistance, electrical insulation, toughness, cold resistance, and mechanical strength. However, high-density polyethylene also has certain shortcomings: poor mechanical properties, easy stress cracking, low surface hardness, etc., which seriously affect the use of high-density polyethylene. Ultra-high molecular weight polyethylene has many excellent properties such as ultra-light, high strength, wear resistance, corrosion resistance, impact resistance, and self-slip properties, so it is widely used in aerospace, military, sports equipment, medicine, industry and other fields. Blending high-density polyethylene and ultra-high molecular weight polyethylene can improve the performance of high-density polyethylene, enhance mechanical properties, surface hardness, processing performance, etc., and at the same time improve the problem of serious entanglement of ultra-high molecular weight polyethylene.

Chinese invention patent CN101003651A uses 50-90wt% ultra-high molecular weight polyethylene and 50-10wt% composite dispersant to blend, and then blends and granulates with elastomer and high-density polyethylene in a twin-screw extruder to achieve modification Purpose. However, the serious entanglement of ultra-high molecular weight polyethylene will affect the blending effect of ultra-high molecular weight polyethylene and high-density polyethylene.

Chinese invention patent CN103305954A blends polyalphaolefin oil and ultra-high molecular weight polyethylene to produce high-quality fibers under low energy consumption conditions such as low spinning temperature and low shear speed, and improves the disadvantage of ultra-high molecular weight polyethylene that is not easy to process . But this patent is only aimed at the modification method of ultra-high molecular weight polyethylene.

To sum up, at present, there is an urgent need to develop a new material to overcome the existing problems of high-density polyethylene, such as poor mechanical properties and easy stress cracking, and at the same time improve the problem of severe entanglement of ultra-high molecular weight polyethylene.

Contents of the invention

In view of the problems existing in the above-mentioned prior art, the object of the present invention is to provide a kind of polyolefin composition and its preparation method and application, through polyalphaolefin oil, ultra-high molecular weight polyethylene, polyethylene wax and high-density polyethylene Used together, the mechanical properties and processing properties of the prepared polyolefin composition are greatly improved.

One aspect of the present invention provides a polyolefin composition, the polyolefin composition comprising: polyalphaolefin, ultra-high molecular weight polyethylene, polyethylene wax and high-density polyethylene.

The inventors of the present application have found through research that ultra-high molecular weight polyethylene has a higher viscosity and high-density polyethylene has a lower viscosity, and the chain segments of ultra-high molecular weight polyethylene are longer, resulting in severe entanglement within and between chain segments. If UHMWPE and HDPE are directly blended, it is difficult to achieve better dispersion and mixing. When UHMWPE is mixed with PAO, UHMWPE swells, and at the same time, PAO expands the gaps between the lamellae, increases the distance between chain segments, and entangles within and between chain segments Relieved, mixed and dissolved to form a semi-dilute solution or a non-solution mixture. The added polyethylene wax acts as a lubricant. After adding high-density polyethylene and mixing, the molecular chain of ultra-high molecular weight polyethylene will pass through the interior of high-density polyethylene to form a "string crystal structure" for blending at the molecular level. The mechanical properties and processability of the modified mixture containing ultra-high molecular weight polyethylene and high-density polyethylene will be greatly improved.

According to the invention, polyalphaolefins may also be referred to as polyalphaolefin oils.

In some preferred embodiments of the present invention, in terms of parts by weight, the content of the polyalphaolefin is 1 to 10 parts, the content of the ultra-high molecular weight polyethylene is 0.1 to 1000 parts, and the content of the polyalphaolefin is 0.1 to 1000 parts. The content of the ethylene wax is 0.1-1000 parts, and the content of the high-density polyethylene is 1-1000 parts.

According to the present invention, in parts by weight, the content of the polyalphaolefin is 1-10 parts, the content of the ultra-high molecular weight polyethylene is 1-100 parts, and the content of the polyethylene wax is 1 part ~100 parts, the content of the high density polyethylene is 10 ~ 100 parts.

In some preferred embodiments of the present invention, the polyalphaolefin is selected from poly C ₃ -C ₁₉ alpha olefins, preferably the polyalphaolefin is selected from poly C _2n alpha olefins, wherein n is 2 to 9, More preferably, the polyalphaolefin is selected from at least one of polybutene-1, polyhexene-1, polyoctene-1, polydecene-1 and polydodecene-1.

According to the present invention, the polyalphaolefin is selected from poly C ₃ -C ₉ alpha olefins, preferably the polyalphaolefin is selected from poly C _2n alpha olefins, wherein n is 2-4.

In some preferred embodiments of the present invention, the polyalphaolefin has a molecular weight in the range of 150-1000 and a density in the range of 0.74 g/cm ³ -0.9 g/cm ³ .

According to the present invention, the molecular weight of the polyalphaolefin can be listed as 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950 and 1000.

According to the present invention, ^the density of the polyalphaolefin can be listed as 0.74g/cm ³ , 0.75g/cm 3 , 0.76g/cm ³ , 0.77g/cm ³ , 0.78g/cm ³ , 0.79g/cm ³ , 0.80g/cm ³ , 0.81g/cm ³ , 0.82g/cm ³ , 0.83g/cm ³ , 0.84g/cm ³ , 0.85g/cm ³ , 0.86g/cm ³ , 0.87g/cm ³ , 0.88g /cm ³ , 0.89 g/cm ³ and 0.9 g/cm ³ .

In some preferred embodiments of the present invention, the ultra-high molecular weight polyethylene has a molecular weight ranging from 1,000,000 to 1,000,000, and a density ranging from 0.925 g/cm ³ to 0.945 g/cm ³ .

According to the present invention, the molecular weight of the ultra -high molecular polyethylene polyethylene can be listed as 1000000, 1500,000, 200000, 2500,000, 3500,000, 4000000, 4500,000, 5500,000, 6000000, 700000,000, 75000000, 8500,000, 9000000, 9000000, 90000,000 9500000 and 10000000.

According to the present invention, the density of the ultra-high molecular weight polyethylene can be listed as 0.925g/cm ³ , 0.930g/cm ³ , 0.935g/cm ³ , 0.940g/cm ³ and 0.945g/cm ³ .

In some preferred embodiments of the present invention, the polyethylene wax has a molecular weight in the range of 2000-5000 and a density in the range of 0.93g/cm ³ -0.98g/cm ³ .

According to the present invention, the molecular weight of the polyethylene wax can be listed as 2000, 2500, 3000, 3500, 4000, 4500 and 5000.

According to the present invention, the density of the polyethylene wax can be listed as 0.93g/cm ³ , 0.935g/cm ^{3 , 0.94g/cm 3 ,} 0.945g/cm ³ , 0.95g/cm ³ , 0.955g/cm ³ , 0.96g/cm ³ , 0.965g/cm ³ , 0.97g/cm ³ , 0.975g/cm ³ and 0.98g/cm ³ .

In some preferred embodiments of the present invention, the molecular weight range of the high-density polyethylene is 50,000-200,000, and the density range is 0.935g/cm ³ -0.955g/cm ³ .

According to the present invention, the molecular weight of the high-density polyethylene can be listed as 50000, 60000, 70000, 80000, 90000, 100000, 110000, 120000, 130000, 140000, 150000, 160000, 170000, 180000, 190000 and 200000.

According to the present invention, the density of the high-density polyethylene can be listed as 0.935g/cm ³ , 0.940g/cm ³ , 0.945g/cm ³ , 0.950g/cm ³ and 0.955g/cm ³ .

In some preferred embodiments of the present invention, the molecular weight ratio of the polyalphaolefin to the ultra-high molecular weight polyethylene is 1:100-1:10000.

According to the present invention, the ratio of the molecular weight of the polyalphaolefin to the ultra-high molecular weight polyethylene can be listed as 1:100, 1:200, 1:300, 1:400, 1:500, 1:600, 1: 700, 1:800, 1:900, 1:1000, 1:1500, 1:2000, 1:2500, 1:3000, 1:3500, 1:4000, 1:4500, 1:5000, 1:5500, 1:6000, 1:6500, 1:7000, 1:7500, 1:8000, 1:8500, 1:9000, 1:9500, 1:10000.

In some preferred embodiments of the present invention, the molecular weight ratio of the polyethylene wax to the ultra-high molecular weight polyethylene is 1:200-1:5000.

According to the present invention, the ratio of the molecular weight of the polyethylene wax to the ultra-high molecular weight polyethylene can be listed as 1:200, 1:300, 1:400, 1:500, 1:600, 1:700, 1: 800, 1:900, 1:1000, 1:1100, 1:1200, 1:1300, 1:1400, 1:1500, 1:1600, 1:1700, 1:1800, 1:1900, 1:2000, 1:2100, 1:2200, 1:2300, 1:2400, 1:2500, 1:2600, 1:2700, 1:2800, 1:2900, 1:3000, 1:3100, 1:3200, 1:3000 3300, 1:3400, 1:3500, 1:3600, 1:3700, 1:3800, 1:3900, 1:4000, 1:4100, 1:4200, 1:4300, 1:4400, 1:4500, 1:4600, 1:4700, 1:4800, 1:4900 and 1:5000.

In some preferred embodiments of the present invention, the molecular weight ratio of the high-density polyethylene to the ultra-high molecular weight polyethylene is 1:2-1:50.

According to the present invention, the ratio of the molecular weight of the high-density polyethylene to the ultra-high molecular weight polyethylene can be 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1 :8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20 , 1:21, 1:22, 1:23, 1:24, 1:25, 1:26, 1:27, 1:28, 1:29, 1:30, 1:31, 1:32, 1 :33, 1:34, 1:35, 1:36, 1:37, 1:38, 1:39, 1:40, 1:41, 1:42, 1:43, 1:44, 1:45 , 1:46, 1:47, 1:48, 1:49, and 1:50.

In some preferred embodiments of the present invention, the tensile strength of the polyolefin composition is greater than 40 MPa, preferably greater than 60 MPa.

Another aspect of the present invention provides a method for preparing a polyolefin composition, comprising:

a) providing a semi-dilute solution or non-solution mixture comprising polyalphaolefin and ultra-high molecular weight polyethylene;

b) adding polyethylene wax to said semi-dilute solution or non-solution mixture to form a first mixture;

c) extruding the first mixture to obtain a second mixture; and

d) blending the high density polyethylene with the obtained second mixture to obtain a polyolefin composition.

The inventors of the present application found that through the above steps, sequentially introducing ultra-high molecular weight polyethylene, polyalphaolefin oil, polyethylene wax, and high-density polyethylene into the system can improve the mechanical properties of the prepared polyolefin composition. properties and processability.

In some preferred embodiments of the present invention, the mass ratio of the polyalphaolefin to the ultra-high molecular weight polyethylene is 1:1-1:100.

According to the present invention, the mass ratio of the polyalphaolefin and the ultra-high molecular weight polyethylene can be listed as 1:1, 1:5, 1:10, 1:15, 1:20, 1:25, 1:30 , 1:35, 1:40, 1:45, 1:50, 1:55, 1:60, 1:65, 1:70, 1:75, 1:80, 1:85, 1:90, 1 :95 and 1:100.

In some preferred embodiments of the present invention, the mass ratio of the polyethylene wax to the semi-dilute solution or non-solution mixture is 1:0.1-1:100.

According to the present invention, the mass ratio of the polyethylene wax to the semi-dilute solution or non-solution mixture can be listed as 1:0.1, 1:0.5, 1:1, 1:5, 1:10, 1:15, 1 :20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, 1:55, 1:60, 1:65, 1:70, 1:75, 1:80 , 1:85, 1:90, 1:95 and 1:100.

In some preferred embodiments of the present invention, the mass ratio of the high-density polyethylene to the second mixture is 1:1-1:100.

According to the present invention, the mass ratio of the high-density polyethylene to the second mixture may be 1:1, 1:5, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, 1:55, 1:60, 1:65, 1:70, 1:75, 1:80, 1:85, 1:90, 1: 95 and 1:100.

According to the present invention, the semi-dilute solution or non-solution mixture comprising polyalphaolefin and ultra-high molecular weight polyethylene can be prepared by the following method:

Polyalphaolefin and ultra-high molecular weight polyethylene are heated and mixed in a container at a mass ratio of 1:0.1-1:100, pre-swelled at 90-150°C, and dissolved at 100-400°C to form a semi-dilute solution or a non-solution mixture.

In some preferred embodiments of the present invention, said step b) is carried out at a temperature of 90°C-200°C, preferably 120°C-180°C.

In some preferred embodiments of the present invention, the temperature of the extrusion molding treatment is 100°C-400°C; preferably, the extrusion molding treatment is carried out in a screw extruder, more preferably, the screw shears The speed is 70rpm-350rpm, and the ratio of screw length to diameter is 40-100.

In some preferred embodiments of the present invention, said step d) is carried out at a temperature of 90°C-200°C, preferably 120°C-180°C.

In a specific embodiment of the present invention, the preparation method of polyolefin composition comprises:

1) Heat and mix polyalphaolefin and ultra-high molecular weight polyethylene in a container at a mass ratio of 1:0.1-1:100, pre-swell at 90-150°C, and dissolve at 100-40°C to form a semi-dilute solution or a non-solution mixture;

2) In the above-mentioned semi-dilute solution or non-solution mixture, polyethylene wax is added according to the mass ratio of polyethylene wax to the mixture of 1:0.1-1:100, and mixed at 90-200°C;

3) Feed the mixture prepared in step 2) into a screw extruder, extrude at 100-400°C to obtain a blend, wherein the screw shear speed is 70-350rpm, the ratio of screw length to diameter (L/ D) is 40-100.

4) In the above extruded blend, add high density polyethylene according to the mass ratio of high density polyethylene to the extruded blend at 1:1-1:100, and blend at 90-200°C to obtain poly Olefin composition.

Another aspect of the present invention provides an application of the above-mentioned polyolefin composition or the polyolefin composition prepared according to the above-mentioned preparation method in the field of spinning.

Another aspect of the present invention provides a method for spinning using the above-mentioned polyolefin composition or the polyolefin composition prepared according to the above-mentioned preparation method, comprising:

The polyolefin composition is sent to the spinneret plate and sprayed out at a speed of 2-5m/min to obtain filaments.

According to the present invention, the polyolefin composition is transported to the spinneret plate through the filter by pressurizing the melt booster pump.

According to the present invention, air or water is used to cool the prepared filaments to 0-50°C and dry them, and then draw the cooled and dried multi-spinners with a roller multi-stage traction device, and super-fold and multi-stage stretch to obtain Final product.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

(1) The present invention adopts "polyalphaolefin-ultrahigh molecular weight polyethylene-polyethylene wax-high-density polyethylene" for modification by blending four kinds of materials. Among them, the polyalphaolefin enters the ultra-high molecular weight polyethylene platelets to open up the gaps, the distance between the chain segments increases, and at the same time, the problem of serious entanglement of the ultra-high molecular weight polyethylene chain segments will be improved. Polyethylene wax is added for lubrication. Then high-density polyethylene is added for blending, and the ultra-high molecular weight polyethylene segments pass through the high-density polyethylene to achieve molecular-scale blending and form a "string crystal" structure.

(2) The strength of the prepared polyolefin composition is increased, and the problem of severe entanglement of ultra-high molecular weight polyethylene segments is effectively improved.

Detailed ways

The present invention will be described in detail through examples below, but the protection scope of the present invention is not limited to the following description.

Those who do not indicate the specific conditions in the examples are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used were not indicated by the manufacturer, and they were all commercially available conventional products.

Parameters such as molecular weight and density of each substance in the present invention are measured by conventional methods and techniques.

Example 1

Polyhexene-1 (molecular weight 500, density 0.8g/cm ³ ) and ultra-high molecular weight polyethylene (molecular weight 5,000,000, density 0.935g/cm ³ ) were heated and mixed in a mixing tank at a mass ratio of 1:50, Pre-swell at 95°C and dissolve at 150°C to form a semi-dilute solution mixture.

Add polyethylene wax (molecular weight 3000, density 0.95g/cm ³ ) to the above semi-dilute solution according to the mass ratio of polyethylene wax and semi-dilute solution mixture as 1:1 and mix to obtain the first mixture. The temperature of the mixing operation is 150°C.

The first mixture was fed into a screw extruder, and extruded at 150° C. to obtain the second mixture, the screw shear speed was 150 rpm, and the ratio of screw length to diameter (L/D) was 60. Using air to cool to 40°C; using xylene as an extractant, and heating and drying to remove the extractant, so as to extract the polyhexene-1 in the mixture;

In the obtained second mixture, high-density polyethylene (molecular weight: 100,000, density: 0.945g/cm ³ ) was added at a mass ratio of high-density polyethylene to the second mixture of 1:5, and blended at 100°C to obtain Polyolefin Composition 1.

After testing, the tensile strength of the obtained polyolefin composition 1 was 70 MPa.

The polyolefin composition 1 is pressurized by a melt booster pump, conveyed to the spinneret die through a filter, sprayed out from the holes of the spinneret die at a speed of 3m/min, and then cooled to room temperature with air or water and dried; Then, the cooled and dried multiple spinnerets are pulled by a roller multi-stage traction device, and super-doubled and multi-stage stretched to obtain the final product.

After testing, the fiber breaking strength was 35.9 LiN/dtex, and the flexural modulus was 3500MPa.

Example 2

Polyhexene-1 (molecular weight 500, density 0.8g/cm ³ ) and ultra-high molecular weight polyethylene (molecular weight 5,000,000, density 0.935g/cm ³ ) were heated and mixed in a mixing tank at a mass ratio of 1:80, Pre-swell at 95°C and dissolve at 150°C to form a semi-dilute solution mixture.

Add polyethylene wax (molecular weight 3000, density 0.95g/cm ³ ) to the above semi-dilute solution according to the mass ratio of polyethylene wax and semi-dilute solution mixture as 1:0.5 and mix to obtain the first mixture. The temperature of the mixing operation is 150°C.

The first mixture was fed into a screw extruder, and extruded at 150° C. to obtain the second mixture, the screw shear speed was 150 rpm, and the ratio of screw length to diameter (L/D) was 60. Use air to cool to 40°C; use xylene as the extractant, and heat and dry to remove the extractant;

In the obtained second mixture, add high-density polyethylene (molecular weight: 100,000, density: 0.945g/cm ³ ) at a mass ratio of high-density polyethylene to the second mixture of 1:2, and blend at 100°C to obtain Polyolefin composition2.

After testing, the tensile strength of the obtained polyolefin composition 2 was 46 MPa.

The polyolefin composition 2 is pressurized by a melt booster pump, conveyed to the spinneret die through a filter, sprayed out from the holes of the spinneret die at a speed of 3m/min, and then cooled to room temperature with air or water and dried; Then, the cooled and dried multiple spinnerets are pulled by a roller multi-stage traction device, and super-doubled and multi-stage stretched to obtain the final product.

After testing, the breaking strength of the fiber is 30.5 LiN/dtex, and the flexural modulus is 2700MPa.

Example 3

Polyhexene-1 (molecular weight 500, density 0.8g/cm ³ ) and ultra-high molecular weight polyethylene (molecular weight 5,000,000, density 0.935g/cm ³ ) were heated and mixed in a mixing tank at a mass ratio of 1:30, Pre-swell at 95°C and dissolve at 150°C to form a semi-dilute solution mixture.

Add polyethylene wax (molecular weight 3000, density 0.95g/cm ³ ) to the above semi-dilute solution according to the mass ratio of polyethylene wax and semi-dilute solution mixture as 1:2 and mix to obtain the first mixture. The temperature of the mixing operation is 150°C.

The first mixture was fed into a screw extruder, and extruded at 150° C. to obtain the second mixture, the screw shear speed was 150 rpm, and the ratio of screw length to diameter (L/D) was 60. Use air to cool to 40°C; use xylene as the extractant, and heat and dry to remove the extractant;

In the obtained second mixture, add high-density polyethylene (molecular weight: 100,000, density: 0.945g/cm ³ ) at a mass ratio of high-density polyethylene to the second mixture of 1:2, and blend at 100°C to obtain Polyolefin Composition3.

After testing, the tensile strength of the obtained polyolefin composition 3 was 42 MPa.

The polyolefin composition 3 is pressurized by a melt booster pump, delivered to the spinneret plate through a filter, sprayed out from the holes of the spinneret platen at a speed of 3m/min, and then cooled to room temperature with air or water and dried; Then, the cooled and dried multiple spinnerets are pulled by a roller multi-stage traction device, and super-doubled and multi-stage stretched to obtain the final product.

After testing, the fiber breaking strength was 29.6 LiN/dtex, and the flexural modulus was 2500MPa.

Example 4

Polyhexene-1 (molecular weight 500, density 0.8g/cm ³ ) and ultra-high molecular weight polyethylene (molecular weight 5,000,000, density 0.935g/cm ³ ) were heated and mixed in a mixing tank at a mass ratio of 1:50, Pre-swell at 95°C and dissolve at 150°C to form a semi-dilute solution mixture.

Add polyethylene wax (molecular weight 3000, density 0.95g/cm ³ ) to the above-mentioned semi-dilute solution according to the mass ratio of polyethylene wax and semi-dilute solution mixture as 1:50 and mix to obtain the first mixture. The temperature of the mixing operation is 150°C.

The first mixture was fed into a screw extruder, and extruded at 150° C. to obtain the second mixture, the screw shear speed was 150 rpm, and the ratio of screw length to diameter (L/D) was 60. Use air to cool to 40°C; use xylene as the extractant, and heat and dry to remove the extractant;

In the obtained second mixture, high-density polyethylene (molecular weight: 100,000, density: 0.945g/cm ³ ) was added at a mass ratio of high-density polyethylene to the second mixture of 1:5, and blended at 100°C to obtain Polyolefin Composition4.

After testing, the tensile strength of the obtained polyolefin composition 4 was 23 MPa.

The polyolefin composition 4 is pressurized by a melt booster pump, delivered to the spinneret plate through a filter, sprayed out from the holes of the spinneret platen at a speed of 3m/min, and then cooled to room temperature with air or water and dried; Then, the cooled and dried multiple spinnerets are pulled by a roller multi-stage traction device, and super-doubled and multi-stage stretched to obtain the final product.

After testing, the fiber breaking strength was 19.5 LiN/dtex, and the flexural modulus was 1700MPa.

Comparative example 1

Ultra-high molecular weight polyethylene (molecular weight: 5,000,000, density: 0.935g/cm ³ ) was heated in a mixing tank and dissolved at 150°C to form a semi-dilute solution mixture.

Add polyethylene wax (molecular weight 3000, density 0.95g/cm ³ ) to the above semi-dilute solution according to the mass ratio of polyethylene wax and semi-dilute solution mixture as 1:1 and mix to obtain the first mixture. The temperature of the mixing operation is 150°C.

The first mixture was fed into a screw extruder, and extruded at 150° C. to obtain the second mixture, the screw shear speed was 150 rpm, and the ratio of screw length to diameter (L/D) was 60. Use air to cool to 40°C; use xylene as the extractant, and heat and dry to remove the extractant;

In the obtained second mixture, high-density polyethylene (molecular weight: 100,000, density: 0.945g/cm ³ ) was added at a mass ratio of high-density polyethylene to the second mixture of 1:5, and blended at 100°C to obtain Polyolefin composition5.

After testing, the tensile strength of the obtained polyolefin composition 5 was 35 MPa.

The polyolefin composition 5 is pressurized by a melt booster pump, delivered to the spinneret plate through a filter, sprayed out from the holes of the spinneret platen at a speed of 3m/min, and then cooled to room temperature with air or water and dried; Then, the cooled and dried multiple spinnerets are pulled by a roller multi-stage traction device, and super-doubled and multi-stage stretched to obtain the final product.

After testing, the breaking strength of the fiber was 16.9 LiN/dtex, and the flexural modulus was 950MPa.

Comparative example 2

Polyhexene-1 (molecular weight 500, density 0.8g/cm ³ ) and ultra-high molecular weight polyethylene (molecular weight 5,000,000, density 0.935g/cm ³ ) were heated and mixed in a mixing tank at a mass ratio of 1:50, Pre-swell at 95°C and dissolve at 150°C to form a semi-dilute solution mixture.

Add polyethylene wax (molecular weight 3000, density 0.95g/cm ³ ) to the above semi-dilute solution according to the mass ratio of polyethylene wax and semi-dilute solution mixture as 1:1 and mix to obtain the first mixture. The temperature of the mixing operation is 200°C.

The first mixture was fed into a screw extruder and extruded at 150° C. to obtain polyolefin composition 6 with a screw shear speed of 150 rpm and a screw length-to-diameter ratio (L/D) of 60. Use air to cool to 40°C; use xylene as the extractant, and heat and dry to remove the extractant;

After testing, the tensile strength of the obtained polyolefin composition 6 was 30 MPa.

The polyolefin composition 6 is pressurized by a melt booster pump, delivered to the spinneret plate through a filter, sprayed out from the holes of the spinneret platen at a speed of 3m/min, and then cooled to room temperature by air or water and dried; Then, the cooled and dried multiple spinnerets are pulled by a roller multi-stage traction device, and super-doubled and multi-stage stretched to obtain the final product.

After testing, the fiber breaking strength was 15.6 LiN/dtex, and the flexural modulus was 800MPa.

Comparative example 3

Polyhexene-1 (molecular weight 500, density 0.8g/cm ³ ) and ultra-high molecular weight polyethylene (molecular weight 5,000,000, density 0.935g/cm ³ ) were heated and mixed in a mixing tank at a mass ratio of 1:50, Pre-swell at 95°C and dissolve at 150°C to form a mixture.

The above mixture was fed into a screw extruder and extruded at 150° C. to obtain a blend with a screw shear speed of 150 rpm and a screw length-to-diameter ratio (L/D) of 60. Use air to cool to 40°C; use xylene as the extractant, and heat and dry to remove the extractant;

In the resulting blend, add high-density polyethylene (molecular weight: 100,000, density: 0.945g/cm ³ ) at a mass ratio of high-density polyethylene to the blend of 1:5, and blend at 100°C to obtain a poly Olefin Composition7.

After testing, the tensile strength of the obtained polyolefin composition 7 was 40 MPa.

The polyolefin composition 7 is pressurized by a melt booster pump, delivered to the spinneret plate through a filter, sprayed out from the holes of the spinneret platen at a speed of 3m/min, and then cooled to room temperature with air or water and dried; Then, the cooled and dried multiple spinnerets are pulled by a roller multi-stage traction device, and super-doubled and multi-stage stretched to obtain the final product.

After testing, the breaking strength of the fiber was 26.4 LiN/dtex, and the flexural modulus was 2300MPa.

It should be noted that the above-mentioned embodiments are only used to explain the present invention, and do not constitute any limitation to the present invention. The invention has been described with reference to typical embodiments, but the words which have been used therein are words of description and explanation rather than words of limitation. The present invention can be modified as prescribed within the scope of the claims of the present invention, and the present invention can be revised without departing from the scope and spirit of the present invention. Although the invention described therein refers to specific methods, materials and examples, it is not intended that the invention be limited to the specific examples disclosed therein, but rather, the invention extends to all other methods and applications having the same function.

Claims (18)

1. A polyolefin composition, the polyolefin composition comprising: polyalphaolefins, ultra high molecular weight polyethylene, polyethylene waxes, and high density polyethylene;

the polyethylene composition comprises, by weight, 1-10 parts of poly-alpha-olefin, 1-100 parts of ultra-high molecular weight polyethylene, 1-100 parts of polyethylene wax and 10-100 parts of high density polyethylene.

2. Polyolefin composition according to claim 1, wherein the polyalphaolefin is selected from the group consisting of poly-C ₃ -C ₁₉ The alpha olefin of (a); and/or

The ultra-high molecular weight polyethylene has a molecular weight range of 1000000-10000000 and a density range of 0.925g/cm ³ -0.945g/cm ³ (ii) a And/or

The polyethylene wax has a molecular weight in the range of 2000-5000 and a density in the range of 0.93g/cm ³ -0.98g/cm ³ (ii) a And/or

The high density polyethylene has a molecular weight range of 50000-200000 and a density range of 0.935g/cm ³ -0.955 g/cm ³ 。

3. Polyolefin composition according to claim 2, wherein the polyalphaolefin is selected from the group consisting of poly-C _2n Wherein n is 2 to 9.

4. Polyolefin composition according to any one of claims 1 to 3, wherein the polyalphaolefin is selected from at least one of polybutene-1, polyhexene-1, polyoctene-1, polydecene-1, and polydodecene-1.

5. Polyolefin composition according to any one of claims 1 to 3, wherein the polyalphaolefin has a molecular weight in the range of from 150 to 1000 and a density in the range of from 0.74g/cm ³ -0.9 g/cm ³ 。

6. Polyolefin composition according to claim 1, characterized in that,

the ratio of the molecular weight of the polyalphaolefin to the ultra-high molecular weight polyethylene is 1 to 1; and/or

The molecular weight ratio of the polyethylene wax to the ultrahigh molecular weight polyethylene is 1; and/or

The ratio of the molecular weight of the high density polyethylene to the molecular weight of the ultra-high molecular weight polyethylene is 1.

7. Polyolefin composition according to any one of claims 1 to 3, wherein the polyolefin composition has a tensile strength of more than 40MPa.

8. Polyolefin composition according to claim 7, wherein the polyolefin composition has a tensile strength of more than 60MPa.

9. A process for the preparation of a polyolefin composition according to any of claims 1 to 8 comprising:

a) Providing a semi-dilute solution or non-solution mixture comprising a polyalphaolefin and an ultra-high molecular weight polyethylene;

b) Adding polyethylene wax to the semi-dilute solution or non-solution mixture to form a first mixture;

c) Carrying out extrusion molding treatment on the first mixture to obtain a second mixture; and

d) Blending a high density polyethylene with the second mixture to produce a polyolefin composition.

10. The production method according to claim 9, wherein the mass ratio of the polyalphaolefin to the ultrahigh molecular weight polyethylene is 1 to 1; and/or

The mass ratio of the polyethylene wax to the semi-dilute solution or non-solution mixture is 1; and/or

The mass ratio of the high-density polyethylene to the second mixture is 1.

11. The method of claim 9 or 10, wherein the step b) is performed at a temperature of 90 ℃ to 200 ℃.

12. The method of claim 11, wherein the step b) is performed at a temperature of 120 ℃ to 180 ℃.

13. The method of claim 9 or 10, wherein the temperature of the extrusion molding process is 100 ℃ to 400 ℃.

14. The method of claim 13, wherein the extrusion molding process is performed in a screw extruder.

15. The method of claim 14, wherein the screw shear rate is from 70rpm to 350rpm and the ratio of screw length to screw diameter is from 40 to 100.

16. The method of claim 9 or 10, wherein the step d) is performed at a temperature of 90 ℃ to 200 ℃.

17. The method of claim 16, wherein the step d) is performed at a temperature of 120 ℃ to 180 ℃.

18. Use of a polyolefin composition according to any of claims 1 to 8 or obtained by the preparation process according to any of claims 9 to 17 in the field of spinning.