Whisker reinforced polyolefin composite material and preparation method thereof

Abstract

The invention relates to a whisker reinforced polyolefin composite material and a preparation method thereof, and belongs to the field of polymer composite materials. According to the preparation method, polyolefin resin, calcium sulfate whiskers, polyethylene wax, an antioxidant 1010 and trimethylolpropane trimethacrylate are adopted to be prepared into composite material particles through a high-speed mixer, an extruder with a 10-micron machine head filter screen, electron accelerator irradiation and a low-temperature pulverizer. The material can be used as a reinforcing and toughening additive for plastic products. The problem of directional distribution of the whiskers in the polyolefin composite material is solved, the whisker reinforced master batch which can be uniformly and directionally distributed in the polyolefin composite material is prepared, and large-scale industrial production can be realized.

Description

Technical Field

[0001] The invention belongs to the field of polymer composite materials, and in particular relates to a whisker-reinforced polyolefin composite material and a preparation method thereof. Background Art

[0002] Calcium sulfate whiskers are an environmentally friendly, low-cost reinforcing and toughening material. They are fibrous sub-nano materials with a diameter of 0.1-10μm and a length of 10-1000μm. They have a high aspect ratio, a uniform cross-section, a complete shape, a perfect internal structure, and a stable size. However, the distribution of calcium sulfate whiskers is disorderly, and they are also randomly distributed when added to plastics. The disorderly arrangement of whiskers cannot fully exert the reinforcing effect of whiskers. If the whiskers can be highly oriented and distributed in a directional manner in the plastic, the high reinforcing effect of whiskers can be exerted. Summary of the invention

[0003] Based on this, the present invention provides a whisker-reinforced polyolefin composite material and a preparation method thereof. The present invention solves the problem of directional distribution of whiskers in polyolefin composite materials, prepares a whisker-reinforced masterbatch that can be uniformly and directionally distributed in the polyolefin composite material, and can realize large-scale industrial production.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] A method for preparing a whisker-reinforced polyolefin composite material comprises the following steps:

[0006] first step:

[0007] Add polyolefin resin, calcium sulfate whisker, polyethylene wax, antioxidant 1010, and trimethylolpropane trimethacrylate into a high-speed mixer and mix at room temperature for 3-5 minutes;

[0008] Step 2:

[0009] The mixed material in the first step is discharged into a single screw extruder for extrusion into a sheet. The extruder head is equipped with a filter screen with an aperture of 10 μm. After being extruded from the filter screen, the sheet is immediately cooled in a cooling water tank, then stretched, and wound up. Subsequently, the sheet is irradiated by an electron accelerator, and the irradiated sheet is crushed by an ultra-low temperature pulverizer at a temperature below -70°C to be crushed into powder with a fineness of less than 300 meshes.

[0010] Step 3:

[0011] Add the polyolefin resin, the powder obtained in the second step, antioxidant 1010 and polyethylene wax into a high-speed mixer, mix them thoroughly at room temperature for 3-5 minutes, and then discharge them into a parallel twin-screw extruder granulator for melt blending, extrusion and granulation to obtain whisker-reinforced polyolefin composite material particles.

[0012] Furthermore, in the first step, the mass ratio of the polyolefin resin, the calcium sulfate whisker, the polyethylene wax, the antioxidant 1010, and the trimethylolpropane trimethacrylate is 80-100: 80-100: 3-5: 0.3-0.5: 2-4.

[0013] Furthermore, the polyolefin resin is one or more of PE, PP, EVA, EEA, and POE, and has a melt flow rate of 15 g / 10 min.

[0014] Furthermore, the calcium sulfate whisker has a diameter of 0.1-10 μm and a length of 10-1000 μm.

[0015] Furthermore, in the second step, the operating temperature of the single screw extruder is: 90±5°C in zone 1, 110±5°C in zone 2, 120±5°C in zone 3, 130±5°C in zone 4, 120±5°C in zone 5, and 120±5°C in the die head.

[0016] Furthermore, in the second step, the temperature of the cooling water is 25°C-50°C.

[0017] Furthermore, in the second step, the linear speed of the coil entering the irradiation chamber is 8-10 m / min, the irradiation dose is 18-22 Mrad, and the irradiation time is 3-5 seconds.

[0018] Furthermore, in the third step, the mass ratio of the polyolefin resin, the powder obtained in the second step, the antioxidant 1010, and the polyethylene wax is 80-100: 80-100: 0.3-0.5: 3-5.

[0019] Furthermore, in the third step, the extrusion process temperature of the twin-screw extruder is: 90±5°C in zone 1, 100±5°C in zone 2, 110±5°C in zone 3, 120±5°C in zone 4, 120±5°C in zone 5, 130±5°C in zone 6, 130±5°C in zone 7, 140±5°C in zone 8, 150±5°C in zone 9, and 140±5°C in the die head.

[0020] Furthermore, the whisker-reinforced polyolefin composite material particles prepared by the preparation method can be used to reinforce polyolefin composite materials.

[0021] Description of the main raw materials used in the present invention:

[0022] Polyethylene wax: commercially available, white flakes, molecular weight 2500-4000;

[0023] Antioxidant 1010: white crystalline powder, anti-heat aging agent;

[0024] Trimethylolpropane trimethacrylate: Radiation crosslinking aid.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention utilizes an extruder to extrude the melt, and the melt passes through a head filter with an aperture of 10 μm, so that the calcium sulfate whiskers randomly distributed in the melt are oriented and arranged in the direction of melt flow and pass through the filter. The calcium sulfate whiskers have a large aspect ratio, and when passing through the filter, they can only be oriented in the direction of melt flow, that is, oriented in the axial direction. After passing through the filter, they immediately enter the cooling water tank for cooling and orientation, and the whiskers are highly orderly arranged.

[0027] 2. The highly oriented and orderly arranged calcium sulfate whiskers are distributed in the melt and then cooled and shaped. The oriented coil is irradiated and cross-linked by an electron accelerator. The regularly distributed and highly oriented whiskers are fixed and shaped inside the polyolefin.

[0028] 3. The radiation cross-linked sheet is crushed at ultra-low temperature and then prepared into a reinforced masterbatch, and the highly oriented state of the calcium sulfate whiskers is fixed inside the masterbatch. DETAILED DESCRIPTION

[0029] The technical solutions and effects of the present invention are further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0030] Example 1

[0031] A method for preparing a whisker-reinforced polyolefin composite material comprises the following steps:

[0032] first step:

[0033] Add 80 kg of polyethylene resin, 80 kg of calcium sulfate whiskers, 3 kg of polyethylene wax, 0.3 kg of antioxidant 1010, and 2 kg of trimethylolpropane trimethacrylate into a high-speed mixer and mix at room temperature for 3 minutes.

[0034] Step 2:

[0035] The mixed materials in the first step are discharged into a single-screw extruder for extrusion into sheets. The extruder head is equipped with a filter screen with an aperture of 10 μm. After being extruded from the filter screen, the sheets are immediately cooled in a cooling water tank at 30±2°C, and then stretched, wound and reeled. Subsequently, the coil is irradiated by an electron accelerator. The linear speed of the coil entering the irradiation room is 8 m / min, the irradiation dose is 20 Mrad, and the irradiation time is 5 seconds. The irradiated coil is crushed by an ultra-low temperature pulverizer at a temperature below -70°C to form a powder with a fineness of less than 300 mesh.

[0036] Step 3:

[0037] 80 kg of polyethylene resin, 80 kg of the powder obtained in the second step, 0.3 kg of antioxidant 1010 and 3 kg of polyethylene wax were added into a high-speed mixer, mixed thoroughly for 3 minutes at room temperature, and then discharged into a parallel twin-screw extruder granulator, melt-blended and extruded to obtain whisker-reinforced polyolefin composite material particles.

[0038] Example 2

[0039] Same as Example 1, except that:

[0040] first step:

[0041] 100 Kg of polypropylene resin, 100 Kg of calcium sulfate whisker, 5 Kg of polyethylene wax, 0.5 Kg of antioxidant 1010, and 4 Kg of trimethylolpropane trimethacrylate were added into a high-speed mixer.

[0042] Step 3:

[0043] Add 100Kg of polypropylene resin, 100Kg of the powder obtained in the second step, 0.5Kg of antioxidant 1010 and 5Kg of polyethylene wax into a high-speed mixer.

[0044] Example 3

[0045] Same as Example 1, except that:

[0046] first step:

[0047] 90 Kg of EVA resin, 90 Kg of calcium sulfate whisker, 4 Kg of polyethylene wax, 0.4 Kg of antioxidant 1010, and 3 Kg of trimethylolpropane trimethacrylate were added into a high-speed mixer.

[0048] Step 3:

[0049] Add 90 kg of EVA resin, 90 kg of the powder obtained in the second step, 0.4 kg of antioxidant 1010, and 4 kg of polyethylene wax into a high-speed mixer.

[0050] The reinforced masterbatch prepared by the present invention was tested and compared, and the base resin of this test was selected as polypropylene resin.

[0051] Formula: 1: Take 90Kg of polypropylene resin (T30S), 10Kg of linear low-density polyethylene resin, 1.20Kg of calcium sulfate whiskers, 2 kg of polyethylene wax, and 0.5 kg of 1010 antioxidant.

[0052] Formula 2: Take 90Kg of polypropylene resin (T30S), 10Kg of linear low-density polyethylene resin, 5Kg of the product of Example 2 of the present invention, 2 kg of polyethylene wax, and 0.5 kg of 1010 antioxidant.

[0053] Formula 1 and Formula 2 were prepared into samples for testing and comparison. The test comparison results are shown in Table 1 below.

[0054] Table 1 Comparison results of sample performance

[0055] project unit Recipe 1 Recipe 2 Tensile Strength MPa 40.1 89.5 Elongation at break MPa 820 876 Notched impact strength <![CDATA[KJ / m 2 ]]> 15.3 28.6 Bending Strength MPa 105 174 Flexural modulus MPa 2860 5623

[0056] It can be seen from the above table that when the product of the present invention is used as a modified reinforcing material, the content of calcium sulfate whiskers in the formula system is the same, and the performance indicators of the samples tested are all better than those of ordinary calcium sulfate whiskers.

[0057] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a whisker-reinforced polyolefin composite material, characterized in that: The preparation method comprises the following steps: first step: Add polyolefin resin, calcium sulfate whisker, polyethylene wax, antioxidant 1010, and trimethylolpropane trimethacrylate into a high-speed mixer and mix at room temperature for 3-5 minutes; Step 2: The mixed material in the first step is discharged into a single screw extruder for extrusion into a sheet. The extruder head is equipped with a filter screen with an aperture of 10 μm. After being extruded from the filter screen, the sheet is immediately cooled in a cooling water tank, then stretched, and wound up. Subsequently, the sheet is irradiated by an electron accelerator, and the irradiated sheet is crushed by an ultra-low temperature pulverizer at a temperature below -70°C to be crushed into powder with a fineness of less than 300 meshes. Step 3: Add the polyolefin resin, the powder obtained in the second step, antioxidant 1010 and polyethylene wax into a high-speed mixer, mix them thoroughly at room temperature for 3-5 minutes, and then discharge them into a parallel twin-screw extruder granulator for melt blending, extrusion and granulation to obtain whisker-reinforced polyolefin composite material particles.

2. The method for preparing a whisker-reinforced polyolefin composite material according to claim 1, wherein In the first step, the mass ratio of the polyolefin resin, the calcium sulfate whisker, the polyethylene wax, the antioxidant 1010, and the trimethylolpropane trimethacrylate is 80-100: 80-100: 3-5: 0.3-0.5: 2-4.

3. The method for preparing a whisker-reinforced polyolefin composite material according to claim 2, wherein: The polyolefin resin is one or more of PE, PP, EVA, EEA, and POE, and has a melt flow rate of 15 g / 10 min.

4. The method for preparing a whisker-reinforced polyolefin composite material according to claim 2, wherein: The calcium sulfate whisker has a diameter of 0.1-10 μm and a length of 10-1000 μm.

5. The method for preparing the whisker reinforced polyolefin composite material according to claim 1, characterized in that: In the second step, the operating temperature of the single screw extruder is: 90±5°C in zone 1, 110±5°C in zone 2, 120±5°C in zone 3, 130±5°C in zone 4, 120±5°C in zone 5, and 120±5°C in the die head.

6. The method for preparing the whisker reinforced polyolefin composite material according to claim 1, characterized in that: In the second step, the temperature of the cooling water is 25°C-50°C.

7. The method for preparing the whisker reinforced polyolefin composite material according to claim 1, characterized in that: In the second step, the linear speed of the coil entering the irradiation chamber is 8-10 m / min, the irradiation dose is 18-22 Mrad, and the irradiation time is 3-5 seconds.

8. The method for preparing the whisker reinforced polyolefin composite material according to claim 1, characterized in that: In the third step, the mass ratio of the polyolefin resin, the powder obtained in the second step, the antioxidant 1010, and the polyethylene wax is 80-100: 80-100: 0.3-0.5: 3-5.

9. The method for preparing the whisker reinforced polyolefin composite material according to claim 1, characterized in that: In the third step, the extrusion process temperature of the twin-screw extruder is: 90±5℃ in zone 1, 100±5℃ in zone 2, 110±5℃ in zone 3, 120±5℃ in zone 4, 120±5℃ in zone 5, 130±5℃ in zone 6, 130±5℃ in zone 7, 140±5℃ in zone 8, 150±5℃ in zone 9, and 140±5℃ in the die.

10. The method for preparing the whisker reinforced polyolefin composite material according to claim 1, characterized in that: The whisker-reinforced polyolefin composite material particles prepared by the preparation method can be used to reinforce polyolefin composite materials.