Low-cost wear-resistant plastic particles and preparation method thereof

Abstract

The invention belongs to the technical field of plastic particles, and particularly relates to low-cost wear-resistant plastic particles and a preparation method thereof.The low-cost wear-resistant plastic particles are prepared from, by mass, 50-70 parts of polypropylene, 30-50 parts of recycled polyethylene and 5-15 parts of wear-resistant reinforcing materials; 3-5 parts of a toughening agent, 0.5-1 part of zinc stearate, 0.5-1 part of polyethylene wax, 2-4 parts of an interfacial compatibilizer and 0.5-1 part of an antioxidant; the wear-resistant reinforcing material comprises modified ceramic microspheres and a graphene-carbon nanotube hybrid material, the wear-resistant reinforcing material in the formula comprises the modified ceramic microspheres and the graphene-carbon nanotube hybrid material, the modified ceramic microspheres and the graphene-carbon nanotube hybrid material have a synergistic effect, the wear resistance and the mechanical property of the plastic particles are remarkably improved, and when the mass part ratio of the modified ceramic microspheres to the graphene-carbon nanotube hybrid material is (5-10): 1, the wear resistance and the mechanical property of the plastic particles are improved. The synergism of the two is better, and the cost is lower. Meanwhile, the recycled polyethylene is used, so that the cost can be reduced, and the problem of performance degradation of the recycled material can be solved by adding the interfacial compatibilizer.

Description

Technical Field

[0001] This invention belongs to the field of plastic granule technology, and particularly relates to a low-cost wear-resistant plastic granule and its preparation method. Background Technology

[0002] Plastic granules, as an important industrial raw material, have wide applications in many fields. Existing wear-resistant plastic granules, such as those published in CN119708677A which relates to the field of plastic granule technology, include the following raw materials in parts by weight: 70-90 parts polypropylene, 80-100 parts polyethylene, 6-8 parts friction-increasing filler, 1-2 parts polyol ester, 1-2 parts calcium stearate, 2-3 parts polyamide, 1-2 parts plasticizer, 1-2 parts high impact toughening agent, 1-3 parts hydrophobic polymer, 2-3 parts antioxidant, and 2-4 parts binder. In the production of plastic granules, this invention uses a mixture of silica, glass fiber, carbon fiber, and nanoparticles as a friction-enhancing filler, combined with a high-impact toughening agent, to effectively improve the wear resistance of the plastic granules. Furthermore, while improving wear resistance, the plastic granules also possess good flame retardancy, support, and hydrophobicity. For example, CN103788462A discloses a wear-resistant plastic granule comprising: ultra-high molecular weight polyethylene, glass fiber, silicone oil, and carbon black. The carbon black accounts for 3%–7% of the weight of the wear-resistant plastic granule, the ultra-high molecular weight polyethylene accounts for 69%–73% of the weight, the glass fiber accounts for 12%–16% of the weight, and the silicone oil accounts for 4%–8% of the weight. Through the above methods, the wear-resistant plastic granules disclosed in this invention are made by mixing various additives and ultra-high molecular weight polyethylene, which further improves the strength and wear resistance, and also has high rigidity, good bending resistance and heat deformation resistance; there are also wear-resistant plastic granules with publication number CN104910498A.

[0003] To improve wear resistance, glass fiber was added to the formulation of the aforementioned plastic granules. While adding glass fiber can improve its wear resistance, there is a problem: glass fiber has high hardness (Mohs hardness ≈ 6.5), which can cause mechanical wear on metal parts such as screws, barrels, and molds during high-temperature melting and mixing, shortening the equipment life. At the same time, glass fiber is prone to forming "floating fibers" (exposed fiber ends) on the surface of the product, resulting in a rough surface that requires subsequent polishing and other treatments, increasing costs. Summary of the Invention

[0004] The purpose of this invention is to provide a low-cost wear-resistant plastic granule and its preparation method, addressing the technical problems of excessive mechanical wear and fiber floating in existing plastic granules due to the addition of glass fibers for wear resistance.

[0005] To achieve the above objectives, the present invention provides a low-cost wear-resistant plastic granule and a method for preparing the same, comprising the following raw materials in parts by weight:

[0006] The composition includes 50-70 parts polypropylene, 30-50 parts recycled polyethylene, and 5-15 parts wear-resistant reinforcing material; 3-5 parts toughening agent, 0.5-1 part zinc stearate, 0.5-1 part polyethylene wax, 2-4 parts interface compatibilizer, and 0.5-1 part antioxidant. The wear-resistant reinforcing material comprises modified ceramic microspheres and graphene-carbon nanotube hybrid material, with a mass ratio of (5-10):1. Increasing the amount of graphene-carbon nanotube hybrid material increases wear resistance, but also increases cost and preparation difficulty.

[0007] Optionally, the modified ceramic microspheres are ceramic microspheres coated with polydopamine; the preparation method is as follows: 1. Immerse the ceramic microspheres in ethanol, ultrasonically clean for 30 minutes to remove surface impurities; rinse several times with deionized water, and dry at 80℃ for later use; 2. Dissolve 0.2g of dopamine hydrochloride in 100mL Tris buffer, pH 7.5-8.5, and magnetically stir at 300rpm until completely dissolved; 3. Add 10g of pretreated ceramic microspheres to the above solution, with a solid-liquid ratio of 1:10; stir at 50℃ and 300rpm for 6 hours until the solution gradually turns brownish-black, ending the reaction; after the reaction, centrifuge at 8000rpm for 5 minutes, collect the solution, and wash with deionized water until the supernatant is colorless; 4. Vacuum dry in a vacuum drying oven at 60℃ for 12 hours to obtain the modified ceramic microspheres. The purity of the dopamine hydrochloride is greater than 95%. Furthermore, the ceramic microspheres are coated with polydopamine, which enhances surface adhesion and avoids processing wear caused by traditional fillers (such as glass fiber).

[0008] Optionally, the particle size of the modified ceramic microspheres is 10-50 μm.

[0009] Optionally, the mass ratio of graphene to carbon nanotubes in the graphene-carbon nanotube hybrid material is 1:1. The preparation method of the graphene-carbon nanotube hybrid material is as follows: 1. Add 50 mg of graphene oxide and 50 mg of carboxylated carbon nanotubes to 200 mL of deionized water, and sonicate at 20 kHz for 1 hour using an ultrasonic cell disruptor to obtain a uniformly dispersed GO-CNT mixture; 2. Add the uniformly dispersed GO-CNT mixture to a magnetic stirrer, add 0.5 g of polyvinylpyrrolidone as a dispersant, and stir magnetically for 30 minutes; add 5 mL of hydrazine hydrate dropwise to the above mixture, and stir at 300 rpm in an 80°C water bath for 6 hours until the solution gradually changes from brownish-yellow to black, then centrifuge at 10000 rpm for 10 minutes, collect the precipitate, and wash it three times with alternating ethanol and water. 3. The precipitate was redispersed in 50 mL of deionized water and sonicated at 20 kHz for 10 minutes using an ultrasonic cell disruptor. It was then transferred to a freeze dryer, pre-frozen at -50°C for 4 hours, and then vacuum-dried for 24 hours to obtain the graphene-carbon nanotube hybrid material. Furthermore, the graphene-carbon nanotube hybrid material, through a 1:1 compounding to form a three-dimensional network structure, significantly reduces the coefficient of friction, and requires only 1-3 parts, making the cost controllable.

[0010] Optionally, the toughening agent is modified waste rubber powder treated with the silane coupling agent. The steps for modifying waste rubber powder with a silane coupling agent are as follows: 1. Soak the waste rubber powder in ethanol, ultrasonically clean it for 30 minutes to remove surface oil and impurities, then rinse it three times with deionized water and dry it at 80℃ to constant weight; 2. Weigh 2-5% of the silane coupling agent KH-550 by weight of the rubber powder, add it to an ethanol / water mixture, with a silane:solvent ratio of 1:10, add acetic acid to adjust the pH to 4-5, and magnetically stir for 30 minutes to fully hydrolyze the silane until the solution becomes turbid and then gradually becomes clear; 3. Add the pretreated rubber powder to the hydrolysate at a solid-liquid ratio of 1:10, and stir at 60℃ and 300 rpm for 4 hours to allow the silane to condense with the -OH / -COOH groups on the rubber surface. Then, centrifuge at 5000 rpm for 5 minutes, collect the rubber powder, wash it three times with ethanol to remove unreacted silane, and finally vacuum dry it at 60℃ for 6 hours to obtain the modified waste rubber powder treated with the silane coupling agent. Furthermore, using waste rubber powder can further reduce costs.

[0011] Optionally, the interface compatibilizer comprises maleic anhydride-grafted polyethylene and / or maleic anhydride-grafted polypropylene.

[0012] Optionally, the antioxidant is one of antioxidant 1010, antioxidant 168, and antioxidant DLTP.

[0013] Optionally, a method for preparing low-cost wear-resistant plastic granules includes the following steps:

[0014] S1 Add the polypropylene and recycled polyethylene in the above formula by mass to a high-speed mixer and premix at 60-80℃ for 3-5 minutes; then add the interface compatibilizer and continue mixing for 3-5 minutes to obtain the premixed resin.

[0015] S2 adds premixed resin to a twin-screw extruder, adds modified ceramic microspheres in the feeding section, adds graphene-carbon nanotube hybrid material in the melting section, adds toughening agent, zinc stearate and polyethylene wax in the mixing section, adds antioxidant in the homogenization section, and then melt extrudes;

[0016] S3 processes the extruded material through stretching, cooling, and pelletizing to obtain the low-cost wear-resistant plastic granules.

[0017] Optionally, in step S2, ultrasonic waves are applied to the mixing section at a frequency of 20 kHz and a power of 300-500 W for 3-5 minutes.

[0018] Optionally, in step S2, the feed section temperature is 160-180℃, and the stirring is carried out for 2-3 minutes; the melting section temperature is 190-200℃, and the stirring is carried out for 3-5 minutes; the mixing section temperature is 200-210℃, and the stirring is carried out for 1-2 minutes; the homogenization section temperature is 190-200℃, and the stirring is carried out for 1-2 minutes; the screw speed is 250-300 rpm.

[0019] The present invention provides a low-cost wear-resistant plastic granule and its preparation method, in which one or more of the above-mentioned technical solutions have at least one of the following technical effects: The wear-resistant reinforcing material in the formulation of the present invention includes modified ceramic microspheres and graphene-carbon nanotube hybrid materials. Through synergistic effect, the wear resistance and mechanical properties of the plastic granules are significantly improved. When the mass ratio of modified ceramic microspheres to the graphene-carbon nanotube hybrid material is (5-10):1, the modified ceramic microspheres, as the macroscopic wear-resistant main body, resist wear through high hardness and rigidity. The graphene-carbon nanotube hybrid material provides nanoscale lubrication and reinforcement, fills the gaps between microspheres, and inhibits the propagation of micro-cracks. The synergy between the two is better, and the cost is also lower. At the same time, the use of recycled polyethylene can reduce costs, and the problem of performance degradation of recycled materials can be solved by adding an interface compatibilizer. Detailed Implementation

[0020] The present invention will be further described below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0021] Example 1

[0022] A low-cost wear-resistant plastic granule comprises the following raw materials in parts by weight:

[0023] The mixture contains 50 parts polypropylene, 50 parts recycled polyethylene, and 5 parts wear-resistant reinforcing material; 4 parts toughening agent, 0.8 parts zinc stearate, 0.8 parts polyethylene wax, 3 parts interface compatibilizer, and 0.8 parts antioxidant; the wear-resistant reinforcing material includes modified ceramic microspheres and graphene-carbon nanotube hybrid material, and the mass ratio of modified ceramic microspheres to graphene-carbon nanotube hybrid material is 8:1.

[0024] The modified ceramic microspheres are ceramic microspheres coated with polydopamine; the particle size of the modified ceramic microspheres is 30 μm; the mass ratio of graphene to carbon nanotubes in the graphene-carbon nanotube hybrid material is 1:1; the toughening agent is modified waste rubber powder treated with silane coupling agent; the interface compatibilizer includes maleic anhydride-grafted polypropylene; the antioxidant is antioxidant 1010.

[0025] Low-cost wear-resistant plastic granules and their preparation method include the following steps:

[0026] S1 Add the polypropylene and recycled polyethylene of the above formula in parts by weight to a high-speed mixer and premix at 80°C for 4 minutes; then add an interface compatibilizer and continue mixing for 4 minutes to obtain a premixed resin;

[0027] S2 adds premixed resin to a twin-screw extruder, adds modified ceramic microspheres in the feeding section, adds graphene-carbon nanotube hybrid material in the melting section, adds toughening agent, zinc stearate and polyethylene wax in the mixing section, adds antioxidant in the homogenization section, and then melt extrudes;

[0028] S3 processes the extruded material through stretching, cooling, and pelletizing to obtain low-cost wear-resistant plastic granules.

[0029] In step S2, ultrasonic waves are applied in the mixing section at a frequency of 20 kHz and a power of 400 W for 4 minutes. In step S2, the temperature in the feeding section is 170°C and the stirring is carried out for 2 minutes. In the melting section, the temperature is 195°C and the stirring is carried out for 4 minutes. In the mixing section, the temperature is 200°C and the stirring is carried out for 1 minute. In the homogenization section, the temperature is 190°C and the stirring is carried out for 1 minute. The screw speed is 250 rpm.

[0030] Example 2

[0031] A low-cost wear-resistant plastic granule comprises the following raw materials in parts by weight:

[0032] The composition includes 60 parts polypropylene, 40 parts recycled polyethylene, 10 parts wear-resistant reinforcing material, 5 parts toughening agent, 1 part zinc stearate, 1 part polyethylene wax, 4 parts interface compatibilizer, and 1 part antioxidant. The wear-resistant reinforcing material includes modified ceramic microspheres and graphene-carbon nanotube hybrid material, and the mass ratio of modified ceramic microspheres to graphene-carbon nanotube hybrid material is 8:1.

[0033] The modified ceramic microspheres are ceramic microspheres coated with polydopamine; the particle size of the modified ceramic microspheres is 10 μm; the mass ratio of graphene to carbon nanotubes in the graphene-carbon nanotube hybrid material is 1:1; the toughening agent is modified waste rubber powder treated with silane coupling agent; the interface compatibilizer includes maleic anhydride-grafted polyethylene; and the antioxidant is antioxidant 168.

[0034] Low-cost wear-resistant plastic granules and their preparation method include the following steps:

[0035] S1 Add the polypropylene and recycled polyethylene of the above formula in parts by weight to a high-speed mixer and premix at 60°C for 3 minutes; then add an interface compatibilizer and continue mixing for 3 minutes to obtain a premixed resin;

[0036] S2 adds premixed resin to a twin-screw extruder, adds modified ceramic microspheres in the feeding section, adds graphene-carbon nanotube hybrid material in the melting section, adds toughening agent, zinc stearate and polyethylene wax in the mixing section, adds antioxidant in the homogenization section, and then melt extrudes;

[0037] S3 processes the extruded material through stretching, cooling, and pelletizing to obtain low-cost wear-resistant plastic granules.

[0038] In step S2, ultrasonic waves are applied in the mixing section at a frequency of 20 kHz and a power of 300 W for 3 minutes. In step S2, the feed section is stirred at a temperature of 160°C for 2 minutes, the melting section at a temperature of 190°C for 3 minutes, the mixing section at a temperature of 200°C for 2 minutes, and the homogenization section at a temperature of 190°C for 1 minute. The screw speed is 250 rpm.

[0039] Example 3

[0040] A low-cost wear-resistant plastic granule comprises the following raw materials in parts by weight:

[0041] The composition includes 70 parts polypropylene, 30 parts recycled polyethylene, and 15 parts wear-resistant reinforcing material; 3 parts toughening agent, 0.5 parts zinc stearate, 0.5 parts polyethylene wax, 2 parts interface compatibilizer, and 0.5 parts antioxidant; the wear-resistant reinforcing material includes modified ceramic microspheres and graphene-carbon nanotube hybrid material, and the mass ratio of modified ceramic microspheres to graphene-carbon nanotube hybrid material is 8:1.

[0042] The modified ceramic microspheres are ceramic microspheres coated with polydopamine; the particle size of the modified ceramic microspheres is 50 μm; the mass ratio of graphene to carbon nanotubes in the graphene-carbon nanotube hybrid material is 1:1; the toughening agent is modified waste rubber powder treated with silane coupling agent; the interface compatibilizer includes maleic anhydride-grafted polyethylene and / or maleic anhydride-grafted polypropylene; the antioxidant is one of antioxidant 1010, antioxidant 168 and antioxidant DLTP.

[0043] Low-cost wear-resistant plastic granules and their preparation method include the following steps:

[0044] S1 Add the polypropylene and recycled polyethylene of the above formula in parts by weight to a high-speed mixer and premix at 80°C for 5 minutes; then add an interface compatibilizer and continue mixing for 5 minutes to obtain a premixed resin;

[0045] S2 adds premixed resin to a twin-screw extruder, adds modified ceramic microspheres in the feeding section, adds graphene-carbon nanotube hybrid material in the melting section, adds toughening agent, zinc stearate and polyethylene wax in the mixing section, adds antioxidant in the homogenization section, and then melt extrudes;

[0046] S3 processes the extruded material through stretching, cooling, and pelletizing to obtain low-cost wear-resistant plastic granules.

[0047] In step S2, ultrasonic waves are applied in the mixing section at a frequency of 20 kHz and a power of 500 W for 5 minutes. In step S2, the feed section is heated to 180°C and stirred for 3 minutes, the melting section is heated to 200°C and stirred for 5 minutes, the mixing section is heated to 210°C and stirred for 2 minutes, and the homogenization section is heated to 200°C and stirred for 2 minutes. The screw speed is 300 rpm.

[0048] Example 4

[0049] Similar to Example 1, except that the mass ratio of the modified ceramic microspheres to the graphene-carbon nanotube hybrid material is 5:1.

[0050] Example 5

[0051] Similar to Example 1, except that the mass ratio of the modified ceramic microspheres to the graphene-carbon nanotube hybrid material is 10:1.

[0052] Comparative Example 1

[0053] Similar to Example 1, except that the wear-resistant reinforcing material is only modified ceramic microspheres.

[0054] Comparative Example 2

[0055] Similar to Example 1, except that the wear-resistant reinforcing material is only a graphene-carbon nanotube hybrid material.

[0056] Comparative Example 3

[0057] Similar to Example 1, except that the modified ceramic microspheres are replaced with ordinary ceramic microspheres of the same particle size.

[0058] Comparative Example 4

[0059] Similar to Example 1, except that the wear-resistant reinforcing material is a hybrid of glass fiber and graphene-carbon nanotubes, with the ratio still being 8:1.

[0060] Comparative Example 5

[0061] Similar to Example 1, except that the wear-resistant reinforcing material is modified ceramic microspheres and glass fiber, with the ratio still being 8:1.

[0062] The plastic granules prepared in Examples 1-5 and Comparative Examples 1-5 were pressed into 100×100mm square sheets with a thickness of 5mm according to standard procedures and then tested as follows:

[0063] The wear rate was tested according to ASTM D1044 / ISO 9352, and the impact resistance test was conducted according to GB / T 1043.1 using a simply supported beam impact test. The following data are shown in Table 1.

[0064] Table 1

[0065]

[0066] As demonstrated in Example 1 and Comparative Examples 1-5, the modified ceramic microspheres and graphene-carbon nanotube hybrid materials exhibit a synergistic effect, significantly improving the wear resistance and mechanical properties of the plastic particles. Compared to using either one alone, the synergistic addition results in a substantial increase in wear resistance. Furthermore, when other wear-resistant materials are replaced, the wear resistance increases significantly, indicating poor synergy with other materials. Higher impact strength values ​​indicate better impact resistance. The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A low-cost wear-resistant plastic granule, characterized in that, The preparation raw materials include the following parts by weight: The mixture comprises 50-70 parts polypropylene, 30-50 parts recycled polyethylene, 5-15 parts wear-resistant reinforcing material, 3-5 parts toughening agent, 0.5-1 part zinc stearate, 0.5-1 part polyethylene wax, 2-4 parts interface compatibilizer, and 0.5-1 part antioxidant. The wear-resistant reinforcing material includes modified ceramic microspheres and graphene-carbon nanotube hybrid material, and the mass ratio of the modified ceramic microspheres to the graphene-carbon nanotube hybrid material is (5-10):

1.

2. The low-cost wear-resistant plastic granules according to claim 1, characterized in that, The modified ceramic microspheres are ceramic microspheres with polydopamine coated on their surface.

3. The low-cost wear-resistant plastic granules according to claim 1, characterized in that, The modified ceramic microspheres have a particle size of 10-50 μm.

4. The low-cost wear-resistant plastic granules according to claim 1, characterized in that, The graphene-carbon nanotube hybrid material has a graphene to carbon nanotube mass ratio of 1:

1.

5. The low-cost wear-resistant plastic granules according to claim 1, characterized in that, The toughening agent is modified waste rubber powder treated with the silane coupling agent.

6. The low-cost wear-resistant plastic granules according to claim 1, characterized in that, The interface compatibilizer includes maleic anhydride-grafted polyethylene and / or maleic anhydride-grafted polypropylene.

7. The low-cost wear-resistant plastic granules according to claim 1, characterized in that, The antioxidant is one of antioxidant 1010, antioxidant 168, and antioxidant DLTP.

8. The method for preparing low-cost wear-resistant plastic granules according to any one of claims 1-7, characterized in that, Includes the following steps: S1 Add the polypropylene and recycled polyethylene in the above formula by mass to a high-speed mixer and premix at 60-80℃ for 3-5 minutes; then add the interface compatibilizer and continue mixing for 3-5 minutes to obtain the premixed resin. S2 adds premixed resin to a twin-screw extruder, adds modified ceramic microspheres in the feeding section, adds graphene-carbon nanotube hybrid material in the melting section, adds toughening agent, zinc stearate and polyethylene wax in the mixing section, adds antioxidant in the homogenization section, and then melt extrudes; S3 processes the extruded material through stretching, cooling, and pelletizing to obtain the low-cost wear-resistant plastic granules.

9. The method for preparing low-cost wear-resistant plastic granules according to claim 8, characterized in that, In step S2, ultrasonic waves are applied to the mixing section at a frequency of 20kHz and a power of 300-500W for 3-5 minutes.

10. The method for preparing low-cost wear-resistant plastic granules according to claim 8, characterized in that, In step S2, the feed section temperature is 160-180℃, and the stirring is carried out for 2-3 minutes; the melting section temperature is 190-200℃, and the stirring is carried out for 3-5 minutes; the mixing section temperature is 200-210℃, and the stirring is carried out for 1-2 minutes; the homogenization section temperature is 190-200℃, and the stirring is carried out for 1-2 minutes; the screw speed is 250-300 rpm.

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