Conductive polypropylene composite material and method for producing the same

Abstract

This invention discloses a conductive polypropylene composite material and its preparation method. The composite material is prepared from the following components in parts by weight: 76.6-84.3 parts polypropylene, 15-22 parts Fe3O4-modified multilayer graphene, 0.2-0.4 parts antioxidant, 0.2-0.4 parts light stabilizer, and 0.3-0.6 parts dispersant. This invention uses Fe3O4-modified multilayer graphene as the conductive material, adding it to polypropylene. Due to the magnetic properties of Fe3O4 itself, the Fe3O4-modified multilayer graphene will become oriented during the material's melt injection molding process. The oriented layered material easily forms conductive pathways. On the other hand, the oriented multilayer graphene reduces agglomeration and stacking, greatly improving the dispersion effect of graphene and significantly enhancing the conductivity of the polypropylene composite material with a very small amount added.

Description

Technical Field

[0001] This invention relates to the field of polymer composite materials technology, and in particular to a conductive polypropylene composite material and its preparation method. Background Technology

[0002] Adding conductive fillers to polymers to prepare conductive polymers with durable and stable conductivity is a mainstream method. Due to its simple process and wide adjustable resistivity range, it has been widely used in many industries such as electronics, energy, chemicals, and aerospace in recent years. Polypropylene, as one of the most common engineering plastics, is seeing an increasing demand for conductive polypropylene as its application fields expand. A common modification method for conductive polypropylene is to add conductive carbon black to achieve conductivity; however, the addition amount usually needs to reach 30-50% or more, leading to significant loss of mechanical properties and high cost, thus limiting the application of this type of material. Summary of the Invention

[0003] The purpose of this invention is to provide a conductive polypropylene composite material and its preparation method to solve the problems in the prior art.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] A conductive polypropylene composite material is prepared from the following components in parts by weight: 76.6-84.3 parts polypropylene, 15-22 parts Fe3O4-modified multilayer graphene, 0.2-0.4 parts antioxidant, 0.2-0.4 parts light stabilizer, and 0.3-0.6 parts dispersant; wherein the Fe3O4-modified multilayer graphene is prepared by the following steps:

[0006] S1. Disperse multilayer graphene in a polysulfonated styrene solution with a concentration of 1-3 wt%, stir at 50-60℃ for 12-24 hours, and separate to obtain pretreated multilayer graphene.

[0007] S2. Disperse the pretreated multilayer graphene in a polydiene dimethyl ammonium chloride solution with a concentration of 1-3 wt%, add NaCl and mix evenly to obtain a dispersion.

[0008] S3. Add Fe3O4 nanoparticles to the dispersion in step S2, add alkali solution to adjust the pH of the dispersion to 11-12, stir for 1-3 hours, filter to separate solid material, wash with water and dry to obtain Fe3O4 modified multilayer graphene; preferably, the alkali solution is one of tetramethylammonium hydroxide, sodium hydroxide and ammonia water.

[0009] In a further embodiment, the polypropylene is homopolymer polypropylene or copolymer polypropylene, and its melt index at 230℃ and 2.16kg is 3-100g / 10min.

[0010] In a further embodiment, the antioxidant is at least one of hindered phenolic antioxidants, phosphite antioxidants, and thioester antioxidants.

[0011] In a further embodiment, the light stabilizer is at least one of UV944, V703, and UV-3808PP5.

[0012] In a further embodiment, the dispersant is one of dispersant E525 and erucamide.

[0013] This invention also discloses a method for preparing the aforementioned conductive polypropylene composite material, comprising the following steps: weighing polypropylene, Fe3O4-modified multilayer graphene, antioxidant, light stabilizer, and dispersant according to the specified ratio, mixing them evenly, and feeding the mixture into a twin-screw extruder through the main feed port. The mixture is then subjected to mixing, extrusion, stranding, and pelletizing to obtain the conductive polypropylene composite material. More preferably, the processing temperature of the twin-screw extruder is 180-210℃, and the screw speed is 100-400 r / min.

[0014] Compared with the prior art, the beneficial effects of the present invention are reflected in:

[0015] (1) In this invention, Fe3O4-modified multilayer graphene is used as a conductive material and added to polypropylene. Due to the magnetic effect of Fe3O4 itself, the Fe3O4-modified multilayer graphene will be oriented during the material melt injection molding process. The oriented layered material is easy to form a conductive path. On the other hand, the oriented multilayer graphene reduces the agglomeration and stacking, which can greatly improve the dispersion effect of graphene and significantly improve the conductivity of polypropylene composite material with a small amount of addition.

[0016] (2) Compared with single-layer graphene materials, multi-layer graphene materials are easier to prepare and have a greater cost advantage; and single-layer graphene is mainly prepared by mechanical exfoliation, which will lead to the destruction of chemical bonds on the surface of the material. When added to polypropylene products, it is easy to agglomerate, thereby reducing the conductivity.

[0017] (3) Compared with ordinary carbon black materials, multilayer graphene has an aspect ratio structure, is easy to orient, and conducts charges in multiple dimensions, resulting in better conductivity under the same addition ratio. Detailed Implementation

[0018] To facilitate understanding of the present invention, a more comprehensive description of the invention is provided below with reference to specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Specific information regarding the raw materials used in the following embodiments and comparative examples is as follows:

[0020] Copolymer polypropylene, manufactured by SK Korea, grade PP BX3800;

[0021] Homopolymer polypropylene, manufactured by Shanghai SECCO Petrochemical Co., Ltd., grade PPS2040;

[0022] Multilayer graphene material, manufactured by Changzhou Sixth Element Materials Technology Co., Ltd.

[0023] Fe3O4 nanomaterials, Zhongke Leiming Technology Co., Ltd.

[0024] Antioxidant 1010, manufactured by BASF, brand name Irganox 1010;

[0025] Antioxidant 168, manufactured by BASF, brand name Irganox 168;

[0026] The antioxidant DSTDP is manufactured by Adifant & Kojuya and its brand name is Naugard DSTDP.

[0027] The light stabilizer UV944 is manufactured by Cytec Chemicals.

[0028] Light stabilizer V703, manufactured by Cytec;

[0029] Light stabilizer UV-3808PP5, manufactured by Cytec.

[0030] Dispersant E525, manufactured by Evonik Degussa;

[0031] Erucamide, manufactured by Jiangsu Zhongteng New Material Technology Co., Ltd.

[0032] All materials are commercially available, commonly used products.

[0033] It is understood that the above raw materials and reagents are merely examples of some specific embodiments of the present invention, making the technical solution of the present invention clearer, and do not mean that the present invention can only use the above reagents. Furthermore, unless otherwise specified, "parts" in the examples and comparative examples refer to parts by weight.

[0034] Any range described in this invention includes the endpoint, any value between the endpoints, and any subrange consisting of the endpoint or any value between the endpoints.

[0035] Example 1

[0036] 79 parts of polypropylene BX3800, 20 parts of Fe3O4-modified multilayer graphene, 0.1 parts of antioxidant 1010, 0.2 parts of antioxidant 168, 0.3 parts of light stabilizer V703, and 0.4 parts of dispersant E525 were weighed and mixed evenly. The mixture was then fed into a twin-screw extruder through the main feed port. The mixture was extruded, drawn into strands, and granulated to obtain a conductive polypropylene composite material.

[0037] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 180℃, Zone 2 180℃, Zone 3 190℃, Zone 4 190℃, Zone 5 190℃, Zone 6 200℃, Zone 7 200℃, Zone 8 210℃, and Zone 9 210℃. The side feed inlet is located in Zone 8, and the screw speed is 300 r / min.

[0038] The Fe3O4-modified multilayer graphene was prepared by the following steps:

[0039] S1.10g of multilayer graphene was placed in a 2wt% polysulfonated styrene solution and stirred at 55°C for 16 hours. After separation, washing with water and drying, pretreated multilayer graphene was obtained.

[0040] S2. Place 10g of pretreated multilayer graphene into a 2wt% polydienedimethylammonium chloride solution, add 0.6mol of NaCl, stir at room temperature for 30min, and then pour into a dispersion.

[0041] S3. Add 8g of Fe3O4 nanoparticles to the dispersion in step S2, adjust the pH of the solution to 12 with tetramethylammonium hydroxide, stir mechanically for 2 hours, wash with distilled water, filter and dry to obtain Fe3O4 modified multilayer graphene.

[0042] Example 2

[0043] 81 parts of copolymer polypropylene BX 3800, 18 parts of Fe3O4 modified multilayer graphene, 0.1 parts of antioxidant 1010, 0.1 parts of antioxidant 168, 0.1 parts of antioxidant DSTDP, 0.2 parts of light stabilizer UV-3808PP5, and 0.5 parts of dispersant erucamide were weighed and mixed evenly. The mixture was then fed into a twin-screw extruder through the main feed port, and extruded, stretched, and granulated to prepare a conductive polypropylene composite material.

[0044] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 180℃, Zone 2 190℃, Zone 3 190℃, Zone 4 190℃, Zone 5 200℃, Zone 6 200℃, Zone 7 210℃, Zone 8 210℃, and Zone 9 210℃. The side feed inlet is located in Zone 8, and the screw speed is 250 r / min.

[0045] The Fe3O4-modified multilayer graphene was prepared by the following steps:

[0046] S1.10g of multilayer graphene was placed in a 3wt% polysulfonated styrene solution and stirred at 60℃ for 18 hours. After separation, washing with water and drying, pretreated multilayer graphene was obtained.

[0047] S2. Place 10g of pretreated multilayer graphene into a 2wt% polydienedimethylammonium chloride solution, add 0.6mol of NaCl, stir at room temperature for 25min, and then pour into a dispersion.

[0048] S3. Add 12g of Fe3O4 nanoparticles to the dispersion in step S2, adjust the pH of the solution to 12 with tetramethylammonium hydroxide, stir mechanically for 1 hour, wash with distilled water, filter and dry to obtain Fe3O4 modified multilayer graphene.

[0049] Example 3

[0050] 78.8 parts of homopolymer polypropylene PP S2040, 20 parts of Fe3O4 modified multilayer graphene, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, 0.4 parts of light stabilizer UV944, and 0.4 parts of dispersant E525 were weighed and mixed evenly. The mixture was then fed into a twin-screw extruder through the main feed port. The mixture was extruded, drawn into strands, and granulated to prepare a conductive polypropylene composite material.

[0051] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 180℃, Zone 2 185℃, Zone 3 185℃, Zone 4 195℃, Zone 5 195℃, Zone 6 200℃, Zone 7 200℃, Zone 8 205℃, and Zone 9 210℃. The side feed inlet is located in Zone 8, and the screw speed is 300 r / min.

[0052] The Fe3O4-modified multilayer graphene was prepared by the following steps:

[0053] S1.10g of multilayer graphene was placed in a 3wt% polysulfonated styrene solution and stirred at 60℃ for 20 hours. After separation, washing with water and drying, pretreated multilayer graphene was obtained.

[0054] S2. Place 10g of pretreated multilayer graphene into a 2wt% polydienedimethylammonium chloride solution, add 0.5mol of NaCl, stir at room temperature for 40min, and then pour into a dispersion.

[0055] S3. Add 6g of Fe3O4 nanoparticles to the dispersion in step S2, adjust the pH of the solution to 11 with sodium hydroxide, stir mechanically for 2 hours, wash with distilled water, filter and dry to obtain Fe3O4 modified multilayer graphene.

[0056] Example 4

[0057] 84.3 parts of copolymer polypropylene BX 3800, 15 parts of Fe3O4 modified multilayer graphene, 0.1 parts of antioxidant 1010, 0.1 parts of antioxidant DSTDP, 0.2 parts of light stabilizer UV-3808PP5, and 0.3 parts of dispersant E525 were weighed and mixed evenly. The mixture was then fed into a twin-screw extruder through the main feed port, and extruded, stretched, and granulated to prepare a conductive polypropylene composite material.

[0058] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 180℃, Zone 2 180℃, Zone 3 190℃, Zone 4 190℃, Zone 5 190℃, Zone 6 190℃, Zone 7 200℃, Zone 8 200℃, and Zone 9 200℃. The side feed inlet is located in Zone 8, and the screw speed is 100 r / min.

[0059] The Fe3O4-modified multilayer graphene was prepared by the following steps:

[0060] S1.10g of multilayer graphene was placed in a 1wt% polysulfonated styrene solution and stirred at 50°C for 12 hours. After separation, washing with water and drying, pretreated multilayer graphene was obtained.

[0061] S2. Place 10g of pretreated multilayer graphene into a 1wt% polydienedimethylammonium chloride solution, add 0.5mol of NaCl, stir at room temperature for 20min, and then add the dispersion.

[0062] S3. Add 3g of Fe3O4 nanoparticles to the dispersion in step S2, adjust the pH of the solution to 11 with sodium hydroxide, stir mechanically for 1 hour, wash with distilled water, filter and dry to obtain Fe3O4 modified multilayer graphene.

[0063] Example 5

[0064] 76.6 parts of homopolymer polypropylene S2040, 22 parts of Fe3O4 modified multilayer graphene, 0.2 parts of antioxidant 1010, 0.2 parts of antioxidant 168, 0.2 parts of light stabilizer UV-3808PP5, 0.2 parts of light stabilizer V703, and 0.6 parts of dispersant E525 were weighed and mixed evenly. The mixture was then fed into a twin-screw extruder through the main feed port, and extruded, stretched, and granulated to obtain a conductive polypropylene composite material.

[0065] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 200℃, Zone 2 200℃, Zone 3 200℃, Zone 4 210℃, Zone 5 210℃, Zone 6 210℃, Zone 7 210℃, Zone 8 210℃, and Zone 9 210℃. The side feed inlet is located in Zone 8, and the screw speed is 400 r / min.

[0066] The Fe3O4-modified multilayer graphene was prepared by the following steps:

[0067] S1.10g of multilayer graphene was placed in a 3wt% polysulfonated styrene solution and stirred at 60℃ for 24 hours. After separation, washing with water and drying, pretreated multilayer graphene was obtained.

[0068] S2. Place 10g of pretreated multilayer graphene into a 3wt% polydienedimethylammonium chloride solution, add 0.7mol of NaCl, stir at room temperature for 40min, and then pour into a dispersion.

[0069] S3. Add 15g of Fe3O4 nanoparticles to the dispersion in step S2, adjust the pH of the solution to 12 with ammonia, stir mechanically for 3 hours, wash with distilled water, filter and dry to obtain Fe3O4 modified multilayer graphene.

[0070] Comparative Example 1

[0071] 79 parts of polypropylene BX3800, 20 parts of multilayer graphene, 0.1 parts of antioxidant 1010, 0.2 parts of antioxidant 168, 0.3 parts of light stabilizer V703, and 0.4 parts of dispersant E525 were weighed and mixed evenly. The mixture was then fed into a twin-screw extruder through the main feed port. The mixture was extruded, drawn into strands, and granulated to obtain a conductive polypropylene composite material.

[0072] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 180℃, Zone 2 180℃, Zone 3 190℃, Zone 4 190℃, Zone 5 190℃, Zone 6 200℃, Zone 7 200℃, Zone 8 210℃, and Zone 9 210℃. The side feed inlet is located in Zone 8, and the screw speed is 300 r / min.

[0073] Comparative Example 2

[0074] Weigh out 49 parts of polypropylene BX3800, 50 parts of single-layer graphene, 0.1 parts of antioxidant 1010, 0.2 parts of antioxidant 168, 0.3 parts of light stabilizer V703, and 0.4 parts of dispersant E525, mix them evenly, and feed them into a twin-screw extruder through the main feed port. Extrusion, stranding, and granulation are then carried out to prepare a conductive polypropylene composite material.

[0075] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 180℃, Zone 2 180℃, Zone 3 190℃, Zone 4 190℃, Zone 5 190℃, Zone 6 200℃, Zone 7 200℃, Zone 8 210℃, and Zone 9 210℃. The side feed inlet is located in Zone 8, and the screw speed is 300 r / min.

[0076] Comparative Example 3

[0077] 79 parts of polypropylene BX3800, 20 parts of carbon black, 0.1 parts of antioxidant 1010, 0.2 parts of antioxidant 168, 0.3 parts of light stabilizer V703, and 0.4 parts of dispersant E525 were weighed and mixed evenly. The mixture was then fed into a twin-screw extruder through the main feed port. The mixture was extruded, drawn into strands, and granulated to prepare a conductive polypropylene composite material.

[0078] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 180℃, Zone 2 180℃, Zone 3 190℃, Zone 4 190℃, Zone 5 190℃, Zone 6 200℃, Zone 7 200℃, Zone 8 210℃, and Zone 9 210℃. The side feed inlet is located in Zone 8, and the screw speed is 300 r / min.

[0079] Comparative Example 4

[0080] Weigh out 44 parts of polypropylene BX3800, 55 parts of carbon black, 0.1 parts of antioxidant 1010, 0.2 parts of antioxidant 168, 0.3 parts of light stabilizer V703, and 0.4 parts of dispersant E525, mix them evenly, and feed them into a twin-screw extruder through the main feed port. Extrusion, stranding, and granulation are then carried out to prepare a conductive polypropylene composite material.

[0081] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 180℃, Zone 2 180℃, Zone 3 190℃, Zone 4 190℃, Zone 5 190℃, Zone 6 200℃, Zone 7 200℃, Zone 8 210℃, and Zone 9 210℃. The side feed inlet is located in Zone 8, and the screw speed is 300 r / min.

[0082] The conductive polypropylene composite materials obtained in Examples 1-5 and Comparative Examples 1-4 were made into specimens and their performance was tested. The test items and test conditions are shown in Table 1, and the test results are shown in Table 2.

[0083] Table 1

[0084] Test Project Test Standards Test conditions Surface resistance GB1410 / Melt Flow Index GB / T 3682 230℃, 2.16kg Tensile strength GB / T 1040 50mm / min Bending strength GB / T 9341 2mm / min Flexural modulus GB / T 9341 2mm / min Cantilever beam notch impact strength GB / T 1843 23℃

[0085] Table 2

[0086]

[0087] As can be seen from Table 2, the conductive polypropylene composite materials prepared in Examples 1-5 have better conductivity and mechanical properties. Under similar conditions of good conductivity, the present invention can add less conductive filler, thereby achieving better mechanical properties.

[0088] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0089] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of this application; that is, all equivalent modifications made in accordance with the scope of the claims of this application shall be within the protection scope of the claims of this application.

Claims

1. A conductive polypropylene composite material, characterized in that: It is prepared from the following components in parts by weight: 76.6-84.3 parts polypropylene, 15-22 parts Fe3O4-modified multilayer graphene, 0.2-0.4 parts antioxidant, 0.2-0.4 parts light stabilizer, and 0.3-0.6 parts dispersant; the Fe3O4-modified multilayer graphene is prepared by the following steps: S1. Disperse multilayer graphene in a polystyrene solution and stir at 50-60℃ for 12-24h to obtain pretreated multilayer graphene. S2. Disperse the pretreated multilayer graphene in a polydienedimethylammonium chloride solution, add NaCl and mix evenly to obtain a dispersion. S3. Add Fe3O4 nanoparticles to the dispersion in step S2, adjust the pH of the dispersion to 11-12, stir for 1-3 hours, filter to separate the solid material, and obtain Fe3O4 modified multilayer graphene after washing and drying.

2. The conductive polypropylene composite material according to claim 1, characterized in that: The concentration of the polysulfonated styrene solution is 1-3 wt%; the concentration of the polydienedimethylammonium chloride solution is 1-3 wt%.

3. The conductive polypropylene composite material according to claim 1, characterized in that: The pH value of the dispersion is adjusted to 11-12 by adding an alkaline solution to the dispersion; the alkaline solution is one of tetramethylammonium hydroxide, sodium hydroxide, or ammonia water.

4. The conductive polypropylene composite material according to any one of claims 1 to 3, characterized in that: The polypropylene is homopolymer polypropylene or copolymer polypropylene, and its melt index is 3-100g / 10min at 230℃ and 2.16kg.

5. The conductive polypropylene composite material according to any one of claims 1 to 3, characterized in that: The antioxidant is at least one of hindered phenolic antioxidants, phosphite antioxidants, and thioester antioxidants.

6. The conductive polypropylene composite material according to any one of claims 1 to 3, characterized in that: The light stabilizer is at least one of UV944, V703, and UV-3808PP5.

7. The conductive polypropylene composite material according to any one of claims 1 to 3, characterized in that: The dispersant is one of dispersant E525 and erucamide.

8. The method for preparing the conductive polypropylene composite material according to any one of claims 1-7, characterized in that: Includes the following steps: Weigh out polypropylene, Fe3O4-modified multilayer graphene, antioxidant, light stabilizer, and dispersant according to the specified ratio, mix them evenly, and feed them into a twin-screw extruder through the main feed port. After mixing, extrusion, stranding, and pelletizing, the conductive polypropylene composite material is obtained.

9. The method for preparing the conductive polypropylene composite material according to claim 8, characterized in that: The processing temperature of the twin-screw extruder is 180-210℃, and the screw speed is 100-400 r / min.

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