Polypropylene insulated power cable and preparation method thereof

Abstract

The invention relates to a polypropylene insulated power cable and a preparation method thereof, and belongs to the technical field of cables. The polypropylene insulation power cable comprises a copper conductive wire core, a metal shielding layer and a sheath layer, the metal shielding layer comprises a conductor shielding layer, a polypropylene insulation layer and an insulation shielding layer which are arranged from inside to outside, and the sheath layer comprises polypropylene, organic modified graphene, lignite wax, an antioxidant and an anti-UV agent; graphene and agarose form a firm covalent bond compound, then glycidyl methacrylate and eugenol are used for coating the outer layer of a graphene / agarose particle core, the dispersity and compatibility of graphene in a system are remarkably improved, and then the tensile strength and elongation at break of a polypropylene sheath layer material are remarkably improved; therefore, the polypropylene insulated power cable has excellent mechanical properties.

Description

Technical Field

[0001] The invention belongs to the technical field of cables and relates to a polypropylene insulated power cable and a preparation method thereof. Background Art

[0002] As an important variety of general synthetic resin, polypropylene (PP) plays an extremely important role in today's industry and daily life. The reason why it has received widespread attention and application is mainly due to its abundant raw material sources, easy processing and molding characteristics, excellent mechanical properties and low toxicity. Due to these characteristics, the application range of polypropylene is very wide, covering almost all fields, including but not limited to packaging materials, automotive parts, household appliances, medical devices and daily consumer goods.

[0003] Especially in the field of cable materials, polypropylene is widely used due to its excellent electrical insulation and heat resistance. However, despite its many advantages, polypropylene also has some disadvantages that cannot be ignored. For example, polypropylene has relatively poor weather resistance, which means that it is easily affected by ultraviolet rays and temperature changes when exposed to outdoor environments for a long time, resulting in a decrease in material performance. In addition, polypropylene is prone to brittle fracture in low temperature environments, which limits its application in cold areas. Polypropylene has poor antistatic properties, which may pose a hidden danger in some occasions that require high safety.

[0004] Due to its excellent electrical conductivity, graphene can effectively prevent the accumulation of static electricity generated during the operation of the cable, thereby improving the overall antistatic ability. In addition, graphene has high mechanical strength, which can provide additional physical protection for the cable and reduce damage to the cable by external factors. At the same time, graphene has high thermal conductivity, which helps the cable dissipate heat during operation and improves the heat resistance of the cable. In terms of weather resistance, the addition of graphene also significantly improves the service life of the cable in the outdoor environment and reduces the degradation of material performance caused by ultraviolet rays and temperature changes. In summary, graphene as a cable sheath material not only enhances the performance of the cable, but also expands its application range, especially in harsh environments. However, graphene as an inorganic filler has poor compatibility with polypropylene, which may lead to uneven performance and reduced strength during the preparation of the composite material. Summary of the invention

[0005] The object of the present invention is to provide a polypropylene insulated power cable and a preparation method thereof. The present invention forms a strong covalent bond complex through graphene and agarose, and then uses glycidyl methacrylate and eugenol to coat the outer layer of the graphene / agarose particle core, which significantly improves the dispersibility and compatibility of graphene in the system, and can effectively improve the crosslinking density of the polypropylene system to form a denser network structure, thereby significantly improving the tensile strength and elongation at break of the polypropylene sheath layer material, so that the polypropylene insulated power cable has excellent mechanical properties.

[0006] The purpose of the present invention can be achieved through the following technical solutions: A polypropylene insulated power cable, comprising a copper conductive core, a metal shielding layer and a sheath layer, wherein a conductive core group is formed by twisting a plurality of copper conductive cores, the metal shielding layer wraps the conductive core group, the sheath layer is arranged on the outer wall of the metal shielding layer, the metal shielding layer comprises a conductor shielding layer, a polypropylene insulating layer and an insulating shielding layer arranged from the inside to the outside, and the sheath layer comprises the following components by weight: Polypropylene 78-86 parts 10-12 parts of organic modified graphene 1.6-1.8 parts of montan wax Antioxidant 2.0-2.4 parts 1.5-1.8 parts of anti-UV agent; The preparation of the organic modified graphene comprises the following steps: S1, grinding graphene, agarose and deionized water after heating and stirring, air cooling to room temperature and freeze drying, adding anhydrous ethanol and mixing, heating and stirring, adding a silane coupling agent and continuing to stir, air cooling to room temperature, centrifuging, washing, and vacuum drying to obtain modified graphene; S2. Under an inert atmosphere, the modified graphene and anhydrous ethanol are ultrasonically mixed, glycidyl methacrylate and eugenol are added, heated and stirred, and then an initiator is added and stirred at a constant temperature. After air cooling to room temperature, the mixture is centrifuged and vacuum dried to obtain organic modified graphene.

[0007] As a preferred technical solution of the present invention, the sheath layer is made of polyethylene / polyvinyl chloride material; the conductor shielding layer is made of semiconductor inner shielding material; the insulating shielding layer is made of semiconductor outer shielding material; a gap is left between the metal shielding layer and the sheath layer, and a plurality of elastic resin fillers are arranged in the gap, and the elastic resin filler is made of pp material.

[0008] As a preferred technical solution of the present invention, the antioxidant is composed of antioxidant 1010 and antioxidant 1076 in a mass ratio of 1.5:1; the anti-UV agent is ultraviolet absorber UV-49.

[0009] As a preferred technical solution of the present invention, in step S1, the heating stirring is stirring at a temperature of 90-95°C and a speed of 400-600 r / min for 10-15 min; the continued stirring time is 60-70 min; and the vacuum drying is vacuum drying at 80°C to constant weight.

[0010] As a preferred technical solution of the present invention, in step S1, the mass ratio of the graphene, agarose, deionized water, anhydrous ethanol and silane coupling agent is 6.0-7.2: 0.8-1.0: 10-12: 30-40: 1.4-1.6; the silane coupling agent is vinyl triethoxy silane.

[0011] As a preferred technical solution of the present invention, in step S2, the ultrasonic mixing is performed at a frequency of 200-300W for 15-20min; the inert atmosphere is a nitrogen atmosphere; the heating and stirring is performed at a temperature of 60-65°C for 20-30min; the continued stirring time is 5-6h; and the vacuum drying is performed at 70°C to constant weight.

[0012] As a preferred technical solution of the present invention, in step S2, the mass ratio of the modified graphene, anhydrous ethanol, glycidyl methacrylate, eugenol and initiator is 14-16:50-60:16-18:3.4-4.0:1.5; and the initiator is azobisisobutyronitrile.

[0013] The invention discloses a preparation method of a polypropylene insulated power cable. The preparation method comprises the following steps: mixing polypropylene, organic modified graphene, lignite wax, an antioxidant and an anti-UV agent, placing the mixture in a twin-screw extruder for melt extrusion at a temperature of 190-210 DEG C, pelletizing, molding to obtain a sheath layer, and melt extruding the sheath layer on a metal shielding layer coated with a conductive wire core group to obtain the cable.

[0014] Beneficial effects of the present invention: The present invention forms a strong covalent bond complex through graphene and agarose, and then uses glycidyl methacrylate and eugenol to coat the outer layer of the graphene / agarose particle core, which significantly improves the dispersibility and compatibility of graphene in the system, and can effectively improve the cross-linking density of the polypropylene system to form a denser network structure, thereby significantly improving the tensile strength and elongation at break of the polypropylene sheath layer material, so that the polypropylene insulated power cable has excellent mechanical properties. DETAILED DESCRIPTION

[0015] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.

[0016] A polypropylene insulated power cable, comprising a copper conductive core, a metal shielding layer and a sheath layer, wherein a conductive core group is formed by twisting a plurality of copper conductive cores, the metal shielding layer wraps the conductive core group, the sheath layer is arranged on the outer wall of the metal shielding layer, and the metal shielding layer comprises a conductor shielding layer, a polypropylene insulating layer and an insulating shielding layer arranged from inside to outside; The sheath layer is made of polyethylene / polyvinyl chloride material; the conductor shielding layer is made of semiconductor inner shielding material; the insulating shielding layer is made of semiconductor outer shielding material; a gap is left between the metal shielding layer and the sheath layer, and a plurality of elastic resin fillers are arranged in the gap, and the elastic resin fillers are made of pp material.

[0017] A preparation method of a polypropylene insulated power cable comprises the following steps: mixing polypropylene, organic modified graphene, lignite wax, an antioxidant and an anti-UV agent, placing the mixture in a twin-screw extruder for melt extrusion at a temperature of 190-210°C, pelletizing, molding to obtain a sheath layer, and melt extruding the sheath layer on a metal shielding layer coated with a conductive wire core group to obtain the cable.

[0018] Example 1 The sheath layer comprises the following components in parts by weight: Polypropylene 78 parts 10 parts of organic modified graphene 1.6 parts of montan wax 2.0 parts of antioxidant 1.5 parts of anti-UV agent; The antioxidant is composed of antioxidant 1010 and antioxidant 1076 in a mass ratio of 1.5:1; the anti-UV agent is ultraviolet absorber UV-49; The preparation of the organic modified graphene comprises the following steps: S1, grinding graphene, agarose and deionized water after heating and stirring, air cooling to room temperature and freeze drying, adding anhydrous ethanol and mixing, heating and stirring, adding a silane coupling agent and continuing to stir, air cooling to room temperature, centrifuging, washing, and vacuum drying to obtain modified graphene; S2. Under an inert atmosphere, the modified graphene and anhydrous ethanol are ultrasonically mixed, glycidyl methacrylate and eugenol are added, heated and stirred, and then an initiator is added and stirred at a constant temperature. After air cooling to room temperature, the mixture is centrifuged and vacuum dried to obtain organic modified graphene.

[0019] In step S1, the heating stirring is stirring at a temperature of 90° C. and a speed of 400 r / min for 10 min; the continued stirring time is 60 min; the vacuum drying is vacuum drying at 80° C. to constant weight; the mass ratio of the graphene, agarose, deionized water, anhydrous ethanol and silane coupling agent is 6.0:0.8:10:30:1.4; and the silane coupling agent is vinyl triethoxysilane.

[0020] In step S2, the ultrasonic mixing is performed at a frequency of 200 W for 15 minutes; the inert atmosphere is a nitrogen atmosphere; the heating and stirring is performed at a temperature of 60° C. for 20 minutes; the stirring time is continued for 5 hours; the vacuum drying is performed at 70° C. to constant weight; the mass ratio of the modified graphene, anhydrous ethanol, glycidyl methacrylate, eugenol and initiator is 14:50:16:3.4:1.5; and the initiator is azobisisobutyronitrile.

[0021] The preparation method of the sheath layer comprises the following steps: polypropylene, organic modified graphene, lignite wax, antioxidant and anti-UV agent are mixed, placed in a twin-screw extruder for melt extrusion at a temperature of 190° C., pelletized and molded to obtain the sheath layer.

[0022] Example 2 The sheath layer comprises the following components in parts by weight: Polypropylene 82 parts Organic modified graphene 11 parts 1.7 parts of montan wax 2.2 parts of antioxidant 1.6 parts of anti-UV agent; The antioxidant is composed of antioxidant 1010 and antioxidant 1076 in a mass ratio of 1.5:1; the anti-UV agent is ultraviolet absorber UV-49; The preparation of the organic modified graphene comprises the following steps: S1, grinding graphene, agarose and deionized water after heating and stirring, air cooling to room temperature and freeze drying, adding anhydrous ethanol and mixing, heating and stirring, adding a silane coupling agent and continuing to stir, air cooling to room temperature, centrifuging, washing, and vacuum drying to obtain modified graphene; S2. Under an inert atmosphere, the modified graphene and anhydrous ethanol are ultrasonically mixed, glycidyl methacrylate and eugenol are added, heated and stirred, and then an initiator is added and stirred at a constant temperature. After air cooling to room temperature, the mixture is centrifuged and vacuum dried to obtain organic modified graphene.

[0023] In step S1, the heating stirring is stirring at a temperature of 92° C. and a speed of 500 r / min for 12 min; the continued stirring time is 65 min; the vacuum drying is vacuum drying at 80° C. to constant weight; the mass ratio of the graphene, agarose, deionized water, anhydrous ethanol and silane coupling agent is 6.6:0.9:11:35:1.5; and the silane coupling agent is vinyl triethoxysilane.

[0024] In step S2, the ultrasonic mixing is performed at a frequency of 250 W for 18 minutes; the inert atmosphere is a nitrogen atmosphere; the heating and stirring is performed at a temperature of 62° C. for 25 minutes; the stirring time is continued for 5.5 hours; the vacuum drying is performed at 70° C. to constant weight; the mass ratio of the modified graphene, anhydrous ethanol, glycidyl methacrylate, eugenol and initiator is 15:55:17:3.7:1.5; and the initiator is azobisisobutyronitrile.

[0025] The preparation method of the sheath layer comprises the following steps: polypropylene, organic modified graphene, lignite wax, antioxidant and anti-UV agent are mixed, placed in a twin-screw extruder for melt extrusion at 200°C, pelletized and molded to obtain the sheath layer.

[0026] Example 3 The sheath layer comprises the following components in parts by weight: Polypropylene 86 parts 12 parts of organic modified graphene 1.8 parts of montan wax 2.4 parts of antioxidant 1.8 parts of anti-UV agent; The antioxidant is composed of antioxidant 1010 and antioxidant 1076 in a mass ratio of 1.5:1; the anti-UV agent is ultraviolet absorber UV-49; The preparation of the organic modified graphene comprises the following steps: S1, grinding graphene, agarose and deionized water after heating and stirring, air cooling to room temperature and freeze drying, adding anhydrous ethanol and mixing, heating and stirring, adding a silane coupling agent and continuing to stir, air cooling to room temperature, centrifuging, washing, and vacuum drying to obtain modified graphene; S2. Under an inert atmosphere, the modified graphene and anhydrous ethanol are ultrasonically mixed, glycidyl methacrylate and eugenol are added, heated and stirred, and then an initiator is added and stirred at a constant temperature. After air cooling to room temperature, the mixture is centrifuged and vacuum dried to obtain organic modified graphene.

[0027] In step S1, the heating stirring is stirring at a temperature of 95° C. and a speed of 600 r / min for 15 min; the continuous stirring time is 70 min; the vacuum drying is vacuum drying at 80° C. to constant weight; the mass ratio of the graphene, agarose, deionized water, anhydrous ethanol and silane coupling agent is 7.2:1.0:12:40:1.6; and the silane coupling agent is vinyl triethoxysilane.

[0028] In step S2, the ultrasonic mixing is performed at a frequency of 300 W for 20 minutes; the inert atmosphere is a nitrogen atmosphere; the heating and stirring is performed at a temperature of 65° C. for 30 minutes; the stirring time is continued for 6 hours; the vacuum drying is performed at 70° C. to constant weight; the mass ratio of the modified graphene, anhydrous ethanol, glycidyl methacrylate, eugenol and initiator is 16:60:18:4.0:1.5; and the initiator is azobisisobutyronitrile.

[0029] The preparation method of the sheath layer comprises the following steps: polypropylene, organic modified graphene, lignite wax, antioxidant and anti-UV agent are mixed, placed in a twin-screw extruder for melt extrusion at a temperature of 210° C., pelletized and molded to obtain the sheath layer.

[0030] Comparative Example 1 Compared with Example 2, the difference in Comparative Example 1 is that graphene is used instead of agarose in step S1, and the other components, preparation steps and parameters are the same.

[0031] Comparative Example 2 Compared with Example 2, the difference in Comparative Example 2 is that no silane coupling agent is used in step S1, and the other components, preparation steps and parameters are the same.

[0032] Comparative Example 3 Compared with Example 2, Comparative Example 3 is different in that step S2 does not use glycidyl methacrylate, and the remaining components, preparation steps and parameters are the same.

[0033] Comparative Example 4 Compared with Example 2, the difference in Comparative Example 4 is that eugenol is not used in step S2, and the other components, preparation steps and parameters are the same.

[0034] Comparative Example 5 Compared with Example 2, the difference of Comparative Example 5 is that step S2; Step S2, under an inert atmosphere, after heating and stirring anhydrous ethanol, glycidyl methacrylate and eugenol, adding an initiator and stirring at a constant temperature, adding modified graphene and mixing, air cooling to room temperature, centrifuging, and vacuum drying to obtain a composite; that is, the composite replaces the organic modified graphene, and the other components, preparation steps and parameters are the same.

[0035] The sheath layers obtained from Examples 1-3 and Comparative Examples 1-5 were subjected to the following performance tests, respectively. The test results are shown in Table 1.

[0036] Mechanical properties test: GB / T 2951.11-2008 tests its tensile strength and elongation at break; Table 1

[0037] From the test results in Table 1, it can be seen that compared with Comparative Examples 1-5, the tensile strength and elongation at break of the sheath layer prepared in Examples 1-3 of the present invention are significantly better than those of the sheath layer prepared in Comparative Examples 1-5.

[0038] Through comparative analysis, it can be seen that this is because the present invention generates active sites on the surface of graphene under the action of ball milling, and a large number of hydroxyl active groups on the surface of agarose interact with these newly formed active sites to form strong covalent bonds, thereby preventing secondary aggregation between graphene sheets, so that graphene is exfoliated and covalently modified at the same time, significantly improving the grafting rate with the silane coupling agent, and then using graphene / agarose as the particle core, using glycidyl methacrylate and eugenol to coat the outer layer of the particle core, eugenol can improve the grafting rate of glycidyl methacrylate, and the introduction of the silane coupling agent The introduction of carbon-carbon double bonds can enable the graphene / agarose complex to participate in the polymerization reaction, increase the bonding strength between the outer layer and the inner layer, and significantly improve the dispersion and compatibility of graphene in the polypropylene system. At the same time, the epoxy groups and carbon chains contained in glycidyl methacrylate can enhance the toughening effect. The non-polar benzene ring structure on eugenol can be used as a compatibilizer to significantly improve the dispersion and compatibility of graphene in the system, and effectively increase the cross-linking density of the polypropylene system to form a denser network structure, thereby significantly improving the tensile strength and elongation at break of the polypropylene sheath layer material.

[0039] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A polypropylene insulated power cable, comprising a copper conductive core, a metal shielding layer and a sheath layer, wherein a conductive core group is formed by twisting a plurality of copper conductive cores, the metal shielding layer wraps the conductive core group, the sheath layer is arranged on the outer wall of the metal shielding layer, the metal shielding layer comprises a conductor shielding layer, a polypropylene insulating layer and an insulating shielding layer arranged from the inside to the outside, characterized in that: The sheath layer comprises the following components in parts by weight: Polypropylene 78-86 parts 10-12 parts of organic modified graphene 1.6-1.8 parts of montan wax Antioxidant 2.0-2.4 parts 1.5-1.8 parts of anti-UV agent; The preparation of the organic modified graphene comprises the following steps: S1, grinding graphene, agarose and deionized water after heating and stirring, air cooling to room temperature and freeze drying, adding anhydrous ethanol and mixing, heating and stirring, adding a silane coupling agent and continuing to stir, air cooling to room temperature, centrifuging, washing, and vacuum drying to obtain modified graphene; S2. Under an inert atmosphere, the modified graphene and anhydrous ethanol are ultrasonically mixed, glycidyl methacrylate and eugenol are added, heated and stirred, and then an initiator is added and stirred at a constant temperature. After air cooling to room temperature, the mixture is centrifuged and vacuum dried to obtain organic modified graphene.

2. A polypropylene insulated power cable according to claim 1, characterized in that: The sheath layer is made of polyethylene / polyvinyl chloride material; the conductor shielding layer is made of semiconductor inner shielding material; the insulating shielding layer is made of semiconductor outer shielding material; a gap is left between the metal shielding layer and the sheath layer, and a plurality of elastic resin fillers are arranged in the gap, and the elastic resin fillers are made of pp material.

3. A polypropylene insulated power cable according to claim 1, characterized in that: The antioxidant is composed of antioxidant 1010 and antioxidant 1076 in a mass ratio of 1.5:1; the anti-UV agent is ultraviolet absorber UV-49.

4. A polypropylene insulated power cable according to claim 1, characterized in that: In step S1, the heating and stirring is stirring at a temperature of 90-95°C and a speed of 400-600 r / min for 10-15 min; the continuous stirring time is 60-70 min; and the vacuum drying is vacuum drying at 80°C to constant weight.

5. A polypropylene insulated power cable according to claim 1, characterized in that: In step S1, the mass ratio of the graphene, agarose, deionized water, anhydrous ethanol and silane coupling agent is 6.0-7.2: 0.8-1.0: 10-12: 30-40: 1.4-1.6; the silane coupling agent is vinyl triethoxy silane.

6. A polypropylene insulated power cable according to claim 1, characterized in that: In step S2, the ultrasonic mixing is performed at a frequency of 200-300W for 15-20min; the inert atmosphere is a nitrogen atmosphere; the heating stirring is performed at a temperature of 60-65°C for 20-30min; the stirring time is continued for 5-6h; and the vacuum drying is performed at 70°C until constant weight.

7. A polypropylene insulated power cable according to claim 1, characterized in that: In step S2, the mass ratio of the modified graphene, anhydrous ethanol, glycidyl methacrylate, eugenol and initiator is 14-16:50-60:16-18:3.4-4.0:1.5; and the initiator is azobisisobutyronitrile.

8. A method for preparing a polypropylene insulated power cable according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: polypropylene, organic modified graphene, lignite wax, antioxidant and anti-UV agent are mixed, placed in a twin-screw extruder for melt extrusion at a temperature of 190-210°C, pelletized, and molded to obtain a sheath layer, and the sheath layer is melt extruded on a metal shielding layer coated with a conductive wire core group to obtain the product.

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