CN111471236A - Polypropylene cable insulating material and preparation method and application thereof - Google Patents
Polypropylene cable insulating material and preparation method and application thereof Download PDFInfo
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- CN111471236A CN111471236A CN202010281059.8A CN202010281059A CN111471236A CN 111471236 A CN111471236 A CN 111471236A CN 202010281059 A CN202010281059 A CN 202010281059A CN 111471236 A CN111471236 A CN 111471236A
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/36—Sulfur-, selenium-, or tellurium-containing compounds
- C08K5/37—Thiols
- C08K5/375—Thiols containing six-membered aromatic rings
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
- H01B3/18—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
- H01B3/30—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes
- H01B3/44—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes vinyl resins; acrylic resins
- H01B3/441—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes vinyl resins; acrylic resins from alkenes
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K2201/00—Specific properties of additives
- C08K2201/014—Additives containing two or more different additives of the same subgroup in C08K
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2201/00—Properties
- C08L2201/08—Stabilised against heat, light or radiation or oxydation
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2203/00—Applications
- C08L2203/20—Applications use in electrical or conductive gadgets
- C08L2203/202—Applications use in electrical or conductive gadgets use in electrical wires or wirecoating
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2207/00—Properties characterising the ingredient of the composition
- C08L2207/10—Peculiar tacticity
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- Organic Insulating Materials (AREA)
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Abstract
The invention discloses a polypropylene cable insulating material, a preparation method and application thereof. The polypropylene composite insulating material comprises 99.5-99.9% of polypropylene matrix and 0.1-0.5% of thiobisphenol compound filler by mass fraction of 100%. The thiobisphenol compound comprises a hindered phenol unit and a sulfur-containing unit, the hindered phenol unit captures free radicals generated in a matrix through proton transfer, and the sulfur-containing unit efficiently decomposes hydroperoxide to be harmless products. The polypropylene cable insulating material with high thermal oxidation stability prepared by the invention has the characteristics of long oxidation induction period, high direct current breakdown strength, difficulty in accumulating space charge and the like, and is suitable for high-voltage direct current cables.
Description
Technical Field
The invention belongs to the technical field of electric and electronic material preparation, and particularly relates to a polypropylene cable insulating material, and a preparation method and application thereof.
Background
The polypropylene is an environment-friendly high-voltage direct-current cable insulating material, and compared with the traditional crosslinked polyethylene insulating material, the polypropylene has the advantages of high working temperature, low conductivity, high breakdown strength, difficulty in accumulating space charge and the like. However, the polypropylene material is easy to age under the action of heat, oxygen, light and the like, so that the breakdown field strength is reduced, and the service life is shortened. Therefore, it is necessary to add an antioxidant to the polypropylene material.
The problems currently faced are: on one hand, when the addition amount of the antioxidant is low, the antioxidant efficiency is low, and the effect of prolonging the service life of the cable is not obvious; when the addition amount of the antioxidant is high, the electrical performance of the cable is greatly reduced. On the other hand, different types of antioxidants have different oxidation resistance mechanisms and efficiencies, and have different influence mechanisms and capacities on the electrical properties of polypropylene. Therefore, when selecting an antioxidant suitable for polypropylene wires and cables, the antioxidant needs to improve both the oxidation resistance and maintain excellent electrical performance. The thiobisphenol compound has the double functions of radical capture and hydroperoxide decomposition, inhibits the formation of a low-density region in the breakdown process, finally improves the breakdown performance of polypropylene, has low molecular weight and greatly improves the oxidation resistance efficiency.
Disclosure of Invention
The invention aims to improve the thermal-oxidative aging resistance of polypropylene for high-voltage direct-current cables on the premise of ensuring the excellent electrical property of the polypropylene, and provides a polypropylene cable insulating material, a preparation method and application thereof. Adding thiobisphenol antioxidants into isotactic polypropylene, wherein hindered phenol units capture free radicals generated in a matrix through proton transfer to inhibit peroxy radicals from generating hydroperoxides, inhibit the formation of a low-density area in a polypropylene material, and finally increase the breakdown strength of the material; the sulfur-containing unit efficiently decomposes the hydroperoxide into harmless products, thereby significantly increasing the service life of the polypropylene.
The first object of the invention is to provide a polypropylene cable insulation material, wherein the polypropylene composite insulation material comprises 99.5-99.9% of a polypropylene matrix and 0.1-0.5% of a thiobisphenol compound filler in a mass fraction of 100%.
The polypropylene matrix is isotactic polypropylene.
The antioxidant is one or two of thiobisphenol compounds 4,4 '-thiobis (6-tert-butyl-3-methylphenol) and 4,4' -thiobis- (2-methyl-6-tert-butylphenol).
The second purpose of the invention is to provide a preparation method of the polypropylene cable insulation material, which comprises the following steps:
A. mixing isotactic polypropylene particles on a double-roller mill for 10 minutes to fully melt the isotactic polypropylene particles, wherein the temperature is set to be 200 ℃;
B. mixing is suspended, antioxidant powder is mixed with polypropylene, and the antioxidant is fully melted in the isotactic polypropylene;
C. the mixture is continuously and fully mixed on a double-roller machine for 15 minutes, the temperature is set to be 200 ℃, and then the mixture is cut into a plurality of parts, wherein each part is 1-2 g;
D. degassing the mixed material, cooling, and performing hot press molding on a tablet press.
The hot pressing of the invention comprises the following steps:
A. placing a part of the mixed material in a mold, wherein the diameter of the mold is 70mm, and the depth of the mold is 70/250 μm;
B. hot pressing the mixed material in a tablet press for 15 minutes, wherein the temperature is set to 200 ℃, and the pressure is set to 20 MPa;
C. the circulating water tank was opened, the tablet press temperature was quenched from 200 ℃ to 80 ℃ in 1 minute and removed.
The third purpose of the invention is to provide the application of the polypropylene cable insulating material, and the high thermal oxidation stability of the polypropylene cable insulating material is improved.
Compared with the prior art, the invention has the following beneficial effects:
1. selecting a thiobisphenol compound as a filler, wherein a hindered phenol unit captures free radicals generated in a matrix through proton transfer, inhibits peroxy radicals from generating hydroperoxide, inhibits the formation of a low-density area in a polypropylene material, and finally increases the breakdown strength of the material; the sulfur-containing unit efficiently decomposes the hydroperoxide into harmless products, thereby significantly increasing the service life of the polypropylene.
2. The thiobisphenol compound is selected as the filler, the molecular weight of the thiobisphenol compound is 358, and the antioxidant efficiency is high; the melting point is close to that of isotactic polypropylene, and the compatibility of the filler and the matrix is improved.
2. Through testing of direct current breakdown strength at 30-90 ℃, the polypropylene cable insulating material with high thermal oxidation stability prepared by the invention has high direct current breakdown strength and is suitable for high-voltage direct current cables.
3. Through the oxidation induction period test at 210 ℃, the polypropylene cable insulating material with high thermal oxidation stability prepared by the invention has a higher oxidation induction period and is suitable for high-voltage direct-current cables.
Drawings
Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:
FIG. 1 shows isotactic polypropylene (a) according to the present invention, two thiobisphenols: the molecular formulae (c) of 4,4 '-thiobis (6-tert-butyl-3-methylphenol) (b) and 4,4' -thiobis- (2-methyl-6-tert-butylphenol);
FIG. 2 is a graph showing the oxidation induction time of the polymer composite prepared in example 1;
FIG. 3 is a graph showing the DC breakdown strength of the polymer composite prepared in example 1 at 30-90 ℃.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.
The experimental test samples of the invention measure the oxidation induction period in a differential scanning calorimeter.
The experimental test sample of the invention measures the direct current breakdown strength on a breakdown strength test platform which consists of a test transformer, a voltage regulator, an impedance voltage divider, an oscilloscope and the like.
The invention provides a method for improving high thermal oxidation stability of a polypropylene cable insulating material. The polypropylene composite insulating material comprises 99.5-99.9% of polypropylene matrix and 0.1-0.5% of thiobisphenol compound filler by mass fraction of 100%.
The polypropylene matrix is isotactic polypropylene, and the polypropylene matrix serving as an environment-friendly high-voltage direct-current cable insulating material has the advantages of high working temperature, high breakdown strength, difficulty in accumulating space charges, easiness in recycling and the like.
Preferably, the antioxidant is one or two of thiobisphenol compounds 4,4 '-thiobis (6-tert-butyl-3-methylphenol) and 4,4' -thiobis- (2-methyl-6-tert-butylphenol). The two thiobisphenol compounds have the molecular weight of 358, the contained functional groups are the same, and the antioxidant efficiency is higher.
The invention provides a preparation method of a polypropylene cable insulating material with high thermal oxidation stability, which comprises the following steps:
A. mixing isotactic polypropylene particles on a double-roller mill for 10 minutes to fully melt the isotactic polypropylene particles, wherein the temperature is set to be 200 ℃;
B. mixing is suspended, antioxidant powder is mixed with polypropylene, and the antioxidant is fully melted in the isotactic polypropylene;
C. the mixture is continuously and fully mixed on a double-roller machine for 15 minutes, the temperature is set to be 200 ℃, and then the mixture is cut into a plurality of parts, wherein each part is 1-2 g;
D. degassing the mixed material, cooling, and hot-press forming on a tablet press
Preferably, the hot pressing method in step C comprises the steps of:
A. placing a part of the mixed material in a mold, wherein the diameter of the mold is 70mm, and the depth of the mold is 70/250 μm;
B. hot pressing the mixed material in a tablet press for 15 minutes, wherein the temperature is set to 200 ℃, and the pressure is set to 20 MPa;
C. the circulating water tank was opened, the tablet press temperature was quenched from 200 ℃ to 80 ℃ in 1 minute and removed.
The invention adopts thiobisphenol compounds with the functions of capturing free radicals and decomposing hydroxide as fillers and isotactic polypropylene with excellent electrical property as a matrix to prepare the polypropylene insulating material for the high-voltage direct-current cable with high thermal-oxidative stability and excellent insulating property by a melt blending method.
Example 1
The embodiment relates to a polypropylene cable insulating material with high thermal oxygen stability, and the polypropylene cable insulating material comprises 99.7% of a polypropylene matrix and 0.3% of a thiobisphenol compound filler in parts by mass of 100%. The preparation method of the polypropylene cable insulating material with high thermal oxygen stability comprises the following steps:
A. mixing 29.91g of isotactic polypropylene particles on a double-roller mill for 10 minutes to fully melt the isotactic polypropylene particles, wherein the temperature is set to 200 ℃;
B. the kneading was suspended, and 0.09g of 4,4 '-thiobis (6-t-butyl-3-methylphenol) and 4,4' -thiobis- (2-methyl-6-tert-butylphenol) were mixed with isotactic polypropylene respectively to be sufficiently melted in the isotactic polypropylene;
C. the mixture is continuously and fully mixed on a double-roller machine for 15 minutes, the temperature is set to be 200 ℃, and then the mixture is cut into a plurality of parts, wherein each part is 1-2 g;
D. degassing the mixed material, cooling, and hot-pressing in a tablet press for 15 minutes at 200 deg.C and 20 MPa; the circulating water tank was opened, the tablet press temperature was quenched from 200 ℃ to 80 ℃ in 1 minute and removed.
Example 2
The embodiment relates to a polypropylene cable insulating material with high thermal oxygen stability, and the polypropylene cable insulating material comprises 99.5% of a polypropylene matrix and 0.5% of a thiobisphenol compound filler in parts by mass of 100%. The other steps are the same as in example 1.
Example 3
The embodiment relates to a polypropylene cable insulating material with high thermal oxygen stability, and the polypropylene cable insulating material comprises 99.9% of a polypropylene matrix and 0.1% of a thiobisphenol compound filler in parts by mass of 100%. The other steps are the same as in example 1.
Comparative example 1
The comparative example relates to a polypropylene cable insulation material with high thermal oxygen stability, and the polypropylene composite insulation material comprises 99.5% of a polypropylene matrix and 0.5% of a thiobisphenol compound filler in percentage by mass of 100%. The preparation method of the polypropylene cable insulation material with high thermal oxygen stability is the same as that of the example 1.
In conclusion, the two thiobisphenol compounds are added into the isotactic polypropylene, wherein the hindered phenol unit captures free radicals generated in the matrix through proton transfer, the formation of hydroperoxide generated by peroxy radicals is inhibited, the formation of a low-density area in the polypropylene material is inhibited, and the breakdown strength of the material is finally increased; the sulfur-containing unit efficiently decomposes the hydroperoxide into harmless products, thereby significantly increasing the service life of the polypropylene. The prepared polypropylene cable insulating material with high thermal oxidation stability not only has a higher oxidation induction period, but also obviously improves the direct current breakdown strength.
Claims (6)
1. The polypropylene cable insulation material is characterized by comprising 99.5-99.9% of polypropylene matrix and 0.1-0.5% of thiobisphenol compound filler by mass fraction of 100%.
2. The polypropylene cable insulation of claim 1, wherein the polypropylene matrix is isotactic polypropylene.
3. The polypropylene cable insulation material as claimed in claim 1, wherein the antioxidant is one or both of thiobis phenolic compounds 4,4 '-thiobis (6-tert-butyl-3-methylphenol) and 4,4' -thiobis- (2-methyl-6-tert-butylphenol).
4. The method for preparing the polypropylene cable insulation material according to claim 1, wherein the method comprises the following steps:
A. mixing isotactic polypropylene particles on a double-roller mill for 10 minutes to fully melt the isotactic polypropylene particles, wherein the temperature is set to be 200 ℃;
B. mixing is suspended, antioxidant powder is mixed with polypropylene, and the antioxidant is fully melted in the isotactic polypropylene;
C. the mixture is continuously and fully mixed on a double-roller machine for 15 minutes, the temperature is set to be 200 ℃, and then the mixture is cut into a plurality of parts, wherein each part is 1-2 g;
D. degassing the mixed material, cooling, and performing hot press molding on a tablet press.
5. The preparation method of the polypropylene cable insulation material as claimed in claim 4, wherein the hot pressing comprises the following steps:
A. placing a part of the mixed material in a mold, wherein the diameter of the mold is 70mm, and the depth of the mold is 70/250 μm;
B. hot pressing the mixed material in a tablet press for 15 minutes, wherein the temperature is set to 200 ℃, and the pressure is set to 20 MPa;
C. the circulating water tank was opened, the tablet press temperature was quenched from 200 ℃ to 80 ℃ in 1 minute and removed.
6. Use of a polypropylene cable insulation according to any one of claims 1 to 3, wherein the high thermo-oxidative stability of the polypropylene cable insulation is improved.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010281059.8A CN111471236A (en) | 2020-04-10 | 2020-04-10 | Polypropylene cable insulating material and preparation method and application thereof |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010281059.8A CN111471236A (en) | 2020-04-10 | 2020-04-10 | Polypropylene cable insulating material and preparation method and application thereof |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114015154A (en) * | 2021-11-09 | 2022-02-08 | 南方电网科学研究院有限责任公司 | Preparation method of environment-friendly high-voltage cable polypropylene insulating material |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114015154A (en) * | 2021-11-09 | 2022-02-08 | 南方电网科学研究院有限责任公司 | Preparation method of environment-friendly high-voltage cable polypropylene insulating material |
| CN114015154B (en) * | 2021-11-09 | 2023-08-18 | 南方电网科学研究院有限责任公司 | Preparation method of environment-friendly high-voltage cable polypropylene insulating material |
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Application publication date: 20200731 |