CN116731252A - Insulating material and preparation method and application thereof - Google Patents

Insulating material and preparation method and application thereof Download PDF

Info

Publication number
CN116731252A
CN116731252A CN202210212275.6A CN202210212275A CN116731252A CN 116731252 A CN116731252 A CN 116731252A CN 202210212275 A CN202210212275 A CN 202210212275A CN 116731252 A CN116731252 A CN 116731252A
Authority
CN
China
Prior art keywords
polypropylene
insulating material
modified polypropylene
modified
methylene
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210212275.6A
Other languages
Chinese (zh)
Inventor
何金良
李琦
袁超
胡军
胡世勋
黄上师
徐绍军
帅萌
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tsinghua University
State Grid Beijing Electric Power Co Ltd
Original Assignee
Tsinghua University
State Grid Beijing Electric Power Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tsinghua University, State Grid Beijing Electric Power Co Ltd filed Critical Tsinghua University
Priority to CN202210212275.6A priority Critical patent/CN116731252A/en
Publication of CN116731252A publication Critical patent/CN116731252A/en
Pending legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08FMACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F255/00Macromolecular compounds obtained by polymerising monomers on to polymers of hydrocarbons as defined in group C08F10/00
    • C08F255/02Macromolecular compounds obtained by polymerising monomers on to polymers of hydrocarbons as defined in group C08F10/00 on to polymers of olefins having two or three carbon atoms
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01BCABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B3/00Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
    • H01B3/18Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
    • H01B3/30Insulators 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
    • H01B3/44Insulators 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
    • H01B3/441Insulators 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
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01BCABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B3/00Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
    • H01B3/18Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
    • H01B3/30Insulators 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
    • H01B3/44Insulators 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
    • H01B3/448Insulators 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 other vinyl compounds

Abstract

The invention provides an insulating material, a preparation method and application thereof. The insulating material modified polypropylene is methylene valerolactone grafted modified polypropylene; the molar content of the methylene valerolactone graft in the modified polypropylene is 1-10mol%. The insulating material can obviously improve the insulating property of the insulating material by comprising the methylene valerolactone grafted and modified polypropylene and controlling the molar content of the grafted matters.

Description

Insulating material and preparation method and application thereof
Technical Field
The invention belongs to the field of materials, and relates to an insulating material, a preparation method and application thereof.
Background
The insulating material is the foundation and guarantee of the development of electrical products, and plays an important role in the development of the motor and the electrical industry. With the rapid development of the power industry, the power grid system advances towards higher voltage levels and larger power transmission capacity, and higher requirements are put on the performance of insulating materials. The main insulating material of the high-voltage direct current cable currently used is crosslinked polyethylene (XLPE), and the insulating effect of the crosslinked polyethylene is not ideal. With the improvement of the voltage class and the conveying capacity of a cable system, the insulating material is kept at a better insulating level mainly by increasing the thickness of the insulating material layer, but the heat dissipation capacity of the insulating material is weakened due to the increase of the thickness of the insulating material, so that the resistivity is further reduced, and the degree of improvement of the insulating level of the insulating material is limited. In addition, the crosslinked polyethylene belongs to a thermosetting material, cannot be recycled after the service life of the cable is over, and a large amount of crosslinked polyethylene waste is generated, so that the environment-friendly effect is not utilized.
As a novel thermoplastic insulating material, polypropylene has better environmental protection performance and electrical insulation performance compared with crosslinked polyethylene, and has received extensive attention in the insulated cable manufacturing industry. However, polypropylene still has a high current density when used as an insulated cable, and is not excellent enough in electrical insulation properties.
Therefore, it is important to develop an insulating material having excellent insulating properties.
Disclosure of Invention
The present invention provides an insulating material which can be made to have excellent insulating properties by making the insulating material include a polypropylene graft-modified with methylene valerolactone and controlling the molar content of the graft.
The invention also provides a preparation method of the insulating material, which has the advantages of easy operation and mild conditions.
The invention also provides an insulated cable comprising the insulating material, and the insulated cable has excellent insulating performance due to the excellent insulating performance of the insulating material.
The first aspect of the invention provides an insulating material, which comprises modified polypropylene, wherein the modified polypropylene is methylene valerolactone grafted and modified polypropylene;
the molar content of the methylene valerolactone graft in the modified polypropylene is 1-10mol%.
The insulating material as described above, wherein the molar content of the methylene valerolactone graft in the modified polypropylene is 3 to 5mol%.
The insulating material as described above, wherein the modified polypropylene has a weight average molecular weight of 300000 ~ 700000g/mol.
The insulating material as described above, wherein the modified polypropylene is a modified homo-polypropylene.
The second aspect of the present invention provides a method for preparing the above-mentioned insulating material, the method comprising: and (3) enabling the polypropylene and the methylene valerolactone to undergo a grafting reaction to obtain the modified polypropylene.
The preparation method as described above, wherein the grafting reaction comprises a process of reacting the reaction system at 45 to 135 ℃;
the reaction system is obtained by adding a mixture of a radical initiator and the methylene valerolactone to the polypropylene.
The preparation method comprises the step of preparing the reaction system, wherein the reaction system further comprises an interfacial agent and a dispersing agent.
The preparation method comprises the step of using 0.01-5 mol% of the free radical initiator.
The preparation method comprises the step of using 0.1-3 mol% of the free radical initiator.
A third aspect of the invention provides an insulated cable comprising the insulating material provided in the first aspect of the invention.
According to the modified polypropylene in the insulating material, the methylene valerolactone is used as a modifier to carry out grafting modification on the polypropylene, and the molar content of the graft in the modified polypropylene is controlled, so that on one hand, heterogeneous nucleation of the modified polypropylene can be promoted, the number of crystal nuclei is increased, the size of the crystal nuclei is reduced, a breakdown channel of current in high-voltage breakdown is prolonged, the breakdown field intensity is increased, on the other hand, a large number of deep charge trap energy levels can be introduced, carriers can be effectively captured, carrier mobility is reduced, and further injection and accumulation of space charges are inhibited. Through the comprehensive effect of the two aspects, the improvement of the insulation performance of the insulation material is realized.
The invention also provides a preparation method of the insulating material, which has the advantages of easy operation and mild condition.
The invention also provides an insulated cable, which comprises the insulating material, and the insulating material is used as an insulating layer material of the insulated cable, so that the insulating performance of the insulated cable can be obviously improved.
Drawings
FIG. 1 is a crystalline morphology of the methylene valerolactone graft modified homo-polypropylene of example 1;
FIG. 2 is a crystalline morphology of the unmodified homo-polypropylene of comparative example 1.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the technical solutions in the embodiments of the present invention will be clearly and completely described in the following in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The first aspect of the invention provides an insulating material, which comprises modified polypropylene, wherein the modified polypropylene is methylene valerolactone grafted modified polypropylene, and the molar content of methylene valerolactone grafts in the modified polypropylene is 1-10mol%.
The modified polypropylene can be directly used as an insulating material, and can also be blended with other polymers to form a composition to be used as the insulating material.
The chemical structural formula of the methylene valerolactone is shown as formula 1:
the methylene valerolactone graft of the present invention refers to a graft portion of the modified polypropylene other than the polypropylene backbone unit.
The inventor researches find that the modified polypropylene obtained by modifying the polypropylene by adopting the methylene valerolactone graft with the specific molar content is easy to nucleate out of phase, and meanwhile, the modified polypropylene has more crystal nucleus number and smaller crystal nucleus size, so that a breakdown channel of current is prolonged and breakdown field strength is increased during high-voltage breakdown; in addition, the grafting group introduces a large number of deep charge trap energy levels, so that carriers can be effectively captured, carrier mobility is reduced, and further injection and accumulation of space charges are inhibited. Through the two functions, the electric insulation performance of the insulation material is improved.
Further, when the molar content of the methylene valerolactone graft in the modified polypropylene is preferably 2 to 7mol%, the insulating property of the insulating material can be further improved.
It is worth mentioning that the weight average molecular weight of the modified polypropylene is also an important factor affecting the insulation properties of the insulation material. When the weight average molecular weight of the modified polypropylene is controlled to 300000 ~ 700000g/mol, the insulating property of the insulating material can be further improved.
The weight average molecular weight of the modified polypropylene of the invention is measured by high temperature GPC, and specifically comprises the following steps: the modified polypropylene was prepared into a sample by PL-GPC 220 type gel permeation chromatography of Polymer Laboratory company, the sample was dissolved in 1,2, 4-trichlorobenzene at a concentration of 1.0mg/ml, the test temperature was 150℃and the solution flow rate was 1.0ml/min. The standard curve was specified using the molecular weight of polystyrene as an internal standard, and the weight average molecular weight of the sample was calculated from the run-out time.
Further, the modified polypropylene of the present invention is a modified homo-polypropylene. Compared with the polypropylene (PP-B), the polypropylene (PP-H) has excellent melting property, tensile property and electrical property, and the melting property, tensile property and electrical property of the polypropylene (PP-H) are equivalent to those of the polypropylene (PP-R), but the cost is lower. Therefore, the insulating material has excellent insulating performance and considerable economic benefit by modifying the insulating material based on the homopolymerized polypropylene.
A second aspect of the present invention provides a method for preparing the insulating material provided in the first aspect, the method comprising: and (3) enabling the polypropylene and the methylene valerolactone to undergo a grafting reaction to obtain the modified polypropylene.
It will be appreciated that the grafting reaction requires the addition of a free radical initiator to promote the formation of free radicals between the polypropylene and the methylene valerolactone and thus the grafting reaction.
The dosages of polypropylene, methylene valerolactone and free radical initiator are important factors influencing the grafting reaction, and the variation of the dosages of the above compounds can lead to the variation of the grafting content, which can directly influence the performance of the polypropylene after grafting modification.
Further, the content of the polypropylene to be added is 0.1 to 25mol%, preferably 3 to 20mol%; the content of the methylene valerolactone to be added is 2 to 20mol%, preferably 2 to 7mol%. Wherein, the content of polypropylene and methylene valerolactone is based on all substances in the whole reaction system.
Further, the grafting reaction comprises a process of reacting the reaction system at 45-135 ℃; wherein the reaction system is obtained by adding a mixture of a radical initiator and methylene valerolactone to polypropylene.
The free radical initiator can initiate the methylene valerolactone to form free radicals, and can also initiate the polypropylene to form free radicals to form active grafting points, so that the methylene valerolactone in the free radical form is grafted on the active grafting points of the polypropylene, and the modified polypropylene is obtained.
The kind of the radical initiator is not particularly limited in the present invention, and radical initiators commonly used in the art, such as peroxide radical initiators, may be selected.
Specifically, the peroxide radical initiator may be at least one selected from dibenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, lauroyl peroxide, t-butyl peroxybenzoate, diisopropyl peroxydicarbonate, t-butyl peroxy (2-ethylhexanoate) and dicyclohexyl peroxydicarbonate.
Further, the peroxide-based radical initiator is preferably benzoic acid peroxide.
The amount of the radical initiator used in the present invention is not particularly limited, and when the amount of the radical initiator is 0.01 to 5mol%, more preferably 0.1 to 3mol%, the grafting reaction efficiency is higher. Wherein the dosage of the free radical initiator is based on all substances in the whole reaction system.
In addition, the proper amount of the free radical initiator can ensure that the polypropylene, the methylene valerolactone and the free radical initiator fully participate in the reaction, thereby reducing the generation of impurities as much as possible.
The grafting reaction of the present invention can be represented by the following reaction process:
1)
2)
3)
in the reaction formula 1), methylene valerolactone forms methylene valerolactone free radical under the action of a free radical initiator;
in reaction formula 2), polypropylene forms polypropylene in free radical form under the action of a free radical initiator;
in the reaction formula 3), the polypropylene in the free radical form obtained in the reaction formula 2) and the methylene free radical obtained in the reaction formula 1) are subjected to grafting reaction to obtain the polypropylene modified by methylene valerolactone.
Furthermore, the interfacial agent and the dispersing agent are added into the reaction system, so that the grafting reaction can be smoothly carried out.
The interfacial agent has swelling effect on polypropylene, so that the polypropylene has a larger reaction area; the dispersing agent can also uniformly disperse reactants, increase the contact area of the reactants, and can more easily obtain the modified polypropylene in a powdery form.
The interfacial agent is an organic solvent having a swelling effect on polypropylene, and can be specifically selected from at least one of an ether solvent, a ketone solvent, an aromatic solvent and an alkane solvent.
The interfacial agent of the present invention is preferably at least one of benzene chloride, polychlorinated benzene, alkane or cycloalkane having 6 or more carbon atoms, benzene, alkyl-substituted benzene having 1 to 4 carbon atoms, aliphatic ether having 2 to 6 carbon atoms, aliphatic ketone having 3 to 6 carbon atoms, decalin, and heptane.
The interfacial agent of the present invention is further preferably at least one of benzene, toluene, xylene, chlorobenzene, tetrahydrofuran, diethyl ether, acetone, hexane, cyclohexane, decalin, and heptane.
The mass of the interfacial agent is preferably 1 to 50% of the mass of the homo-polypropylene, and more preferably 5 to 20%.
The dispersing agent of the invention is preferably water or aqueous solution of sodium chloride, and the mass of the dispersing agent is preferably 50-400% of the mass content of the homo-polypropylene.
A third aspect of the invention provides an insulated cable comprising the insulating material provided in the first aspect of the invention. In particular, the insulation material provided in the first aspect of the present invention may be used as an insulation layer material for insulated cables. Since the insulating material provided in the first aspect of the present invention has good insulating properties, an insulated cable comprising the insulating material also has good insulating properties.
The insulating material of the present invention and its properties will be specifically described below by way of specific embodiments.
Example 1
The insulating material of the embodiment is methylene valerolactone grafted and modified homopolypropylene, wherein the model of the homopolypropylene is T30s, and the molar content of the methylene valerolactone graft in the modified homopolypropylene is 5mol%.
Comparative example 1
The insulating material of this comparative example was unmodified homo-polypropylene, wherein the model of homo-polypropylene was T30s.
Test examples
1. The polymer crystal morphology was observed with a polarizing microscope for the methylene valerolactone graft-modified homo-polypropylene of example 1 and the unmodified homo-polypropylene of comparative example 1.
FIG. 1 is a crystal morphology diagram of the methylene valerolactone graft-modified homo-polypropylene of example 1, and FIG. 2 is a crystal morphology diagram of the unmodified homo-polypropylene of comparative example 1. As shown in FIGS. 1 and 2, the introduction of the methylene valerolactone graft had little effect on the crystalline structure of the polypropylene matrix. However, as can be seen from FIG. 2, the unmodified T30 s-homo-polypropylene has a large crystal nucleus size and a small number of crystal nuclei, and as can be seen from FIG. 1, the T30 s-homo-polypropylene modified by methylene valerolactone grafting has a small crystal nucleus size and a large number of crystal nuclei. The smaller crystal nucleus size and the larger crystal nucleus number can enable the breakdown channel of the current to be lengthened during high-voltage breakdown, the breakdown field intensity is increased, and therefore the insulation performance of the insulation material is improved. The insulating material of example 1 thus has more excellent insulating properties than the insulating material of comparative example 1.
2. The insulating materials of example 1 and comparative example 1 were sampled and tested for current density at electric field strengths of 5kV/mm, 10kV/mm, 15kV/mm, 20kV/mm, 25kV/mm, 30kV/mm, 35kV/mm, 40kV/mm, 45kV/mm, 50kV/mm, 55kV/mm, 60kV/mm, 65kV/mm, 70kV/mm, 75kV/mm, 80kV/mm, respectively, and the test results are shown in Table 1.
TABLE 1
As can be seen from the data in table 1, the current density of the insulating material of the T30s homo-polypropylene modified by the methylene valerolactone grafting is smaller than that of the insulating material of the unmodified T30s homo-polypropylene under different electric field intensities, thereby indicating that the insulating material of the T30s homo-polypropylene modified by the methylene valerolactone grafting has better insulating property.
The above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims (10)

1. An insulating material, characterized in that the insulating material comprises modified polypropylene, wherein the modified polypropylene is methylene valerolactone grafted modified polypropylene;
the molar content of the methylene valerolactone graft in the modified polypropylene is 1-10mol%.
2. The insulation material according to claim 1, wherein the molar content of the methylene valerolactone graft in the modified polypropylene is 3 to 5mol%.
3. Insulation material according to claim 1 or 2, characterized in that the modified polypropylene has a weight average molecular weight of 300000 ~ 700000g/mol.
4. An insulation material according to any one of claims 1-3, characterized in that the modified polypropylene is a modified homo-polypropylene.
5. A method of producing the insulating material according to any one of claims 1 to 4, comprising: and (3) enabling the polypropylene and the methylene valerolactone to undergo a grafting reaction to obtain the modified polypropylene.
6. The method according to claim 5, wherein the grafting reaction comprises a process of reacting the reaction system at 45 to 135 ℃;
the reaction system is obtained by adding a mixture of a radical initiator and the methylene valerolactone to the polypropylene.
7. The method of claim 6, wherein the reaction system further comprises an interfacial agent and a dispersant.
8. The process according to claim 6 or 7, wherein the free radical initiator is used in an amount of 0.01 to 5mol%.
9. The process according to claim 8, wherein the free radical initiator is used in an amount of 0.1 to 3mol%.
10. An insulated cable comprising the insulation material of any one of claims 1-4.
CN202210212275.6A 2022-03-04 2022-03-04 Insulating material and preparation method and application thereof Pending CN116731252A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210212275.6A CN116731252A (en) 2022-03-04 2022-03-04 Insulating material and preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210212275.6A CN116731252A (en) 2022-03-04 2022-03-04 Insulating material and preparation method and application thereof

Publications (1)

Publication Number Publication Date
CN116731252A true CN116731252A (en) 2023-09-12

Family

ID=87913877

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210212275.6A Pending CN116731252A (en) 2022-03-04 2022-03-04 Insulating material and preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN116731252A (en)

Similar Documents

Publication Publication Date Title
CN1255895C (en) Composition for electrolyte, electrolyte and process for producing same, and cell contg. same
CN111393785B (en) Antioxidant grafted high-voltage direct-current cable crosslinked polyethylene insulating material and preparation method thereof
US20030232240A1 (en) Polymer electrolyte with effective leakage resistance and lithium battery using the same
CN1621424A (en) Modified coupling agent and its preparing process and use
CN111234424B (en) Flaky boron nitride/polyvinylidene fluoride composite material and preparation method thereof
AU2020102276A4 (en) Preparation method of cable insulating layer material having polyolefin grafting polar group
Zhou et al. Recyclable polypropylene-based insulation materials for HVDC cables: Progress and perspective
CN1587308A (en) Process for preparing polyolefine/montmorillonite nano non-halogen flame-resisting material
CN114605742A (en) Preparation method of polypropylene-based insulating material modified by multiple functional groups for polypropylene cable insulation
JPS6019745B2 (en) Peroxide composition, its production method, its use
Zha et al. Effect of multi-dimensional zinc oxide on electrical properties of polypropylene nanocomposites for HVDC cables
CN102453218A (en) Preparation method of composite silane coupling agent modified silicon micropowder
CN116731252A (en) Insulating material and preparation method and application thereof
CN110894320A (en) Method for improving charge characteristic of insulation space of polypropylene high-voltage direct-current cable
CN111393572B (en) Recyclable antioxidant grafted polyolefin high-voltage direct-current cable insulation material and preparation method thereof
CN116731253A (en) Insulating material and preparation method and application thereof
US20230174698A1 (en) Polypropylene Graft Containing Anhydride Group and Preparation Method for Polypropylene Graft
CN110003505B (en) Modification method of polypropylene-based insulating material for high-voltage direct-current cable
CN116632325A (en) Solid electrolyte, preparation method thereof, heterojunction nanofiber and all-solid-state lithium battery
Liang et al. Preparation and electrical properties of 4-allyloxy-2-hydroxybenzophenone grafted polypropylene for HVDC cables
CN114106504A (en) Thermoplastic medium-voltage cable insulating material and preparation method thereof
CN109942933A (en) A kind of direct current cables Insulation Material and preparation method thereof inhibiting space charge
CN113571235B (en) Cable with thermoplastic insulating layer
CN117143410B (en) Heat-resistant composite low-voltage cable and preparation method thereof
CN111100371A (en) Homo-polypropylene material for power cable and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination