CN-122010591-A - Three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material and preparation method thereof

CN122010591ACN 122010591 ACN122010591 ACN 122010591ACN-122010591-A

Abstract

The invention discloses a three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material and a preparation method thereof, and belongs to the technical field of insulating materials, wherein the material consists of 18% -22% of three-dimensional whisker network reinforced phase, 70% -76% of silicon oxide-aluminum oxide composite mesoporous matrix, 3% -5% of anti-condensation functional component and 0.5% -1.5% of interface coupling agent KH550, wherein double whiskers form a through network according to the mass ratio of 2% -3:1, the mesoporous matrix is in bimodal pore size distribution, and the anti-condensation component is a composite system of fluorosilane and double nano particles. The preparation method realizes material performance optimization through the cooperative steps of in-situ whisker network construction, sol-gel compounding, ALD transition layer deposition, radiation crosslinking, plasma modification and the like. The dielectric strength of the obtained material is more than or equal to 27kV/mm, the compressive strength is more than or equal to 4.2MPa, the condensation inhibition rate of a 95% RH environment for 72 hours is more than or equal to 96%, the dielectric attenuation rate of a high humidity 3000 hour is less than or equal to 4%, the material can resist the extreme environment of salt fog, is suitable for long-acting insulation protection of power equipment in high-humidity strong corrosion scenes such as ocean platforms, chemical industry parks and the like, and has remarkable industrial application value.

Inventors

ZHANG JIE
ZHANG JIAN
CHEN ZHI
LI LONG
XU BIN
ZHEN YU
WEI TINGTING
TENG YUE
ZHAO JIAN
SUN SIJIA
WANG RUOMIN
FANG ZHENBANG

Assignees

国网安徽省电力有限公司电力科学研究院
安徽新力电业科技有限责任公司
武汉疏能新材料有限公司

Dates

Publication Date: 20260512
Application Date: 20260302

Claims (10)

1. The preparation method of the three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material is characterized by comprising the following steps of: (1) Mixing SiC whiskers and mullite whiskers according to a mass ratio of 2-3:1, performing ultrasonic cleaning on the mixture by using 5-8% dilute hydrochloric acid at 80 ℃, washing the mixture by using deionized water to neutrality, performing vacuum drying, adding deionized water and a dispersing agent, performing ultrasonic dispersion, and performing ball milling to form a suspension; (2) Adding a temperature control agent into the suspension, uniformly stirring, injecting into a mold, preserving heat by adopting a gradient freezing process, applying a pressure of 5-8 MPa for 2-3 hours at a temperature of-20 ℃, and finally removing an ice crystal template by freeze drying to obtain a whisker framework; (3) Mixing materials according to a molar ratio of SiO 2 to Al 2 O 3 of 3-5:1, using ethyl orthosilicate as a silicon source, aluminum isopropoxide as an aluminum source, ethanol as a solvent and hydrochloric acid as a catalyst, controlling a molar ratio of water to ethyl orthosilicate of 4-6:1, stirring and hydrolyzing for 4-6 hours at 30-40 ℃, adding methyl methacrylate monomer and initiator, and stirring to complete in-situ polymerization to obtain composite sol; (4) Vacuum dipping the whisker skeleton into composite sol, adding a condensation preventing functional component and an interface coupling agent, performing ultrasonic dispersion for 20min, adjusting the pH to 8-9 by using ammonia water, performing constant-temperature reaction for 3h at 50 ℃, and then placing into an atomic layer deposition device, taking trimethylaluminum and deionized water as precursors, and depositing an Al 2 O 3 transition layer at 5-10 nm at 50 ℃ to obtain a composite gel system; (5) Standing the composite gel system at 60 ℃ for 8-12 h for gelation, and aging for 24h by using ethanol-deionized water mixed solution at 70 ℃, wherein the wet gel is obtained by using gamma-ray irradiation to complete crosslinking; (6) Drying the wet gel for 6-8 hours at 40-50 ℃ and 8-10 MPa, and then performing plasma treatment for 5-10 minutes under 100-150W power in an argon atmosphere to obtain a dry composite material; (7) And roasting the dry composite material by adopting a gradient roasting process to obtain the three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material.
2. The method for preparing the three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material according to claim 1, wherein the gradient freezing process in the step (2) is that the temperature is gradually reduced from-5 ℃ to-20 ℃ at a cooling rate of 1 ℃ per minute, and the temperature is kept for 4 hours; the process conditions of freeze drying are-50 ℃ and drying is carried out for 8-12 hours; The temperature control agent is CaF 2 , and the addition amount is 1.5% -2.5% of the whisker mass.
3. The preparation method of the three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material is characterized in that the addition amount of methyl methacrylate monomer in the step (3) is 1% -2% of the total mass of sol.
4. The method for preparing the three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material according to claim 1, wherein the initiator is benzoyl peroxide, and the addition amount of the initiator is 0.3% -0.5% of the mass of the monomer.
5. The method for preparing the three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material according to claim 1, wherein the dispersing agent is tetramethyl ammonium hydroxide, and the adding amount of the dispersing agent is 0.5% -1% of the mass of the whisker.
6. The preparation method of the three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material is characterized in that the gamma-ray irradiation dose in the step (5) is 50-80 kGy, and the irradiation time is 1-2 hours.
7. The method for preparing the three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material according to claim 1, wherein the gradient roasting process in the step (7) is characterized in that the temperature rise rate of 20-200 ℃ is 2 ℃ per minute, the temperature is kept for 2 hours, the temperature rise rate of 200-600 ℃ is 5 ℃ per minute, the temperature is kept for 3 hours, the temperature rise rate of 600-700 ℃ is 2 ℃ per minute, the temperature is kept for 2 hours, and the material is cooled along with a furnace.
8. The method for preparing the three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material according to claim 1, wherein the anti-condensation functional component in the step (4) is a composite system consisting of perfluorooctyl triethoxysilane, nano TiO 2 and nano ZnO according to a mass ratio of 5-7:2-3:1.
9. The method for preparing the three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material according to claim 1, wherein the interface coupling agent in the step (4) is gamma-aminopropyl triethoxysilane.
10. The three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material is prepared by the preparation method of any one of claims 1-9, and is characterized by comprising, by mass, 18% -22% of a three-dimensional whisker network reinforced phase, 70% -76% of a silicon oxide-aluminum oxide composite mesoporous matrix, 3% -5% of an anti-condensation functional component and 0.5% -1.5% of an interface coupling agent; the three-dimensional whisker network reinforcement phase is a continuous through network formed by compounding SiC whiskers and mullite whiskers according to a mass ratio of 2-3:1; The molar ratio of SiO 2 to Al 2 O 3 in the silicon oxide-aluminum oxide composite mesoporous matrix is 3-5:1, and the silicon oxide-aluminum oxide composite mesoporous matrix is in bimodal pore size distribution; The anti-condensation functional component is a composite system composed of perfluorooctyl triethoxysilane, nano TiO 2 and nano ZnO according to the mass ratio of 5-7:2-3:1, and the perfluorooctyl triethoxysilane is grafted on the whisker surface and mesoporous pore wall in situ; the interface coupling agent is gamma-aminopropyl triethoxysilane.

Description

Three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material and preparation method thereof Technical Field The invention belongs to the technical field of insulating materials, and particularly relates to a three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material and a preparation method thereof. Background The mesoporous insulating material has irreplaceable application value in the fields of power equipment insulation, high-frequency electronic packaging and the like by virtue of the characteristics of high specific surface area, low dielectric constant and low heat conductivity coefficient. The existing mesoporous insulating material is difficult to adapt to a high-humidity complex service environment, firstly, the mechanical property is weak, the mesoporous structure leads to high brittleness and poor impact resistance of the material, microcracks are easy to generate in the processing or service process, the insulation reliability is directly reduced, secondly, the anti-condensation capability is lost, mesoporous channels are easy to absorb water vapor and form condensation in the high-humidity environment, the breakdown strength of the material is suddenly reduced by more than 30%, insulation failure accidents are induced, thirdly, the performance cooperativity is poor, the mechanical property can be slightly improved by the traditional reinforcing means (such as single particle filling and short fiber doping), the integrity of the mesoporous structure is damaged, the insulation performance and the anti-condensation effect are mutually restricted, and multi-performance synchronous optimization cannot be realized. In the prior art, whiskers are used as one-dimensional reinforcements, and are tried to be used for modifying composite materials due to the advantages of high specific strength and high modulus, but the advantages are obvious limitations, such as the disclosed mesoporous titanium oxide whisker molding material only focuses on catalytic performance, no anti-condensation function design, no continuous network formed by the whiskers in a dispersed state, limited mechanical reinforcing effect (the compressive strength is less than or equal to 2.5 MPa), the mullite whisker reinforced silica aerogel is adopted, the mechanical performance is improved, but the mesoporous structure is single (single pore diameter distribution), the water vapor adsorption-desorption balance cannot be regulated and controlled, no interface modification design is adopted, the whiskers and a matrix are easily stripped, and the service stability is poor in a high-humidity environment. Most of the existing anti-condensation technologies rely on surface hydrophobic coatings, the coatings are weak in binding force with a substrate and easy to fall off, long-acting anti-condensation cannot be achieved, the compatibility of coating materials and mesoporous insulation systems is poor, mesoporous pore channels are easy to be blocked after the coating materials are coated, and inherent insulation performance of the materials is damaged. In conclusion, development of a composite system which can not only keep excellent insulation and heat insulation performance of mesoporous materials, but also strengthen mechanical properties through a three-dimensional whisker network, and simultaneously integrates long-acting condensation prevention, corrosion resistance and self-repairing functions becomes a key for solving the insulation problem of high-humidity complex environments. Therefore, the three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material and the preparation method thereof are improved and designed. Disclosure of Invention Aiming at the defects in the prior art, the invention provides a three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material and a preparation method thereof, which are used for solving the problems in the prior art. In order to solve the technical problems, the invention adopts the following technical scheme: The preparation method of the three-dimensional whisker network reinforced mesoporous composite anti-condensation insulating material comprises the following steps: (1) Mixing SiC whiskers and mullite whiskers according to a mass ratio of 2-3:1, performing ultrasonic cleaning on the mixture by using 5-8% dilute hydrochloric acid at 80 ℃, washing the mixture by using deionized water to neutrality, performing vacuum drying, adding deionized water and a dispersing agent, performing ultrasonic dispersion, and performing ball milling to form a suspension; (2) Adding a temperature control agent into the suspension, uniformly stirring, injecting into a mold, preserving heat by adopting a gradient freezing process, applying a pressure of 5-8 MPa for 2-3 hours at a temperature of-20 ℃, and finally removing an ice crystal template by