CN-121976426-A - Polyphenyl sulfone sulfoxide fiber-based composite insulating paper and preparation method thereof

CN121976426ACN 121976426 ACN121976426 ACN 121976426ACN-121976426-A

Abstract

The invention discloses a polyphenylene sulfone sulfoxide fiber-based composite insulating paper and a preparation method thereof, which takes polyphenylene sulfone sulfoxide fibers and various fiber pulp as main raw materials, the polyphenylsulfone sulfoxide fiber-based composite insulating paper is prepared by combining wet forming with hot pressing. According to the invention, the polydopamine coating is formed on the surface of the fiber through dopamine modification, so that the modified polyphenylene sulfone sulfoxide chopped fiber is led into a hydrogen bonding mechanism, the mechanical property of the composite insulating paper is enhanced, and the modified carbon nitride nano particles are led into the composite insulating paper as a filler to improve the compactness of the composite material and enhance the electrical insulating property of the composite insulating paper. The polyphenylene sulfone sulfoxide fiber-based composite insulating paper prepared by the invention has the characteristics of excellent mechanical property, high electrical insulation, high temperature resistance, corrosion resistance, flame retardance and the like. Meanwhile, the preparation method has the advantages of low cost of raw materials, short process flow and simple and convenient operation, can effectively reduce the cost of industrial production, and promotes the industrial production and practical application of the insulating paper.

Inventors

CAI WEILONG
Que Hualong
JIA MENGKE
WU MEIHUA
WANG WEI
LIU LONGMIN
CHEN HUAIYIN
LI YONGZHAO
HONG XIAOYUN

Assignees

福州大学
清源创新实验室

Dates

Publication Date: 20260505
Application Date: 20260401

Claims (10)

1. A preparation method of polyphenylene sulfone sulfoxide fiber-based composite insulating paper is characterized by comprising the following steps: s1, polyphenyl sulfone sulfoxide fiber surface modification, namely dispersing polyphenyl sulfone sulfoxide chopped fibers in deionized water, adding dopamine hydrochloride, adjusting the pH value to 8.5, stirring at room temperature for 5-12 h, washing and vacuum drying to obtain polydopamine modified polyphenyl sulfone sulfoxide chopped fibers; S2, dissociating fibers, namely sequentially adding polydopamine modified polyphenylene sulfone sulfoxide chopped fibers and fiber pulp into a pre-dispersed hydrolyzed dispersing agent according to the mass ratio of (20-80) (80-20), and respectively implementing a segmented fluffing process to obtain polyphenylene sulfone sulfoxide fiber pulp, wherein the fluffing rotating speed is 1500-4500 r/min, and the fluffing rotating speed is 20000-40000 r; S3, preparing modified carbon nitride nano particles, namely placing the carbon nitride nano particles into hydrogen peroxide solution, stirring the carbon nitride nano particles at room temperature for 100-140 min, filtering, washing and drying in vacuum to obtain hydroxylated carbon nitride nano particles, adding the hydroxylated carbon nitride nano particles into solution containing silane coupling agent, performing ultrasonic dispersion for 0.5-2 h, heating and stirring for 8-24 h, and centrifuging, washing, drying and grinding to obtain the modified carbon nitride nano particles; S4, preparing a polyphenylsulfone sulfoxide composite slurry, namely ultrasonically dispersing the modified carbon nitride nano particles obtained in the step S3 into deionized water to obtain a suspension, adding the suspension into the polyphenylsulfone sulfoxide fiber slurry obtained in the step S2, and carrying out fluffing dispersion at a fluffing rotation speed of 1500-4500 r/min to obtain the polyphenylsulfone sulfoxide composite slurry with a fluffing rotation speed of 30000-50000 r; S5, preparing the polyphenylene sulfone sulfoxide fiber-based composite insulating paper, namely adopting a wet papermaking forming process to the polyphenylene sulfone sulfoxide composite slurry obtained in the step S4, dehydrating and drying in vacuum to obtain the polyphenylene sulfone sulfoxide composite base paper, and carrying out hot-pressing process treatment on the polyphenylene sulfone sulfoxide composite base paper to obtain the polyphenylene sulfone sulfoxide fiber-based composite insulating paper.
2. The method for preparing a polyphenylene sulfone sulfoxide fiber-based composite insulating paper according to claim 1, wherein the polyphenylene sulfone sulfoxide chopped fibers in step S1 have a length of 3-15 mm and a diameter of 1-26 μm.
3. The preparation method of the polyphenylsulfone sulfoxide fiber-based composite insulating paper according to claim 1, wherein the mass ratio of the polyphenylsulfone sulfoxide chopped fibers to the dopamine hydrochloride in the step S1 is 1 (0.3-0.8).
4. The method for preparing a polyphenylene sulfone sulfoxide fiber-based composite insulating paper according to claim 1, wherein the fiber pulp in the step S2 is one or more of polyphenylene sulfone sulfoxide, polyphenylene sulfide, meta-aramid, para-aramid, cellulose fiber, polysulfonamide, polyimide and polyethylene terephthalate fiber pulp.
5. The method for preparing the polyphenylene sulfone sulfoxide fiber-based composite insulating paper according to claim 1, wherein the dispersant in the step S2 comprises one or more of polyethylene oxide, cationic polyacrylamide and anionic polyacrylamide, and the amount of the dispersant is 0.1-2.5 wt% of the total amount of the polyphenylene sulfone sulfoxide chopped fibers and the fiber pulp.
6. The method for preparing a polyphenylene sulfone sulfoxide fiber-based composite insulating paper according to claim 1, wherein the particle size of the carbon nitride nanoparticles in the step S3 is 20-100 nm, and the addition amount is 0.5-15 wt% of the total amount of polyphenylene sulfone sulfoxide chopped fibers and fiber pulp.
7. The preparation method of the polyphenylsulfone sulfoxide fiber-based composite insulating paper according to claim 1 is characterized in that in the step S3, the solution of the silane coupling agent is ethanol of the silane coupling agent, the volume ratio of absolute ethanol to deionized water in the ethanol solution is 9:1, the silane coupling agent comprises one or more of gamma-aminopropyl triethoxysilane, gamma-glycidol ether oxypropyl trimethoxysilane, gamma-aminopropyl trimethoxysilane, gamma-methacryloxypropyl trimethoxysilane and gamma-mercaptopropyl trimethoxysilane, and the dosage of the silane coupling agent is 0.5-10 wt% of that of carbon nitride nanoparticles.
8. The method for preparing the polyphenylsulfone sulfoxide fiber-based composite insulating paper according to claim 1, wherein the concentration of the hydrogen peroxide solution in the step S3 is 30 wt%, and the solid-to-liquid ratio of the carbon nitride nano particles to the hydrogen peroxide solution is 1:30-50.
9. The preparation method of the polyphenylsulfone sulfoxide fiber-based composite insulating paper according to claim 1, wherein the vacuum drying temperature in the step S5 is 80-105 ℃, the vacuum drying time is 10-15 min ℃, the hot pressing process temperature is 250-300 ℃, the pressure is 10-25 MPa, and the time is 0.5-10 min.
10. A polyphenylene sulfone sulfoxide fiber-based composite insulating paper, which is characterized by being prepared by the preparation method of any one of claims 1-9.

Description

Polyphenyl sulfone sulfoxide fiber-based composite insulating paper and preparation method thereof Technical Field The invention belongs to the technical field of electrical materials, and particularly relates to polyphenylene sulfone sulfoxide fiber-based composite insulating paper and a preparation method thereof. Background In large-scale electrical equipment, insulating paper is used as a core base material for liner, inter-turn, inter-phase and slot insulation, and plays a vital role in guaranteeing long-term stable operation of the equipment. At present, the most commonly used material in the electrical insulation field is meta-aramid insulation paper. Meta-aramid fiber is recognized as an ideal substrate for electrical insulation papers and films by virtue of its good insulation and mechanical properties. However, due to the higher production cost of meta-aramid paper, there is still room for further improvement in electrical insulation strength and thermo-oxidative stability properties, which are not matched with the properties thereof. Chinese patent CN119507268a discloses a polyphenylene sulfide fiber composite insulating paper and a preparation process thereof, wherein the polyphenylene sulfide fiber composite insulating paper is prepared by making polyphenylene sulfide fiber and aramid pulp in a composite manner, so that the dielectric constant and production cost of the composite insulating paper are remarkably reduced. However, the composite insulating paper prepared by the process has poor mechanical strength, the mechanical strength is only 20.5-36.2N/cm, the polyphenylene sulfide is easy to thermally shrink at high temperature, and the long-term safety and stability of the composite insulating paper can be influenced when the instantaneous temperature is too high. In recent years, the incorporation of nanoparticles into insulating paper systems has become an important approach to improving overall performance. The nano particles can form a uniformly dispersed reinforcing phase among fibers by virtue of a unique nano effect, so that microscopic pores and gaps are effectively filled, and the compactness of the insulating paper is improved. Meanwhile, the characteristics of high insulation, heat conduction, thermal stability and the like of the nano particles are favorable for further improving the comprehensive performance of the composite insulating paper. Chinese patent CN114613561a discloses a method for preparing meta-aramid/nano alumina insulation paper, which improves the electrical insulation strength of the composite paper by doping nano alumina particles in the aramid paper. Although the existing partially modified insulating paper improves the performance in a certain aspect by adding nano fillers, the problems of uneven performance, high raw material cost and the like caused by the increase of the complexity of the production process and poor dispersibility of additives are often accompanied, and the large-scale application is difficult to realize. Under the background, the development of novel composite insulating paper which has excellent electrical insulation performance, thermo-oxidative stability and good mechanical toughness, and is simple in production process and controllable in cost becomes one of the key technical problems to be solved urgently in the field of electrical materials. The polyphenylsulfone sulfoxide fiber (PPSSO) is a novel high-performance fiber, has excellent electrical insulation property, thermal stability, chemical corrosion resistance and thermo-oxidative stability, can be used for a long time at a temperature of above 260 ℃ and has a limiting oxygen index of 36%, no molten drop and self-extinguishment after combustion, the production cost is far lower than that of meta-aramid fiber, and has wide application prospect in the field of electrical insulation materials. However, the polyphenylene sulfone sulfoxide fiber is not easy to be formed by a wet papermaking process, so that the paper forming adhesion is poor, the uniformity is unstable, and the further application is influenced. Disclosure of Invention Aiming at the problems that the polyphenylene sulfone sulfoxide fiber is difficult to form in a wet papermaking process, the paper forming adhesiveness is poor and the uniformity is unstable, the invention aims to provide a preparation method of the polyphenylene sulfone sulfoxide fiber-based composite insulating paper, which takes the polyphenylene sulfone sulfoxide fiber as a framework and various fiber pulps as bonding fibers, effectively improves the bonding force among the fibers, adopts dopamine to modify the surfaces of the polyphenylene sulfone sulfoxide fiber, and improves the hydrogen bond bonding strength between chopped fibers and the pulps, thereby improving the mechanical strength of the composite insulating paper. In addition, the modified carbon nitride nano particles are added to fill and regulate defects of the internal structure of