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CN-121975228-A - Polypropylene-based nano composite film with high energy storage density and preparation method and application thereof

CN121975228ACN 121975228 ACN121975228 ACN 121975228ACN-121975228-A

Abstract

The invention provides a high energy storage density polypropylene-based nano composite film which is prepared by casting, irradiating and stretching polypropylene-boron nitride composite particles and PCOE@PMMA@BaTiO 3 double-shell structure nano particles. The composite film provided by the invention has high dielectric property and energy storage density. The invention provides a quantifiable high-performance dielectric solution for high-power application scenes such as an electric automobile inverter, pulse power equipment and the like.

Inventors

  • JIA FUXIANG
  • WAN YUANYUAN
  • ZHANG XIAO
  • DU FEIFEI
  • WANG WEIGUANG
  • YUAN WENBO

Assignees

  • 山东京博聚烯烃新材料有限公司
  • 浙江京博聚烯烃新材料有限公司

Dates

Publication Date
20260505
Application Date
20260211

Claims (10)

  1. 1. The polypropylene-based nano composite film with high energy storage density is characterized by being prepared from polypropylene-boron nitride composite particles and PCOE@PMMA@BaTiO 3 double-shell structure nano particles through casting, irradiation and stretching.
  2. 2. The composite film according to claim 1, wherein the mass ratio of the polypropylene-boron nitride composite particles to the PCOE@PMMA@BaTiO 3 double shell structure nanoparticles is 1000 (1-100).
  3. 3. The composite film according to claim 1, wherein the polypropylene-boron nitride composite particles have xylene solubles content of 1.0-5.0%, and aluminum, magnesium, titanium, calcium, and iron content of less than 2 ppm, and a melt flow ratio of 4-7.
  4. 4. The composite film according to claim 1, wherein the method for preparing the polypropylene-boron nitride composite particles comprises the steps of: 1) The polypropylene resin is treated after being deashed by adopting a deashing agent, and the deashed polypropylene resin is obtained; 2) Hydroxylating boron nitride and then carrying out silane surface modification to obtain boron nitride nanosheets; 3) And mixing and granulating the deashed polypropylene resin and the boron nitride nano-sheet to obtain the polypropylene-boron nitride composite particles.
  5. 5. The composite film according to claim 4, wherein the method for preparing the de-ashing agent comprises the steps of: soaking Amberlite XAD-16 resin in absolute ethyl alcohol, washing with 5% HCl to neutrality, washing with 2% NaOH to neutrality, and drying to obtain a deashing agent carrier; impregnating, washing and drying the deashing agent carrier, the beta-diketone compound and the quaternary ammonium salt compound at constant temperature to obtain a deashing agent; the mass ratio of the polypropylene resin to the deashing agent is 1 (0.1-1); the preparation method of the boron nitride nanosheets comprises the following steps: reflux-treating hexagonal boron nitride powder in a mixed solution of concentrated nitric acid and concentrated sulfuric acid to obtain hydroxylated hexagonal boron nitride; Dispersing the hydroxylated hexagonal boron nitride in a solvent for ultrasonic treatment, and centrifuging at a high speed to obtain a supernatant fluid to obtain a boron nitride nanosheet; performing silane surface modification on the boron nitride nanosheets and a silanization reagent to obtain boron nitride nanosheets; The mass ratio of the polypropylene resin after the ash removal to the boron nitride nano-sheet is 100 (0.1-5); and during mixing and granulating, an antioxidant is also added, and is one or more selected from antioxidant 1010, antioxidant 1076, antioxidant 330, antioxidant 245, antioxidant 168, antioxidant 1098, antioxidant BHT and antioxidant 626.
  6. 6. The composite film according to claim 1, wherein the preparation method of the PCOE@PMMA@BaTiO 3 double shell structure nanoparticle comprises the following steps: hydroxylating the BaTiO 3 nano-particles to obtain hydroxylated BaTiO 3 nano-particles; Performing amino functionalization modification on the hydroxylated BaTiO 3 nano-particles to obtain amino functionalized BaTiO 3 nano-particles; Reacting the amino-functionalized BaTiO 3 nano-particles with an initiator to obtain Br-APS-BT nano-particles with the initiator on the surfaces; the Br-APS-BT nano particles with the initiator on the surfaces react with methyl methacrylate monomers to obtain PMMA@BaTiO 3 nano particles with core-shell structures; Reacting the PMMA@BaTiO 3 nano particles with the core-shell structure with allylamine to obtain a terminal allylation macromonomer; And copolymerizing the terminal allylated macromer with cyclooctene to form a flexible PCOE second shell layer, so as to obtain the PCOE@PMMA@BaTiO 3 double-shell structure nanoparticle.
  7. 7. The composite film according to claim 6, wherein the modifier used for the amino-functional modification is selected from KH-550, 3-aminopropyl triethoxysilane, aminobutyl silane, methylaminopropyl silane, KH-792; The initiator is selected from the group consisting of ethyl 2-bromoisobutyrate, hydroxyethyl 2-bromoisobutyrate, acryloyloxyethyl 2-bromoisobutyrate, and 3- (trimethoxysilyl) propyl 2-bromo-2-methylpropionate.
  8. 8. A method for producing a composite film according to any one of claims 1 to 7, comprising the steps of: mixing polypropylene-boron nitride composite particles and PCOE@PMMA@BaTiO 3 double-shell structure nano particles for casting to obtain a casting film; and (3) carrying out stretching and annealing after the cast film is irradiated to obtain the high energy storage density polypropylene-based nano composite film.
  9. 9. The production method according to claim 8, wherein the casting machine screw temperature of casting is 150 to 220 ℃ and the casting roll temperature is 80 to 100 ℃; The irradiation is carried out by adopting 60 Co-gamma ray source, the irradiation temperature is 20-30 ℃, and the irradiation dose is 2-10 kGy; the stretching is that the biaxial stretching preheating temperature is 155-165 ℃, the stretching ratio is 3.0 x 3.0-5.0 x 5.0, and the stretching speed is 60%/s-100%/s; the annealing temperature is 100-140 ℃.
  10. 10. Use of the composite film according to any one of claims 1-7 in electric vehicle inverters, pulse power equipment.

Description

Polypropylene-based nano composite film with high energy storage density and preparation method and application thereof Technical Field The invention belongs to the technical field of capacitors, and particularly relates to a high energy storage density polypropylene-based nano composite film, a preparation method and application thereof. Background In recent years, as electronic power systems are developed toward high efficiency, miniaturization, and high reliability, there is an increasing demand for high-performance thin film capacitors. The film capacitor plays a key role in the fields of energy conversion, electric power regulation, pulse power and the like due to the advantages of high voltage resistance, low loss, long service life and the like. However, conventional polymer film materials have significant limitations in dielectric properties and energy storage density, and it is difficult to meet the requirements of modern power electronics for higher energy storage. Polypropylene (PP) has good insulating properties and processing suitability as a common polymer dielectric material, but its inherent low dielectric constant limits its performance in high energy density applications. Particularly, under the working conditions of high frequency and high electric field, the pure polypropylene film is easy to have the problems of increased dielectric loss, reduced energy storage efficiency and the like, and the long-term stability and the energy storage capacity of the capacitor are affected. The prior art has the limitation that the limited biaxially oriented polypropylene of the commercial polypropylene-based film is used as a main stream dielectric material, and has high breakdown field strength (600 MV/m) and ultralow loss, but the energy storage density at room temperature is only 1.8-2.0J/cm 3, and the requirement of high energy storage cannot be met. Therefore, a novel high-energy-storage-density polypropylene-based nano composite film is developed, has high dielectric property and energy storage density, and has important significance for pushing the application of next-generation high-performance film capacitors. Disclosure of Invention In view of the above, the technical problem to be solved by the invention is to provide a high energy storage density polypropylene-based nano composite film, a preparation method and application thereof. The invention provides a high energy storage density polypropylene-based nano composite film which is prepared by casting, irradiating and stretching polypropylene-boron nitride composite particles and PCOE@PMMA@BaTiO 3 double-shell structure nano particles. Preferably, the mass ratio of the polypropylene-boron nitride composite particles to the PCOE@PMMA@BaTiO 3 double-shell structure nano particles is 1000 (1-100). Preferably, the content of xylene solubles in the polypropylene-boron nitride composite particles is 1.0-5.0%, and the contents of aluminum, magnesium, titanium, calcium and iron elements are all less than 2 ppm, and the melt flow ratio is 4-7. Preferably, the preparation method of the polypropylene-boron nitride composite particle comprises the following steps: 1) The polypropylene resin is treated after being deashed by adopting a deashing agent, and the deashed polypropylene resin is obtained; 2) Hydroxylating boron nitride and then carrying out silane surface modification to obtain boron nitride nanosheets; 3) And mixing and granulating the deashed polypropylene resin and the boron nitride nano-sheet to obtain the polypropylene-boron nitride composite particles. Preferably, the preparation method of the deashing agent comprises the following steps: soaking Amberlite XAD-16 resin in absolute ethyl alcohol, washing with 5% HCl to neutrality, washing with 2% NaOH to neutrality, and drying to obtain a deashing agent carrier; impregnating, washing and drying the deashing agent carrier, the beta-diketone compound and the quaternary ammonium salt compound at constant temperature to obtain a deashing agent; the mass ratio of the polypropylene resin to the deashing agent is 1 (0.1-1); the preparation method of the boron nitride nanosheets comprises the following steps: reflux-treating hexagonal boron nitride powder in a mixed solution of concentrated nitric acid and concentrated sulfuric acid to obtain hydroxylated hexagonal boron nitride; Dispersing the hydroxylated hexagonal boron nitride in a solvent for ultrasonic treatment, and centrifuging at a high speed to obtain a supernatant fluid to obtain a boron nitride nanosheet; performing silane surface modification on the boron nitride nanosheets and a silanization reagent to obtain boron nitride nanosheets; The mass ratio of the polypropylene resin after the ash removal to the boron nitride nano-sheet is 100 (0.1-5); and during mixing and granulating, an antioxidant is also added, and is one or more selected from antioxidant 1010, antioxidant 1076, antioxidant 330, antioxidant 245, antioxidant 168, anti