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CN-122011257-A - Thermochromic polymer, electrochromic polymer film with crosslinked structure and preparation method of electrochromic polymer film

CN122011257ACN 122011257 ACN122011257 ACN 122011257ACN-122011257-A

Abstract

The invention provides a thermally crosslinked electrochromic polymer, an electrochromic polymer film with a crosslinked structure and a preparation method thereof, belonging to the technical field of functional high polymer materials and organic electrochromic. The epoxy group in the thermally crosslinked electrochromic polymer is a thermal crosslinking unit, the triphenylamine derivative is an electrochromic unit, and a and b are independently any integer of 5-15. The electrochromic polymer has a main chain of a non-conjugated structure, and a triphenylamine derivative electrochromic unit and an epoxy group thermal crosslinking group are grafted on a side chain to form a precursor capable of being processed in a solution, and the precursor is formed on a conductive substrate in a spin coating, spray coating or printing mode and is subjected to heating in-situ crosslinking to form a three-dimensional network structure film.

Inventors

  • QIN QI
  • ZHANG LING
  • ZHANG CHENG

Assignees

  • 浙江工业大学

Dates

Publication Date
20260512
Application Date
20260326

Claims (9)

  1. 1. A thermally crosslinked electrochromic polymer characterized in that, the structural formula of the thermally crosslinked electrochromic polymer is as follows: ; wherein a is any integer of 5-15, and the ratio of a to b is 1:3-5.
  2. 2. The thermally crosslinked electrochromic polymer according to claim 1, wherein the epoxy groups in the thermally crosslinked electrochromic polymer are thermally crosslinked units and the triphenylamine derivative is an electrochromic unit.
  3. 3. The method for preparing the thermally crosslinked electrochromic polymer according to claim 1 or 2, characterized in that 4-methoxy-N- (4-methoxyphenyl) -N- (4-vinylphenyl) aniline, glycidyl methacrylate and a catalyst are subjected to polymerization reaction in an organic solvent to obtain the thermally crosslinked electrochromic polymer; the catalyst is azodiisobutyronitrile, and the organic solvent is acetone or tetrahydrofuran.
  4. 4. The method according to claim 3, wherein the molar ratio of the 4-methoxy-N- (4-methoxyphenyl) -N- (4-vinylphenyl) aniline, the glycidyl methacrylate and the catalyst is 1:0.8-1.2:1.0-1.5.
  5. 5. The method according to claim 3 or 4, wherein the polymerization reaction is carried out at a temperature of 60 to 80 ℃ for 36 to 50 hours.
  6. 6. A method for preparing an electrochromic polymer film having a crosslinked structure from the thermally crosslinked electrochromic polymer according to claim 1 or 2, comprising the steps of: 1) Mixing the thermocrosslinking electrochromic polymer, an amine crosslinking agent and an organic solvent to obtain a mixed solution; 2) And thermally curing the wet film in an oxygen-free atmosphere to obtain the electrochromic polymer film with the crosslinked structure.
  7. 7. The method according to claim 6, wherein the amine cross-linking agent comprises one or more of 4,4' -diaminodiphenyl methane, tetraethylenepentamine and polyethyleneimine, the organic solvent comprises dichloromethane, trichloromethane or tetrahydrofuran, and the concentration of the mixed solution is 8-12 mg/mL.
  8. 8. The method according to claim 6 or 7, wherein the coating mode is spray coating, spin coating or screen printing, the anaerobic atmosphere is nitrogen atmosphere or argon atmosphere, the heat curing temperature is 120-170 ℃, and the heat curing time is 4-5.5 h.
  9. 9. The electrochromic polymer film with a crosslinked structure prepared by the method according to any one of claims 6 to 8, wherein the electrochromic polymer film with a crosslinked structure has a structural formula: ; wherein a is any integer of 5-15, and the ratio of a to b is 1:3-5.

Description

Thermochromic polymer, electrochromic polymer film with crosslinked structure and preparation method of electrochromic polymer film Technical Field The invention relates to the technical field of functional high polymer materials and organic electrochromic, in particular to a thermally crosslinked electrochromic polymer, an electrochromic polymer film with a crosslinked structure and a preparation method thereof. Background The electrochromic material can generate reversible color and transparency change under the stimulation of an external electric field, and has wide application prospect in the fields of intelligent windows, low-power-consumption display, antiglare mirror surfaces, self-adaptive camouflage and the like. Among many electrochromic materials, conductive polymers have been widely studied for their advantages of rich colors, fast response speed, high optical contrast, and the like. However, the current mainstream of conductive polymers based on long conjugated main chains (such as polyaniline, polythiophene and derivatives thereof) face fundamental challenges in practical applications. First, in terms of synthesis, such materials generally require construction of a conjugated backbone by a palladium-catalyzed aryl coupling reaction (e.g., suzuki, stille coupling), which is complicated, costly, and difficult to control precisely in terms of degree of polymerization and molecular weight. Second, in terms of processing, its rigid conjugated backbone results in very poor solubility, often requiring modification by the introduction of long flexible alkyl chains, which in turn compromises its electrochemical properties. Most critical is that its extended pi-conjugated system results in a strong intrinsic absorption of the material in the eigenstate (neutral state), usually in grey or pale yellow, which makes it difficult to achieve the "colorless" and "highly transparent" states required for applications such as smart windows. In addition, such linear polymer films generally have problems of poor mechanical strength, weak adhesion, easy swelling and peeling in electrolyte, and the like, resulting in insufficient cycle stability and durability. In order to break through the bottleneck, the research thought is gradually changed from optimizing the conjugated main chain to completely new material system design. Epoxy resins are widely used in the coating and composite fields due to their excellent adhesion, mechanical properties and a well-established thermal curing crosslinking process. Therefore, the functional polymer which takes the unconjugated flexible chain as the main framework and grafts electrochromic units (such as triphenylamine) and reactive epoxy groups on the side chains has important significance. Disclosure of Invention The invention aims to provide a thermally crosslinked electrochromic polymer, an electrochromic polymer film with a crosslinked structure and a preparation method thereof, the thermal crosslinking electrochromic polymer has simple synthesis process, low cost and high colorless transparency in neutral state. In order to achieve the above object, the present invention provides the following technical solutions: The invention provides a thermally crosslinked electrochromic polymer, which has the structural formula: ; wherein a is any integer of 5-15, and the ratio of a to b is 1:3-5. Preferably, the epoxy group in the thermally crosslinked electrochromic polymer is a thermally crosslinked unit, and the triphenylamine derivative is an electrochromic unit. The invention also provides a preparation method of the thermal crosslinking electrochromic polymer, which comprises the steps of carrying out polymerization reaction on 4-methoxy-N- (4-methoxyphenyl) -N- (4-vinylphenyl) aniline, glycidyl methacrylate and a catalyst in an organic solvent to obtain the thermal crosslinking electrochromic polymer; the catalyst is azodiisobutyronitrile, and the organic solvent is acetone or tetrahydrofuran. Preferably, the molar ratio of the 4-methoxy-N- (4-methoxyphenyl) -N- (4-vinylphenyl) aniline, the glycidyl methacrylate and the catalyst is 1:0.8-1.2:1.0-1.5. Preferably, the temperature of the polymerization reaction is 60-80 ℃, and the time of the polymerization reaction is 36-50 h. The invention also provides a method for preparing the electrochromic polymer film with the crosslinked structure by using the thermally crosslinked electrochromic polymer, which comprises the following steps: 1) Mixing the thermocrosslinking electrochromic polymer, an amine crosslinking agent and an organic solvent to obtain a mixed solution; 2) And thermally curing the wet film in an oxygen-free atmosphere to obtain the electrochromic polymer film with the crosslinked structure. Preferably, the amine cross-linking agent comprises one or more of 4,4' -diaminodiphenyl methane, tetraethylenepentamine and polyethyleneimine, the organic solvent comprises dichloromethane, trichloromethane or tetrahydrofuran, and