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CN-122006609-A - Polyaniline polynuclear microcapsule loaded with corrosion inhibitor, preparation method thereof and self-repairing anti-corrosion coating prepared by polyaniline polynuclear microcapsule

CN122006609ACN 122006609 ACN122006609 ACN 122006609ACN-122006609-A

Abstract

The invention discloses a polyaniline polynuclear microcapsule loaded with a corrosion inhibitor and a preparation method thereof, and a self-repairing anti-corrosion coating prepared by the polyaniline polynuclear microcapsule, wherein S1, a photo-curing material, a photoinitiator, an organic solvent and the corrosion inhibitor are mixed to be used as an oil phase, an aqueous dispersion liquid of an emulsifier is used as a water phase, the oil phase and the water phase are mixed and emulsified to obtain an oil-in-water emulsion, S2, sodium p-styrenesulfonate is added into the oil-in-water emulsion, ultraviolet light is cured and washed to obtain a wet sulfonated polymer polynuclear microcapsule, then ultrasonic is carried out in deionized water to obtain a sulfonated polymer polynuclear microcapsule aqueous dispersion liquid, and S3, aniline is dripped into the sulfonated polymer polynuclear microcapsule aqueous dispersion liquid, and an initiator aqueous solution containing protonic acid is dripped to initiate aniline polymerization to obtain the polyaniline polynuclear microcapsule. When the polynuclear microcapsule is used for anticorrosive paint, even if the polynuclear microcapsule is locally damaged, the rest core material can be protected by wall material complex coacervate, so that the time difference of 'sequential release' is formed, and the core material can be slowly released.

Inventors

  • HAO QINGJUN
  • CHANG XU
  • Fan Jianhu
  • LUO JING
  • LIU REN
  • CHEN BO

Assignees

  • 中铁东南投资有限公司
  • 华侨大学
  • 江南大学

Dates

Publication Date
20260512
Application Date
20260206

Claims (10)

  1. 1. The preparation method of the polyaniline polynuclear microcapsule loaded with the corrosion inhibitor is characterized by comprising the following steps of: S1, weighing a photo-curing material, a photoinitiator, an organic solvent and a corrosion inhibitor, uniformly mixing to obtain an oil phase, taking an aqueous dispersion of an emulsifier as a water phase, mixing the oil phase and the water phase, and emulsifying for one time to obtain an oil-in-water emulsion; S2, adding sodium p-styrenesulfonate into the oil-in-water emulsion, performing ultraviolet light curing after complete dissolution, then alternately washing with absolute ethyl alcohol and deionized water to obtain wet sulfonated polymer polynuclear microcapsule, then transferring the wet sulfonated polymer polynuclear microcapsule into deionized water, and performing ultrasonic treatment to uniformly disperse the microcapsule to obtain sulfonated polymer polynuclear microcapsule aqueous dispersion; S3, dropwise adding aniline into the aqueous dispersion of the sulfonated polymer polynuclear microcapsule, stirring, dropwise adding an initiator aqueous solution containing protonic acid under ice bath conditions to initiate aniline polymerization, reacting 12-36 h under ice bath conditions, and settling and washing to obtain the polyaniline polynuclear microcapsule.
  2. 2. The preparation method according to claim 1, wherein in the step S1, the photo-curing material is one or more of pentaerythritol triacrylate, dipentaerythritol pentaacrylate, N' -methylenebisacrylamide, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, wherein the Hansen solubility delta p is 6-18; The organic solvent is one or more of cyclohexane, n-hexane, petroleum ether and n-heptane, and its hansen solubility delta p is 0.
  3. 3. The preparation method according to claim 1, wherein in the step S1, the photoinitiator is one or more of 2-hydroxy-2-methylphenyl propane-1-one, 1-hydroxycyclohexylphenyl ketone, bis (1- (2, 4-difluorophenyl) -3-pyrrolyl) titanocene, 2-methyl-1- (4-methylthiophenyl) -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone; the corrosion inhibitor is one or more of methyl benzotriazole, 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, benzotriazole, oleic acid imidazoline, butyl benzotriazole and thiadiazole.
  4. 4. The preparation method of claim 1, wherein in the step S1, the oil phase comprises, by weight, 80-100 parts of a photo-curing material, 1-4 parts of a photo-initiator, 20-50 parts of an organic solvent and 10-30 parts of a corrosion inhibitor; The water phase is aqueous dispersion of emulsifying agent with mass concentration of 0.5-5%, and the emulsifying agent in the water phase is one or more of polyvinyl alcohol, polyethylene glycol, sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, polystyrene-maleic anhydride copolymer, tween-60, tween-80, span-60, span-80, cetyl trimethyl ammonium bromide, gelatin and acacia; the mass ratio of the oil phase to the water phase is 4:1-1:4.
  5. 5. The preparation method of claim 1, wherein in the step S2, 15-25 parts of sodium p-styrenesulfonate is calculated according to parts by weight, and the ultraviolet light curing condition is that the wavelength is 230-420 nm and the curing time is 1-10 min.
  6. 6. The preparation method of claim 1, wherein in the step S3, the protonic acid is one or more of hydrochloric acid, sulfuric acid, phytic acid and phosphoric acid, the initiator is one or more of ammonium persulfate, potassium persulfate, hydrogen peroxide and potassium permanganate, the molar ratio of the initiator to the aniline is 1:2-4:1, the mass ratio of the aniline to the sulfonated polymer polynuclear microcapsule is 1:20-1:2, and the mass ratio of the protonic acid to the aniline is 10:1-1:1.
  7. 7. A corrosion inhibitor-loaded polyaniline polynuclear microcapsule prepared by the preparation method according to any one of claims 1 to 6.
  8. 8. The corrosion inhibitor-loaded polyaniline polynuclear microcapsule according to claim 7, wherein the material of the shell layer comprises polyaniline and a photo-curing material, the polyaniline polynuclear microcapsule has a particle size of 5-30 μm, the polynuclear microcapsule has a wall thickness of 1.3-2.5 μm, the micronucleus unit has a particle size of 0.5-3 μm, and the corrosion inhibitor loading rate is 30% -60%.
  9. 9. A self-repairing anticorrosive paint containing the polyaniline polynuclear microcapsule loaded with the corrosion inhibitor according to claim 8, which is characterized by comprising the polyaniline polynuclear microcapsule loaded with the corrosion inhibitor and a film-forming resin, wherein the polyaniline polynuclear microcapsule loaded with the corrosion inhibitor accounts for 5-15 wt% of the total mass of the paint.
  10. 10. A coating prepared from the self-healing anticorrosive paint of claim 9, wherein the coating is prepared by adding polyaniline polynuclear microcapsules loaded with corrosion inhibitors into film-forming resin and curing.

Description

Polyaniline polynuclear microcapsule loaded with corrosion inhibitor, preparation method thereof and self-repairing anti-corrosion coating prepared by polyaniline polynuclear microcapsule Technical Field The invention relates to the technical field of anti-corrosion coating, in particular to a polyaniline polynuclear microcapsule loaded with a corrosion inhibitor, a preparation method thereof and a self-repairing anti-corrosion coating prepared by the same. Background The metal material is used as a core base material in industrial production, infrastructure construction and high-end equipment manufacture, and the corrosion problem in the service process of the metal material is a key factor for restricting the service life of equipment, causing potential safety hazard and causing huge economic loss. The development of efficient, long-acting and environment-friendly metal corrosion prevention technology is an important research topic in the fields of current material science and engineering. The anti-corrosion coating has the advantages of convenience in construction, controllable cost, direct protection effect and the like, and becomes the most common technical means for protecting metal corrosion. The traditional corrosion-resistant coating is mainly used for isolating a corrosion medium from contact with a metal matrix through a physical barrier effect, such as an epoxy resin coating, a polyurethane coating and the like, but the coating is easy to generate microcracks or damages due to internal stress, mechanical collision, temperature change and other factors in the preparation and service processes, once the integrity of the coating is damaged, the corrosion medium can rapidly permeate to the metal surface and cause local corrosion, and the coating does not have damage repair capability, so that the protective performance is drastically reduced. In order to solve the problem, researchers develop functional anti-corrosion coatings such as sacrificial anode coatings, passivation coatings and the like, and form a protective barrier through electrochemical reaction of active ingredients in the coatings and metals, but the active ingredients of the coatings are often consumed in a large amount at the early stage of service, and long-term protection effect is difficult to realize. Polyaniline (PANI) as a conductive polymer with special doping-dedoping properties exhibits unique advantages in the field of metal corrosion protection. The anticorrosion mechanism is mainly that the quinoid structure in polyaniline molecular chain can generate oxidation-reduction reaction with the metal surface, so as to promote the metal surface to form a compact oxidation passivation film and inhibit the anodic dissolution process. However, the pure polyaniline coating has the defects of large brittleness, poor flexibility, insufficient adhesion with a matrix and the like, and is easy to crack under complex working conditions, and meanwhile, the single polyaniline coating lacks the active response capability to damage, once the polyaniline coating is damaged, the anti-corrosion effect is rapidly lost, so that the application of the polyaniline coating in a severe environment is limited. To impart self-healing capabilities to coatings, microcapsule technology is widely introduced into corrosion-resistant coating systems. By encapsulating functional substances such as corrosion inhibitors, repairing agents and the like in the microcapsules, when the coating is subjected to microcrack, the mechanical force generated in the crack propagation process can trigger the microcapsules to crack, and the internal functional substances are released, so that the dual effects of crack filling and corrosion inhibition are realized. The corrosion-resistant microcapsules reported at present are mostly of a single-core structure, however, the capsule wall thickness of the single-core microcapsules is generally uneven, the thinner part is easy to break, and the inner core material is released rapidly. The polyaniline and microcapsule technology are combined to be an effective idea for improving the corrosion resistance of the coating. In the existing researches, part of the proposal takes polyaniline as microcapsule wall material or is directly dispersed in a coating matrix after being mixed with a corrosion inhibitor, but most of the proposal is single-core microcapsule, and lacks long-acting corrosion inhibition capability. Based on the defects of the prior art, there is a need to develop an anti-corrosion coating system with active self-repairing capability, long-acting anti-corrosion performance and excellent mechanical performance. Disclosure of Invention Aiming at the problems in the prior art, the invention provides a polyaniline multi-core microcapsule loaded with a corrosion inhibitor, a preparation method thereof and a self-repairing anti-corrosion coating prepared by the same. The invention combines an emulsion template method, a photop