阅读说明：本技术 一种基于聚苯胺复合微胶囊防腐涂料及制备方法 (Polyaniline composite microcapsule-based anticorrosive paint and preparation method thereof ) 是由 罗静 张嘉琪 刘仁 董佳豪 于 2019-07-18 设计创作，主要内容包括：本发明公开了一种基于聚苯胺复合微胶囊的防腐涂料,所述防腐涂料由树脂、固化剂、聚苯胺复合微胶囊组成；所述的聚苯胺复合微胶囊的结构为芯材为缓蚀剂,壳层为具有pH响应性的光交联聚合物,壳材外由聚苯胺纳米粒子所包覆。(The invention discloses an anticorrosive coating based on polyaniline composite microcapsules, which consists of resin, a curing agent and polyaniline composite microcapsules; the polyaniline composite microcapsule has the structure that a core material is a corrosion inhibitor, a shell layer is a photo-crosslinked polymer with pH responsiveness, and the shell material is coated by polyaniline nanoparticles.)

1. The anticorrosive paint based on the polyaniline composite microcapsules is characterized by comprising resin, a curing agent and the polyaniline composite microcapsules; the polyaniline composite microcapsule has the structure that a core material is a corrosion inhibitor, a shell material is a photo-crosslinked polymer with pH responsiveness, and the shell material is coated by polyaniline nano-particles.

2. the anticorrosive paint based on polyaniline composite microcapsules as claimed in claim 1, wherein the anticorrosive paint comprises 64-66 wt% of resin, 32-33 wt% of curing agent, 0.5-5 wt% of polyaniline composite microcapsules and 1-3 wt% of resin and curing agent.

3. The anticorrosive paint based on polyaniline composite microcapsules according to claim 1, wherein the particle size of the polyaniline composite microcapsules is 5-30 μm, the thickness of the capsule wall is 1-2 μm, and the content of the core material is 2-5%.

4. The preparation method of the polyaniline composite microcapsule-based anticorrosive paint according to claim 1, which is characterized by comprising the following steps:

Step 1, mixing a water phase containing polyaniline nanoparticles with an oil phase containing monofunctional alkene monomers, bifunctional alkene monomers and a photoinitiator to prepare an emulsion, and initiating polymerization to obtain a hollow microcapsule; stirring and dipping the hollow microcapsule in a corrosion inhibitor solution to obtain a polyaniline composite microcapsule; the mono-functionality alkene monomer and the bi-functionality alkene monomer account for 50 vol% of the oil phase;

And 2, mixing the polyaniline composite microcapsule, resin and a curing agent to obtain the anticorrosive paint based on the polyaniline composite microcapsule.

5. the preparation method of the anticorrosive paint based on polyaniline composite microcapsules according to claim 4, wherein the preparation method of the polyaniline nanoparticles comprises the following steps: preparing a copolymer obtained by a hydrophobic monomer and a hydrophilic monomer under the action of an initiator into a micellar solution, adding aniline, ammonium persulfate or potassium persulfate into the micellar solution, and reacting to obtain polyaniline nanoparticles; the molar ratio of ammonium persulfate or potassium persulfate to aniline is 1: 1.

6. The preparation method of the anticorrosive paint based on polyaniline composite microcapsules as claimed in claim 5, wherein the molar ratio of the hydrophobic monomer to the hydrophilic monomer is 2: 1-1: 3, and the hydrophilic monomer is one or more of 2-acrylamido-2-methylpropanesulfonic acid, 1, 2-dihydroxy-3-propanesulfonic acid, N- (2-aminoethyl) -2-aminoethanesulfonic acid, ethylenediamine ethanesulfonic acid, 1, 4-dihydroxybutane-2-sulfonic acid, and p-toluenesulfonic acid; the hydrophobic monomer is one or a mixture of styrene, N-alkyl acrylamide, (2-acrylamide-2-methyl propyl) dimethyl ammonium, acrylate and styrene derivatives thereof; the initiator is one or more of azodiisobutyronitrile, azodiisoheptonitrile, dibenzoyl peroxide, lauroyl peroxide, tert-amyl peroxyneodecanoate, ditetradecyl peroxydicarbonate, diisopropyl peroxydicarbonate, potassium persulfate, ammonium persulfate and di-tert-butyl peroxide.

7. The preparation method of the anticorrosive paint based on polyaniline composite microcapsules according to claim 5, wherein the concentration of the polymer micelle solution is 50-200 mg/mL; the molar ratio of the added amount of the monomer aniline to the hydrophilic monomer is 1: 1-3: 1; the water contact angle of the polyaniline nano particles is 50-70 degrees, and the particle size of the polyaniline nano particles is 100-200 nm.

8. The method of claim 4, wherein the monofunctional vinyl polymer monomer in step 1 is one or more selected from the group consisting of dimethylaminoethyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isooctyl (meth) acrylate, hydroxyethyl (meth) acrylate, ethylhexyl (meth) acrylate, and (meth) acrylic acid; the bifunctionality dilute polymer monomer is one or a mixture of more of 1, 6-hexanediol diacrylate, ethylene glycol di (methyl) acrylate, diethylene glycol diacrylate, neopentyl glycol diethoxy acrylate and divinyl benzene; the photoinitiator is one or a mixture of more of 2-benzyl-2-dimethylamino-1- (4-morpholinylphenyl) butanone, 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide, 2-isopropyl thioxanthone and 2-hydroxy-2-methyl-p-hydroxyethyl ether phenyl acetone-1; the solvent in the oil phase is one or a mixture of more of chlorobenzene, toluene, xylene, hexane, bromopropane, dichloroethane, trichloromethane, ethyl acetate and n-pentane; the total amount of the added mono-functionality alkene monomer and the added di-functionality alkene monomer accounts for 50-70 vol% of the oil phase; the addition amount of the photoinitiator accounts for 2-4 wt% of the total amount of the reactive monomer.

9. The preparation method of the anticorrosive paint based on polyaniline composite microcapsules according to claim 4, wherein the concentration of the polyaniline-containing nanoparticles in step 1 is 5 mg/mL-40 mg/mL; the total amount of the oil-soluble solvent added accounts for 30-50 vol% of the oil phase; the volume ratio of the oil phase to the water phase is controlled to be 1.5: 1-1: 3; the size of the drops in the emulsion is 5-30 μm.

10. The preparation method of the anticorrosive paint based on polyaniline composite microcapsules according to claim 4, wherein the corrosion inhibitor in the step 1 comprises one or more of methylbenzotriazole, 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, benzotriazole, oleic acid imidazoline, butyl benzotriazole and thiadiazole; the concentration of the corrosion inhibitor is 5-20 mg/mL.

Technical Field

The invention relates to an anticorrosive coating based on polyaniline composite microcapsules and a preparation method thereof, belonging to the field of metal anticorrosive coatings.

Background

Metal corrosion is a ubiquitous phenomenon in national production and life, and brings great loss to national economy. The coating method is the most economic, most extensive and most effective means for dealing with metal corrosion at present, but the coating is easy to have defects in the coating and using process, the repair process of the damaged coating is complicated, time-consuming and labor-consuming, and the coating with the self-repairing and anti-corrosion functions becomes a current research hotspot. The intrinsic self-repairing coating can be divided into an intrinsic type and an external-aid type, and the intrinsic self-repairing coating has high requirement on a coating substrate, complex preparation process and high cost; the externally-applied self-repairing coating based on the repairing agent usually needs a large amount of repairing agent, and the compactness of the coating is easy to damage. The corrosion inhibitor has the advantages of small dosage, quick response, low cost and wide application. However, direct mixing of the corrosion inhibitor with the coating tends to reduce the activity, so that it is often necessary to encapsulate it. Compared with the encapsulation of inorganic nano materials, polymer micelles and other materials, the microcapsules are more and more emphasized by people because of higher loading capacity, more excellent barrier property and designability.

To date, microcapsule-coated active substances applied in anticorrosive coatings are generally Hexamethylene Diisocyanate (HDI), castor oil, Triethanolamine (TEA), and the like, and form a shielding layer through oxidation or reaction with water to realize corrosion prevention, and some active substances are Mercaptobenzothiazole (MBT), Benzotriazole (BTA), and the like, which directly act on a metal substrate to improve the corrosion prevention capability. When the external force is strong or the external environment (such as temperature, pH value and light intensity) changes, the microcapsules are broken or respond, the coated active substances are overflowed, and the corrosion rate is prevented or reduced. The microcapsules can only realize corrosion prevention through the release of the core material, but the shell materials of the microcapsules are mostly polyurethane, polyurea-formaldehyde, styrene and the like, only prevent corrosive media from contacting with a metal base material, and do not have the corrosion prevention effect. It is assumed that if the shell material of the microcapsule has the same anti-corrosion effect, the release of the coated corrosion inhibitor and the combined action of the shell material can realize the double anti-corrosion effect when corrosion occurs.

In summary, a multifunctional microcapsule which has an anticorrosion effect on both a core material and a shell material and can respond to external environmental changes is still lacking in the field of metal anticorrosion coatings.

Disclosure of Invention

According to the invention, polyaniline nanoparticles and microcapsule shell materials are organically combined to prepare the microcapsule with the shell material being polyaniline and the core material containing the corrosion inhibitor, so that the microcapsule shell material and the core material are synergistically anticorrosive, and the effect is more remarkable.

The anticorrosive paint based on the polyaniline composite microcapsules is characterized by comprising resin, a curing agent and the polyaniline composite microcapsules; the polyaniline composite microcapsule has a composite structure, a core material is a corrosion inhibitor, a shell material is a pH-responsive photo-crosslinking product, and the shell material is coated by polyaniline nanoparticles.

In one embodiment, the anticorrosive paint comprises 64-66 wt% of resin, 32-33 wt% of curing agent, 0.5-5 wt% of polyaniline composite microcapsule, and preferably 1-4 wt% of resin and curing agent.

In one embodiment, the polyaniline composite microcapsule has a particle size of 5-30 μm, a capsule wall thickness of 1-2 μm, and a core material content of 2-5%.

In one embodiment, the method is specifically characterized in that:

step 1, mixing a water phase containing polyaniline nanoparticles with an oil phase containing a reactive monomer or prepolymer and a photoinitiator to prepare an emulsion, and initiating polymerization to obtain a hollow microcapsule; stirring and dipping the hollow microcapsule in a corrosion inhibitor solution to obtain a composite microcapsule;

And 2, mixing the polyaniline composite microcapsule, resin and a curing agent to obtain the anticorrosive paint based on the polyaniline composite microcapsule.

In one embodiment, the preparation method of the polyaniline nanoparticles comprises the following steps: preparing a copolymer obtained by a hydrophobic monomer and a hydrophilic monomer under the action of an initiator into a micellar solution, adding aniline, ammonium persulfate or potassium persulfate into the micellar solution, and reacting to obtain the polyaniline nanoparticles. The molar ratio of ammonium persulfate or potassium persulfate to aniline is 1: 1. In one embodiment, the molar ratio of the hydrophobic monomer to the hydrophilic monomer is 2:1 to 1:3, and the hydrophilic monomer is one or more of 2-acrylamido-2-methylpropanesulfonic acid, 1, 2-dihydroxy-3-propanesulfonic acid, N- (2-aminoethyl) -2-aminoethanesulfonic acid, ethylenediamine ethanesulfonic acid, 1, 4-dihydroxybutane-2-sulfonic acid, and p-toluenesulfonic acid; the hydrophobic monomer is one or a mixture of styrene, N-alkyl acrylamide, (2-acrylamide-2-methyl propyl) dimethyl ammonium, acrylate and styrene derivatives thereof; the initiator is one or a mixture of more of azodiisobutyronitrile, azodiisoheptonitrile, dibenzoyl peroxide, lauroyl peroxide, tert-amyl peroxyneodecanoate, ditetradecyl peroxydicarbonate, diisopropyl peroxydicarbonate, potassium persulfate, ammonium persulfate and di-tert-butyl peroxide.

In one embodiment, the concentration of the polymer micelle solution is 50-200 mg/mL; the molar ratio of the added amount of the monomer aniline to the hydrophilic monomer is 1: 1-3: 1; the water contact angle of the polyaniline nano particles is 50-70 degrees, and the particle size of the polyaniline nano particles is 100-200 nm.

In one embodiment, the reactive monomer or prepolymer in step 1 is one or more of dimethylamino ethyl methacrylate, 2-methyl methacrylate, 2-ethyl methacrylate, 1, 6-hexanediol diacrylate, and ethylene glycol dimethacrylate; the photoinitiator is one or a mixture of more of 2-benzyl-2-dimethylamino-1- (4-morpholinylphenyl) butanone, 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide, 2-isopropyl thioxanthone and 2-hydroxy-2-methyl-p-hydroxyethyl ether phenyl acetone-1; the solvent in the oil phase is one or a mixture of more of chlorobenzene, toluene, xylene, hexane, bromopropane, dichloroethane, trichloromethane, ethyl acetate and n-pentane; the total amount of the added reactive monomer or prepolymer accounts for 50-70 vol% of the oil phase; the addition amount of the photoinitiator accounts for 2-4 wt% of the total amount of the reactive monomer.

In one embodiment, the concentration of the polyaniline-containing nanoparticles in step 1 is 5 mg/mL-40 mg/mL; the total amount of the oil-soluble solvent added accounts for 30-50 vol% of the oil phase; the volume ratio of the oil phase to the water phase is controlled to be 1.5: 1-1: 3; the size of the drops in the emulsion is 5-30 μm.

In one embodiment, the corrosion inhibitor in step 1 comprises one or more of methylbenzotriazole, 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, benzotriazole, oleic acid imidazoline, butyl benzotriazole and thiadiazole; the concentration of the corrosion inhibitor is 5-20 mg/mL.

Has the advantages that:

The invention provides a polyaniline composite microcapsule-based anticorrosive paint and a preparation method thereof. When the coating is not damaged, the coating on the metal substrate can isolate the substrate from a corrosive medium; when the external environment of the coating changes or the coating is damaged under the action of strong external force, microcapsules in the coating are damaged, active molecules coated by the microcapsules overflow, and the synergistic corrosion prevention of the microcapsule shell material and the core material is realized under the combined action of polyaniline on the microcapsule shell material, so that the corrosion prevention effect is greatly improved. The prepared anticorrosive paint can be widely applied to the fields of pipeline transportation, machining, ships, electronic appliances and the like.

Drawings

Fig. 1 is a flow chart of the preparation of polyaniline-based composite microcapsules in the present invention.

Fig. 2 is a picture of the depth of field of emulsion emulsified in example 1 by using polyaniline nanoparticles obtained in the molar ratio of 2-acrylamido-2-methylpropanesulfonic Acid (AMPS) to styrene (St) of 1:2 and the molar ratio of AMPS to aniline of 1:2 as a particle emulsifier.

Fig. 3 is an electron scanning microscope picture of the polyaniline hollow composite microcapsule obtained by photo-polymerization in example 2, in which polyaniline nanoparticles obtained by reaction of AMPS and St at a molar ratio of 1:3 and aniline at a molar ratio of 1:3 are used as a particle emulsifier, and the polyaniline hollow composite microcapsule is crushed.

FIG. 4 is a Tafel polarization curve test chart of the composite anticorrosive paint obtained in examples 1 and 2. Epoxy is a pure Epoxy coating without PANI microcapsules added, 1 wt% for example 1 and 2 wt% for example 2.

Detailed Description

The invention is further illustrated, but not limited, by the following examples.