阅读说明：本技术 一种改性聚苯胺/环氧树脂复合防腐涂料及其制备方法 (Modified polyaniline/epoxy resin composite anticorrosive paint and preparation method thereof ) 是由 王海花 张盼 费贵强 马永宁 刘璇 孙立宇 于 2020-07-07 设计创作，主要内容包括：本发明公开了一种改性聚苯胺/水性环氧树脂复合防腐涂料及其制备方法,包括：将2-氨基苯磺酸与高分子表面活性剂溶于稀盐酸中,滴加入苯胺和含有水溶性引发剂的稀盐酸,得到聚苯胺；将长链烷烃与四甲基乙二胺溶于乙醇溶液中并进行冷凝回流连续反应,得到阳离子性双子表面活性剂；将聚苯胺水溶液加入溶解有阳离子性双子表面活性剂的水溶液中,得到阳离子型双子表面活性剂改性的聚苯胺；将改性的聚苯胺溶于水中使其分散,加入环氧树脂乳液、固化剂、水、消泡剂、流平剂和润湿剂进行分散,得到阳离子型双子表面活性剂改性聚苯胺/环氧树脂复合防腐涂料。本发明的涂料用于金属表面防腐,可大幅提高金属的防腐蚀能力、耐水性等。(The invention discloses a modified polyaniline/waterborne epoxy resin composite anticorrosive paint and a preparation method thereof, wherein the preparation method comprises the following steps: dissolving 2-aminobenzenesulfonic acid and a high molecular surfactant in dilute hydrochloric acid, and dropwise adding aniline and dilute hydrochloric acid containing a water-soluble initiator to obtain polyaniline; dissolving long-chain alkane and tetramethyl ethylenediamine in an ethanol solution, and carrying out condensation reflux continuous reaction to obtain a cationic gemini surfactant; adding the polyaniline aqueous solution into an aqueous solution dissolved with a cationic gemini surfactant to obtain polyaniline modified by the cationic gemini surfactant; dissolving the modified polyaniline in water to disperse, and adding the epoxy resin emulsion, the curing agent, the water, the defoaming agent, the flatting agent and the wetting agent to disperse to obtain the cationic gemini surfactant modified polyaniline/epoxy resin composite anticorrosive paint. The coating is used for metal surface corrosion prevention, and can greatly improve the corrosion resistance, water resistance and the like of metal.)

1. A preparation method of a modified polyaniline/waterborne epoxy resin composite anticorrosive paint is characterized by comprising the following steps:

dissolving 2-aminobenzenesulfonic acid and a high molecular surfactant in dilute hydrochloric acid, dropwise adding aniline and dilute hydrochloric acid containing a water-soluble initiator under an ice bath condition, and continuously reacting after dropwise adding to obtain a reaction solution; carrying out vacuum filtration on the reaction solution, washing to be neutral, and carrying out vacuum drying on filter residues to obtain polyaniline;

dissolving long-chain alkane and tetramethyl ethylenediamine in an ethanol solution, and carrying out condensation reflux continuous reaction; recrystallizing to obtain cationic gemini surfactant;

adding a polyaniline aqueous solution into an aqueous solution dissolved with a cationic gemini surfactant, reacting at room temperature, carrying out vacuum filtration and cleaning on the reacted solution, and drying filter residues to obtain the polyaniline modified by the cationic gemini surfactant;

dissolving the cationic gemini surfactant modified polyaniline in water to disperse, then adding the mixture into the epoxy resin emulsion in proportion to stir, and then adding the aqueous epoxy resin curing agent, water, the defoaming agent, the flatting agent and the wetting agent in proportion to disperse to obtain the cationic gemini surfactant modified polyaniline/epoxy resin composite anticorrosive paint.

2. The preparation method of the modified polyaniline/aqueous epoxy resin composite anticorrosive paint according to claim 1, characterized in that: in the preparation process of the polyaniline, 5-10 parts of high molecular surfactant and 5-10 parts of water-soluble initiator are added into 1 part of 2-aminobenzenesulfonic acid by mass.

3. The preparation method of the modified polyaniline/aqueous epoxy resin composite anticorrosive paint according to claim 1, characterized in that: in the preparation process of the cationic gemini surfactant, 4-7 parts of brominated alkane and 1.16 parts of tetramethylethylenediamine are dissolved in 20 parts of ethanol solution by mass;

the recrystallization adopts a mixed solvent of acetone and isopropanol.

4. The preparation method of the modified polyaniline/aqueous epoxy resin composite anticorrosive paint according to claim 1, characterized in that: in the preparation process of the cationic gemini surfactant modified polyaniline, 0.2 part of polyaniline and 0.2 part of N' N-bis (alkyl dimethyl) -1, 2-dibromide ethylene diammonium salt are dissolved in 100 parts of water by mass.

5. The preparation method of the modified polyaniline/aqueous epoxy resin composite anticorrosive paint according to claim 1, characterized in that: in the preparation process of the composite anticorrosive paint, 0.2 part of modified polyaniline is dissolved in 10 parts of water, and 30 parts of aqueous epoxy resin emulsion, 10 parts of aqueous epoxy resin curing agent, 0.2 part of flatting agent, 0.2 part of wetting agent and 0.05 part of defoaming agent are added.

6. The preparation method of the modified polyaniline/aqueous epoxy resin composite anticorrosive paint according to claim 1, characterized in that: the epoxy resin is selected from one or a mixture of more than one of 50-55% of solid content value in any proportion.

7. The preparation method of the modified polyaniline/aqueous epoxy resin composite anticorrosive paint according to claim 1, characterized in that: the high molecular surfactant is one or a mixture of more of polyoxyethylene octyl phenol ether-10, ammonium alkyl alcohol polyoxyethylene (3) sulfate, allyloxy nonyl phenol polyoxyethylene (10) ether sulfate and sodium dodecyl diphenyl ether disulfonate in any proportion;

the water-soluble initiator is one or a mixture of more of potassium persulfate, sodium persulfate and ammonium persulfate in any proportion.

8. The preparation method of the modified polyaniline/aqueous epoxy resin composite anticorrosive paint according to claim 1, characterized in that: the cationic gemini surfactant is one or a mixture of more of N 'N-bis (alkyl dimethyl) -1, 2-ethylene dibromide diammonium salt, N' N-bis (tetradecyl dimethyl) -1, 2-ethylene dibromide diammonium salt, N 'N-bis (hexadecyl dimethyl) -1, 2-ethylene dibromide diammonium salt and N' N-bis (octadecyl dimethyl) -1, 2-ethylene dibromide diammonium salt in any proportion.

9. The preparation method of the modified polyaniline/waterborne epoxy resin composite anticorrosive paint according to claim 1, characterized in that: the defoaming agent is one or a mixture of more of aluminum stearate, polyoxypropylene propylene glycol ether and mannitol in any proportion;

the leveling agent is one or a mixture of more of polyether modified polydimethylsiloxane copolymer and polyether modified siloxane in any proportion;

the wetting agent is one or a mixture of more of an organic silicon gemini surfactant and a high ethoxylation nonionic surfactant in any proportion.

10. A modified polyaniline/waterborne epoxy resin composite anticorrosive paint is characterized in that: comprises the following components in parts by mass:

0.2 part of modified polyaniline, 10 parts of water, 30 parts of aqueous epoxy resin emulsion, 10 parts of aqueous epoxy resin curing agent, 0.2 part of flatting agent, 0.2 part of wetting agent and 0.05 part of defoaming agent;

the modified polyaniline is N' N-bis (alkyl dimethyl) -1, 2-dibromide ethylene diammonium salt modified polyaniline.

Technical Field

The invention belongs to the field of preparation of anticorrosive coatings, and particularly relates to a modified polyaniline/epoxy resin composite anticorrosive coating and a preparation method thereof.

Background

Epoxy resin has excellent bonding strength and film forming property and can be applied to the field of metal corrosion prevention, but if metal is only coated with epoxy resin, the corrosion prevention effect is not good. The epoxy resin can be compounded with polyaniline, and the polyaniline can generate oxidation-reduction reaction on the surface of metal to form a compact oxidation film, so that the metal is protected from corrosion. In order to solve the problems of poor solubility and mechanical property of polyaniline, the research that polyaniline is modified by adopting N' N-bis (alkyl dimethyl) -1, 2-dibromide ethylene diammonium salt and is used for preparing cationic gemini surfactant modified polyaniline is not reported basically.

Compared with polyaniline, the cationic gemini surfactant modified polyaniline has the following advantages: (1) the introduction of the cationic gemini surfactant improves the dispersibility of polyaniline in the aqueous epoxy resin, thereby improving the stability, compatibility, rigidity and bonding strength of the anticorrosive paint; (2) meanwhile, the water resistance of the coating is enhanced, and the corrosion resistance of the metal surface is further improved.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a preparation method of a modified polyaniline/epoxy resin anticorrosive coating. The product of the invention can realize the unification of compatibility, rigidity and bonding strength of the anticorrosive paint, solves the common technical problems of poor stability, low water resistance, poor adhesive force and the like of the polyaniline/water-based epoxy resin composite anticorrosive paint, is used for metal surface anticorrosion, and can greatly improve the anticorrosion capability, water resistance and the like of metal.

In order to achieve the purpose, the invention adopts the following technical means:

a preparation method of a modified polyaniline/waterborne epoxy resin composite anticorrosive paint comprises the following steps:

dissolving 2-aminobenzenesulfonic acid and a high molecular surfactant in dilute hydrochloric acid, dropwise adding aniline and dilute hydrochloric acid containing a water-soluble initiator under an ice bath condition, and continuously reacting after dropwise adding to obtain a reaction solution; carrying out vacuum filtration on the reaction solution, washing to be neutral, and carrying out vacuum drying on filter residues to obtain polyaniline;

dissolving long-chain alkane and tetramethyl ethylenediamine in an ethanol solution, and carrying out condensation reflux continuous reaction; recrystallizing to obtain cationic gemini surfactant;

adding a polyaniline aqueous solution into an aqueous solution dissolved with a cationic gemini surfactant, reacting at room temperature, carrying out vacuum filtration and cleaning on the reacted solution, and drying filter residues to obtain the polyaniline modified by the cationic gemini surfactant;

dissolving the cationic gemini surfactant modified polyaniline in water to disperse, then adding the mixture into the epoxy resin emulsion in proportion to stir, and then adding the aqueous epoxy resin curing agent, water, the defoaming agent, the flatting agent and the wetting agent in proportion to disperse to obtain the cationic gemini surfactant modified polyaniline/epoxy resin composite anticorrosive paint.

As a further improvement of the invention, in the preparation process of the polyaniline, 5-10 parts of the high molecular surfactant and 5-10 parts of the water-soluble initiator are added to 1 part of 2-aminobenzenesulfonic acid by mass.

As a further improvement of the invention, in the preparation process of the cationic gemini surfactant, 4-7 parts of brominated alkane and 1.16 parts of tetramethylethylenediamine are dissolved in 20 parts of ethanol solution by mass;

the recrystallization adopts a mixed solvent of acetone and isopropanol.

As a further improvement of the invention, in the preparation process of the cationic gemini surfactant modified polyaniline, 0.2 part of polyaniline and 0.2 part of N' N-bis (alkyl dimethyl) -1, 2-dibromide ethylene diammonium salt are dissolved in 100 parts of water in parts by mass.

As a further improvement of the invention, in the preparation process of the composite anticorrosive paint, in parts by mass, every 0.2 part of modified polyaniline is dissolved in 10 parts of water, and 30 parts of aqueous epoxy resin emulsion, 10 parts of aqueous epoxy resin curing agent, 0.2 part of leveling agent, 0.2 part of wetting agent and 0.05 part of defoaming agent are added.

As a further improvement of the invention, the epoxy resin is selected from one or a mixture of more than one of the solid content values of 50-55% in any proportion.

As a further improvement of the invention, the high molecular surfactant is one or a mixture of more of polyoxyethylene octyl phenol ether-10, ammonium alkyl alcohol polyoxyethylene (3) sulfate, ammonium allyloxy nonylphenol polyoxyethylene (10) ether sulfate and sodium dodecyl diphenyl ether disulfonate in any proportion;

the water-soluble initiator is one or a mixture of more of potassium persulfate, sodium persulfate and ammonium persulfate in any proportion.

As a further improvement of the invention, the cationic gemini surfactant is one or a mixture of more of N ' N-bis (alkyl dimethyl) -1, 2-ethylene dibromide, N ' N-bis (dodecyl dimethyl) -1, 2-ethylene dibromide, N ' N-bis (tetradecyl dimethyl) -1, 2-ethylene dibromide, N ' N-bis (hexadecyl dimethyl) -1, 2-ethylene dibromide and N ' N-bis (octadecyl dimethyl) -1, 2-ethylene dibromide in any ratio.

As a further improvement of the invention, the defoaming agent is one or a mixture of more of aluminum stearate, polyoxypropylene propylene glycol ether and mannitol in any proportion;

the leveling agent is one or a mixture of more of polyether modified polydimethylsiloxane copolymer and polyether modified siloxane in any proportion;

the wetting agent is one or a mixture of more of an organic silicon gemini surfactant and a high ethoxylation nonionic surfactant in any proportion.

A modified polyaniline/water-based epoxy resin composite anticorrosive paint comprises the following components in parts by mass:

0.2 part of modified polyaniline, 10 parts of water, 30 parts of aqueous epoxy resin emulsion, 10 parts of aqueous epoxy resin curing agent, 0.2 part of flatting agent, 0.2 part of wetting agent and 0.05 part of defoaming agent;

the modified polyaniline is N' N-bis (alkyl dimethyl) -1, 2-dibromide ethylene diammonium salt modified polyaniline.

Compared with the prior art, the invention has the following advantages:

the preparation method adopts N' N-bis (alkyl dimethyl) -1, 2-dibromide ethylene diammonium salt modified polyaniline and water-based epoxy resin to prepare the anticorrosive paint. The cationic gemini surfactant modified polyaniline has the advantages that when the prepared product is used for metal surface corrosion prevention, the dispersibility of the cationic gemini surfactant modified polyaniline in the water-based epoxy resin is improved, so that the stability, the compatibility, the rigidity and the bonding strength of the coating are improved, the water resistance of the coating is enhanced, and the corrosion prevention performance of the metal surface is further improved. The product of the invention can realize the unification of compatibility, rigidity and bonding strength of the anticorrosive paint, solves the common technical problems of poor stability, low water resistance, poor adhesive force and the like of the polyaniline/water-based epoxy resin composite anticorrosive paint, is used for metal surface anticorrosion, and can greatly improve the anticorrosion capability, water resistance and the like of metal.

The composite anticorrosive paint of the invention adopts N' N-bis (alkyl dimethyl) -1, 2-dibromide ethylene diammonium salt modified polyaniline, so that the composite anticorrosive paint has the technical advantages of good stability, high water resistance, good adhesive force and the like. The coating is used for corrosion prevention of metal surfaces, and can greatly improve the corrosion resistance, water resistance and the like of metals.

Drawings

FIG. 1 is a scanning electron micrograph of a product prepared according to an embodiment of the present invention and a corresponding corrosion schematic.

FIG. 2 Bode diagram (A), Bode phase diagram (B), Nyquist diagram (C) and tafel polarization diagram (D) for polyaniline/epoxy resin (SPANI/WEB) and N' N-bis (dodecyldimethyl) -1, 2-ethylenediammonium dibromide modified polyaniline/epoxy resin (SPANI-GS12/WEB) of inventive example 1;

FIG. 3 optical diagrams of polyaniline/epoxy resin (a) and polyaniline/epoxy resin (b) modified with N 'N-bis (dodecyldimethyl) -1, 2-dibromide ethylenediammonium salt of inventive example 1 before salt spray test and polyaniline/epoxy resin (c) and polyaniline/epoxy resin (d) modified with N' N-bis (dodecyldimethyl) -1, 2-dibromide ethylenediammonium salt of inventive example 1 after 720 hours of salt spray test;

FIG. 4 is a graph of water absorption for polyaniline/epoxy resin (a) and inventive example 1N' N-bis (dodecyldimethyl) -1, 2-dibromide ethylenediammonium salt modified polyaniline/epoxy resin (b);

FIG. 5 is a graph showing the film hardness of polyaniline/epoxy resin (a) and N' N-bis (dodecyldimethyl) -1, 2-ethylenediammonium dibromide-modified polyaniline/epoxy resin (b) according to example 1 of the present invention.

Detailed Description

The invention relates to a preparation method of a modified polyaniline/waterborne epoxy resin composite anticorrosive paint, which comprises the following steps:

dissolving 2-aminobenzenesulfonic acid and a high molecular surfactant in dilute hydrochloric acid, dropwise adding aniline and dilute hydrochloric acid containing a water-soluble initiator under an ice bath condition, and continuing to react after dropwise adding. Then carrying out vacuum filtration on the reaction solution, washing to be neutral, and carrying out vacuum drying on filter residues to obtain polyaniline;

dissolving long-chain alkane and tetramethyl ethylenediamine in an ethanol solution, and carrying out condensation reflux continuous reaction at the temperature of 80 ℃. Then recrystallizing the obtained product by using a mixed solvent of acetone and isopropanol to obtain a cationic gemini surfactant N' N-bi (alkyl dimethyl) -1, 2-ethylene dibromide diammonium salt;

adding a polyaniline aqueous solution into an aqueous solution in which a cationic surfactant N' N-bis (alkyl dimethyl) -1, 2-ethylene dibromide diammonium salt is dissolved to react at room temperature, carrying out vacuum filtration on the solution after reaction, washing the solution for multiple times by using deionized water, and naturally drying filter residues to obtain the cationic gemini surfactant modified polyaniline;

dissolving the modified polyaniline in water to disperse, adding the modified polyaniline into a semi-finished epoxy resin emulsion according to a certain proportion, quickly stirring, adding a water-based epoxy resin curing agent, water and a certain amount of defoaming agent, flatting agent and wetting agent according to a certain proportion, and dispersing at a high speed to obtain the cationic gemini surfactant modified polyaniline/epoxy resin composite anticorrosive paint.

Preferably, the specific dosage of the method is as follows:

1) dissolving 1 part by mass of 2-aminobenzenesulfonic acid and 5-10 parts by mass of a high molecular surfactant in 50-100 parts by mass of 1M/L hydrochloric acid to obtain a mixed solution A;

2) dissolving 5-10 parts of water-soluble initiator in 50-100 parts of 1M/L hydrochloric acid to obtain a mixed solution B;

3) and cooling the mixed solution A to 0-5 ℃, reacting for 0.5 hour, then separately and simultaneously dropwise adding the solution B and 5 parts of aniline for 1-2 hours. Then continuously reacting for 4 hours to obtain a mixed solution C;

4) carrying out vacuum filtration on the mixed solution C, washing to be neutral, carrying out vacuum filtration to obtain filter residues, and carrying out vacuum drying to obtain polyaniline;

5) dissolving 4-7 parts of brominated alkane and 1.16 parts of tetramethylethylenediamine in 20 parts of ethanol solution, condensing and refluxing at 80 ℃, and continuously reacting for 33 hours to obtain solution D;

6) drying the solution D, then recrystallizing with a mixed solution of acetone and isopropanol, naturally airing a recrystallized product, and recovering a finished cationic gemini surfactant N' N-bis (alkyl dimethyl) -1, 2-ethylene dibromide diammonium salt;

7) dissolving 0.2 part of polyaniline and 0.2 part of N' N-bis (alkyl dimethyl) -1, 2-ethylene dibromide diammonium salt in 100 parts of water, and continuously reacting for 6 hours at room temperature to obtain a solution E;

8) carrying out vacuum filtration on the solution E, washing the solution E for 3 times by using water, carrying out vacuum filtration to obtain filter residues, and then naturally airing the filter residues to obtain the cationic gemini surfactant modified polyaniline;

9) dissolving 0.2 part of modified polyaniline in 10 parts of water, adding 30 parts of finished product type aqueous epoxy resin emulsion, uniformly stirring, then adding 10 parts of aqueous epoxy resin curing agent, 0.2 part of flatting agent, 0.2 part of wetting agent and 0.05 part of defoaming agent, and dispersing at high speed to obtain the cationic gemini surfactant modified polyaniline/epoxy resin composite anticorrosive paint.

The invention also provides a modified polyaniline/water-based epoxy resin composite anticorrosive paint which comprises the following components in parts by mass:

0.2 part of modified polyaniline, 10 parts of water, 30 parts of aqueous epoxy resin emulsion, 10 parts of aqueous epoxy resin curing agent, 0.2 part of flatting agent, 0.2 part of wetting agent and 0.05 part of defoaming agent;

the modified polyaniline is N' N-bis (alkyl dimethyl) -1, 2-dibromide ethylene diammonium salt modified polyaniline, and is specifically prepared by the methods in the steps 1) to 8.

The invention adopts N' N-bis (alkyl dimethyl) -1, 2-dibromide ethylene diammonium salt modified polyaniline for the first time to prepare the modified polyaniline/epoxy resin composite anticorrosive coating. When the prepared product is used for metal surface corrosion prevention, the dispersibility of the modified polyaniline in the water-based epoxy resin is improved, so that the stability, compatibility, rigidity and bonding strength of the anticorrosive coating are improved, the water resistance of the coating is enhanced, and the corrosion resistance of the metal surface is further improved. The product of the invention can realize the unification of compatibility, rigidity and bonding strength of the anticorrosive paint, solves the common technical problems of poor stability, low water resistance, poor adhesive force and the like of the polyaniline/water-based epoxy resin composite anticorrosive paint, is used for metal surface anticorrosion, and can greatly improve the anticorrosion capability, water resistance and the like of metal.

The technical solutions of the present invention will be described in detail below with reference to specific examples and drawings, but the present invention is not limited to the examples.