CN102604533A - Polyaniline-graphene composite based anticorrosive paint and preparation method thereof - Google Patents

Abstract

The invention provides an anti-corrosion coating based on polyaniline and graphene composite material and a preparation method. It is composed of the following components in terms of weight fraction: film-forming substance 20-90; polyaniline and graphene composite material 0.1-20; pigment 1-10; filler 1-10; anti-sagging agent 0.1-3; dispersant 0.1- 4; leveling agent 0.01-2; defoamer 0.01-2; solvent 1-50. Graphene in the obtained coating of the present invention can provide excellent physical anticorrosion effect because of the high diameter-thickness ratio and good flexibility, and the polyaniline loaded on the surface of graphene can provide electrochemical anticorrosion effect, and the synergistic mechanism of the two makes The coating has excellent metal corrosion protection properties. The anti-corrosion paint of the invention can realize the passivation and corrosion inhibition of the metal substrate, avoid the use of heavy metals such as chromium that can cause environmental pollution, and is simple to prepare, low in cost, and easy to industrialized mass production.

Description

A kind of anticorrosion coating based on polyaniline and graphene composite material and preparation method

technical field

What the present invention relates to is a kind of anticorrosion paint. The invention also relates to a preparation method of the anticorrosion paint.

Background technique

Mica powder, aluminum powder, and glass flakes with a scaly structure can reduce the permeability of the anti-corrosion coating and thus play a role in physical anti-corrosion. Therefore, they are often used as fillers in anti-corrosion coatings, for example (Chinese Patent No. ZL91111830 .6) The preparation method of glass flake anticorrosion coating is proposed. However, since this flake structure can only provide physical anti-corrosion and cannot achieve the ideal anti-corrosion effect, it is often used together with chromate and other electrochemical anti-corrosion pigments to improve the anti-corrosion effect of the coating. In recent years, polyaniline with oxidation-reduction potential has been found to passivate the metal surface, so it can replace chromium-based and lead-based anti-corrosion fillers and be added to anti-corrosion coatings to achieve electrochemical anti-corrosion. Liu Fuchun et al. (Chinese Patent No.: 101643619B) will Aluminum powder and glass flakes are modified by polyaniline to prepare anti-corrosion coatings with both physical and electrochemical anti-corrosion functions, which not only significantly improves the anti-corrosion performance of the coatings, but also avoids the use of toxic chromates.

Graphene is a new carbonaceous material with a two-dimensional sheet structure that has been newly discovered in recent years by a single layer of carbon atoms. Graphene has excellent electrical properties and a high aspect ratio (> 200) and thin lamellar structure (<1nm), so it can be assumed that it has better physical anti-corrosion effect than the currently commonly used mica powder, aluminum powder, glass flakes, etc. Therefore, if polyaniline is loaded on the surface of graphene and used as a filler, it will provide excellent physical and chemical corrosion protection at the same time, thereby significantly improving the corrosion resistance of coatings. Related research has not yet been reported.

Contents of the invention

The object of the present invention is to provide a kind of anticorrosion coating based on polyaniline and graphene composite material with excellent metal corrosion protection performance. The object of the present invention is also to provide a method for preparing an anti-corrosion coating based on polyaniline and graphene composite material, which has simple preparation process, low cost and is easy to realize industrial production.

The purpose of the present invention is achieved like this:

The anticorrosion coating based on polyaniline and graphene composite material of the present invention is made of following components by weight fraction: film-forming substance 20-90; Polyaniline and graphene composite material 0.1-20; Pigment 1-10; Filler 1- 10; anti-sagging agent 0.1-3; dispersant 0.1-4; leveling agent 0.01-2; defoamer 0.01-2; solvent 1-50.

The film-forming substance is any one of alkyd resin, phenolic resin, epoxy resin, fluorocarbon resin, chlorinated rubber, chlorinated vinyl, perchloroethylene resin or polyurethane resin.

The pigment is a commonly used pigment for coatings, such as any one of titanium dioxide, zinc oxide, iron oxide red or phthalocyanine green.

The filler is a filler commonly used in coatings, such as any one of calcium carbonate, talcum powder, quartz sand and barite powder.

The solvent is a commonly used solvent in the preparation of coatings, such as any one or a mixture of two or more of toluene, xylene, butanol, butanone or cyclohexanone.

The polyaniline and graphene composite material is a sheet sandwich structure with graphene or graphene oxide in the middle and polyaniline nanoparticles on the surface. The mass ratio of polyaniline to graphene or graphene oxide is 0.1- 500:1.

The anti-sagging agent is one of montmorillonite, bentonite, kaolin, fumed silica or a mixture of more than two in any proportion.

The dispersant, leveling agent, and defoamer are commonly used auxiliary agents for coatings. Dispersants such as Disperbyk 163, Disperbyk 111, Disperbyk 115, Disperbyk 192, Disperbyk 191, Disperbyk 190, etc. from BYK Chemical Company, Germany; leveling agents such as BYK-353, BYK-354, BYK-355, BYK from BYK Chemical Company, Germany -331, etc., defoamers such as BYK-053, BYK-065, BYK-055, BYK-053 of German BYK Chemical Company.

The preparation method of the anticorrosion coating based on polyaniline and graphene composite material of the present invention is carried out as follows:

(1) Preparation of polyaniline and graphene composite materials

1) Prepare a dispersion of graphene oxide or graphene containing aniline and hydrochloric acid, wherein the concentration of aniline is 0.01-1mol/L, the concentration of hydrochloric acid is 0.01-0.2mol/L, and the concentration of graphene oxide or graphene is 0.01-10mg /mL, stir well and pre-cool to 0-10°C;

2) Prepare an aqueous solution of an oxidizing agent containing hydrochloric acid, wherein the concentration of the oxidizing agent in the solution is 0.01-1mol/L, and pre-cool it to 0-10°C, the concentration of hydrochloric acid is 0.01-0.2mol/L, and the oxidizing agent is ammonium persulfate or potassium persulfate;

3) Slowly drop the aqueous solution of the oxidizing agent containing hydrochloric acid into the graphene oxide or graphene dispersion containing aniline and hydrochloric acid under stirring, react at 0-10°C for 0.5-10h, centrifuge, filter, wash and dry, and then grind To less than 200 mesh, wherein the volume ratio of the dispersion of graphene oxide or graphene containing aniline, hydrochloric acid and the aqueous solution of oxidizing agent containing hydrochloric acid is 1:1;

(2) Add dispersants, leveling agents, defoamers, anti-sagging agents, pigments, and fillers to the film-forming substances and solvents, stir for 10-120 minutes, and then grind until the fineness is less than 60 microns before discharging;

(3) under stirring, polyaniline and graphene composite material are joined in the film-forming material mixture that step (2) obtains, carry out uniform dispersion, obtain polyaniline and graphene anticorrosion coating;

Among them, each component is constituted by weight fraction: film-forming substance 20-90; polyaniline and graphene composite material 0.1-20; pigment 1-10; filler 1-10; anti-sagging agent 0.1-3; dispersant 0.1 -4; leveling agent 0.01-2; defoamer 0.01-2; solvent 1-50.

The preparation method of the anti-corrosion coating based on polyaniline and graphene composite material of the present invention selects the corresponding curing agent and consumption according to the difference of film-forming substances, and some film-forming substances can also form films without using curing agents; curing under normal temperature conditions After 7-15 days, polyaniline and graphene anticorrosion coatings are formed.

Graphene in the obtained coating of the present invention can provide excellent physical anticorrosion effect because of the high diameter-thickness ratio and good flexibility, and the polyaniline loaded on the surface of graphene can provide electrochemical anticorrosion effect, and the synergistic mechanism of the two makes The coating has excellent metal corrosion protection properties.

The anti-corrosion paint of the invention can realize the passivation and corrosion inhibition of the metal substrate, avoid the use of heavy metals such as chromium that can cause environmental pollution, and is simple to prepare, low in cost, and easy to industrialized mass production.

Detailed ways

Comparative Example 1

Put 0.6 parts of dispersant (Disperbyk191), 1.2 parts of leveling agent (BYK 331), 1 part of defoamer (BYK 053), 0.6 parts of anti-sagging agent (Montolian clay), 2 parts of pigment (titanium dioxide), filler (calcium carbonate) 2 parts, polyaniline (commercial polyaniline produced by Changchun Applied Chemistry) 20 parts, add 60 parts of epoxy resin (two parts of A-type epoxy resin E-44) and 30 parts of solvent (toluene), stir After 20 minutes, it was ground in a sand mill, and the fineness was less than 45 microns, and then the material was discharged to prepare anti-corrosion coating component 1. The 591 type curing agent was dissolved in butanol to prepare a 50% solution as component 2. According to the weight ratio of component 1: component 2 is equal to 100:40, mix the two components evenly, apply a film on the 150mm×75mm×2mm steel plate of No. The film thickness was 400 μm. The coating film was immersed in 3.5% NaCl aqueous solution, and its Tafel curve was tested with CHI-660 electrochemical workstation.

Example 1

Prepare polyaniline/graphene composites as follows

a) Prepare a dispersion of graphene containing aniline and hydrochloric acid, wherein the concentration of aniline is 0.5 mol/L, the concentration of hydrochloric acid is 0.2 mol/L, and the concentration of graphene is (10 mg/mL). Stir evenly and pre-cool to 5°C .

b) Prepare an aqueous solution of ammonium persulfate containing hydrochloric acid, wherein the concentration of ammonium persulfate in the solution is 0.5 mol/L, and pre-cool it to 5° C., and the concentration of hydrochloric acid is 0.2 mol/L.

c) Slowly drop (b) solution into (a) solution under stirring, wherein the volume ratio of (a) solution to (b) solution is 1:1, react at 5°C for 1h, centrifuge, filter, wash and dry After grinding to less than 200 mesh, the polyaniline/graphene composite material is obtained.

Put 0.6 parts of dispersant (Disperbyk191), 1.2 parts of leveling agent (BYK 331), 1 part of defoamer (BYK 053), 0.6 parts of anti-sagging agent (Montolian clay), 2 parts of pigment (titanium dioxide), filler (calcium carbonate) 2 parts, polyaniline/graphene composite material 20 parts, add 60 parts of epoxy resin (two parts of A-type epoxy resin E-44) and 30 parts of solvent (toluene), stir 20 minutes, then in sand Grinding in the mill, the fineness is less than 45 microns, and the material is discharged to prepare the anti-corrosion coating component 1, and the 591 type curing agent is dissolved in butanol to prepare a 50% solution as the component 2. According to the weight ratio of component 1: component 2 is equal to 100:40, mix the two components evenly, apply a film on the 150mm×75mm×2mm steel plate of No. The film thickness was 400 μm. The coating film was immersed in 3.5% NaCl aqueous solution, and its Tafel curve was tested with CHI-660 electrochemical workstation.

Example 2

Prepare polyaniline/graphene composites as follows

a) Prepare a graphene oxide dispersion containing aniline and hydrochloric acid, wherein the concentration of aniline is 1mol/L, the concentration of hydrochloric acid is 0.01mol/L, and the concentration of graphene oxide or graphene is (5mg/mL), pre-cool after stirring evenly to 10°C.

b) Prepare an aqueous solution of potassium persulfate containing hydrochloric acid, wherein the concentration of potassium persulfate in the solution is 1 mol/L, and the concentration of hydrochloric acid is 0.01 mol/L, and pre-cool it to 10°C.

c) Slowly drop (b) solution into (a) solution under stirring, wherein the volume ratio of (a) solution to (b) solution is 1:1, react at 10°C for 1 hour, centrifuge, filter, wash and dry After grinding to less than 200 mesh, the polyaniline/graphene oxide composite material is made.

Mix 0.6 parts of dispersant (Disperbyk191), 1.2 parts of leveling agent (BYK331), 1 part of defoamer (BYK 053), 0.6 parts of anti-sagging agent (Montolian clay), 2 parts of pigment (titanium dioxide), filler ( Calcium carbonate) 2 parts, polyaniline/graphene oxide composite material 20 parts, add 60 parts of epoxy resin (two parts of A-type epoxy resin E-44) and 30 parts of solvent (toluene), stir 20 minutes, then in sand Grinding in the mill, the fineness is less than 45 microns, and the material is discharged to prepare the anti-corrosion coating component 1, and the 591 type curing agent is dissolved in butanol to prepare a 50% solution as the component 2. According to the weight ratio of component 1: component 2 is equal to 100:40, mix the two components evenly, apply a film on the 150mm×75mm×2mm steel plate of No. The film thickness was 400 μm. Immerse the film in 3.5% NaCl aqueous solution, and test its Tafel curve with CHI-660 electrochemical workstation. Table 1 has provided the corrosion potential result of comparative example and embodiment 1, 2, as can be seen from table 1, this polyaniline/graphene composite material endows coating with excellent anticorrosion property, compared with simple polyaniline The anti-corrosion performance is significantly improved.

The corrosion potential result of table 1 comparative example and embodiment 1,2

Example Corrosion potential (V) Comparative Example 1 -0.523 Example 1 -0.247 Example 2 -0.209

Claims (4)

1. the protective system based on polyaniline and graphene composite material is characterized in that: be made up of following component in weight fraction: filmogen 20-90; Polyaniline and graphene composite material 0.1-20; Pigment 1-10; Filler 1-10; Anti-sagging agent 0.1-3; Dispersion agent 0.1-4; Flow agent 0.01-2; Skimmer 0.01-2; Solvent 1-50.

2. the protective system based on polyaniline and graphene composite material according to claim 1 is characterized in that described filmogen is any one in Synolac, resol, epoxy resin, fluorocarbon resin, chlorinated rubber, ethylene chloride, supervinyi chloride resin or the urethane resin.

3. the protective system based on polyaniline and graphene composite material according to claim 1; It is characterized in that described polyaniline and graphene composite material are that a kind of centre that obtains according to following method is Graphene or graphene oxide; The surface is the lamella sandwich structure of polyaniline nano particulate, and the mass ratio of polyaniline and Graphene or graphene oxide is 0.1-500: 1 matrix material:

1) preparation contains the graphene oxide of aniline, hydrochloric acid or the dispersion liquid of Graphene; Wherein aniline concentration is 0.01-1mol/L; Concentration of hydrochloric acid is 0.01-0.2mol/L, and the concentration of graphene oxide or Graphene is 0.01-10mg/mL, and the back precooling that stirs is to 0-10 ℃;

2) preparation contains the aqueous solution of oxygenant of hydrochloric acid, and wherein the concentration of the oxygenant in the solution is 0.01-1mol/L, and with its precooling to 0-10 ℃, concentration of hydrochloric acid is 0.01-0.2mol/L, oxygenant is ammonium persulphate or Potassium Persulphate;

The aqueous solution that 3) will contain the oxygenant of hydrochloric acid under agitation slowly splashes in the dispersion liquid of the graphene oxide that contains aniline, hydrochloric acid or Graphene; At 0-10 ℃ of reaction 0.5-10h; Be ground to less than 200 orders after centrifugal, filtration, the washing and drying, the volume ratio of dispersion liquid and the aqueous solution of the oxygenant that contains hydrochloric acid that wherein contains graphene oxide or the Graphene of aniline, hydrochloric acid is 1: 1.

4. preparation method based on the protective system of polyaniline and graphene composite material is characterized in that carrying out as follows:

(1) preparation of polyaniline and graphene composite material

1) preparation contains the graphene oxide of aniline, hydrochloric acid or the dispersion liquid of Graphene; Wherein aniline concentration is 0.01-1mol/L; Concentration of hydrochloric acid is 0.01-0.2mol/L, and the concentration of graphene oxide or Graphene is 0.01-10mg/mL, and the back precooling that stirs is to 0-10 ℃;

2) preparation contains the aqueous solution of oxygenant of hydrochloric acid, and wherein the concentration of the oxygenant in the solution is 0.01-1mol/L, and with its precooling to 0-10 ℃, concentration of hydrochloric acid is 0.01-0.2mol/L, oxygenant is ammonium persulphate or Potassium Persulphate;

The aqueous solution that 3) will contain the oxygenant of hydrochloric acid under agitation slowly splashes in the dispersion liquid of the graphene oxide that contains aniline, hydrochloric acid or Graphene; At 0-10 ℃ of reaction 0.5-10h; Be ground to less than 200 orders after centrifugal, filtration, the washing and drying, the volume ratio of dispersion liquid and the aqueous solution of the oxygenant that contains hydrochloric acid that wherein contains graphene oxide or the Graphene of aniline, hydrochloric acid is 1: 1;

(2) dispersion agent, flow agent, skimmer, anti-sagging agent, pigment, filler are joined in filmogen and the solvent, stir 10-120min, grind then, fineness is less than discharging after 60 microns;

(3) under agitation join polyaniline and graphene composite material in the filmogen mixture that step (2) obtains, carry out homodisperse, obtain polyaniline and Graphene protective system;

Wherein each component constitutes in weight fraction: filmogen 20-90; Polyaniline and graphene composite material 0.1-20; Pigment 1-10; Filler 1-10; Anti-sagging agent 0.1-3; Dispersion agent 0.1-4; Flow agent 0.01-2; Skimmer 0.01-2; Solvent 1-50.