阅读说明：本技术 氨基化go/磺化聚苯胺改性水性环氧树脂防腐涂料 (Aminated GO/sulfonated polyaniline modified waterborne epoxy resin anticorrosive paint ) 是由 杨建军 陈虹雨 于倩倩 曹忠富 陈春俊 吴庆云 吴明元 张建安 刘久逸 于 2021-07-29 设计创作，主要内容包括：本发明公开了一种氨基化GO/磺化聚苯胺改性水性环氧树脂防腐涂料,涉及一种涂料,其中氨基化GO/磺化聚苯胺复合材料采用聚乙烯亚胺(PEI)改性氧化石墨烯(GO)和磺酸接枝的聚苯胺分散液超声后原位还原制得,将其复合材料加入到水性环氧树脂(EP)中,合成了一种新型防腐涂料。本发明的水性环氧树脂防腐涂料采用氨基化GO/磺化聚苯胺复合材料作为防腐填料,对腐蚀性电解质扩散具有优异的阻隔性能,合成工艺简单且对环境无污染、原料易得、反应条件易于控制、稳定性好等特点。可广泛应用于日常生活,工业,建筑等各领域。(The invention discloses an aminated GO/sulfonated polyaniline modified waterborne epoxy resin anticorrosive coating, and relates to a coating, wherein an aminated GO/sulfonated polyaniline composite material is prepared by performing ultrasonic in-situ reduction on Polyethyleneimine (PEI) modified Graphene Oxide (GO) and a polyaniline dispersion liquid grafted by sulfonic acid, and the composite material is added into a waterborne epoxy resin (EP) to synthesize a novel anticorrosive coating. The waterborne epoxy resin anticorrosive paint disclosed by the invention adopts the aminated GO/sulfonated polyaniline composite material as an anticorrosive filler, has excellent barrier property on the diffusion of corrosive electrolyte, and has the characteristics of simple synthesis process, no pollution to the environment, easiness in obtaining raw materials, easiness in controlling reaction conditions, good stability and the like. Can be widely applied to various fields of daily life, industry, building and the like.)

1. An aminated GO/sulfonated polyaniline modified waterborne epoxy resin anticorrosive paint is characterized in that the preparation method of the anticorrosive paint comprises the following steps:

step 1, preparing aminated graphene oxide and sulfonated polyaniline;

step 2, preparing the aminated graphene oxide dispersion liquid obtained in the step 1 with the concentration of 5mg/ml, adding the sulfonated polyaniline obtained in the step 1 into the dispersion liquid, performing ultrasonic treatment, adding hydrazine hydrate, reacting for 12 hours at 90-95 ℃, drying, and grinding to obtain SPG powder; wherein the mass ratio of the sulfonated polyaniline to the hydrazine hydrate to the aminated graphene oxide is 1: 1: 1;

and 3, dispersing the SPG powder obtained in the step 2 in deionized water to prepare SPG water dispersion with the concentration of 10mg/ml, adding a water-based epoxy curing agent, performing ultrasonic treatment for 1h, removing excessive solvent by using a rotary evaporator, adding E-51 epoxy resin, and stirring for 30min, wherein the mass ratio of the water-based epoxy curing agent to the E-51 epoxy resin is 3: 1, obtaining a target product; wherein the mass fraction of the SPG powder in the total mass of the target product after water removal is 1 to 3 wt%.

2. The aminated GO/sulfonated polyaniline modified waterborne epoxy resin anticorrosive paint of claim 1, wherein the preparation steps of the aminated graphene oxide in the step 1 are as follows:

step 1.1, uniformly mixing graphite powder and mixed acid, and adding sodium nitrate and potassium permanganate, wherein the mass volume ratio of the graphite powder to the mixed acid is 1:30(g: ml), and the mass ratio of the graphite powder to the potassium permanganate to the sodium nitrate is 1: 4: 1.25, stirring for 2-3h at 35-39 ℃, adding deionized water, and stirring for 1-2h at 90-95 ℃, wherein the volume ratio of the deionized water to the mixed acid is 2: 1-1.5:1, and sequentially adding 30 percent of H with the volume ratio of 1:10₂O₂Stirring with 1mol/L hydrochloric acid water solution, washing, centrifuging, and freeze-drying to obtain solid graphene oxide; preparing a graphene oxide aqueous dispersion and a polyethyleneimine aqueous solution, wherein the mass ratio of graphene oxide to polyethyleneimine is 1:5, mixing for 24h, centrifuging, washing and drying to obtain solid aminated graphene oxide.

3. The aminated GO/sulfonated polyaniline modified waterborne epoxy resin anticorrosive paint of claim 2, wherein the mixed acid in step 1.1 is a mixture of sulfuric acid and phosphoric acid, and the volume ratio of the sulfuric acid to the phosphoric acid is 9:1-9: 2.

4. The aminated GO/sulfonated polyaniline modified waterborne epoxy resin anticorrosive paint according to claim 1, wherein the sulfonated polyaniline in the step 1 is prepared by the following steps:

step 1.2, dissolving aniline in 1mol/L hydrochloric acid with the mass concentration range of 90-95mg/ml to obtain aniline solution, dissolving ammonium persulfate in water with the mass concentration range of 0.3-0.4mg/ml to obtain ammonium persulfate solution, then uniformly stirring the aniline solution and the ammonium persulfate solution with the volume ratio of 5:4, cooling to 0 ℃, then transferring the mixture into a three-neck flask, stirring for 12 hours at the temperature of-5 ℃, filtering, washing and drying to obtain a primary product; dissolving a primary product in 1, 2-dichloroethane, wherein the mass ratio of the primary product to the 1, 2-dichloroethane is 1:29-1:30, heating, and performing ultrasonic dispersion to obtain a solution A; dissolving chlorosulfonic acid in 1, 2-dichloroethane, wherein the mass ratio of chlorosulfonic acid to 1, 2-dichloroethane is 1: 1.6-1: 1.7, obtaining a solution B; dropwise adding the solution B into the solution A with the volume ratio of 10:1, reacting at 75-80 ℃ for 5h, filtering, washing, drying, and grinding to obtain sulfonated polyaniline powder.

Technical Field

The invention belongs to the field of high polymer materials, and particularly relates to an aminated GO/sulfonated polyaniline modified waterborne epoxy resin anticorrosive paint.

Background

Waterborne epoxy resin anticorrosive coatings can reduce the degradation of metals in corrosive media and are of high interest in the industrial field due to their effectiveness, economy and ease of operation. However, the water-based epoxy resin anticorrosive paint can form defects (cracks and pores) due to the evaporation of a solvent in a film forming process, the defects provide a path for corrosive particles to enter a substrate, the corrosion prevention period of the coating is shortened, and the shielding performance is poor. The invention synthesizes a novel water-based epoxy resin anticorrosive paint which can repair the defects and obviously improve the anticorrosive performance.

Graphene Oxide (GO) is an attractive material that combines two-dimensional cellular and atomically thin nanostructures with a variety of active oxygen functional groups. Polyethyleneimine (PEI) is a weakly alkaline aliphatic polymer, high-density amine groups which are easy to protonate exist, and PEI can react with epoxy groups on the surface of graphene oxide through amine groups to form covalent bonds, so that aminated graphene oxide (PG) is synthesized. Polyaniline (PANI) is one of important conjugated conductive polymers, and has excellent stability and conductivity. In recent years, the research on GO/PANI composite materials shows that the composite materials are insoluble in conventional solvents, are difficult to process and seriously obstruct the practical application of the composite materials. Therefore, the improvement of the solubility of the GO/PANI composite material plays an important role in the application of the GO/PANI composite material. The synthesis of Sulfonated Polyaniline (SPANI) is the most successful method for preparing soluble conductive PANI, the conjugated structure of SPANI can promote the dispersibility of novel GO in water through pi-interaction, and the problem that the graphene lamellar structure is easy to agglomerate is solved. According to the invention, the amination graphene oxide aqueous dispersion is prepared by adopting an in-situ polymerization method and compounded with SPANI, an amination GO/sulfonated polyaniline composite material (SPG) is synthesized, defects (cracks and pores) caused by film forming of a water-based epoxy coating can be repaired, corrosive electrolyte diffusion is blocked, the water-based epoxy resin anti-corrosive coating has excellent anti-corrosive performance, and the anti-corrosive performance of the water-based epoxy resin anti-corrosive coating can be obviously improved.

Disclosure of Invention

The invention aims to provide an aminated GO/sulfonated polyaniline modified waterborne epoxy resin anticorrosive paint which can be durably and stably applied to the field of steel corrosion prevention.

In order to achieve the purpose, the invention adopts the technical scheme that:

an aminated GO/sulfonated polyaniline modified waterborne epoxy resin anticorrosive paint, wherein the preparation method of the anticorrosive paint comprises the following steps:

step 1, preparing aminated graphene oxide and sulfonated polyaniline;

step 2, preparing the aminated graphene oxide dispersion liquid obtained in the step 1 with the concentration of 5mg/ml, adding the sulfonated polyaniline obtained in the step 1 into the dispersion liquid, performing ultrasonic treatment, adding hydrazine hydrate, reacting for 12 hours at 90-95 ℃, drying, and grinding to obtain SPG powder; wherein the mass ratio of the sulfonated polyaniline to the hydrazine hydrate to the aminated graphene oxide is 1: 1: 1;

and 3, dispersing the SPG powder obtained in the step 2 in deionized water to prepare SPG water dispersion with the concentration of 10mg/ml, adding a water-based epoxy curing agent, performing ultrasonic treatment for 1h, removing excessive solvent by using a rotary evaporator, adding E-51 epoxy resin, and stirring for 30min, wherein the mass ratio of the water-based epoxy curing agent to the E-51 epoxy resin is 3: 1, obtaining a target product; wherein the mass fraction of the SPG powder in the total mass of the target product after water removal is 1 to 3 wt%.

Further, the preparation steps of the aminated graphene oxide in the step 1 are as follows:

step 1.1, uniformly mixing graphite powder and mixed acid, and adding sodium nitrate and potassium permanganate, wherein the mass volume ratio of the graphite powder to the mixed acid is 1:30(g: ml), and the mass ratio of the graphite powder to the potassium permanganate to the sodium nitrate is 1: 4: 1.25, stirring for 2-3h at 35-39 ℃, adding deionized water, and stirring for 1-2h at 90-95 ℃, wherein the volume ratio of the deionized water to the mixed acid is 2: 1-1.5:1, and sequentially adding 30 percent of H with the volume ratio of 1:10₂O₂Stirring with 1mol/L hydrochloric acid water solution, washing, centrifuging, and freeze-drying to obtain solid graphene oxide; preparing a graphene oxide aqueous dispersion and a polyethyleneimine aqueous solution, wherein the mass ratio of graphene oxide to polyethyleneimine is 1:5, mixing for 24h, centrifuging, washing and drying to obtain solid aminated graphene oxide.

3. The aminated GO/sulfonated polyaniline modified waterborne epoxy resin anticorrosive paint of claim 2, wherein the mixed acid in step 1.1 is a mixture of sulfuric acid and phosphoric acid, and the volume ratio of the sulfuric acid to the phosphoric acid is 9:1-9: 2.

Further, the preparation of the sulfonated polyaniline in the step 1 comprises the following steps:

step 1.2, dissolving aniline in 1mol/L hydrochloric acid with the mass concentration range of 90-95mg/ml to obtain aniline solution, dissolving ammonium persulfate in water with the mass concentration range of 0.3-0.4mg/ml to obtain ammonium persulfate solution, then uniformly stirring the aniline solution and the ammonium persulfate solution with the volume ratio of 5:4, cooling to 0 ℃, then transferring the mixture into a three-neck flask, stirring for 12 hours at the temperature of-5 ℃, filtering, washing and drying to obtain a primary product; dissolving a primary product in 1, 2-dichloroethane, wherein the mass ratio of the primary product to the 1, 2-dichloroethane is 1:29-1:30, heating, and performing ultrasonic dispersion to obtain a solution A; dissolving chlorosulfonic acid in 1, 2-dichloroethane, wherein the mass ratio of chlorosulfonic acid to 1, 2-dichloroethane is 1: 1.6-1: 1.7, obtaining a solution B; dropwise adding the solution B into the solution A with the volume ratio of 10:1, reacting at 75-80 ℃ for 5h, filtering, washing, drying, and grinding to obtain sulfonated polyaniline powder.

The beneficial technical effects of the invention are as follows:

(1) the method has the characteristics of simple synthesis process, no environmental pollution, easy control of reaction conditions, good stability and the like.

(2) The polyethyleneimine has the characteristics of high reaction activity, cheap and easily-obtained raw materials, no pollution and the like, is easy to react with the graphene oxide, and is very favorable for the dispersibility of the graphene oxide. The method can be applied to industrial production, and can greatly reduce the production cost, and the development and application have great development prospects.

(3) The sulfonated polyaniline is beneficial to the dispersion of the prepared novel graphene oxide, has excellent corrosion resistance, and can improve the corrosion resistance of the water-based epoxy resin anticorrosive paint.

(4) The synthesized aminated graphene oxide/sulfonated polyaniline composite material can repair defects (cracks and pores) caused by film formation of an epoxy coating, prevent corrosive electrolyte from diffusing, and remarkably improve the corrosion resistance of the water-based epoxy resin anticorrosive paint.

Drawings

FIG. 1 is a graph showing the effect of tinplate coated with the waterborne epoxy resin anticorrosive coatings of examples 1-3 and comparative examples 1-3 of the present invention in salt spray for different periods of time.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1: an aminated GO/sulfonated polyaniline modified waterborne epoxy resin anticorrosive paint, which comprises the following steps:

(1) uniformly mixing 2.4g of graphite powder with 72ml of mixed acid, adding 3g of sodium nitrate and 9.6g of potassium permanganate, stirring for 2-3H at 35-39 ℃, adding 123ml of deionized water, stirring for 1-2H at 90-95 ℃, and sequentially adding 30ml of 30% H₂O₂And 300ml of 1mol/L hydrochloric acid aqueous solution are stirred, washed, centrifuged and freeze-dried to obtain the solid Graphene Oxide (GO). 100mg of GO was weighed and ultrasonically dispersed in 100mL of deionized water, and 0.5g of poly was weighedEthyleneimine (PEI) was ultrasonically dispersed in 50mL deionized water. Dripping the PEI solution into the GO solution, stirring for 24 hours, then centrifugally washing and drying to obtain an aminated graphene oxide (PG) solid product;

(2) weighing 9.3g of aniline dissolved in 100mL of 1mol/L hydrochloric acid, 28.6g of ammonium persulfate dissolved in 80mL of water, uniformly stirring the two solutions, cooling to 0 ℃, transferring the solution into a three-neck flask, stirring for 12 hours at the temperature of minus 5 ℃, filtering, washing, drying and grinding to obtain Polyaniline (PANI) powder. Weighing 2g of PANI powder, dissolving in 50ml of 1, 2-dichloroethane, heating, ultrasonically dispersing, weighing 3.63g of chlorosulfonic acid, dissolving in 5ml of 1, 2-dichloroethane, mixing the two liquids, reacting for 5 hours at 75-80 ℃, filtering, washing, drying, and grinding to obtain Sulfonated Polyaniline (SPANI) powder;

(3) weighing 0.1g SPANI, dissolving the SPANI in 20mL PG dispersion liquid with the concentration of 5mg/mL, carrying out ultrasonic treatment for 2h, adding about 1mL hydrazine hydrate, reacting at 90-95 ℃ for 12h, drying, and grinding to obtain aminated GO/sulfonated polyaniline composite material (SPG) powder;

(4) weighing 0.061g of SPG powder, dispersing the SPG powder in 6.1mL of deionized water, stirring the mixture with 4.5g of water-based epoxy curing agent for 10min, performing ultrasonic treatment for 1h, removing excessive solvent by using a rotary evaporator, adding 1.5g E-51 epoxy resin, and stirring for 30min to obtain the composite anticorrosive paint composite material with the mass fraction of 1% (namely, the SPG powder accounts for 1% of the total mass of the composite anticorrosive paint composite material after water is removed, namely 0.061/(0.061+4.5+1.5) ═ 0.01, namely 1 wt%).

Example 2: steps 1-3 in this embodiment are identical to those in embodiment 1, and are not repeated herein. The preparation method of the aminated GO/sulfonated polyaniline modified waterborne epoxy resin anticorrosive coating provided by the embodiment is only different from the step 4 of the embodiment 1, and the step 4 is specifically as follows:

weighing 0.122g of SPG powder, dispersing in 12.2mL of deionized water, stirring with 4.5g of water-based epoxy curing agent for 10min, carrying out ultrasonic treatment for 1h, removing excessive solvent by using a rotary evaporator, adding 1.5g E-51 epoxy resin, and stirring for 30min to obtain the composite anticorrosive paint composite material with the mass fraction of 2 wt%.

Example 3: steps 1-3 in this embodiment are identical to those in embodiment 1, and are not repeated herein. The preparation method of the aminated GO/sulfonated polyaniline modified waterborne epoxy resin anticorrosive coating provided by the embodiment is only different from the step 4 of the embodiment 1, and the step 4 is specifically as follows:

weighing 0.186g of SPG solid powder, dispersing in 18.6mL of deionized water, stirring with 4.5g of water-based epoxy curing agent for 10min, performing ultrasonic treatment for 1h, removing excessive solvent by using a rotary evaporator, adding 1.5g E-51 epoxy resin, and stirring for 30min to obtain the composite anticorrosive paint composite material with the mass fraction of 3 wt%.

The performance test process method comprises the following steps:

the prepared latex is processed into a standard sample according to the national standard, and various performances of the latex are tested.

1. The adhesion is tested according to the national standard GB/T9286-1988, and an adhesion tester is adopted to test the sample.

2. The water absorption is tested according to the national standard GB/T8810-.

3. Hardness was tested according to the national standard GB/T6739-.

4. The lowest film forming temperature is tested according to the national standard GB/T9267-2008, and a sample is directly measured by adopting a lowest film forming temperature tester.

5. The contact angle is measured according to the national standard GB/T8810-88, and the contact angle measuring instrument is used for measuring the sample.

6. The viscosity was measured according to the national standard GB/T10247-2008, using a viscometer for the test of the sample.

7. The salt spray resistance is tested according to the national standard GB/T1771-2007, and the sample is placed in a salt spray resistance test box for 850h, wherein the specification of the sample is 100mm multiplied by 150 mm.

The following table shows the performance test result data of the aminated GO/sulfonated polyaniline composite modified waterborne epoxy resin anticorrosive paint prepared by the method of the invention in the above examples 1-3.

Comparative example 1

The preparation method of the pure water epoxy resin anticorrosive paint comprises the following steps:

stirring 4.5g of water-based epoxy curing agent for 10min, performing ultrasonic treatment for 1h, removing excessive solvent by a rotary evaporator, adding 1.5g E-51 epoxy resin, and stirring for 30min to obtain the pure water-based epoxy resin anticorrosive paint.

Comparative example 2

A preparation method of a graphene oxide water-based epoxy resin anticorrosive paint comprises the following steps:

(1) preparing graphene oxide; same as in step (1) of example 1.

(2) Weighing 0.122gGO solid powder, dispersing in 12.2mL deionized water, stirring with 4.5g of water-based epoxy curing agent for 10min, performing ultrasonic treatment for 1h, removing excessive solvent by a rotary evaporator, adding 1.5g E-51 epoxy resin, and stirring for 30min to obtain the 2 wt% composite anticorrosive paint composite material.

Comparative example 3

A preparation method of an aminated GO water-based epoxy resin anticorrosive paint comprises the following steps:

(1) preparing Graphene Oxide (GO); same as in step (1) of example 1.

(2) Preparation of aminated graphene oxide (PG): same as in step (2) of example 1.

(3) Weighing 0.122gPG solid powder, dispersing in 12.2mL deionized water, stirring with 4.5g of water-based epoxy curing agent for 10min, performing ultrasonic treatment for 1h, removing excessive solvent by a rotary evaporator, adding 1.5g E-51 epoxy resin, and stirring for 30min to obtain the 2 wt% composite anticorrosive paint composite material.

Test example: the anticorrosive coatings prepared in examples 1-3 and comparative examples 1-2 were coated on tinplate painted with an "x" on the surface, and then placed in a salt spray test chamber to be continuously sprayed for 30d with a 5% NaCl solution as a spraying medium.

The results are shown in FIG. 1, where EP refers to the material obtained in comparative example 1, GO refers to the composite material obtained in comparative example 2, PG refers to the composite material obtained in comparative example 3, and SPG1-SPG3 refer to the composite materials obtained in examples 1-3.

It can be seen from fig. 1 that there are a lot of corrosion products and bubbles around the scratch of the EP-only coating, and the corrosion products at the scratch of GO or PG are significantly reduced compared to the EP coating, while the surface of the samples of SPG1-SPG3 covered significantly less corrosion products, with the SPG 2 sample, corrosion products being minimal and almost none.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.