阅读说明：本技术 一种席夫碱基阳离子表面活性剂/go疏水涂层的制备方法 (Preparation method of Schiff base cationic surfactant/GO hydrophobic coating ) 是由 刘峥 陈则胜 魏润芝 吴富城 于 2020-10-28 设计创作，主要内容包括：本发明提供了一种席夫碱基阳离子表面活性剂/GO疏水涂层。该涂层包括席夫碱基阳离子表面活性剂/GO复合材料和环氧树脂基体。环氧树脂涂层作为一种有机涂层是一种良好的防腐涂料,但由于在固化过程中环氧涂层容易引起一些微孔,且聚合物链之间总是存在一些空隙。本专利提出将席夫碱基阳离子表面活性剂/GO复合材料作为填料加入到环氧树脂中,以赋予环氧涂层疏水性能,进一步提高环氧树脂的耐腐蚀性。(The invention provides a Schiff base cationic surfactant/GO hydrophobic coating. The coating comprises a Schiff base cationic surfactant/GO composite material and an epoxy resin matrix. Epoxy resin coatings are a good corrosion protection coating as an organic coating, but since the epoxy coating tends to cause some micro-pores during curing, there are always some voids between the polymer chains. The Schiff base cationic surfactant/GO composite material is added into epoxy resin as a filler so as to endow the epoxy coating with hydrophobic property and further improve the corrosion resistance of the epoxy resin.)

1. A schiff base cationic surfactant/GO hydrophobic coating characterized by: comprises a Schiff base cationic surfactant/GO composite material and an epoxy resin matrix.

2. The schiff base cationic surfactant/GO hydrophobic coating of claim 1, comprising adding 0.01g of the schiff base cationic surfactant/GO composite to 2g of the epoxy resin.

3. The schiff base cationic surfactant/GO hydrophobic coating of claim 2, wherein the schiff base cationic surfactant is prepared from ethanolamine, 4-dimethylaminobenzaldehyde and dodecyl bromide as raw materials by a method comprising:

accurately weighing 0.6108g of ethanolamine and 1.4919g of 4-dimethylaminobenzaldehyde in a round-bottom flask, dissolving the ethanolamine and the 4-dimethylaminobenzaldehyde in 20mL of ethanol, adding 0.15mL of glacial acetic acid as a catalyst, stirring and reacting at 70 ℃ for 5 hours, distilling the ethanol solvent under reduced pressure after the reaction is finished to separate out a precipitate, recrystallizing and purifying the precipitate by using ethyl acetate, and drying the recrystallized precipitate in vacuum to obtain a light yellow crystal intermediate 4-dimethylaminobenzaldehyde ethanolamine Schiff base;

accurately weighing 0.64g of the 4-dimethylaminobenzaldehyde ethanolamine Schiff base intermediate prepared in the step (1) in a three-neck flask, adding 20mL of ethanol to dissolve the intermediate, slowly dropwise adding 0.83g of dodecyl bromide under stirring, refluxing and stirring at 80 ℃ after dropwise adding is finished, reacting for 48 hours, distilling under reduced pressure after the reaction is finished to evaporate an ethanol solvent, precipitating, performing suction filtration, washing with acetone to remove unreacted substances, repeating for 5 times, and finally performing vacuum drying on the obtained precipitate to obtain the orange powdery Schiff base cationic surfactant.

4. The schiff base cationic surfactant/GO hydrophobic coating of claim 2, wherein the preparation method of the schiff base cationic surfactant/GO composite material comprises the following steps: weighing 0.1g of graphene oxide GO in 20mL of dimethylformamide DMF, performing ultrasonic treatment for 40min to uniformly disperse GO in DMF, sequentially adding 0.3g of Schiff base cationic surfactant obtained in the step (2), 0.08g of dicyclohexylcarbodiimide and 0.009g of 4-dimethylaminopyridine, stirring and reacting the mixed solution for 6h at 60 ℃ under the protection of nitrogen, performing centrifugal separation on the solution for 10min after the reaction is finished, controlling the rotating speed of a centrifuge at 4000r/min, washing the precipitate with distilled water, performing centrifugation again, repeating for 5 times, and finally performing vacuum drying to obtain the Schiff base cationic surfactant/GO composite material.

5. The schiff base cationic surfactant/GO hydrophobic coating of claim 2, wherein the schiff base cationic surfactant/GO coating is prepared by a method comprising: using 4X 1.3X 0.2cm³Weighing 0.01g of Schiff base cationic surfactant/GO composite material prepared according to claim 4 in 1mL of acetone by taking a carbon steel test piece as a base material of a hydrophobic coating, performing ultrasonic treatment for 40min to uniformly disperse the composite material, adding 1g of polyamide curing agent, stirring uniformly, adding 1g of epoxy resin and 0.1g of defoaming agent, stirring and curing for 1h, coating the coating on the surface of the carbon steel by using a coating instrument, and curing at room temperature for 7 days to prepare the Schiff base cationic surfactant/GO hydrophobic coating on the carbon steel base material.

Technical Field

The invention belongs to the technical field of anticorrosive paint preparation, and particularly relates to a Schiff base cationic surfactant/GO hydrophobic coating and a preparation method thereof.

Background

The epoxy resin coating is used as an organic coating and has excellent mechanical properties, acid and alkali resistance, wear resistance and insulativity. In addition, it can be regarded as a good anticorrosive coating. However, epoxy coatings suffer from a number of disadvantages, including the tendency to cause some microvoids in the epoxy coating during the curing process, and the constant presence of voids between the polymer chains. Both of these defects cause corrosive media in the environment to readily penetrate the coating and come into contact with the metal material, causing corrosion of the metal surface, and various types of fillers and pigments are often added to the coating to improve coating properties. The nano graphene oxide is used as a stable nano material, and can effectively fill up a gap formed in the curing process of the organic coating after being added into the coating, prevent corrosive media from permeating into the metal surface from the gap of the coating, and greatly improve the corrosion resistance of the coating. The molecular structure of the surfactant simultaneously has a hydrophilic polar group and a hydrophobic long-chain nonpolar group, the hydrophilic group is used as a corrosion inhibitor and is adsorbed on the surface of metal, and the hydrophobic long-chain nonpolar group forms a hydrophobic barrier in the solution, so that the contact between a corrosion medium and the surface of the metal is blocked, a protective film is formed, and the effect of slowing down the corrosion of the metal is achieved. The Schiff base compound is a commonly used corrosion inhibitor in industry, if Schiff base is introduced into a surfactant to prepare the Schiff base cationic surfactant, the corrosion inhibition performance of the Schiff base compound can be further improved by virtue of hydrophobic long-chain non-polar groups in the structure of the surfactant. Meanwhile, the Schiff base cationic surfactant and the graphene oxide are combined together to be used as a filler to be added into the epoxy resin, so that the respective advantages can be fully exerted, the hydrophobic property of the epoxy resin coating is endowed, and the corrosion resistance of the epoxy resin can be effectively improved.

According to the method, based on the idea of fully utilizing the strong hydrophobic property of the Schiff base cationic surfactant and the high corrosion resistance of oxidized graphene, the Schiff base cationic surfactant/GO composite material is prepared by a graft blending method and added into an epoxy resin coating, and the Schiff base cationic surfactant/GO hydrophobic coating is prepared on the surface of carbon steel.

Disclosure of Invention

The purpose of the invention is as follows: epoxy resin coating is a good anticorrosive coating as an organic coating, but since epoxy coating easily causes some micro-pores during curing, and there are always some voids between polymer chains. The application provides that the Schiff base cationic surfactant/GO composite material is prepared by means of good hydrophobic property of the Schiff base cationic surfactant and high anti-corrosion property of GO, and the composite material is added into epoxy resin as a filler, so that the hydrophobic property of an epoxy coating is endowed, and the corrosion resistance of the epoxy resin is further improved.

The invention idea is as follows: the Schiff base cationic surfactant is prepared from ethanolamine, 4-dimethylaminobenzaldehyde and dodecyl bromide serving as raw materials, wherein the dodecyl bromide gives a long hydrophobic chain to a product, so that the Schiff base cationic surfactant has a corrosion inhibition performance and a good hydrophobic performance, and the reaction formula is as follows:

the nano Graphene Oxide (GO) can fill up the gap of the organic coating and has barrier property to corrosive media. The surface of the nano Graphene Oxide (GO) has rich carboxyl, and the reaction formula shows that hydroxyl exists in the structure of the Schiff base cationic surfactant, so that the Schiff base cationic surfactant can be connected to the Graphene Oxide (GO) by a grafting method to form a corrosion-resistant composite material with strong hydrophobic property, and the reaction formula is as follows:

the application provides a preparation scheme of a Schiff base cationic surfactant/GO hydrophobic coating, which mainly comprises the following contents:

a Schiff base cationic surfactant/GO hydrophobic coating is characterized by comprising a Schiff base cationic surfactant/GO composite material and an epoxy resin matrix.

The Schiff base cationic surfactant/GO hydrophobic coating is characterized by comprising 0.01g of Schiff base cationic surfactant/GO composite material added into 2g of epoxy resin in parts by mass.

The Schiff base cationic surfactant/GO hydrophobic coating is characterized in that the preparation method of the Schiff base cationic surfactant/GO composite material comprises the following steps: 0.6108g of ethanolamine and 1.4919g of 4-dimethylaminobenzaldehyde are accurately weighed and dissolved in 20mL of ethanol, 0.15mL of glacial acetic acid is added as a catalyst, the mixture is stirred and reacted for 5 hours at 70 ℃, the ethanol solvent is distilled out under reduced pressure after the reaction is finished, the ethyl acetate is used for recrystallization, and finally the light yellow crystal intermediate Schiff base is obtained by vacuum drying. Accurately weighing 0.64g of Schiff base intermediate into a three-neck flask, adding 20mL of ethanol to dissolve the Schiff base intermediate, slowly dropwise adding 0.83g of dodecyl bromine under the condition of stirring, refluxing and stirring at 80 ℃ to react for 48 hours after dropwise adding, removing the ethanol solvent through reduced pressure distillation after the reaction is finished, continuously washing the product with acetone under the condition of suction filtration to remove unreacted substances, and finally performing vacuum drying on the product to obtain the orange powdery Schiff base cationic surfactant. Weighing 0.1g of Graphene Oxide (GO) in 20mL of Dimethylformamide (DMF), performing ultrasonic treatment for 40min to uniformly disperse the GO in the DMF, sequentially adding 0.3g of Schiff base cationic surfactant, 0.08g of dicyclohexylcarbodiimide and 0.009g of 4-dimethylaminopyridine, stirring and reacting the mixed solution at 60 ℃ for 6h under the protection of nitrogen, centrifuging the solution at the speed of 4000r/min for 10min after the reaction is finished, continuously washing and centrifuging a bottom product with distilled water, and finally performing vacuum drying to obtain the Schiff base cationic surfactant/GO composite material.

The Schiff base cationic surfactant/GO hydrophobic coating is characterized in that the preparation method of the Schiff base cationic surfactant/GO hydrophobic coating comprises the following steps: using 4X 1.3X 0.2cm³The carbon steel test piece is used as a base material of the anti-corrosion coating, 0.01g of Schiff base cationic surfactant/GO composite material is weighed into 1mL of acetone, ultrasonic treatment is carried out for 40min to enable the composite material to be uniformly dispersed, 1g of polyamide curing agent is added to be uniformly stirred, 1g of epoxy resin and 0.1g of defoaming agent are added to be stirred and cured for 1 h. Coating the coating on the surface of carbon steel by using a coating instrument, and curing at room temperature for 7 days to prepare the hydrophobic coating of cationic surfactant/GO with Schiff bases on the carbon steel substrate.

The coating obtained by the preparation method has hydrophobic performance, and has more excellent corrosion resistance compared with a pure epoxy resin coating.

Drawings

FIG. 1 Infrared Spectroscopy of Schiff base cationic surfactant

FIG. 2 mass spectrum of Schiff base cationic surfactant

FIG. 3 Schiff base cationic surfactant/GO infrared spectrum

FIG. 4 is a contact angle diagram of the coating, wherein (a) the epoxy coating; (b) the method comprises the following steps GO epoxy coating.

FIG. 5 A.C. impedance spectrum of the coating

Detailed Description

The following examples are further illustrative of the present invention and are not intended to be limiting thereof.

Example 1.

1 preparation method of Schiff base cationic surfactant:

accurately weighing 0.6108g of ethanolamine and 1.4919g of 4-dimethylaminobenzaldehyde in a round bottom flask, dissolving the ethanolamine and the 4-dimethylaminobenzaldehyde in 20mL of ethanol, adding 0.15mL of glacial acetic acid as a catalyst, stirring and reacting at 70 ℃ for 5h, distilling the ethanol solvent under reduced pressure after the reaction is finished, separating out a precipitate, performing recrystallization purification by using ethyl acetate, performing vacuum drying on the recrystallized precipitate, and finally obtaining a light yellow crystal intermediate 4-dimethylaminobenzaldehyde ethanolamine Schiff base;

accurately weighing 0.64g of the 4-dimethylaminobenzaldehyde ethanolamine Schiff base intermediate prepared in the step (1) in a three-neck flask, adding 20mL of ethanol to dissolve the intermediate, slowly dropwise adding 0.83g of dodecyl bromide under stirring, refluxing and stirring at 80 ℃ after dropwise adding is finished, reacting for 48 hours, distilling under reduced pressure after the reaction is finished to evaporate ethanol solvent, precipitating, performing suction filtration, washing with acetone to remove unreacted substances, repeating for 5 times, and finally performing vacuum drying on the precipitate to obtain the orange powdery Schiff base cationic surfactant.

2. The method for preparing the Schiff base cationic surfactant/GO composite material comprises the following steps: weighing 0.1g of graphene oxide GO in 20mL of dimethylformamide DMF, performing ultrasonic treatment for 40min to uniformly disperse GO in DMF, sequentially adding 0.3g of Schiff base cationic surfactant obtained in the step (2), 0.08g of dicyclohexylcarbodiimide and 0.009g of 4-dimethylaminopyridine, stirring and reacting the mixed solution for 6h at 60 ℃ under the protection of nitrogen, performing centrifugal separation on the solution for 10min after the reaction is finished, controlling the rotating speed of the centrifugal machine at 4000r/min, washing the precipitate with distilled water, performing centrifugation again, repeating for 5 times, and finally performing vacuum drying to obtain the Schiff base cationic surfactant/GO composite material.

3 method of preparing schiff base cationic surfactant/GO coating: using 4X 1.3X 0.2cm³The preparation method comprises the following steps of taking a carbon steel test piece as a base material of a hydrophobic coating, weighing 0.01g of prepared Schiff base cationic surfactant/GO composite material in 1mL of acetone, carrying out ultrasonic treatment for 40min to uniformly disperse the composite material, adding 1g of polyamide curing agent, stirring uniformly, adding 1g of epoxy resin and 0.1g of defoaming agent, stirring, curing for 1h, coating the coating on the surface of the carbon steel by using a coating instrument, and curing at room temperature for 7 days to prepare the Schiff base cationic surfactant/GO coating on the carbon steel base material.

4 Schiff base cationic surfactant/GO infrared spectroscopic analysis

FIG. 1 is an infrared spectrum of Schiff base cationic surfactant 3319cm^-1Is the stretching vibration peak of hydroxyl, 2952cm^-1And 2861cm^-1Are respectively-CH₃and-CH₂Peak of stretching vibration of-1650 cm^-1Is the stretching vibration peak of Schiff base, 1598cm^-1Is the stretching vibration peak of benzene ring skeleton, 1191cm^-1Is the C-N stretching vibration peak; FIG. 3 is the infrared spectrum of Schiff base cationic surfactant/GO, 3157 cm^-1Is the stretching vibration peak of hydroxyl in graphene oxide, 2923cm^-1And 2846cm^-1Are respectively-CH₃and-CH₂Peak of stretching vibration of-1621 cm^-1Is the stretching vibration peak of the Schiff base.

5. Schiff base cationic surfactant/GO coating performance analysis

Fig. 4 is a contact angle graph of the coating, and it can be seen from fig. 4b that the addition of the schiff base cationic surfactant/GO significantly improves the hydrophobic property of the epoxy resin coating, and the contact angle of the blank epoxy resin coating is 66 °, the contact angle of the epoxy resin coating to which the graphene oxide is added is 70 °, and the contact angle of the schiff base cationic surfactant/GO hydrophobic coating is 91.5 °, as measured by a throughput angle method.

Fig. 5 is an electrochemical alternating current impedance diagram of the coating, and it can be seen from the diagram that the capacitive arc radius of the schiff base cationic surfactant/GO hydrophobic coating is far larger than that of the blank epoxy resin coating, which indicates that the impedance value of the schiff base cationic surfactant/GO hydrophobic coating is far larger than that of the blank epoxy resin coating, and the schiff base cationic surfactant/GO hydrophobic coating shows more excellent corrosion inhibition performance.