Polyaniline-coated plasma modified basalt material and preparation method of anticorrosive coating of polyaniline-coated plasma modified basalt material

Abstract

The invention relates to a polyaniline-coated plasma modified basalt material and a preparation method of an anticorrosive coating of the polyaniline-coated plasma modified basalt material. The preparation method comprises the following steps: firstly, adding basalt flakes and an H2O2 aqueous solution into a ball-milling tank, mixing, sealing, and putting into a plasma ball mill; vacuumizing to a vacuum state, introducing mixed gas of oxygen and argon, and then vacuumizing to 100pa; after modification, washing, centrifuging and drying to obtain plasma modified basalt scales; secondly, uniformly mixing aniline and KH550 grafted plasma modified basalt scales in the composite functional reagent solution to obtain a solution A; ultrasonically dissolving copper chloride and ammonium persulfate in deionized water to obtain a solution B; placing the solution A and the solution B in a 0 DEG C ice bath for 30 minutes, adding the solution B into the solution A, and stirring and reacting at 0 DEG C; and after the reaction is finished, washing, centrifuging and drying to obtain the PMB-coated Mo material. And finally, dispersing PMB-coated Mo in an epoxy resin / solvent system, and adding a polyamide curing agent to prepare the anticorrosive coating. The invention provides a new insight for the preparation of the long-acting protective coating.

Description

Technical Field

[0001] The present invention relates to the technical field of functional anti-corrosion coatings, and in particular to a polyaniline-coated plasma-modified basalt material and a preparation method of the anti-corrosion coating thereof. Background Art

[0002] Metal corrosion remains a pressing engineering challenge worldwide, causing significant economic losses and posing a threat to the safety of equipment operations. Currently, organic coatings are widely considered one of the most effective methods for preventing metal corrosion. However, traditional organic coatings are limited by their single barrier protection and are unable to effectively inhibit the penetration and diffusion of corrosive media, resulting in a gradual decline in the coating's corrosion resistance. Therefore, there is an urgent need to develop a new organic coating with long-lasting corrosion resistance to enhance the service stability and service life of metal materials in complex environments.

[0003] Basalt flakes are widely used in the corrosion protection field due to their abundant resources, excellent chemical resistance, thermal stability, and insulating properties. Incorporating basalt flakes into organic coatings effectively prolongs the penetration path of corrosive media within the coating, thereby enhancing the coating's shielding properties. However, due to the poor interfacial compatibility between the relatively smooth basalt flakes and the resin, they are prone to agglomeration and sedimentation, which in turn creates microscopic defects in the coating, significantly weakening its protective effectiveness. Consequently, much research has focused on modifying basalt flakes to enhance their protective properties.

[0004] By modifying basalt flakes with conductive polymers, the corrosion resistance of the coating can be effectively enhanced. Polyaniline, due to its excellent conductivity and unique redox properties, can induce the formation of a dense oxide film on easily passivated metal surfaces, thereby providing anodic protection for the metal substrate. However, polyaniline composite coatings still face many challenges in practical applications. First, polyaniline easily agglomerates in the resin, leading to the formation of microscopic defects within the coating and weakening its shielding properties. Second, the disordered dispersion of polyaniline in the insulating organic coating limits its passivation effect on the metal surface. Finally, polyaniline also faces the problem of gradually decreasing redox activity and stability during the passivation process. Summary of the Invention

[0005] In order to achieve the above objectives, the present invention proposes a method for preparing a polyaniline-coated plasma-modified basalt material and an anti-corrosion coating thereof. The specific scheme is as follows:

[0006] A method for preparing a polyaniline-coated plasma-modified basalt material comprises the following steps:

[0007] Step 1: Preparation of plasma-modified basalt flakes

[0008] Basalt flakes and H2O2 aqueous solution are added to a ball mill jar and mixed, which is then sealed and placed in a plasma ball mill. Before modification, the jar is evacuated to a vacuum state using a vacuum pump, and then a mixed gas of oxygen and argon is introduced, and then the jar is evacuated again to 100±2Pa using a vacuum pump. After modification at a set power and speed, the basalt flakes are washed with deionized water, centrifuged, and vacuum-dried at 60±2°C to obtain plasma-modified basalt flakes.

[0009] Step 2: Preparation of polyaniline-coated plasma-modified basalt flakes, referred to as PMB@Mo

[0010] (1) adding the plasma-modified basalt flakes obtained in step 1 to a mixed solution of alcohol and deionized water containing a KH550 silane coupling agent, placing the mixture in an oil bath at 80±2°C with magnetic stirring for 3 hours, washing with deionized water and alcohol, centrifuging, and vacuum drying at 60±2°C to obtain KH550 grafted plasma-modified basalt flakes;

[0011] (2) ultrasonically dissolving the composite functional reagent in deionized water, mixing aniline and KH550 grafted plasma-modified basalt flakes in the composite functional reagent solution, and magnetically stirring for 30 min to obtain solution A;

[0012] (3) Ultrasonic dissolution of copper chloride and ammonium persulfate in deionized water to obtain solution B;

[0013] (4) Solution A and solution B were placed in an ice bath at 0°C for 30 min, and then solution B was added to solution A. The mixture was magnetically stirred in an ice bath at 0±1°C under inert gas protection for 24±0.5 h. After the reaction was completed, the mixture was washed with deionized water and alcohol, centrifuged, and freeze-dried to obtain PMB@Mo material.

[0014] The method for preparing a polyaniline-coated plasma-modified basalt material preferably comprises the following steps: in step 1, the concentration of the H2O2 aqueous solution is 0.1-0.3 mol / L, the weight ratio of basalt flakes to the H2O2 aqueous solution is 1:1-10, and the flow rate ratio of oxygen to argon is 1:1-4.

[0015] The preferred embodiment of the method for preparing a polyaniline-coated plasma-modified basalt material is as follows: in step 1, a vacuum pump pumps the pressure in the tank to 100±2Pa; and the basalt flakes are modified for 20-60 minutes at a set plasma power of 300-600W and a rotation speed of 500-1500r / min.

[0016] The method for preparing a polyaniline-coated plasma-modified basalt material, preferably, in step (2), the composite functional reagent includes 0.005-0.03 mol / L of 5-sulfosalicylic acid, 0.05-0.1 mol / L of polyvinylpyrrolidone, and 0.005-0.02 mol / L of sodium molybdate dihydrate.

[0017] The preferred embodiment of the method for preparing the polyaniline-coated plasma-modified basalt material is that in step (2), the mass ratio of aniline to KH550 grafted flakes is 1:1-6.

[0018] The preferred embodiment of the method for preparing the polyaniline-coated plasma-modified basalt material is characterized in that in step 2 (3), the concentration ratio of copper chloride, ammonium persulfate and aniline is 5-10:1-2:10.

[0019] An anti-corrosion coating of polyaniline-coated plasma-modified basalt material, prepared by the following method:

[0020] Step 1: Dissolve 20 g of epoxy resin (E44) in an organic solvent containing 40 ± 2 wt% of epoxy resin and stir magnetically for 15 min.

[0021] Step 2: adding 30±2 wt% of PMB@Mo to the total mass of epoxy resin and polyamide curing agent (650), ultrasonically dispersing at 40±5°C for 60±5 min and then magnetically stirring for 3 h to obtain a dispersed PMB@Mo epoxy resin coating;

[0022] Step 3: Add 80±2 wt% of the curing agent to the PMB@Mo epoxy resin coating dispersed in step 2, slowly and evenly stir with a magnetic stirrer for 20±2 min, and then ultrasonically treat at a temperature of 15±5°C for 30±2 min;

[0023] Step 4: The obtained coating is applied to the pretreated aluminum alloy surface, and after curing, a PMB@Mo coating with a thickness of 120±3 μm is formed.

[0024] The preferred embodiment of the polyaniline-coated plasma-modified basalt anti-corrosion coating is that, in step 1, the organic solvent is xylene and n-butanol mixed in a mass ratio of 28:12.

[0025] Beneficial effects

[0026] The surface of basalt flakes was hydroxylated using plasma, effectively increasing the number of hydroxyl groups on the surface of the basalt flakes. Subsequently, KH550 was used as a bridging agent to ensure that the multifunctional filler of sodium molybdate encapsulated in orderly distributed polyaniline capsules was polymerized on the surface of the plasma-modified basalt flakes.

[0027] By adding PMB@Mo to epoxy resin, spherical polyaniline is introduced for the first time onto the surface of two-dimensional lamellar basalt flakes, which solves the problem of poor compatibility between traditional basalt flakes and epoxy resin and greatly improves the anti-corrosion performance of the coating. The polyaniline evenly dispersed on the surface of the basalt flakes avoids the agglomeration of polyaniline. In addition, the evenly distributed polyaniline can shorten the charge transfer distance, ensure that each polyaniline participates in the passivation reaction, and induce metal passivation to form a dense and uniform oxide film. On the one hand, the sodium molybdate inside the polyaniline can maintain the redox activity of the polyaniline; on the other hand, as the service time increases, the polyaniline at the damaged part of the coating will release sodium molybdate and Al 3+ This multifunctional material method significantly improves the anti-corrosion performance of the coating and shows broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 SEM morphologies of basalt flakes, plasma-modified basalt flakes, and PMB@Mo powder;

[0029] Among them, (a) is the SEM morphology of basalt flakes; (b) is the SEM morphology of plasma-modified basalt flakes; (c) is the SEM morphology of PMB@Mo;

[0030] Figure 2 FTIR images of basalt flakes, plasma-modified basalt flakes, polyaniline, and PMB@Mo provided in the embodiments of the present invention;

[0031] Figure 3 The cross-sectional SEM morphology of the basalt flake / epoxy resin coating in Comparative Example 1 and the PMB@Mo / epoxy resin coating in Example 1;

[0032] (a) is the cross-sectional morphology of the coating with direct addition of basalt flakes; (b) is the cross-sectional morphology of the coating with addition of PMB@Mo;

[0033] Figure 4 Nyquist and Bode plots of the scratch coatings provided in Example 1 and Comparative Example 1 when immersed in a 3.5 wt % NaCl solution for different times;

[0034] Wherein (a) is the Nyquist plot of the scratch coating with basalt flakes added in comparative example 1; (a1) is the Bode plot of the scratch coating with basalt flakes added in comparative example 1; (b) is the Nyquist plot of the scratch coating with PMB@Mo added in example 1; (b1) is the Bode plot of the scratch coating with PMB@Mo added in example 1;

[0035] Figure 5Cyclic voltammetry curves of the powders provided in Example 1, Comparative Examples 2, and 3 in a 3.5 wt % NaCl solution;

[0036] Wherein (a) is the cyclic voltammetry curve of the single polyaniline powder provided in Comparative Example 2; (b) is the cyclic voltammetry curve of the mixed powder of polyaniline and basalt flakes provided in Comparative Example 3; (c) is the cyclic voltammetry curve of the PMB@Mo powder provided in Example 1. DETAILED DESCRIPTION

[0037] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0038] Example 1

[0039] A method for preparing a polyaniline-coated plasma-modified basalt material comprises the following steps:

[0040] Step 1: Preparation of plasma-modified basalt flakes

[0041] 2.0 g of basalt flakes and a 0.2 mol / L H2O2 aqueous solution were added to a ball mill and mixed. The ball mill was sealed and placed in a plasma ball mill. Before modification, the tank was evacuated to a vacuum state using a vacuum pump, and then a mixed gas of oxygen and argon with a flow rate of 50:100 sccm / min was introduced. The tank was then evacuated to 100 Pa using a vacuum pump for a second time. The basalt flakes were modified at a power of 500 W and a speed of 1200 r / min for 30 min, washed three times with deionized water at 4000 r / min for 10 min, and dried in vacuum at 60°C for 12 h to obtain plasma-modified basalt flakes. Figure 1 The surface of the basalt flakes shown in (a) is smooth; as shown in (b), the surface of the plasma-modified flakes is also relatively smooth, indicating that the plasma-modified basalt flakes do not destroy the surface morphology of the filler;

[0042] Step 2: Preparation of polyaniline-coated plasma-modified basalt flakes, referred to as PMB@Mo

[0043] (1) adding the plasma-modified basalt flakes obtained in step 1 to a mixed solution of alcohol and deionized water containing KH550 silane coupling agent, placing the mixture in an 80°C oil bath with magnetic stirring for 3 hours, centrifuging the mixture in alcohol-deionized water at 4000 r / min for 10 minutes three times, and vacuum drying at 60°C for 12 hours to obtain KH550 grafted plasma-modified basalt flakes;

[0044] (2) 0.3 mol / L aniline and 5.2 g of KH550 grafted plasma-modified basalt flakes were mixed with 0.01 mol / L 5-sulfosalicylic acid, 0.09 mol / L polyvinylpyrrolidone, and 0.01 mol / L sodium molybdate dihydrate in 25 mL of deionized water and stirred magnetically for 30 min to obtain solution A;

[0045] (3) Ultrasonic dissolution of a mixture of 0.05 mol / L copper chloride, 0.3 mol / L ammonium persulfate, and aniline in 25 mL of deionized water to obtain solution B;

[0046] (4) Solution A and solution B were placed in an ice bath at 0°C for 30 min, and then solution B was added to solution A. The mixture was stirred magnetically in an ice bath at 0°C under inert gas protection for 24 h. After the reaction was completed, the mixture was washed alternately with deionized water and alcohol three times. The mixture was centrifuged and freeze-dried at -50°C for 24 h to obtain the PMB@Mo material.

[0047] like Figure 1 As shown in (c), polyaniline is evenly and orderly coated on the surface of basalt flakes.

[0048] like Figure 2 As shown, basalt scales are present at 1018 cm -1 Represents the asymmetric stretching vibration of Si-O-Si. After plasma modification, at 3441cm -1 There is a more obvious hydroxyl stretching vibration peak at 1575cm, indicating that plasma modification can endow the basalt flake surface with a large number of hydroxyl groups. -1 and 1493cm -1 1304cm-1 is attributed to the stretching vibration of the quinone structure and the benzene structure. -1 The peak at 1142 cm is related to the stretching of aromatic secondary amines. -1 The peak at 1018 cm is attributed to the vibration of the polyaniline quinone ring structure. -1 represents the asymmetric stretching vibration of Si-O-Si in basalt flakes, indicating that polyaniline has been successfully coated on the surface of basalt flakes. In addition, 850 cm -1 This indicates that sodium molybdate has been successfully adsorbed inside the polyaniline hollow balloon.

[0049] A method for preparing an anti-corrosion coating of polyaniline-coated plasma-modified basalt material, the preparation method is as follows:

[0050] Step 1: 20g of epoxy resin and 8g of organic solvent (xylene:n-butanol = 28:12) were magnetically stirred for 15min;

[0051] Step 2: 10.8 g of PMB@Mo was added to epoxy resin, ultrasonically dispersed at 40 °C for 60 min, and then magnetically stirred for 3 h to obtain a dispersed PMB@Mo epoxy resin coating;

[0052] Step 3: Add 16 g of curing agent to the PMB@Mo epoxy resin coating dispersed in step 2, stir slowly and evenly with a magnetic stirrer for 20 minutes, and then ultrasonically treat at a temperature of 15°C for 30 minutes;

[0053] Step 4: Apply the obtained coating to the pretreated aluminum alloy surface and form a coating with a thickness of 120±3 μm after curing at room temperature for 7 days.

[0054] Examples and Comparative Examples

[0055] Comparative Example 1

[0056] This comparative example provides an epoxy resin coating with only basalt flakes added, and the specific preparation method is as follows: dissolve 20g of epoxy resin in a 40wt.% xylene / n-butanol = 28:12 mixed organic solvent and magnetically stir for 15min; take 8.64g of basalt flakes and add them to the epoxy resin, ultrasonicate for 1h and then magnetically stir for 3h to obtain a dispersed basalt flake epoxy resin coating; take 16g of curing agent and add it to the above mixture, slowly magnetically stir it evenly, and ultrasonicate it at 15°C for 30min, apply the prepared coating to the pretreated aluminum alloy, and obtain a coating of about 120μm after curing.

[0057] Comparison of Example 1 and Comparative Example 1: Figure 3 As shown in (a), after adding basalt flakes directly, obvious defects can be observed in the cross section of the basalt flake / epoxy coating. Figure 3 The PMB@Mo shown in (b) is more tightly bonded to the epoxy resin.

[0058] like Figure 4 As shown in (a)(a1), for the basalt flake / epoxy coating, the capacitance arc radius decreases gradually, |Z| 0.01Hz From 7.40×10 6 Ω·cm 2 Down to 1.51×10 6 Ω·cm 2 , indicating that the protective effect is gradually lost. In contrast, Figure 4 In (b) (b1), after adding PMB@Mo into epoxy resin, the capacitor arc radius gradually increases, |Z| 0.01Hz From 1.60×10 7 Ω·cm 2 Increased to 4.35×10 7 Ω·cm2 , which indicates that the introduction of PMB@Mo endows the epoxy resin coating with passivation and self-healing properties.

[0059] Comparative Example 2

[0060] This comparative example provides a method of adding only an equivalent amount of polyaniline powder as an electrode material to test a cyclic voltammetry curve.

[0061] Comparative Example 3

[0062] This comparative example provides a mixed powder of polyaniline and basalt flakes added in an equivalent amount as an electrode material to test a cyclic voltammetry curve.

[0063] like Figure 5 As shown, compared with the two powders of Comparative Examples 2 and 3 in Example 1, the cyclic voltammetry curve of the PMB@Mo powder shows a higher peak current.

[0064] In addition, as the redox process proceeds, the peak current decreases slowly after the 10th cycle, indicating that the introduction of sodium molybdate can enhance the redox ability and stability of polyaniline.

[0065] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing polyaniline-coated plasma-modified basalt material, characterized in that: The following steps are involved: Step 1: Preparation of plasma-modified basalt flakes Basalt flakes and H2O2 aqueous solution are added to a ball mill jar and mixed, which is then sealed and placed in a plasma ball mill. Before modification, the jar is evacuated to a vacuum state using a vacuum pump, and then a mixed gas of oxygen and argon is introduced, and then the jar is evacuated again to 100±2Pa using a vacuum pump. After modification at a set power and speed, the basalt flakes are washed with deionized water, centrifuged, and vacuum-dried at 60±2°C to obtain plasma-modified basalt flakes. Step 2: Preparation of polyaniline-coated plasma-modified basalt flakes, referred to as PMB@Mo (1) adding the plasma-modified basalt flakes obtained in step 1 to a mixed solution of alcohol and deionized water containing a KH550 silane coupling agent, placing the mixture in an oil bath at 80±2°C with magnetic stirring for 3 hours, washing with deionized water and alcohol, centrifuging, and vacuum drying at 60±2°C to obtain KH550 grafted plasma-modified basalt flakes; (2) ultrasonically dissolving the composite functional reagent in deionized water, mixing aniline and KH550 grafted plasma-modified basalt flakes in the composite functional reagent solution, and magnetically stirring for 30 min to obtain solution A; (3) Ultrasonic dissolution of copper chloride and ammonium persulfate in deionized water to obtain solution B; (4) Solution A and solution B were placed in an ice bath at 0°C for 30 min, and then solution B was added to solution A. The mixture was magnetically stirred in an ice bath at 0±1°C under inert gas protection for 24±0.5 h. After the reaction was completed, the mixture was washed with deionized water and alcohol, centrifuged, and freeze-dried to obtain PMB@Mo material.

2. The method for preparing a polyaniline-coated plasma-modified basalt material as claimed in claim 1, characterized in that: In step 1, the concentration of the H2O2 aqueous solution is 0.1-0.3 mol / L, the weight ratio of basalt flakes to the H2O2 aqueous solution is 1:1-10, and the flow rate ratio of oxygen to argon is 1:1-4.

3. The method for preparing a polyaniline-coated plasma-modified basalt material as claimed in claim 1, characterized in that: In step 1, the basalt flakes are modified for 20-60 minutes at a plasma power of 300-600 W and a rotation speed of 500-1500 r / min.

4. The method for preparing a polyaniline-coated plasma-modified basalt material as claimed in claim 1, wherein: In step 2 (2), the composite functional reagent includes 0.005-0.03 mol / L of 5-sulfosalicylic acid, 0.05-0.1 mol / L of polyvinylpyrrolidone, and 0.005-0.02 mol / L of sodium molybdate dihydrate.

5. The method for preparing a polyaniline-coated plasma-modified basalt material as claimed in claim 1, characterized in that: In step 2 (2), the mass ratio of aniline to KH550 grafted flakes is 1:1-6.

6. The method for preparing a polyaniline-coated plasma-modified basalt material as claimed in claim 1, characterized in that: In step 2 (3), the concentration ratio of copper chloride, ammonium persulfate and aniline is 5-10:1-2:

10.

7. A method for preparing an anti-corrosion coating of polyaniline-coated plasma-modified basalt material according to any one of claims 1 to 6, characterized in that: The preparation method is as follows: Step 1: Dissolve 20 g of epoxy resin (E44) in an organic solvent containing 40 ± 2 wt% of epoxy resin and stir magnetically for 15 min. Step 2: adding 30±2 wt% of PMB@Mo to the total mass of epoxy resin and polyamide curing agent (650), ultrasonically dispersing at 40±5°C for 60±5 min and then magnetically stirring for 3 h to obtain a dispersed PMB@Mo epoxy resin coating; Step 3: Add 80±2 wt% of the curing agent to the PMB@Mo epoxy resin coating dispersed in step 2, slowly and evenly stir with a magnetic stirrer for 20±2 min, and then ultrasonically treat at a temperature of 15±5°C for 30±2 min; Step 4: Apply the obtained coating to the pretreated aluminum alloy surface, and after curing, form a PMB@Mo coating with a thickness of 120±3 μm.

8. The method for preparing an anti-corrosion coating of polyaniline-coated plasma-modified basalt material according to claim 6, characterized in that: In step 1, the organic solvent is xylene and n-butanol mixed in a mass ratio of 28:12.

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