Anticorrosive functional composite filler, preparation method and application

Abstract

The application discloses a kind of anticorrosion functional composite fillers, preparation method and application, preparation method includes: respectively with fly ash, lamellar material as main filler, it is uniformly mixed with aniline, oxidizing agent, metal ion dopant, acid dopant, ethanol and water, after a certain time of reaction, functional fly ash filler and functional lamellar filler are prepared;Functional fly ash filler and functional lamellar filler are prepared under the action of chemical modifier and have long-acting anticorrosion filler with specific orientation.The application adopts the above-mentioned anticorrosion functional composite filler, preparation method and application, fly ash, lamellar material, metal oxide are compounded into functional filler with long-acting corrosion inhibition effect, and it is applied to water-based paint system, and excellent shielding performance and catalytic passivation activity are given to coating.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of coating technology, in particular to a corrosion-resistant functional composite filler, a preparation method and application. BACKGROUND

[0002] Coating protection technology is an effective means to slow down the corrosion of metals, but there are often some pore defects in the coating, making it difficult to block harsh corrosive media. With the improvement of environmental protection requirements, solvent-based coatings are gradually changing to water-based coatings, and these pore defects are more obvious in water-based coatings, which puts higher requirements on corrosion-resistant fillers.

[0003] In the coating, the uniform dispersion of fillers is the basic guarantee for the excellent shielding performance of the coating. In conventional coating systems, dispersing aids are often added to the formulation to improve their dispersion, which may result in gaps between the filler and the coating matrix interface. In addition, the micro-morphology and compactness of the filler are also factors that affect the shielding performance of the coating, such as the obvious barrier advantage of lamellar materials compared to other fillers, and the structure of dense fillers can enhance the impermeability of the coating.

[0004] The internal dense micro-bead structure of fly ash is beneficial to the shielding performance of the coating. In addition, fly ash has potential pozzolanic activity, making it widely used in the field of concrete.

[0005] A kind of alkali-activated slag / fly ash steel surface corrosion-resistant coating and its preparation method (application number: 201710896943.0), sodium water glass is used as alkali activator to activate the pozzolanic activity of fly ash, and the bonding force and corrosion resistance of steel are improved by enhancing the cementitious properties of fly ash and concrete. However, the preparation method does not use the improved shielding performance of fly ash to achieve excellent corrosion resistance, and the alkali activation process may damage the dense structure of fly ash, thereby reducing the corrosion resistance, which is very disadvantageous to the metal protection process.

[0006] The corrosion inhibition properties of the coating are very important at the interface between the coating and the substrate. A kind of nitrogen-containing carbon quantum dots / polyaniline modified epoxy anticorrosive coating (application number: 202210283928.X) achieves corrosion resistance through passivation effect, and the composite filler prepared has conductivity, which makes the addition amount in the coating cannot be too high, which is not conducive to the barrier performance of the coating. In addition, this process only composites two fillers with corrosion inhibition effect, and does not improve the performance of the corrosion-resistant filler, and the polyaniline in the composite filler is still a conventional catalytic passivation corrosion mechanism.

[0007] In summary, the existing publicly disclosed fly ash-based corrosion-resistant filler and corrosion-inhibiting functional composite filler technology cannot simultaneously solve the problems of insufficient corrosion shielding performance and rust prevention performance of conventional coatings. SUMMARY

[0008] The application aims to provide an anticorrosion functional composite filler, a preparation method and an application, so as to solve the problem that the conventional coating cannot simultaneously solve the insufficient corrosion shielding performance and rust prevention performance of the conventional coating.

[0009] To achieve the above-mentioned purpose, the application provides an anticorrosion functional composite filler, which comprises, in terms of weight fraction, fly ash 300-500 parts, sheet material 50-300 parts, metal ion dopant 20-50 parts, acid dopant 20-50 parts, aniline 30-80 parts, oxidizing agent 50-150 parts, and chemical modifier 20-60 parts.

[0010] Preferably, the sheet material is one or more of graphene, graphene oxide, mica, and glass flake.

[0011] Preferably, the metal ion dopant is one or more of ferric nitrate, cerium nitrate, and ferric chloride.

[0012] Preferably, the acid dopant is one or more of phosphoric acid, perfluorooctanoic acid, rosemary acid, tannic acid, and ethylenediaminetetraacetic acid.

[0013] Preferably, the oxidizing agent is one or more of ammonium persulfate, hydrogen peroxide, potassium iodate, and potassium chromate.

[0014] Preferably, the chemical modifier is one or more of dopamine hydrochloride, gamma-aminopropyl triethoxysilane, gamma-(2,3-epoxypropoxy)propyl trimethoxysilane, and gamma-mercaptopropyl triethoxysilane.

[0015] A preparation method of the anticorrosion functional composite filler as described above, comprising the following steps:

[0016] S1, according to the mass ratio of fly ash: anhydrous ethanol: deionized water = 18-50:10-18:2-15, the fly ash is dispersed into the anhydrous ethanol solution and the deionized water, and then aniline, an oxidizing agent, a metal ion dopant, and an acid dopant are sequentially added, so as to polymerize a layer of polyaniline-metal oxide structure on the surface of the fly ash under the action of ultrasonic assistance and mechanical stirring, thereby obtaining a functionalized fly ash filler.

[0017] S2, according to the mass ratio of sheet material: anhydrous ethanol: deionized water = 5-30:3-5:1-16, the sheet material is dispersed into the anhydrous ethanol solution and the deionized water, and then aniline, an oxidizing agent, a metal ion dopant, and an acid dopant are sequentially added, so as to polymerize a layer of polyaniline-metal oxide structure on the surface of the sheet material under the action of ultrasonic assistance and mechanical stirring, thereby obtaining a functionalized sheet filler.

[0018] S3, according to the mass ratio of functionalized fly ash filler: functionalized sheet filler: anhydrous ethanol: deionized water = 1-24:4-20:5-15:1-12, the functionalized fly ash filler, the functionalized sheet filler, the chemical modifier, the anhydrous ethanol and the deionized water are uniformly mixed and then put into a star type ball mill, and the chemical modifier is used for compounding under the action of centrifugal force to obtain the anticorrosion functional composite filler.

[0019] In the above-mentioned poly aniline-metal oxide composite structure layer, the poly aniline promotes the Fe element in the anode reaction area to lose electrons to form a passivation film (γ-Fe2O3), avoiding the generation of loose porous rust (α-Fe2O3). The metal oxide converts the oxygen molecules in the system into active oxygen atoms to promote the formation of the passivation film.

[0020] The conductive polymer-metal oxide is composed of poly aniline with substrate passivation effect and metal oxide with oxygen transmission effect, and a large number of cations with corrosion inhibition effect are loaded. The poly aniline is a P-type semiconductor, and the metal oxide is an N-type, and the two types of substances form a heterojunction that improves the respective corrosion inhibition characteristics. The heterojunction strengthens the anode protection behavior of the poly aniline structure to the metal, and also improves the oxygen storage and transmission capacity of the metal oxide. In the polymerization process, the acid anions with metal ion chelation effect and hydrophobic shielding effect are loaded in the functional filler through doping by an acid dopant, so that the fly ash and sheet material with only shielding effect obtain the ability to passivate the metal substrate and the oxygen transmission capacity, and the anticorrosion performance of the filler is strengthened.

[0021] The functionalized fly ash filler and the functionalized sheet filler are compounded by centrifugal force and chemical adhesion to prepare an anticorrosion functional composite filler with a specific structure, which provides excellent shielding performance for the coating.

[0022] In the above-mentioned poly aniline-metal oxide composite structure layer, the poly aniline promotes the Fe element in the anode reaction area to lose electrons to form a passivation film (γ-Fe2O3), avoiding the generation of loose porous rust (α-Fe2O3). The metal oxide converts the oxygen molecules in the system into active oxygen atoms to promote the formation of the passivation film.

[0023] The above-mentioned metal oxide is formed by a metal ion dopant under the action of an oxidant, which is a composite structure coexisting with metal ions and metal oxides. The metal ion participates in the passivation reaction of the substrate, and the metal oxide processes the oxygen in the corrosion environment.

[0024] In view of the incomplete passivation effect of the existing poly aniline filler, a metal ion dopant and an acid dopant are used to strengthen the passivation effect of the poly aniline structure.

[0025] Ordinary polyaniline is promoted to lose electrons quickly by the fast electron gain and loss of the doping-dedoping process, which promotes Fe element to lose electrons quickly, so as to form dense gamma-Fe2O3, thereby achieving the effect of protecting the underlying metal, but it has no protection effect on the cathode area.

[0026] After being doped by metal ions, the metal ions free in the system are combined with active oxygen in the system to form corresponding metal oxides outside the anode area of the substrate, thereby enhancing the passivation area. In addition, the acid dopant loads the acid anions with iron ion chelation and complex passivation effects in the composite structure, at this time, a passivation layer with iron ion chelation product is formed on the surface of the substrate.

[0027] The acid anions in the acid dopant can also be organic acids with hydrophobic effect, which provide a hydrophobic shielding layer for the functional composite filler and strengthen the shielding performance of the filler.

[0028] A water-based anticorrosion functional coating, comprising: the above-mentioned anticorrosion functional composite filler 30-60 parts, propylene glycol methyl ether 10-20 parts, deionized water 20-30 parts, resin 50-100 parts, curing agent 30-60 parts.

[0029] Preferably, the resin is one or more of a water-based epoxy emulsion, a water-based polyurethane, and a water-based acrylic resin.

[0030] Preferably, the curing agent is one or more of an isocyanate, a fatty amine curing agent, and a polyamide curing agent.

[0031] Therefore, the present application adopts the above-mentioned anticorrosion functional composite filler, preparation method and application, and has the following technical effects:

[0032] (1) The fly ash, sheet material and metal oxide are compounded into a functional filler with long-term corrosion inhibition effect, and are applied to the water-based coating system to endow the coating with excellent shielding performance and catalytic passivation activity.

[0033] (2) For the shielding performance, the glass microsphere shape and sheet structure in the fly ash are compounded, which improves the impermeability of the coating; in addition, the hydrophobic acid anions in the composite filler construct an effective hydrophobic network in the filler, which further strengthens the shielding effect of the filler.

[0034] (3) For passivation performance, a layer of polyaniline-metal oxide structure layer is polymerized on the surface of the composite filler, which endows the filler with excellent anodic passivation and catalytic passivation; the doping-dedoping process of polyaniline itself promotes the formation of a dense passivation film on the bottom of the substrate; the metal oxide can convert oxygen molecules in the system into active oxygen atoms, and through catalysis, it promotes the formation of a passivation film on the bottom of the substrate; the heterojunction structure formed by polyaniline and metal oxide effectively improves the inhibition behavior of the filler to metal corrosion; with the help of the doping mechanism of polyaniline, metal cations and acid anions are doped into the functional filler, the metal cations promote the formation of a passivation film, and the acid anions slow down the corrosion of the underlying metal through chelation / complexation with iron ions. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 EIS test spectrum of the sample prepared by the anticorrosive coating in application example one after immersion for 30 days, wherein part (a) is a Nyquist plot, and part (b) is a Bode plot;

[0036] Figure 2 EIS test spectrum of the sample prepared by the anticorrosive coating in application example two after immersion for 30 days, wherein part (a) is a Nyquist plot, and part (b) is a Bode plot;

[0037] Figure 3 EIS test spectrum of the sample prepared by the anticorrosive coating in application comparative example one after immersion for 30 days, wherein part (a) is a Nyquist plot, and part (b) is a Bode plot;

[0038] Figure 4 EIS test spectrum of the sample prepared by the anticorrosive coating in application comparative example two after immersion for 30 days, wherein part (a) is a Nyquist plot, and part (b) is a Bode plot;

[0039] Figure 5 EIS test spectrum of the sample prepared by the anticorrosive coating in application comparative example three after immersion for 30 days, wherein part (a) is a Nyquist plot, and part (b) is a Bode plot. DETAILED DESCRIPTION

[0040] The technical solutions of the present application are further described below by means of the drawings and examples.

[0041] Unless otherwise defined, the technical terms or scientific terms used in the present application shall have the usual meanings understood by those skilled in the art to which the present application belongs.

[0042] Example one

[0043] An anticorrosive functional composite filler is prepared by the following method:

[0044] S1, 300 parts of fly ash, 150 parts of anhydrous ethanol solution and 50 parts of deionized water were added into a beaker, and mechanical stirring was carried out under ultrasonic action, then 50 parts of aniline, 10 parts of ferric nitrate, 10 parts of cerium nitrate, 30 parts of rosemary acid, 10 parts of tannic acid, 30 parts of ammonium persulfate were added, and the reaction was carried out at 50℃ for 6 hours, and then the functionalized fly ash filler was obtained after filtration, alcohol washing and drying.

[0045] S2, 30 parts of graphene, 20 parts of mica, 50 parts of anhydrous ethanol solution and 10 parts of deionized water were added into a beaker, and mechanical stirring was carried out under ultrasonic action, then 30 parts of aniline solution, 10 parts of perfluorooctanoic acid, 20 parts of potassium chromate were added, and the reaction was carried out at room temperature for 12 hours, and then the functionalized sheet filler was obtained after filtration, alcohol washing and freeze-drying.

[0046] S3, 20 parts of functionalized sheet filler and 20 parts of functionalized fly ash filler were placed in an alloy dispersion tank, then 5 parts of dopamine hydrochloride, 5 parts of γ-aminopropyl triethoxysilane, 10 parts of γ-(2,3-epoxypropoxy) propyl trimethoxysilane, 30 parts of anhydrous ethanol solution and 5 parts of deionized water were added, and ball milling was carried out in a planetary ball mill for 6 hours, and then the anti-corrosion functional composite filler was obtained after filtration and drying.

[0047] An aqueous anti-corrosion coating was prepared by the following method:

[0048] An aqueous anti-corrosion coating was prepared by the following method:

[0049] Example two

[0050] An anti-corrosion functional composite filler was prepared by the following method:

[0051] S1, 300 parts of fly ash, 150 parts of anhydrous ethanol solution and 50 parts of deionized water were added into a beaker, and mechanical stirring was carried out under ultrasonic action, then 50 parts of aniline, 10 parts of ferric nitrate, 10 parts of cerium nitrate, 30 parts of rosemary acid, 10 parts of tannic acid, 30 parts of ammonium persulfate were added, and the reaction was carried out at 50℃ for 6 hours, and then the functionalized fly ash filler was obtained after filtration, alcohol washing and drying.

[0052] S2, 150 parts of graphene oxide, 150 parts of glass flake, 30 parts of anhydrous ethanol solution and 160 parts of deionized water were added into a beaker, and mechanical stirring was carried out under ultrasonic action, then 50 parts of aniline solution, 30 parts of cerium nitrate, 50 parts of potassium iodate were added, and reaction was carried out at room temperature for 18 hours, and functionalized sheet filler was obtained after filtration, alcohol washing and freeze drying.

[0053] S3, 100 parts of functionalized sheet filler and 120 parts of functionalized fly ash filler were placed in an alloy dispersion tank, then 60 parts of γ-mercaptopropyl triethoxysilane, 75 parts of anhydrous ethanol and 55 parts of deionized water were added, and ball milling was carried out in a planetary ball mill for 18 hours, and then the anti-corrosion functional composite filler was obtained after filtration and drying.

[0054] An aqueous anti-corrosion coating was prepared by the following method:

[0055] In a 250 mL beaker, 50 parts of anti-corrosion functional composite filler, 60 parts of aliphatic amine curing agent, 30 parts of deionized water and 10 parts of propylene glycol methyl ether were added, and mixed uniformly to prepare an aqueous anti-corrosion coating, which was sprayed on a Q235B material steel plate to prepare an anti-corrosion coating, and the steel plate specification was 150 mm x 70 mm x 3 mm.

[0056] Example Three

[0057] An anti-corrosion functional composite filler was prepared by the following method:

[0058] S1, 180 parts of fly ash, 100 parts of anhydrous ethanol solution and 150 parts of deionized water were added into a beaker, and mechanical stirring was carried out under ultrasonic action, then 60 parts of aniline, 30 parts of cerium nitrate, 25 parts of phosphoric acid, 5 parts of rosemary acid, 5 parts of tannic acid, 5 parts of ethylenediaminetetraacetic acid, 20 parts of hydrogen peroxide and 10 parts of ammonium persulfate were added, and reaction was carried out at 50°C for 6 hours, and functionalized fly ash filler was obtained after filtration, alcohol washing and drying.

[0059] S2, 15 parts of graphene oxide, 85 parts of glass flake, 30 parts of anhydrous ethanol solution and 160 parts of deionized water were added into a beaker, and mechanical stirring was carried out under ultrasonic action, then 45 parts of aniline solution, 25 parts of cerium nitrate and 40 parts of potassium iodate were added, and reaction was carried out at room temperature for 18 hours, and functionalized sheet filler was obtained after filtration, alcohol washing and freeze drying.

[0060] S3, 50 parts of functionalized sheet filler and 25 parts of functionalized fly ash filler were placed in an alloy dispersion tank, then 20 parts of γ-mercaptopropyl triethoxysilane, 30 parts of γ-(2,3-epoxypropoxy) propyl trimethoxysilane, 25 parts of anhydrous ethanol and 35 parts of deionized water were added, and ball milling was carried out in a planetary ball mill for 12 hours, and then the anti-corrosion functional composite filler was obtained after filtration and drying.

[0061] An aqueous anticorrosive coating is prepared by the following method:

[0062] An aqueous anticorrosive coating is prepared by the following method:

[0063] Example Four

[0064] An anticorrosive functional composite filler is prepared by the following method:

[0065] S1, 220 parts of fly ash, 100 parts of anhydrous ethanol solution and 80 parts of deionized water are added to a beaker, and mechanical stirring is carried out under ultrasonic action, then 20 parts of aniline, 15 parts of ferric chloride, 10 parts of ferric nitrate, 20 parts of phosphoric acid, 10 parts of rosemary acid, 15 parts of ethylenediaminetetraacetic acid, 20 parts of hydrogen peroxide, 20 parts of ammonium persulfate are added, and the reaction is carried out at 50°C for 6 hours, and then the functional fly ash filler is obtained after suction filtration, alcohol washing and drying.

[0066] S2, 150 parts of graphene oxide, 100 parts of glass flake, 30 parts of anhydrous ethanol solution and 160 parts of deionized water are added to a beaker, and mechanical stirring is carried out under ultrasonic action, then 20 parts of aniline solution, 5 parts of cerous nitrate, 40 parts of potassium iodate are added, and the reaction is carried out at room temperature for 18 hours, and then the functional layered filler is obtained after suction filtration, alcohol washing and freeze-drying.

[0067] S3, 25 parts of the functional layered filler and 60 parts of the functional fly ash filler are placed in an alloy dispersion tank, then 15 parts of γ-aminopropyl triethoxysilane, 25 parts of γ-mercaptopropyl triethoxysilane, 25 parts of anhydrous ethanol and 35 parts of deionized water are added, and ball milling is carried out in a planetary ball mill for 12 hours, and then the anticorrosive functional composite filler is obtained after suction filtration and drying.

[0068] An aqueous anticorrosive coating is prepared by the following method:

[0069] An aqueous anticorrosive coating is prepared by the following method:

[0070] Comparative Example One

[0071] An anticorrosive filler is prepared by the following method:

[0072] S1, 300 parts of fly ash, 150 parts of anhydrous ethanol solution and 50 parts of deionized water were added into a beaker, and mechanical stirring was carried out under ultrasonic action, then 50 parts of aniline, 10 parts of ferric nitrate, 10 parts of cerium nitrate, 40 parts of rosemary acid, 30 parts of ammonium persulfate were added, and the reaction was carried out at 50℃ for 6 hours, and then functionalized fly ash filler was obtained after filtration, alcohol washing and drying.

[0073] S2, 30 parts of graphene, 20 parts of mica, 50 parts of anhydrous ethanol solution and 10 parts of deionized water were added into a beaker, and mechanical stirring was carried out under ultrasonic action, then 30 parts of aniline solution, 10 parts of perfluorooctanoic acid, 20 parts of potassium chromate were added, and the reaction was carried out at room temperature for 12 hours, and then functionalized sheet filler was obtained after filtration, alcohol washing and freeze-drying.

[0074] A kind of preparation of water-based anticorrosive paint, prepared by the following method:

[0075] In a 250mL beaker, 15 parts of functionalized fly ash filler, 15 parts of functionalized sheet filler, 70 parts of water-based epoxy emulsion, 55 parts of aliphatic amine curing agent, 22 parts of deionized water, 12 parts of propylene glycol methyl ether were added, and mixed uniformly to prepare water-based anticorrosive paint, which was sprayed on Q235B material steel plate to prepare anticorrosive coating, and the steel plate specification was 150mm×70mm×3mm.

[0076] Comparative example two

[0077] A kind of composite filler, prepared by the following method:

[0078] 400 parts of fly ash filler and 100 parts of graphene oxide, 50 parts of glass flake were placed in an alloy dispersion tank, then 20 parts of γ-(2,3-epoxypropoxy) propyl trimethoxysilane, 30 parts of γ-aminopropyl triethoxysilane, 100 parts of anhydrous ethanol and 30 parts of deionized water were added, and ball milling was carried out in a planetary ball mill for 6 hours, and then functional composite filler was obtained after filtration and drying.

[0079] A kind of water-based anticorrosive paint, prepared by the following method:

[0080] In a 250mL beaker, 40 parts of functional composite filler, 60 parts of water-based epoxy emulsion, 45 parts of aliphatic amine curing agent, 20 parts of deionized water, 20 parts of propylene glycol methyl ether were added, and mixed uniformly to prepare water-based anticorrosive paint, which was sprayed on Q235B material steel plate to prepare anticorrosive coating, and the steel plate specification was 150mm×70mm×3mm.

[0081] Comparative example three

[0082] A kind of anticorrosive composite filler, prepared by the following method:

[0083] S1, 360 parts of fly ash, 100 parts of anhydrous ethanol solution and 20 parts of deionized water were added into a beaker, and mechanical stirring was carried out under ultrasonic action, then 40 parts of aniline, 15 parts of phosphoric acid, 30 parts of potassium iodate were added, and the reaction was carried out at 50℃ for 6 hours, and then functional fly ash filler was obtained after filtration, alcohol washing and drying.

[0084] S2, 30 parts of graphene, 20 parts of graphene oxide, 30 parts of anhydrous ethanol solution and 30 parts of deionized water were added into a beaker, and mechanical stirring was carried out under ultrasonic action, then 10 parts of aniline solution, 15 parts of perfluorooctanoic acid, 30 parts of ammonium persulfate were added, and the reaction was carried out at room temperature for 6 hours, and then functional layered filler was obtained after filtration, alcohol washing and freeze-drying.

[0085] S3, 60 parts of functional layered filler and 5 parts of functional fly ash filler were placed in an alloy dispersion tank, then 50 parts of dopamine hydrochloride, 30 parts of anhydrous ethanol and 60 parts of deionized water were added, and ball milling was carried out in a planetary ball mill for 12 hours, and then functional composite filler was obtained after filtration and drying.

[0086] An aqueous anticorrosive coating was prepared by the following method:

[0087] In a 250 mL beaker, 55 parts of functional composite filler, 55 parts of aqueous epoxy emulsion, 50 parts of aliphatic amine curing agent, 25 parts of deionized water and 15 parts of propylene glycol methyl ether were added and uniformly mixed to prepare an aqueous anticorrosive coating, which was sprayed on a Q235B material steel plate to prepare an anticorrosive coating layer, and the steel plate had a specification of 150 mm x 70 mm x 3 mm.

[0088] Anticorrosion performance test

[0089] The samples prepared in Example 1, Example 2 and Comparative Examples 1-3 were placed in a 3.5% sodium chloride solution for electrochemical impedance spectroscopy (EIS) test of the aqueous anticorrosive coating.

[0090] A three-electrode system was used, and a saturated calomel electrode, a platinum electrode and a region exposed to the sodium chloride solution were used as a reference electrode, a counter electrode and a working electrode, respectively. After the coating sample was immersed in the sodium chloride solution for 30 days, the performance test was carried out under a 20 mV sinusoidal disturbance in a frequency range of 100 kHz to 0.01 Hz, and the test area of the sample was 7.069 cm 2 , and the specific results are shown in Table 1:

[0091] Table 1 EIS test results of the aqueous anticorrosive coating of the examples and comparative examples

[0092]

[0093]

[0094] AsFigures 1-5 The images shown are EIS test spectra of the anti-corrosion coatings prepared in Examples 1, 2, and 1 to 3 after immersion for 30 days.

[0095] like Figure 1 (b) and Figure 2 As shown in Figure (b), the anti-corrosion coatings of Example 1 and Example 2 consistently exhibit high impedance moduli at low frequencies, with values ​​of 1.15 × 10⁻⁶. 10 Ω·cm 2 and 1.65×10 10 Ω·cm 2 The high impedance modulus indicates that the anti-corrosion coating has excellent shielding performance against corrosive media, and the functional composite filler with a specific structure effectively blocks corrosive media.

[0096] like Figure 1 (a) and Figure 2 As shown in Figure (a), the Nyquist plots of the samples from Examples 1 and 2 both show a large capacitive arc, indicating that there is no obvious delamination behavior inside the sample and the coating has a low water absorption rate during immersion. This indicates that the anti-corrosion composite filler has good interfacial bonding performance with the coating system after chemical polymerization and surface modification.

[0097] In Comparative Example 1, the Nyquist plot of the sample shows a standard semicircle describing the arc resistance. Figure 3 In (a), its impedance modulus curve exhibits a standard resistance plateau. Figure 3 (b) indicates that the corrosive medium reached the substrate surface at this point, and the metal substrate did not show any tendency to corrode. The impedance modulus of the sample at this point is 6.70 × 10⁻⁶. 8 Ω·cm 2 .

[0098] like Figure 5 (a) and Figure 5 As shown in Figure (b), in Comparative Example 3, the functional fly ash filler and the functional lamellar filler were added to the coating in a blended form. Compared to Example 1, this reduced the shielding performance of the coating, indicating that the composite process of the two functional materials is essential. However, in Figure 1 In the example, the sample of Example 1 exhibited high capacitive arc characteristics and strong low-frequency impedance modulus value, which indicates that the functional composite filler has efficient passivation behavior and also proves the important role of metal ions in the functional modification process.

[0099] like Figure 4 (a) and Figure 4In the middle (b), in the comparative example two, the fly ash filler and the sheet filler are not functionally modified, and only the functional composite is carried out in the planetary ball mill, therefore, the composite filler only shows the shielding performance, and has no passivation effect on the metal substrate. In the EIS result, the Nyquist diagram of the sample shows two obvious capacitive arcs Figure 4 In the middle (a), the low frequency impedance modulus of the sample is only 1.26*10 7 Ω·cm 2 This shows that the coating has obvious defects, the corrosion medium reaches the metal substrate and serious corrosion reaction occurs. Compared with the first example, the filler is not functionally modified, and no organic hydrophobic shielding layer is constructed, which leads to poor performance of the sample in the comparative example two, and also shows that the unfunctionalized fly ash filler and sheet filler have poor interface combination with the coating matrix, causing some pore defects in the coating.

[0100] In the comparative example three, the fly ash filler and the sheet filler are functionally passivated and modified, and the composite process is also carried out. However, compared with the second example, the metal ion dopant is not added in the passivation functional modification process in the comparative example three, so that only a polyaniline shell layer is generated on the surface of the functional filler. In the second example, a polyaniline-metal oxide composite shell layer is generated on the surface of the functional filler, and the polyaniline generated in the comparative example three has no cation passivation strengthening effect. From the EIS result, it can be seen that the low frequency impedance modulus of the sample in the comparative example three is 3.2*10 9 Ω·cm 2 which is about one order of magnitude lower than that of the sample in the second example, indicating that the catalytic passivation behavior of the metal oxide and the cation strengthening passivation behavior have obvious gain effect on the corrosion prevention process.

[0101] Therefore, the application adopts the above-mentioned anti-corrosion functional composite filler, preparation method and application, constructs a polymer layer with passivation effect on the surface of the filler through chemical polymerization, loads metal ions and acid anions with passivation effect on the surface of the filler through doping, constructs a metal oxide and organic acid functional layer with oxygen transmission function on the surface of the filler, and finally composites the two kinds of functional anti-corrosion fillers through the planetary ball mill to prepare a functional filler with long-term anti-corrosion effect.

[0102] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the application but not to limit it, although the application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the application can still be modified or replaced by equivalents, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the application.

Claims

1. An anticorrosion functional composite filler, characterized by, By weight parts, including: fly ash 300-500 parts, sheet material 50-300 parts, metal ion dopant 20-50 parts, acid dopant 20-50 parts, aniline 30-80 parts, oxidizing agent 50-150 parts, chemical modifier 20-60 parts; The preparation method of the anti-corrosion functional composite filler comprises the following steps: S1, according to the mass ratio of fly ash: anhydrous ethanol: deionized water = 18~50: 10~18: 2~15, disperse fly ash into anhydrous ethanol solution and deionized water, add aniline, oxidizing agent, metal ion dopant, acid dopant in turn, polymerize a layer of polyaniline-metal oxide structure on the surface of fly ash under the action of ultrasonic assistance and mechanical stirring, and obtain functionalized fly ash filler; S2, according to the mass ratio of sheet material: anhydrous ethanol: deionized water = 5~30: 3~5: 1~16, disperse the sheet material into anhydrous ethanol solution and deionized water, add aniline, oxidizing agent, metal ion dopant, acid dopant in turn, polymerize a layer of polyaniline-metal oxide structure on the surface of the sheet material under the action of ultrasonic assistance and mechanical stirring, and obtain functionalized sheet filler; S3, according to the mass ratio of functionalized fly ash filler: functionalized sheet filler: anhydrous ethanol: deionized water = 1~24: 4~20: 5~15: 1~12, uniformly mix the functionalized fly ash filler, functionalized sheet filler, chemical modifier, anhydrous ethanol and deionized water, and then put them into a star type ball mill, and composite by using the chemical modifier under the action of centrifugal force to obtain an anti-corrosion functional composite filler.

2. The anticorrosion functional composite filler according to claim 1, characterized in that: The sheet material is one or more of graphene, graphene oxide, mica and glass flake.

3. The anticorrosion functional composite filler according to claim 1, characterized in that: The metal ion dopant is one or more of ferric nitrate, cerium nitrate and ferric chloride.

4. The anticorrosion functional composite filler according to claim 1, characterized in that: The acid dopant is one or more of phosphoric acid, perfluorooctanoic acid, rosemary acid, tannic acid and ethylenediaminetetraacetic acid.

5. The anticorrosion functional composite filler according to claim 1, characterized in that: The oxidizing agent is one or more of ammonium persulfate, hydrogen peroxide, potassium iodate and potassium chromate.

6. The anticorrosion functional composite filler according to claim 1, characterized in that: The chemical modifier is one or more of dopamine hydrochloride, γ-aminopropyl triethoxysilane, γ-(2,3-epoxypropoxy) propyl trimethoxysilane and γ-mercaptopropyl triethoxysilane.

7. A method for preparing the anticorrosive functional composite filler according to any one of claims 1 to 6, characterized by, The preparation method comprises the following steps: S1, according to the mass ratio of fly ash: anhydrous ethanol: deionized water = 18~50: 10~18: 2~15, disperse fly ash into anhydrous ethanol solution and deionized water, add aniline, oxidizing agent, metal ion dopant, acid dopant in turn, polymerize a layer of polyaniline-metal oxide structure on the surface of fly ash under the action of ultrasonic assistance and mechanical stirring, and obtain functionalized fly ash filler; S2, according to the mass ratio of sheet material: anhydrous ethanol: deionized water = 5~30: 3~5: 1~16, disperse the sheet material into anhydrous ethanol solution and deionized water, add aniline, oxidizing agent, metal ion dopant, acid dopant in turn, polymerize a layer of polyaniline-metal oxide structure on the surface of the sheet material under the action of ultrasonic assistance and mechanical stirring, and obtain functionalized sheet filler; S3, according to the functionalized fly ash filler: functionalized sheet filler: anhydrous ethanol: deionized water = 1~24: 4~20: 5~15: 1~12 mass ratio, the functionalized fly ash filler, functionalized sheet filler, chemical modifier, anhydrous ethanol and deionized water are uniformly mixed and put into a star type ball mill, and the composite is obtained by using the chemical modifier under the action of centrifugal force to obtain the anticorrosion functional composite filler.

8. An aqueous anticorrosive functional coating, characterized by, It comprises: Anticorrosion functional composite filler 30-60 parts, propylene glycol methyl ether 10-20 parts, deionized water 20-30 parts, resin 50-100 parts, curing agent 30-60 parts; the anticorrosion functional composite filler is the anticorrosion functional composite filler of any one of claims 1-6.

9. The waterborne anticorrosive functional coating according to claim 8, characterized in that: The resin is one or more of water-based epoxy emulsion, water-based polyurethane and water-based acrylic resin.

10. The waterborne anticorrosive functional coating according to claim 8, characterized in that: The curing agent is one or more of isocyanate, aliphatic amine curing agent and polyamide curing agent.

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