An impact-resistant anticorrosive coating for glass fiber reinforced plastic pipes and a preparation method thereof

Abstract

This invention provides an impact-resistant and anti-corrosion coating for fiberglass pipes and its preparation method: A Fe-N-C catalyst is prepared; core-shell structured anti-corrosion and antibacterial fibers are prepared; the Fe-N-C catalyst, nano-titanium dioxide, carbon nanotubes, mica powder, anti-corrosion and antibacterial fibers, dispersant, ethanol, and deionized water are mixed and stirred evenly to obtain a dispersion; then, an epoxy resin defoamer and a curing agent are added, and the mixture is stirred evenly to obtain the coating. The coating provided by this invention not only has good adhesion to the fiberglass surface but also good barrier properties, effectively reducing the oxygen content of the coating and thus playing an active anti-corrosion role. It also has good impact resistance, and the preparation method is simple.

Description

Technical fields:

[0001] This invention relates to the field of anti-corrosion coating technology, specifically to an impact-resistant anti-corrosion coating for fiberglass pipes and its preparation method. Background technology:

[0002] Fiberglass reinforced plastic (FRP) pipes are a composite material made of glass fiber and resin. They possess advantages such as light weight, corrosion resistance, and high strength, and are widely used in petroleum, chemical, urban water supply and drainage, sewage treatment, and marine development industries. FRP pipes are particularly advantageous and have promising application prospects in buried pipelines, long-distance transport pipelines, and large-scale water pipelines.

[0003] Despite the many advantages of fiberglass pipes, they are inevitably subject to significant impact and corrosion in harsh environments over long periods. Over time, the pipes will be severely damaged, affecting their normal use. Therefore, it is necessary to perform surface coating modification treatment on fiberglass pipes.

[0004] Patent application number 201710732649.6 discloses a photocurable graphene-based solvent-free epoxy fiberglass coating and its preparation method. The photocurable graphene-based solvent-free epoxy fiberglass coating is made from the following raw materials in the specified percentages: resin, monomer (reactive diluent), glass powder, photoinitiator A, photoinitiator B, defoamer, adhesion promoter, and graphene oxide. During the curing process, graphene oxide is reduced to graphene, thereby improving the coating's adhesion, wear resistance, and corrosion resistance. Patent application number 201710336987.8 discloses an anti-corrosion fiberglass composite coating material. The fiberglass composite coating material comprises, by weight, 5-15 parts of silicone resin, 8-17 parts of polytetrafluoroethylene, 2-8 parts of nano-glass fiber, 5-12 parts of stearamide, 2-10 parts of expandable graphite, 8-15 parts of light calcium carbonate, 2-10 parts of silane coupling agent, 5-15 parts of trimethylolpropane triacrylate, and 2-10 parts of preservative. The preservative component comprises, by weight, 10-20 parts of chitosan, 5-10 parts of disodium EDTA, 1-6 parts of nano-silver, and 5-12 parts of dispersed rosin sizing agent emulsion. While the anti-corrosion coatings provided in the above-mentioned prior art can improve the anti-corrosion performance of fiberglass surfaces to a certain extent, they are all based on passive corrosion protection, making long-term corrosion protection difficult to achieve, and their strength also needs further improvement. Summary of the Invention:

[0005] The technical problem to be solved by the present invention is to provide an impact-resistant and anti-corrosion coating for fiberglass pipes and its preparation method, which addresses the shortcomings of the prior art. The coating provided by the present invention not only has good adhesion to the fiberglass surface, but also has good barrier properties, which can effectively reduce the oxygen content of the coating and thus play an active anti-corrosion role. It also has good impact resistance and a simple preparation method.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A method for preparing an impact-resistant and corrosion-resistant coating for fiberglass pipes includes the following steps:

[0008] (1) 3-chloropropyltriethoxysilane and 1,10-phenanthroline-5-amine were added to DMF and stirred until homogeneous. The mixture was then reacted under nitrogen protection. After the reaction was completed, triethylamine was added to the reaction system to adjust the pH of the system to neutral. The solvent was removed to obtain the organosilane precursor.

[0009] (2) Add the iron salt and the organosilane precursor prepared above to ethanol, then mix with an aqueous solution containing hexadecyltrimethylammonium bromide and sodium hydroxide solution, then add tetraethyl orthosilicate, stir the reaction, cool to room temperature after the reaction is completed, wash the solid and dry it, and place it in a tube furnace for calcination treatment. The calcined powder is treated with hydrogen fluoride solution to obtain Fe-NC catalyst.

[0010] (3) Pullulan polysaccharide and ethyl cellulose were added to DMF and stirred until the solid dissolved to obtain a shell solution. Carvacrol and DMF were mixed to obtain a core solution. The shell solution and core solution were placed in a syringe and spun using coaxial electrospinning to obtain an anti-corrosion and antibacterial fiber with a core-shell structure.

[0011] (4) Mix Fe-NC catalyst, nano titanium dioxide, carbon nanotubes, mica powder, anti-corrosion and antibacterial fiber, dispersant, ethanol and deionized water evenly to obtain a dispersion. Then add epoxy resin defoamer and curing agent, stir and mix evenly to obtain a coating.

[0012] As a preferred embodiment of the above technical solution, in step (1), the reaction temperature is 65-75℃ and the time is 70-75h.

[0013] As a preferred embodiment of the above technical solution, in step (1), the ratio of 3-chloropropyltriethoxysilane to 1,10-phenanthroline-5-amine is (0.2-0.5) ml: 0.2 g.

[0014] As a preferred embodiment of the above technical solution, in step (2), the iron salt is ferrous sulfate heptahydrate, and the concentration of the sodium hydroxide solution is 1-2 mol / L; the ratio of the iron salt, organosilane precursor, hexadecyltrimethylammonium bromide, sodium hydroxide solution, and tetraethyl orthosilicate is 10-15 mg: 90-95 mg: 0.1-0.2 g: 0.4-0.5 ml: 0.1-0.5 ml.

[0015] As a preferred embodiment of the above technical solution, in step (2), the temperature of the stirring reaction is 80°C and the time is 2-3h; the temperature of the calcination treatment is 900°C, the calcination atmosphere is nitrogen, the heating rate during calcination is 3-5°C / min, and the calcination time is 2-3h.

[0016] As a preferred embodiment of the above technical solution, in step (2), the concentration of the hydrofluoric acid solution is 10-15wt%, and the ratio of solid to hydrofluoric acid solution used during treatment is 1g:50-100ml.

[0017] As a preferred embodiment of the above technical solution, in step (3), the mass ratio of pullulan polysaccharide to ethyl cellulose is 1:(2-4).

[0018] As a preferred embodiment of the above technical solution, in step (3), during spinning, the flow ratio of the shell solution to the core solution is (2-3):1; the flow rates of the shell solution and the core solution are 0.05-0.1 ml / h and 0.1-0.2 ml / h, respectively; the positive voltage and negative voltage during spinning are 16 kV and 3 kV, respectively; and the distance between the spinneret and the collector is 10 cm.

[0019] As a preferred embodiment of the above technical solution, in step (4), the defoamer is SN-154 defoamer, the curing agent is water-based epoxy curing agent, and the dispersant is SN5029 dispersant.

[0020] As a preferred embodiment of the above technical solution, in step (4), the amounts of each component by weight are as follows: 2-3 parts of anti-corrosion and antibacterial fiber, 2-5 parts of nano titanium dioxide, 2-5 parts of carbon nanotubes, 5-8 parts of mica powder, 1-2 parts of Fe-NC catalyst, 30-50 parts of epoxy resin, 0.1-0.2 parts of defoamer, 0.2-0.3 parts of water-based epoxy curing agent, 0.2-0.3 parts of dispersant, 20-30 parts of ethanol, and 20-30 parts of deionized water.

[0021] By adopting the above technical solution, the present invention has the following beneficial effects:

[0022] This invention modifies an epoxy resin matrix by adding nano-titanium dioxide, carbon nanotubes, and mica powder. Nano-titanium dioxide is an inorganic nanomaterial with high activity, high stability, and non-toxicity. Its finer particle size enhances the wear resistance, hardness, and chemical corrosion resistance of the epoxy resin. This is because nano-titanium dioxide has extremely small particle size, a large specific surface area, and high chemical activity, enabling it to strongly interact with molecules in the epoxy resin, thereby enhancing its chemical properties. Carbon nanotubes are nanomaterials with excellent mechanical, electrical, and chemical stability. Adding them to epoxy resin forms a uniformly dispersed CNT / epoxy resin composite material, effectively improving the strength, toughness, and impact resistance of the epoxy resin. The hollow structure and extremely high aspect ratio of carbon nanotubes allow them to act as a reinforcing phase, forming an effective load transfer mechanism through interpenetration with epoxy resin molecules, thereby improving the mechanical properties of the epoxy resin. Mica powder is a natural nanomaterial with excellent insulation properties, high-temperature resistance, and chemical stability. Adding mica powder to epoxy resin can significantly improve its impact resistance and abrasion resistance. This is because the layered structure of mica powder can inhibit crack propagation in epoxy resin under impact, while its excellent insulation properties can effectively slow down the damage of electric current to epoxy resin, thereby improving its impact resistance and abrasion resistance.

[0023] This invention also incorporates a Fe-NC catalyst into the epoxy resin matrix. First, a Phen precursor is prepared, then pre-coordinated and anchored with iron ions. Tetraethyl orthosilicate is then added to control the growth of the Fe-Phen coordination compound. Tetraethyl orthosilicate exhibits faster hydrolysis and condensation, facilitating growth within the nanospheres. The framework is doped with organosilicon, which has stronger hydrophobicity than inorganic silica. Therefore, during subsequent etching with hydrofluoric acid solution, the organosilicon is well preserved, while the inorganic silica is etched away, resulting in hollow spheres. The Fe-NC catalyst prepared by this invention has a large specific surface area and a porous structure, increasing contact with the reaction medium. The mesoporous structure facilitates mass transfer, resulting in excellent oxygen reduction activity. When used for pipeline corrosion protection, it effectively improves the barrier properties of the coating and reduces its oxygen content, thus providing active corrosion protection.

[0024] To address the problem of microbial corrosion of pipes during use, this invention also uses pullulan and ethyl cellulose to form a nanofiber shell and carvacrol as the core material to prepare fibers with anti-corrosion and antibacterial properties. Adding these fibers to an epoxy resin matrix can effectively improve the anti-corrosion and antibacterial properties of the coating. Detailed implementation method:

[0025] To better understand the present invention, the following embodiments are provided for further illustration. These embodiments are only for explaining the present invention and do not constitute any limitation on the present invention.

[0026] In the following examples and comparative examples, the waterborne epoxy resin is waterborne epoxy resin H228; the nano-titanium dioxide is anatase-type nano-titanium dioxide with an average particle size of 10 nm; the carbon nanotubes have a purity >95%, a length of 10-20 μm, and a diameter of 5-10 nm; the mica powder has a mesh size of 600 mesh, a water content <0.5%, a whiteness of 60-65%, and a bulk density of 0.2-0.3 g / cm³. 3 .

[0027] Example 1

[0028] A method for preparing an impact-resistant and corrosion-resistant coating for fiberglass pipes includes the following steps:

[0029] (1) 0.2 ml of 3-chloropropyltriethoxysilane and 0.2 g of 1,10-phenanthroline-5-amine were added to DMF and stirred until homogeneous. The mixture was then reacted for 72 h under nitrogen protection at 70 °C. After the reaction was completed, triethylamine was added to the reaction system to adjust the pH to neutral. The solvent was removed to obtain the organosilane precursor.

[0030] (2) 10 mg of ferrous sulfate heptahydrate and 90 mg of the organosilane precursor prepared above were added to ethanol, then mixed with 0.1 g of hexadecyltrimethylammonium bromide, 0.4 ml of 2 mol / L sodium hydroxide solution, and 20 ml of deionized water. Then, 0.1 ml of tetraethyl orthosilicate was added, and the mixture was stirred at 80 °C for 2 h. After the reaction was completed, the mixture was cooled to room temperature, washed, dried, and calcined in a tube furnace under a nitrogen atmosphere at a rate of 3 °C / min to 900 °C for 2 h. The calcined powder was then treated with a 10 wt% hydrogen fluoride solution for 3 h to obtain the Fe-NC catalyst; the specific surface area of ​​this catalyst was 111.2 m². 2 / g, total pore volume is 1.25cm³ 3 / g, half-wave potential is 0.91V;

[0031] (3) Add 1g pullulan and 2-4g ethyl cellulose to 50ml DMF and stir until the solid dissolves to obtain a shell solution. Mix 1g carvacrol and 50ml DMF to obtain a core solution. Place the shell solution and core solution into a syringe and spin them using coaxial electrospinning to obtain anti-corrosion and antibacterial fibers with a core-shell structure. During spinning, the flow ratio of the shell solution to the core solution is 2:1; the flow rates of the shell solution and the core solution are 0.1ml / h and 0.2ml / h, respectively; the positive voltage and negative voltage during spinning are 16kV and 3kV, respectively; and the distance between the spinneret and the collector is 10cm.

[0032] (4) Mix 2 parts Fe-NC catalyst, 2 parts nano titanium dioxide, 2 parts carbon nanotubes, 5 parts mica powder, 2 parts anti-corrosion and antibacterial fiber, 0.2 parts SN5029 dispersant, 20 parts ethanol and 20 parts deionized water evenly to obtain a dispersion. Then add 50 parts waterborne epoxy resin, 0.1 parts SN-154 defoamer and 0.2 parts waterborne epoxy curing agent, stir and mix evenly to obtain a coating.

[0033] Example 2

[0034] A method for preparing an impact-resistant and corrosion-resistant coating for fiberglass pipes includes the following steps:

[0035] (1) 0.5 ml of 3-chloropropyltriethoxysilane and 0.2 g of 1,10-phenanthroline-5-amine were added to DMF and stirred until homogeneous. The mixture was then reacted for 72 h under nitrogen protection at 70 °C. After the reaction was completed, triethylamine was added to the reaction system to adjust the pH to neutral. The solvent was removed to obtain the organosilane precursor.

[0036] (2) 12 mg of ferrous sulfate heptahydrate and 92 mg of the organosilane precursor prepared above were added to ethanol, then mixed with 0.15 g of hexadecyltrimethylammonium bromide, 0.4 ml of 2 mol / L sodium hydroxide solution, and 20 ml of deionized water. Then, 0.2 ml of tetraethyl orthosilicate was added, and the mixture was stirred at 80 °C for 3 h. After the reaction was completed, the mixture was cooled to room temperature, washed, dried, and calcined in a tube furnace under a nitrogen atmosphere at a rate of 3 °C / min to 900 °C for 3 h. The calcined powder was then treated with a 10 wt% hydrogen fluoride solution for 5 h to obtain the Fe-NC catalyst; the specific surface area of ​​this catalyst was 113.1 m². 2 / g, total pore volume is 1.33cm³ 3 / g, half-wave potential is 0.95V;

[0037] (3) Add 1g pullulan and 3g ethyl cellulose to 50ml DMF and stir until the solid dissolves to obtain a shell solution. Mix 1g carvacrol and 50ml DMF to obtain a core solution. Place the shell solution and core solution into a syringe and spin them using coaxial electrospinning to obtain anti-corrosion and antibacterial fibers with a core-shell structure. During spinning, the flow ratio of the shell solution to the core solution is 3:1; the flow rates of the shell solution and the core solution are 0.08ml / h and 0.2ml / h, respectively; the positive voltage and negative voltage during spinning are 16kV and 3kV, respectively; and the distance between the spinneret and the collector is 10cm.

[0038] (4) Mix 2 parts Fe-NC catalyst, 3 parts nano titanium dioxide, 3 parts carbon nanotubes, 8 parts mica powder, 2 parts anti-corrosion and antibacterial fiber, 0.25 parts SN5029 dispersant, 30 parts ethanol and 20 parts deionized water evenly to obtain a dispersion. Then add 50 parts waterborne epoxy resin, 0.2 parts SN-154 defoamer and 0.2 parts waterborne epoxy curing agent, stir and mix evenly to obtain a coating.

[0039] Example 3

[0040] A method for preparing an impact-resistant and corrosion-resistant coating for fiberglass pipes includes the following steps:

[0041] (1) 0.3 ml of 3-chloropropyltriethoxysilane and 0.2 g of 1,10-phenanthroline-5-amine were added to DMF and stirred until homogeneous. The mixture was then reacted for 72 h under nitrogen protection at 70 °C. After the reaction was completed, triethylamine was added to the reaction system to adjust the pH to neutral. The solvent was removed to obtain the organosilane precursor.

[0042] (2) 15 mg of ferrous sulfate heptahydrate and 95 mg of the organosilane precursor prepared above were added to ethanol, then mixed with 0.2 g of hexadecyltrimethylammonium bromide, 0.45 L of 2 mol / L sodium hydroxide solution, and 20 ml of deionized water. Then, 0.4 ml of tetraethyl orthosilicate was added, and the mixture was stirred at 80 °C for 3 h. After the reaction was completed, the mixture was cooled to room temperature, washed, dried, and calcined in a tube furnace under a nitrogen atmosphere at a rate of 5 °C / min to 900 °C for 3 h. The calcined powder was then treated with a 10 wt% hydrogen fluoride solution for 5 h to obtain the Fe-NC catalyst; the specific surface area of ​​this catalyst was 112.8 m². 2 / g, total pore volume is 1.31cm³ 3 / g, half-wave potential is 0.98V;

[0043] (3) Add 1g pullulan and 4g ethyl cellulose to 50ml DMF and stir until the solid dissolves to obtain a shell solution. Mix 1g carvacrol and 50ml DMF to obtain a core solution. Place the shell solution and core solution into a syringe and spin them using coaxial electrospinning to obtain anti-corrosion and antibacterial fibers with a core-shell structure. During spinning, the flow ratio of the shell solution to the core solution is 3:1; the flow rates of the shell solution and the core solution are 0.1ml / h and 0.2ml / h, respectively; the positive voltage and negative voltage during spinning are 16kV and 3kV, respectively; and the distance between the spinneret and the collector is 10cm.

[0044] (4) Mix 2 parts Fe-NC catalyst, 5 parts nano titanium dioxide, 5 parts carbon nanotubes, 8 parts mica powder, 2 parts anti-corrosion and antibacterial fiber, 0.3 parts SN5029 dispersant, 30 parts ethanol and 30 parts deionized water evenly to obtain a dispersion. Then add 50 parts waterborne epoxy resin, 0.2 parts SN-154 defoamer and 0.3 parts waterborne epoxy curing agent, stir and mix evenly to obtain a coating.

[0045] Comparative Example 1

[0046] No Fe-NC catalyst was added to the coating, and other conditions were the same as in Example 3.

[0047] Comparative Example 2

[0048] No anti-corrosion and antibacterial fibers were added to the coating, and other conditions were the same as in Example 3.

[0049] The coatings prepared in the above embodiments and comparative examples were applied to the surface of a fiberglass substrate, with a coating thickness controlled at 100±2μm. After standing for 24 hours, the coatings were dried, and their performance was tested. The test results are shown in Table 1. The adhesion grade was tested according to GB / T9286-1998 standard, the impact resistance was tested according to GB / T1732-1993, and the salt spray resistance was tested according to the salt spray test in GB / T1771.

[0050] Table 1

[0051]

[0052] As can be seen from the above distinguishing features, compared with the comparative example, the addition of self-made anti-corrosion and antibacterial fibers and Fe-NC catalyst to the epoxy resin matrix in this invention not only improves the anti-corrosion performance of the coating, but also improves the impact resistance of the material to a certain extent.

[0053] Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to this invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A method for preparing an impact-resistant and anti-corrosion coating for fiberglass pipes, characterized in that, Includes the following steps: (1) 3-chloropropyltriethoxysilane and 1,10-phenanthroline-5-amine were added to DMF and stirred until homogeneous. The mixture was then reacted under nitrogen protection. After the reaction was completed, triethylamine was added to the reaction system to adjust the pH of the system to neutral. The solvent was removed to obtain the organosilane precursor. (2) Add the iron salt and the organosilane precursor prepared above to ethanol, then mix with an aqueous solution containing hexadecyltrimethylammonium bromide and sodium hydroxide solution, then add tetraethyl orthosilicate, stir the reaction, cool to room temperature after the reaction is completed, wash the solid and dry it, and place it in a tube furnace for calcination treatment. The calcined powder is treated with hydrogen fluoride solution to obtain the Fe-NC catalyst. (3) Add pullulan and ethyl cellulose to DMF and stir until the solid dissolves to obtain a shell solution. Mix carvacrol and DMF to obtain a core solution. Place the shell solution and core solution in a syringe and spin them using coaxial electrospinning to obtain an anti-corrosion and antibacterial fiber with a core-shell structure. (4) By weight, 1-2 parts Fe-NC catalyst, 2-5 parts nano titanium dioxide, 2-5 parts carbon nanotubes, 5-8 parts mica powder, 2-3 parts anti-corrosion and antibacterial fiber, 0.2-0.3 parts dispersant, 20-30 parts ethanol and 20-30 parts deionized water are mixed and stirred evenly to obtain a dispersion. Then, 30-50 parts epoxy resin, 0.1-0.2 parts defoamer and 0.2-0.3 parts curing agent are added and stirred evenly to obtain a coating.

2. The method for preparing an impact-resistant and anti-corrosion coating for fiberglass pipes according to claim 1, characterized in that: In step (1), the reaction temperature is 65-75℃ and the time is 70-75h.

3. The method for preparing an impact-resistant and anti-corrosion coating for fiberglass pipes according to claim 1, characterized in that: In step (1), the ratio of 3-chloropropyltriethoxysilane to 1,10-phenanthroline-5-amine is (0.2-0.5) mL: 0.2 g.

4. The method for preparing an impact-resistant and anti-corrosion coating for fiberglass pipes according to claim 1, characterized in that: In step (2), the iron salt is ferrous sulfate heptahydrate, and the concentration of the sodium hydroxide solution is 1-2 mol / L; the ratio of the iron salt, organosilane precursor, hexadecyltrimethylammonium bromide, sodium hydroxide solution, and tetraethyl orthosilicate is 10-15 mg: 90-95 mg: 0.1-0.2 g: 0.4-0.5 mL: 0.1-0.5 mL.

5. The method for preparing the anti-impact anticorrosive coating for glass steel pipes according to claim 1, characterized in that: In step (2), the temperature of the stirring reaction is 80℃ and the time is 2-3h; the temperature of the calcination treatment is 900℃, the calcination atmosphere is nitrogen, the heating rate during calcination is 3-5℃ / min, and the calcination time is 2-3h.

6. The method for preparing an impact-resistant and anti-corrosion coating for fiberglass pipes according to claim 1, characterized in that: In step (2), the concentration of the hydrogen fluoride solution is 10-15 wt%, and the ratio of solid to hydrogen fluoride solution used during treatment is 1 g: 50-100 mL.

7. The method for preparing an impact-resistant and anti-corrosion coating for fiberglass pipes according to claim 1, characterized in that: In step (3), the mass ratio of pullulan to ethyl cellulose is 1:(2-4).

8. The method for preparing an impact-resistant and anti-corrosion coating for fiberglass pipes according to claim 1, characterized in that: In step (3), during spinning, the flow rate ratio of the shell solution to the core solution is (2-3):1; the flow rates of the shell solution and the core solution are 0.05-0.1 mL / h and 0.1-0.2 mL / h, respectively; the positive voltage and negative voltage during spinning are 16 kV and 3 kV, respectively; and the distance between the spinneret and the collector is 10 cm.

9. The method for preparing an impact-resistant and anti-corrosion coating for fiberglass pipes according to claim 1, characterized in that: In step (4), the defoaming agent is SN-154 defoaming agent, the curing agent is waterborne epoxy curing agent, and the dispersing agent is SN5029 dispersing agent.

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