A high-viscosity resin coating with visual detection of hydrogen fluoride, and its preparation method and application

Abstract

The present invention belongs to the technical field of responsive materials and specifically relates to a high-viscosity resin coating for visual detection of hydrogen fluoride, a preparation method thereof, and an application thereof. The coating comprises, by weight percentage, 10-50 wt% of acrylate, 0-30 wt% of vinyl ether, 2-40 wt% of vinyl carbazole, 0.1-10 wt% of initiator, and the remainder of solvent. The coating is evenly applied on the outer wall of a hydrogen fluoride storage tank. Upon contact with hydrogen fluoride, the coating rapidly responds to color change within 5 seconds, enabling timely detection of hydrogen fluoride leakage and preventing safety accidents.

Description

Technical Field

[0001] The present invention belongs to the technical field of responsive materials, and in particular relates to a high-viscosity resin coating for visual detection of hydrogen fluoride, a preparation method thereof, and an application thereof. Background Art

[0002] Hydrogen fluoride (HF), an important basic raw material in the fluorine chemical industry, plays an irreplaceable role in the preparation of organic or inorganic fluorides such as fluoroolefins. However, liquid HF is highly volatile and can cause severe damage to the skin and bones, or even death, when exposed to air. Hydrogen fluoride gas is stored in tanks. Due to its corrosive nature, it is prone to leakage. Currently, leaks caused by HF during transportation and storage have caused numerous serious safety accidents, endangering people's lives and property. Therefore, timely detection of HF gas leaks is of great significance to ensuring life safety and normal production.

[0003] To address the issue of hydrogen fluoride leakage, materials such as carbon steel, nickel-copper, and resin that are resistant to fluorine and hydrogen fluoride corrosion have been reported, and a series of standards for the safe storage and transportation of hydrogen fluoride have been established, such as the "AHF Storage and Transportation Standard" (GB7746-2011). Despite this, safety accidents caused by hydrogen fluoride leaks occur frequently, and the cause of these accidents is the failure to promptly detect hydrogen fluoride leaks. Currently, there are few reports on hydrogen fluoride detection. Patent 2021103680666 discloses a method for preparing smart fabrics for information storage and visual detection of hydrogen fluoride, resulting in a fast-response fabric. However, azophenylmaleimide is a very expensive monomer, making it unsuitable for industrial production. Moreover, the monomer itself is orange, and the resulting fabric changes color to orange-red when placed in an acidic environment. The color change from orange to orange-red is not obvious, and the color boundary is difficult to distinguish. Moreover, the monomer is highly susceptible to contamination of other substances or equipment during use. As a dye, azophenylmaleimide is prone to environmental and water pollution. Summary of the Invention

[0004] To address the above-mentioned issues, the present invention proposes a high-viscosity resin coating for visual detection of hydrogen fluoride, as well as a preparation method and application thereof. A polymer with a rapid stimulus response is obtained through free radical polymerization, which is then coated on the outer wall of a hydrogen fluoride storage tank. The polymer can rapidly respond to and change color within 5 seconds after contact with hydrogen fluoride, enabling timely detection of hydrogen fluoride leaks and avoiding the occurrence of safety accidents.

[0005] To address the potential safety risks associated with HF leaks, the inventors developed a polymer resin coating that can be applied to the outer walls of HF storage tanks. When HF leaks, the coating instantly turns blue-green, enabling visual detection of HF and providing early warning of safety incidents. The technical solutions of the present invention are as follows:

[0006] A high-viscosity resin coating with visual detection of hydrogen fluoride comprises, by weight percentage, 10-50 wt% of acrylate, 0-30 wt% of vinyl ether, 2-40 wt% of vinyl carbazole, 0.1-10 wt% of initiator, and the remainder of solvent.

[0007] Preferably, the acrylate is one of methacrylate, methyl acrylate, ethyl acrylate, and fluorine-containing acrylate.

[0008] Preferably, the vinyl ether substance is one of hydroxybutyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, hydroxyethyl vinyl ether, and cyclohexyl vinyl ether.

[0009] Preferably, the solvent is one of N,N-dimethylformamide, butyl acetate, ethyl acetate, and dimethyl sulfoxide.

[0010] Preferably, the initiator is one of azobisisobutyronitrile (AIBN), dibenzoyl peroxide (BPO), tert-butyl peroxypivalate (TBPPPI), azobisisoheptanenitrile, and dicyclohexyl peroxydicarbonate.

[0011] A high-viscosity resin coating with visual detection of hydrogen fluoride is prepared by adding acrylate, vinyl ether and vinyl carbazole into a solvent, stirring and dissolving them to obtain a clear and transparent solution, adding an initiator, heating under stirring conditions, and performing a polymerization reaction for a period of time. After the reaction is completed, a transparent high-viscosity resin coating is obtained.

[0012] Preferably, the viscosity of the high-viscosity resin solution is 500-8000 Pa·s.

[0013] Preferably, the temperature is raised to 60-90°C and the polymerization reaction is carried out for 16-24 hours. The temperature and reaction time are determined according to the half-life of the initiator. At this temperature and reaction time, the monomer reaction will be more complete, and the obtained resin will have a higher molecular weight, greater strength, better film-forming properties, and excellent performance. The high solid content is conducive to transportation.

[0014] The above-mentioned high-viscosity resin coating for visual detection of hydrogen fluoride is used in detecting hydrogen fluoride leakage. The high-viscosity resin coating is diluted and evenly applied on the outer wall of the hydrogen fluoride storage tank, and then dried.

[0015] Preferably, the high-viscosity resin coating is diluted 10-20 times with a solvent to better evenly coat the solution on the outer wall of the HF storage tank. Further preferably, the mass ratio of the solvent required during the reaction to the solvent used for dilution is 2-5:5-8.

[0016] Preferably, the drying temperature is 60-100° C. and the drying time is 5-18 hours. Under these conditions, the film-forming property is good.

[0017] Preferably, the coating method may be brush coating or casting method.

[0018] The present invention combines resin polymers with good film-forming application properties to obtain a novel copolymer based on carbazole groups. The color development properties of the copolymer are used to detect the presence of hydrogen fluoride components, which can be used to prepare visual hydrogen fluoride leakage detection materials. The copolymer prepared by the present invention has excellent reversible cycle stability and has good application prospects. N-vinyl carbazole (NVC), as an important class of organic heterocyclic small molecules, has excellent photoelectric properties, good intramolecular electron transfer function, and relatively excellent thermal stability. NVC is also relatively cheap. Because the carbazole group is a basic functional group, the N atom of the carbazole group is protonated to form a salt structure under the stimulation of an acidic component (hydrogen fluoride), and the color changes from colorless to blue-green. When the basic component (such as ammonia, triethylamine, etc.) continues to stimulate, the ammonium salt structure changes to the N atom, completing the deprotonation reaction and restoring the original colorlessness. Acrylate monomers have good film-forming properties, high degree of polymerization, strong processability and low cost, making them the best choice for preparing coatings; initiators have a short half-life and low cost; vinyl ether monomers are soft monomers. By introducing ether monomers with different functional groups (such as hydroxyl and cyclohexyl) into the polymer chain, the solubility, elasticity, cross-linking ability and adhesion of the resin can be greatly improved, making the coating performance even better.

[0019] The coating of the present invention changes from colorless to light blue when exposed to hydrogen fluoride and trifluoroacetic acid, but does not respond (does not change color) when exposed to acidic components such as formic acid, acetic acid, and hydrogen chloride. This is because anhydrous hydrogen fluoride is highly corrosive and acidic. The strong acidity and fuming liquid properties increase the stimuli-responsiveness caused by contact with the carbazole groups in the coating. Secondly, the carbazole groups are large-space groups, and the nitrogen atoms involved in the stimuli-responsiveness are surrounded by the benzene rings of the carbazole groups to provide protection. Hydrogen chloride molecules, for example, are difficult to contact with nitrogen atoms due to their large size, while hydrogen fluoride molecules have a F atom radius comparable to that of hydrogen atoms and a small size, making them easy to contact with nitrogen atoms.

[0020] To prevent the harm to life and property caused by hydrogen fluoride leaks, a high-viscosity resin coating for visual detection of hydrogen fluoride, along with its preparation method and application, has been proposed, leveraging the resin's film-forming properties. First, a responsive resin solution is obtained by copolymerizing acrylates, vinyl ethers, and vinyl carbazole. The chromogenic group carbazole is chemically bonded to the polymer structure. The abundant hydroxyl and ester groups in the polymer enhance adhesion to hydrogen fluoride storage tanks. When hydrogen fluoride leaks, it undergoes a protonation reaction with the carbazole groups on the outer layer of the tank, causing the coating to turn a clear, high-resolution light blue (blue-green) within 5 seconds. This color change, repeated 30 times under the stimulation of ammonia (an alkaline component), allows for rapid stimulus responsiveness. This coating has promising application prospects in the field of visual detection of HF gas leaks.

[0021] The present invention proposes a high-viscosity resin coating for visual detection of hydrogen fluoride, as well as its preparation method and application. A polymer with a rapid stimulus response is obtained through free radical polymerization and then coated on the outer wall of a hydrogen fluoride storage tank. The coating has excellent moldability and adhesion. After contact with hydrogen fluoride, the coating can quickly respond to color change within 5 seconds, enabling timely detection of hydrogen fluoride leaks and avoiding safety accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a structural characterization diagram of the polymer in Example 1;

[0023] Figure 2 This is the structural characterization diagram of the polymer NMR fluorine spectrum in Example 1;

[0024] Figure 3 This is the GPC characterization diagram of the polymer in Example 1;

[0025] Figure 4 The color and stimulus response changes of the resin coating prepared in Example 1;

[0026] Figure 5 Stimulus response changes of the resin coating prepared in Example 2 in different acidic aqueous solutions;

[0027] Figure 6 This is the UV-visible spectrum of the coating prepared in Example 3. DETAILED DESCRIPTION

[0028] The technical solutions in this embodiment are described in detail below, but the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0029] Example 1

[0030] A high-viscosity resin coating with visual detection of hydrogen fluoride:

[0031]

[0032] 15 g of trifluoroethyl methacrylate, 10 g of vinyl carbazole, 0.25 g of azobisisobutyronitrile (AIBN) and 20 g of N,N-dimethylformamide (DMF) were added to a single-necked flask and stirred to dissolve to obtain a clear and transparent solution. The solution was heated to 70 °C under magnetic stirring and reacted for 20 h. After the reaction, a transparent high-viscosity resin (polymer) coating with a viscosity of 2000 Pa·s was obtained.

[0033] Take out 1mL of resin coating into a centrifuge tube, add N,N-dimethylformamide to 10mL, and conduct a stimulus response test. When TFA reagent (30μL of trifluoroacetic acid) is added to the centrifuge tube, the coating in the centrifuge tube gradually changes from transparent and colorless to blue-green. When triethylamine (25μL) is added to the test tube, the color returns to the original colorless, as shown in FIG. Figure 4 As shown in the figure, when the carbazole group in the resin structure comes into contact with trifluoroacetic acid (TFA), a protonation reaction will immediately occur, and the coating will change from colorless to blue. After adding triethylamine, a deprotonation reaction will occur, and the color will return to its original colorless state, thus forming a rapid HF visual detection. The stimulus response process is as follows:

[0034]

[0035] A portion of the resin coating was taken out and precipitated in anhydrous ethanol, filtered and dried to obtain polymer powder, which was then subjected to structural characterization. Figure 1-3 shown. Figure 1 It is a polymer 1 In the H NMR spectrum, the absorption peak at 7.25 ppm is the solvent absorption peak of deuterated chloroform, the absorption peak at 6.55-8.23 ppm is the chemical shift value of the hydrogen of the benzene ring on the copolymer, the absorption peak of the methylene on the vinyl carbazole is at 0.9-2.1 ppm, and the absorption peak of the methylene (close to the trifluoromethyl) in the TFEMA structure is at 4.22-5.45 ppm; Figure 2 It is a polymer 1 F NMR spectrum, the chemical shift at -72.41 ppm is the chemical shift value of fluorine on trifluoroethyl methacrylate, combined with Figure 3 The permeation chromatography curve of the polymer (TFEMA-co-NVC) once again verified that trifluoroethyl methacrylate and vinyl carbazole did copolymerize; Figure 3This is the gel permeation chromatography analysis curve of the copolymer P (TFEMA-co-NVC) (the mobile phase is THF). It can be seen from the figure that there is only one absorption peak, indicating that only one substance is obtained after the reaction, indicating that the monomers TFEMA and NVC do undergo a copolymerization reaction, wherein the molecular weight of the polymer is 49863 and the molecular weight distribution index is 1.69.

[0036] 2 mL of the resin coating was diluted to 10 mL by adding N,N-dimethylformamide, and then evenly coated on a 4*4 cm carbon steel surface by a casting method. The coating was then dried in an 80°C oven for 6 hours. An adhesion test (adhesion test according to GB / T 9286-1998) showed that the coating reached level 3. After HF gas stimulation, the coating changed from colorless to blue-green.

[0037] Example 2

[0038] A high-viscosity resin coating with visual detection of hydrogen fluoride:

[0039]

[0040] 20 g of methyl methacrylate, 10 g of vinyl carbazole, 2 g of vinyl ethyl ether, 0.15 g of azobisisobutyronitrile (AIBN) and 20 g of butyl acetate were added to a single-necked flask and stirred to dissolve to obtain a clear and transparent solution. The solution was heated to 70°C under magnetic stirring and reacted for 18 h. After the reaction, a transparent high-viscosity polymer resin coating with a viscosity of 5500 Pa·s was obtained.

[0041] 1mL of resin coating was taken out into a centrifuge tube, butyl acetate was added to 10mL, and a stimulus response test was performed. When 30μL of TFA reagent was added to the centrifuge tube, the coating in the centrifuge tube gradually changed from transparent and colorless to blue-green. When 25μL of triethylamine was added to the test tube, the color returned to its original colorless state. After 30 cycles of alternating stimulation, rapid stimulus response was achieved.

[0042] Example 3

[0043] A high-viscosity resin coating with visual detection of hydrogen fluoride:

[0044] 30 g of ethyl methacrylate, 10 g of vinyl carbazole, 3 g of vinyl hydroxybutyl ether, 0.29 g of azobisisobutyronitrile (AIBN) and 40 g of butyl acetate were added to a single-necked flask and stirred to dissolve to obtain a clear and transparent solution. The solution was heated to 75°C under magnetic stirring and reacted for 20 h. After the reaction, a transparent high-viscosity polymer resin coating with a viscosity of 4200 Pa·s was obtained.

[0045] 2 mL of the resin coating was taken out and diluted to 10 mL with butyl acetate. The coating was then evenly coated on a 4*4 cm carbon steel surface by a casting method. The coating was placed in an 80°C oven and dried for 6 hours. The adhesion test (adhesion test was conducted in accordance with GB / T 9286-1998) showed that the coating reached level 2. After HF gas stimulation, the coating changed from colorless to blue-green.

[0046] Comparative Example 1

[0047] A high-viscosity resin coating with visual detection of hydrogen fluoride:

[0048] 10 g of ethyl methacrylate, 10 g of methyl methacrylate, 0.25 g of azobisisobutyronitrile (AIBN) and 20 g of butyl acetate were added to a single-necked flask, stirred and dissolved to obtain a clear and transparent solution, and heated to 70 °C under magnetic stirring for 24 h. After the reaction, a transparent high-viscosity polymer resin coating with a viscosity of 3200 Pa·s was obtained.

[0049] 1 mL of resin coating was taken out to a centrifuge tube, and butyl acetate was added to 10 mL for a stimulus response test. When TFA reagent (30 μL) was added to the centrifuge tube, the color of the coating in the centrifuge tube did not change.

[0050] Comparative Example 2

[0051] A high-viscosity resin coating with visual detection of hydrogen fluoride:

[0052] 10 g of ethyl methacrylate, 3 g of vinyl hydroxybutyl ether, 0.1 g of azobisisobutyronitrile (BPO) and 20 g of butyl acetate were added to a single-necked flask, stirred and dissolved to obtain a clear and transparent solution. The temperature was raised to 70 ° C under magnetic stirring and reacted for 20 h. After the reaction, a transparent high-viscosity polymer resin coating with a viscosity of 1500 Pa·s was obtained.

[0053] 1 mL of the resin solution was taken out to a centrifuge tube, and butyl acetate was added to 10 mL for a stimulus response test. When TFA reagent (30 μL) was added to the centrifuge tube, the color of the coating in the centrifuge tube did not change.

[0054] Test example

[0055] Take out 1mL of the resin coating in Example 2 and put it into the bottle. Add butyl acetate to 10mL. Add formic acid (1mL), acetic acid (1mL), hydrochloric acid vapor (1cm 3 ) and anhydrous hydrogen fluoride (1cm 3 ), only the bottle into which hydrogen fluoride was introduced achieved a rapid stimulus response within 5 seconds, producing a color change, as shown in the following example. Figure 5 shown.

[0056] Take out 1 mL of the high-viscosity polymer resin coating of Example 3 and dilute it to 10 mL with butyl acetate. Spin-coat the solution on a PDMS (polydimethylsiloxane) substrate by a spin coating method, and dry (oven-dry or vacuum-dry) to obtain a sample. Prepare a total of 3 samples, namely sample A, sample B, and sample C. At the same time, the substrate without the spin-coated coating is used as sample D. The above samples are subjected to ultraviolet spectroscopy detection, and sample D is used for baseline calibration. Sample A and sample B are placed in an air environment with 1% HF. Sample A is placed in the environment for 3 seconds, and sample B is placed in the environment for 5 seconds. Sample C is not placed in the air environment with 1% HF. Samples A, B, and C are immediately placed in the instrument for detection, and the coating of sample B changes from colorless to blue after being placed in the environment for 5 seconds. The specific detection results of the above samples are as follows: UV-visible spectra. Figure 6 As shown, the coating polymer in sample B undergoes protonation 5 seconds after encountering HF stimulation, resulting in an increase in absorbance at 630 nm, which is macroscopically manifested as a blue color.

[0057] Based on this, the high-viscosity resin coating for visual detection of hydrogen fluoride provided by the present invention can be set on the outer wall of the HF storage tank. When hydrogen fluoride leaks and encounters the outer coating, it will immediately turn blue-green, thereby reminding the staff of HF leakage, achieving the purpose of preventing accidents and effectively ensuring safety.

[0058] The present invention proposes a high-viscosity resin coating for visual detection of hydrogen fluoride and a preparation method thereof. A polymer with a rapid stimulus response is obtained through free radical polymerization and then coated on the outer wall of a hydrogen fluoride storage tank. The coating has excellent moldability and adhesion. After contact with hydrogen fluoride, the coating can quickly respond to color change within 5 seconds, enabling timely detection of hydrogen fluoride leaks and avoiding safety accidents.

Claims

1. Application of a high-viscosity resin coating in visual detection of hydrogen fluoride, characterized in that: The high viscosity resin coating comprises, by weight percentage, 10-50 wt% of acrylate, 0-30 wt% of vinyl ether, 2-40 wt% of vinyl carbazole, 0.1-10 wt% of initiator, and the remainder of solvent; The vinyl ether substance is one of hydroxybutyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, hydroxyethyl vinyl ether, and cyclohexyl vinyl ether; The acrylate is one of methacrylate, methyl acrylate, ethyl acrylate, and fluorine-containing acrylate; The initiator is one of azobisisobutyronitrile, dibenzoyl peroxide, tert-butyl peroxypivalate, azobisisoheptanenitrile, and dicyclohexyl peroxydicarbonate; the solvent is one of N,N-dimethylformamide, butyl acetate, ethyl acetate, and dimethyl sulfoxide; Used to detect hydrogen fluoride leakage, dilute the high-viscosity resin coating and evenly apply it on the outer wall of the hydrogen fluoride storage tank, then dry it.

2. The application of the high-viscosity resin coating according to claim 1 in the visual detection of hydrogen fluoride, characterized in that: Acrylate, vinyl ether and vinyl carbazole are added to a solvent, stirred and dissolved to obtain a clear and transparent solution, an initiator is added, the temperature is raised under stirring conditions, and polymerization reaction is carried out for a period of time to obtain a transparent high-viscosity resin coating.

3. The application of the high-viscosity resin coating in the visual detection of hydrogen fluoride according to claim 2, characterized in that: The temperature is raised to 60-90° C. and the polymerization reaction is carried out for 16-24 hours.

4. The use of the high-viscosity resin coating according to claim 2 in the visual detection of hydrogen fluoride, characterized in that: The viscosity of the high-viscosity resin coating is 500-8000 Pa·s.

5. The application of the high-viscosity resin coating according to claim 1 in the visual detection of hydrogen fluoride, characterized in that: Dilute high viscosity resin coating 10-20 times with solvent.

6. The use of the high-viscosity resin coating according to claim 1 in the visual detection of hydrogen fluoride, characterized in that: The drying temperature is 60-100° C. and the drying time is 5-18 hours.

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