Two-component coating with radionuclide adsorption and peelable functions as well as preparation method and application of two-component coating

Abstract

The invention relates to the technical field of polymer composite materials and radiation protection, in particular to a two-component coating with radionuclide adsorption and peelable functions as well as a preparation method and application thereof, and the two-component coating comprises a component A and a component B, wherein the component A is prepared from the following raw materials in parts by weight: 50 to 70 parts of amino-terminated polydimethylsiloxane; 20 to 30 parts of modified polyaspartic acid ester resin; 5 to 10 parts of diethyltoluenediamine; 20-40 parts of a composite functional filler; 2-5 parts of fumed silica; 2 to 4 parts of ethylene bis-12-hydroxystearic acid amide; 1-2 parts of a dispersant; 0.5 to 1 part of a defoaming agent; the component B comprises an isocyanate prepolymer; the composite functional filler comprises organic bentonite, crown ether and bis (2, 4, 4-trimethylpentyl) phosphonic acid. Through molecular structure design and function compounding, the synergistic effect of rapid curing, high strength, good peelability and efficient decontamination of radionuclides is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high polymer composite materials and radiation protection, and particularly relates to a two-component coating with radionuclide adsorption and peelable functions, a preparation method thereof and application thereof. BACKGROUND

[0002] During the operation, maintenance and decommissioning of nuclear power facilities, the surfaces of equipment and buildings are easily contaminated by radionuclides (such as 137 Cs, 90 Sr, 60 Co, etc.). Traditional decontamination methods (such as high-pressure water flushing and chemical reagent scrubbing) have low efficiency, generate a large amount of secondary waste liquid, and pose a high risk of radiation exposure to operators.

[0003] Peelable coating is a highly efficient decontamination technology, which forms a solidified film on the contaminated surface, fixes the contaminants in the film, and then removes the contaminants by peeling off the film. In recent years, researchers have attempted to develop composite peelable coatings. The closest prior art, US6458441B1, US5763734A, US2021238463A1, WO9823692A1, CN114773973A, CN118185451A, WO2021132383A1, CN114854291A, CN109207049A (relating to two-component modified polyurethane peelable coating), JP2005255928A (relating to solvent-free organic silicon), JPH0616944A (relating to organic silicon solidified coating film), and DE19653585A1 describe a polyurea dispersion that is transparent, high gloss, UV resistant, temperature resistant (-30 to 80°C), and resistant to deposits after drying at 20 to 100°C (preferably at 20 to 80°C), which is well adhered on one hand and can be easily removed by peeling on the other hand. However, its adhesion is weak, and it does not have the function of selective adsorption of radionuclides.

[0004] In the prior art, polyurea coatings are widely used due to their excellent mechanical properties and rapid curing characteristics, but their peelability is poor; silicone coatings have good peelability but lack mechanical strength. In addition, traditional peelable coatings are mainly aimed at physical loose contamination, and lack the ability of active and selective adsorption and purification of chemically adsorbed radionuclides, especially uranium (U), cesium (Cs), strontium (Sr), etc.

[0005] Therefore, the development of a new type of coating that can firmly adhere to the substrate to provide protection, efficiently adsorb and fix radionuclides, and be completely peeled off when needed, is of great significance for the decontamination of nuclear facilities, waste minimization, and personnel protection.

[0006] In view of this, the present invention aims to provide a two-component organosilicon-modified polyurea coating and its preparation method, which has both high efficiency in removing radionuclides and peelable properties. The coating has the advantages of high strength, corrosion resistance and rapid curing of polyurea materials, as well as the easy peelability and chemical stability of organosilicon materials. It can also efficiently adsorb radionuclides through specific functional fillers, so as to achieve the comprehensive goals of surface protection, pollution removal and waste minimization. Summary of the Invention

[0007] To address the shortcomings of existing technologies, a two-component organosilicon-modified polyurea coating and its preparation method are provided, which combine highly efficient radionuclide removal capabilities with peelable properties. This coating possesses the advantages of high strength, corrosion resistance, and rapid curing of polyurea materials, as well as the easy peelability and chemical stability of organosilicon materials. Furthermore, it can efficiently adsorb radionuclides through specific functional fillers, achieving the comprehensive goals of surface protection, contamination removal, and waste minimization.

[0008] To solve the above problems, the technical solution of the present invention is as follows:

[0009] A two-component coating that combines radionuclide adsorption and peelability includes component A and component B;

[0010] Component A comprises the following raw materials in parts by weight:

[0011] 50-70 parts of amino-terminated polydimethylsiloxane;

[0012] 20-30 parts of modified polyaspartic acid ester resin;

[0013] 5-10 parts of diethyltoluenediamine;

[0014] 20-40 parts of composite functional filler;

[0015] 2-5 parts of fumed silica;

[0016] 2-4 parts of ethylene bis-12-hydroxystearamide;

[0017] 1-2 parts dispersant;

[0018] 0.5-1 part defoamer;

[0019] The dispersants are BYK-2013, BYK-110, and BYK-164, and the defoamers are Deqian AP1622 and BYK-A530.

[0020] Component B includes isocyanate prepolymer;

[0021] The composite functional filler includes organic bentonite, crown ether, and bis(2,4,4-trimethylpentyl)phosphonic acid (trade name Cyanex 272).

[0022] As an improvement to the two-component coating of this invention, which combines radionuclide adsorption and peelability, component A comprises the following raw materials in parts by weight:

[0023] Component A comprises the following raw materials in parts by weight:

[0024] 55-65 parts of amino-terminated polydimethylsiloxane;

[0025] 22-28 parts of modified polyaspartic ester resin;

[0026] 6-9 parts of diethyltoluenediamine;

[0027] 25-35 parts of composite functional filler;

[0028] 3-4 parts of fumed silica;

[0029] Ethylene bis-12-hydroxystearamide 2.5-3.5 parts;

[0030] Dispersant 1.2-1.8 parts;

[0031] 0.6-0.9 parts of defoamer.

[0032] As an improvement to the two-component coating of this invention, which combines radionuclide adsorption and peelability, component A comprises the following raw materials in parts by weight:

[0033] 60 parts of amino-terminated polydimethylsiloxane;

[0034] 25 parts of modified polyaspartic acid ester resin;

[0035] 8 parts of diethyltoluenediamine;

[0036] 30 parts of composite functional filler;

[0037] 3.5 parts of fumed silica;

[0038] 3 parts of ethylene bis-12-hydroxystearamide;

[0039] 1.5 parts dispersant;

[0040] 0.7 parts of defoamer.

[0041] As an improvement to the two-component coating of the present invention that combines radionuclide adsorption and peelability, the volume ratio of component A to component B is 1:(0.5-2), preferably 1:1.

[0042] As an improvement of the two-component coating of the present invention, which combines radionuclide adsorption and peelability, the NCO mass content of the isocyanate prepolymer is 8%-16%.

[0043] As an improvement to the two-component coating of the present invention, which combines radionuclide adsorption and peelability, the molar ratio (NCO:NH) of isocyanate groups to amine groups after mixing component A and component B is 1.05-1.10.

[0044] As an improvement of the two-component coating of the present invention, which has both radionuclide adsorption and peelable functions, the crown ether is dicyclohexyl-18-crown-6 (DCH18C6), and the mass ratio of the organo-bentonite, crown ether and bis(2,4,4-trimethylpentyl)phosphonic acid Cyanex 272 is 100:(15-25):(20-30).

[0045] As an improvement of the two-component coating of the present invention, which has both radionuclide adsorption and peelable functions, the isocyanate prepolymer is compounded from hexamethylene diisocyanate (HDI) trimer and isophorone diisocyanate (IPDI) in a mass ratio of (55-65):(45-35).

[0046] This invention also provides a method for preparing a two-component coating that combines radionuclide adsorption and peelability, comprising at least the following steps:

[0047] (1) Preparation of component A: Amine-terminated polydimethylsiloxane, modified polyaspartic acid ester resin, and diethyltoluene diamine were added to a dispersion vessel and stirred. Then, fumed silica, dispersant, defoamer and ethylene bis-12-hydroxystearamide were added and stirred. Finally, composite functional filler slurry was added and dispersed. After the fineness was tested to be ≤30μm, the material was discharged to obtain component A.

[0048] (2) Preparation of component B: Prepare isocyanate prepolymer with NCO content of 8%-16%;

[0049] (3) Package components A and B separately and mix them according to the ratio during construction.

[0050] This invention also provides an application of a two-component coating with both radionuclide adsorption and peelable functions in the surface protection and radioactive contamination decontamination of nuclear facilities and equipment.

[0051] Compared with the prior art, the present invention has the following significant advantages:

[0052] By successfully combining the strength of polyurea, the peelability of organosilicon, and the adsorption properties of functional fillers through physical compounding, the performance contradictions were resolved. The crown ether in the composite functional filler has extremely high selective complexation ability for Cs and Sr; Cyanex272 has excellent extraction performance for U. The two work synergistically to achieve highly efficient adsorption (>98%) of a variety of key nuclides.

[0053] This invention also features excellent peelability. Specifically, ethylene bis-12-hydroxystearamide, as a peelability modifier, can form a weak boundary layer at the coating-substrate interface, ensuring that the coating can be completely and cleanly peeled off after service, leaving no residue. The system has a high solids content and low VOC (coating VOC content <120g / L). It converts liquid pollution into solid waste, greatly reducing the generation of secondary waste liquid and the risk of radiation exposure to operators. The two-component design is suitable for conventional spraying equipment, with fast curing speed and high efficiency.

[0054] In summary, this invention combines the high strength and toughness of polyurea with the peelability and chemical stability of organosilicon through molecular design, and innovatively introduces composite functional fillers, enabling the cured coating to efficiently and selectively adsorb the radioactive nuclide Cs. + 、Sr 2+ And U, and can be completely peeled off from the substrate surface after decontamination, fixing radioactive contaminants in the coating for removal, thus achieving integrated protection, decontamination, and waste minimization, which is particularly suitable for surface contamination control during the decommissioning and maintenance of nuclear facilities. This invention effectively combines four major functions—rapid curing, high strength and corrosion resistance, good peelability, and efficient decontamination of radionuclides—through molecular structure innovation and functional composite innovation. Attached Figure Description

[0055] Figure 1 The images show the FTIR infrared spectra of Embodiment 1 and Comparative Example 3 of the present invention.

[0056] Figure 2 The images show the FTIR infrared spectra of Examples 1, 1, and 3 of this invention.

[0057] Figure 3 These are the infrared difference spectra of Example 1 and Comparative Example 1 in this invention.

[0058] Figure 4 This is a graph showing the glass transition temperature change, modulus, and loss factor analysis of Example 1 in this invention.

[0059] Figure 5 The above are electron energy spectrum information diagrams of Example 1 and Comparative Example 1 in this invention. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Unless otherwise stated, all performance tests in this section are conducted under standard environmental conditions of temperature (23±2)℃ and relative humidity (50±5)%, and follow the following test standards:

[0061] Tensile strength and elongation at break: determined according to GB / T 528-2009 Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber, using type I dumbbell-shaped specimens.

[0062] Tear strength: Tested according to GB / T 529-2008 Determination of tear strength of vulcanized rubber or thermoplastic rubber (trouser-shaped, right-angled and crescent-shaped specimens), using right-angled specimens.

[0063] Peelability: Tested and evaluated as follows: A 1.0 mm dry film thickness coating was sprayed onto a 150 mm × 70 mm × 1 mm 304 stainless steel sheet (surface polished to Ra = 0.8 μm, cleaned and dried with ethanol), and cured at room temperature for 24 hours. Subsequently, starting from one corner of the coating with a blade, an attempt was made to peel the coating off the substrate by hand at approximately 90° or 180° angles. The ease of peeling and the surface condition of the substrate were used to rate the coating, according to the following criteria:

[0064] Advantages: It can be used to easily peel off the coating from the corners and can peel off the entire coating film continuously and completely with uniform and moderate force (feel), without the coating itself breaking, and without any visible paint residue on the substrate surface.

[0065] Good: It can be completely peeled off, but it feels difficult during the peeling process, or the coating is slightly elongated or thinned, but there is basically no residue on the substrate surface.

[0066] Poor: Cannot be peeled off; the coating breaks due to cohesive failure during peeling, or a large area of ​​the coating is firmly adhered to the substrate and cannot be peeled off.

[0067] Radionuclide adsorption rate: The sample and solution were prepared according to the method described in the instruction manual. The concentration change of the solution before and after adsorption was determined by inductively coupled plasma mass spectrometry (ICP-MS) and calculated.

[0068] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0069] The preparation of the composite functional filler, component B, and two-component coating are described in detail below. These preparation processes are applicable to Examples 1-5 below.

[0070] (I) Preparation of composite functional fillers:

[0071] First, organo-modified bentonite was prepared: 100 parts by weight of sodium-based bentonite (800 mesh) was dispersed in deionized water to prepare a slurry with a solid content of 10%. 30 parts by weight of octadecyltrimethylammonium chloride (OTAC) were added, and the mixture was reacted at 75°C for 3 hours. After the reaction, the mixture was repeatedly washed with deionized water and ethanol until no chloride ions were detected (no white precipitate was found when tested with 0.1 mol / L AgNO3 solution). After filtration, the mixture was vacuum dried at 70°C for 6 hours and then ground through an 800-mesh sieve to obtain organo-modified bentonite.

[0072] Preparation of composite functional filler slurry: 100 parts by weight of the above-mentioned organo-modified bentonite were dispersed in 30 parts by weight of S-150 solvent oil. Corresponding parts by weight of dicyclohexyl-18-crown-6 (DCH18C6) and corresponding parts by weight of Cyanex 272 were added sequentially. The mixture was sheared and dispersed at 5000 rpm for 40 minutes at 55°C to form a uniform paste slurry, which was then sealed for later use.

[0073] (II) Preparation of component B:

[0074] Weigh out a measured amount of isocyanate prepolymer under dry conditions with ambient humidity below 60%. This prepolymer is a compound of hexamethylene diisocyanate (HDI) trimer and isophorone diisocyanate (IPDI) prepolymer. All equipment and containers in contact with the material must be kept clean and dry to prevent moisture contamination.

[0075] First, add the weighed hexamethylene diisocyanate (HDI) into a dry vacuum reactor equipped with a stirrer, thermometer, and condenser. Turn on the stirrer and slowly and evenly add the weighed IPDI at a low speed of 100-300 rpm.

[0076] After feeding, adjust and maintain the stirring speed at 500-800 rpm to ensure thorough mixing of the two prepolymers. Mix for 30 minutes until the entire system becomes a homogeneous and transparent liquid, with no visible layering or streaks. During mixing, control the material temperature between room temperature and 50°C to avoid localized overheating. After uniform mixing, perform vacuum degassing at a vacuum degree of -0.09 MPa for 20-30 minutes. After passing inspection, filter and fill using a 200-300 mesh filter.

[0077] (III) Preparation of two-component coatings:

[0078] Application and Curing: Mix component A and component B in the specified proportions and apply using a two-component sprayer. Spray until the dry film thickness is 1.0 mm. The surface drying time of the coating at room temperature is ≤10 minutes, and the complete curing time is 6 hours.

[0079] Example 1

[0080] Preparation of component A of the coating:

[0081] Component A (resin base) is prepared according to the following weight ratio:

[0082] Amine-terminated polydimethylsiloxane (amine value 2.0 mmol / g): 60 parts

[0083] Modified polyaspartic acid ester resin: 25 parts

[0084] Diethyltoluenediamine (DETDA): 8 parts

[0085] Composite functional filler slurry: 30 parts

[0086] Fumed silica (thixotropic agent): 3 parts

[0087] Ethylene bis-12-hydroxystearamide (peelability modifier): 3 parts

[0088] Dispersant (BYK-164): 1.5 parts

[0089] Defoamer (BYK-530): 0.5 parts

[0090] Preparation process: Amine-terminated polydimethylsiloxane, modified polyaspartic acid ester resin, and DETDA were added to a dispersion vessel and stirred at 500 rpm for 10 minutes. Fumed silica, dispersant, defoamer, and ethylene bis-12-hydroxystearamide were added, and the stirring speed was increased to 1500 rpm, and dispersion was continued for 30 minutes. Finally, the composite functional filler slurry was added, the stirring speed was increased to 2000 rpm, and dispersion was continued for 30 minutes. After the fineness was checked and found to be ≤30 μm, the material was discharged to obtain component A.

[0091] Preparation of component B of the coating:

[0092] Component B (curing agent) is prepared according to the following weight ratio:

[0093] 60 parts of hexamethylene diisocyanate (HDI) trimer

[0094] 40 parts of isophorone diisocyanate (IPDI) prepolymer (NCO% = 11%)

[0095] Application and Curing: Mix component A and component B in the specified proportions and apply using a two-component sprayer. Spray until the dry film thickness is 1.0 mm. The surface drying time of the coating at room temperature is ≤10 minutes, and the complete curing time is 6 hours.

[0096] Comparative Example 1

[0097] Prepare a coating without composite functional fillers. Component A does not contain composite functional filler slurry, and the remaining components and preparation process are the same as in Example 1.

[0098] Comparative Example 2

[0099] Prepare a coating that does not contain ethylene bis-12-hydroxystearamide (peelability modifier). Component A does not contain ethylene bis-12-hydroxystearamide; the remaining components and preparation process are the same as in Example 1.

[0100] Comparative Example 3

[0101] Uses a conventional polyurea system (without silicone modification).

[0102] Tests were conducted on Example 1 and Comparative Example 1 / 3, and the results are shown in [the table below]. Figures 1-5 .

[0103] from Figure 1 It can be seen that both Example 1 and Comparative 3 show the characteristic peaks of polyurea: NH, C=O, CN. Example 1 shows a strong characteristic peak of organosilicon: Si-O-Si (1080 cm⁻¹). -1 Si-CH31260cm -1 800cm- 1 The COC peak of crown ethers is 1120 cm⁻¹. 1 The P=O peak of Cyanex 272 is 1230 cm⁻¹. 1 The modified Example 1 retained the four characteristic peaks of polyurea, with slight changes in intensity and position, and new characteristic peaks appeared, proving that these functional fillers were effectively introduced into the final composite coating.

[0104] from Figure 2 The upper middle peak represents the characteristic peak of polyurea; the middle peak represents the strong and broad peak of Si-O-Si inserted into the polyurea chain; the lower peak contains crown ether and Cyanex 272 functional additives.

[0105] from Figure 3 The infrared difference spectrum shows that: polyurea: 3320 cm⁻¹ 1 It is a hydrogen-bonded NH stretching vibration, 1640 cm⁻¹ 1 The stretching vibration of the urea carbonyl group (C=O) is 1540 cm⁻¹. 1 It is an NH bending vibration, 1220 cm- 1 It is a CN stretching vibration.

[0106] from Figure 4It can be seen that this polyurea-silicone coating successfully combines the advantages of pure polyurea and pure organosilicon through a clever microphase separation structure. As shown in the DSC and DMA curves, the glass transition temperature of the organosilicon soft segment shifts from -120℃ to -110℃, while that of the polyurea hard segment shifts from 80℃ to 60℃, causing the two Tg values ​​to converge. This migration phenomenon proves that the two phases are not completely miscible, forming independent phase regions (microphase separation), while also exhibiting beneficial interfacial interactions. As a result, the storage modulus curve of this material is exceptionally flat and high over a wide temperature range of -30℃ to 80℃, stabilizing at approximately 10. 8.8 This coating avoids the problems of a sharp drop in modulus at high temperatures in pure polyurea and the consistently low modulus in pure organosilicon. Therefore, in environments with drastic temperature variations, such as nuclear facilities, this coating achieves more balanced and stable mechanical properties, providing more reliable protection.

[0107] from Figure 5 It can be seen that the U and Cs peaks of the high-energy region embodiment are very obvious and have high intensity, while the corresponding peaks of the comparative example are almost invisible. The Sr peak of the low-energy region embodiment is obvious, and there are B and Si peaks. The comparative example only has a very weak Sr peak and no B and Si peaks. The results show that the embodiment has excellent decontamination effect and can effectively adsorb U, Cs and Sr, while the comparative example has almost no adsorption capacity.

[0108] Example 2

[0109] This embodiment provides a two-component coating that combines radionuclide adsorption and peelability, characterized in that it includes component A and component B;

[0110] Component A comprises the following raw materials in parts by weight:

[0111] 55 parts of amino-terminated polydimethylsiloxane;

[0112] 22 parts of modified polyaspartic acid ester resin;

[0113] 8 parts of diethyltoluenediamine;

[0114] 35 parts of composite functional filler;

[0115] 2.5 parts of fumed silica;

[0116] 2.5 parts of ethylene bis-12-hydroxystearamide;

[0117] 1.2 parts dispersant;

[0118] 0.8 parts of defoamer;

[0119] Component B includes an isocyanate prepolymer; the NCO content of the isocyanate prepolymer is 12% by mass; after mixing components A and B, the molar ratio of isocyanate groups to amine groups (NCO:NH) is 1.07. The isocyanate prepolymer is compounded from hexamethylene diisocyanate (HDI) trimer and isophorone diisocyanate (IPDI) at a mass ratio of 58:42.

[0120] The composite functional filler includes organo-bentonite, crown ether, and Cyanex 272. The crown ether is dicyclohexyl-18-crown-6 (DCH18C6), and the mass ratio of organo-bentonite, crown ether, and Cyanex 272 is 100:18:28.

[0121] The volume ratio of component A to component B is 1:1.

[0122] Its preparation method includes at least the following steps:

[0123] (1) Preparation of component A: Amine-terminated polydimethylsiloxane, modified polyaspartic acid ester resin, and diethyltoluene diamine were added to a dispersion vessel and stirred. Then, fumed silica, dispersant, defoamer and ethylene bis-12-hydroxystearamide were added and stirred. Finally, composite functional filler slurry was added and dispersed. After the fineness was tested to be ≤30μm, the material was discharged to obtain component A.

[0124] (2) Preparation of component B: Prepare an isocyanate prepolymer with an NCO content of 12%;

[0125] (3) Package components A and B separately and mix them according to the ratio during construction.

[0126] Example 3

[0127] This embodiment provides a two-component coating that combines radionuclide adsorption and peelability, characterized in that it includes component A and component B;

[0128] Component A comprises the following raw materials in parts by weight:

[0129] 65 parts of amino-terminated polydimethylsiloxane;

[0130] 21 parts of modified polyaspartic acid ester resin;

[0131] 6 parts of diethyltoluenediamine;

[0132] 28 parts of composite functional filler;

[0133] 3.5 parts of fumed silica;

[0134] 3.5 parts of ethylene bis-12-hydroxystearamide;

[0135] 1.6 parts dispersant;

[0136] 0.7 parts of defoamer;

[0137] Component B includes an isocyanate prepolymer; the NCO content of the isocyanate prepolymer is 11% by mass; after mixing components A and B, the molar ratio of isocyanate groups to amine groups (NCO:NH) is 1.08. The isocyanate prepolymer is compounded from hexamethylene diisocyanate (HDI) trimer and isophorone diisocyanate (IPDI) at a mass ratio of 62:38.

[0138] The composite functional filler includes organo-modified bentonite, crown ether, and Cyanex 272. The crown ether is dicyclohexyl-18-crown-6 (DCH18C6), and the mass ratio of organo-modified bentonite, crown ether, and Cyanex 272 is 100:22:23.

[0139] The volume ratio of component A to component B is 1:1.

[0140] Its preparation method includes at least the following steps:

[0141] (1) Preparation of component A: Amine-terminated polydimethylsiloxane, modified polyaspartic acid ester resin, and diethyltoluene diamine were added to a dispersion vessel and stirred. Then, fumed silica, dispersant, defoamer and ethylene bis-12-hydroxystearamide were added and stirred. Finally, composite functional filler slurry was added and dispersed. After the fineness was tested to be ≤30μm, the material was discharged to obtain component A.

[0142] (2) Preparation of component B: Prepare an isocyanate prepolymer with an NCO content of 11%;

[0143] (3) Package components A and B separately and mix them according to the ratio during construction.

[0144] Example 4

[0145] This embodiment provides a two-component coating that combines radionuclide adsorption and peelability, characterized in that it includes component A and component B;

[0146] Component A comprises the following raw materials in parts by weight:

[0147] 55 parts of amino-terminated polydimethylsiloxane;

[0148] 27 parts of modified polyaspartic acid ester resin;

[0149] 7 parts of diethyltoluenediamine;

[0150] 32 parts of composite functional filler;

[0151] 4.5 parts of fumed silica;

[0152] 3.2 parts of ethylene bis-12-hydroxystearamide;

[0153] 1.4 parts dispersant;

[0154] 0.9 parts of defoamer;

[0155] Component B includes isocyanate prepolymer; the NCO content of the isocyanate prepolymer is 13%; after mixing components A and B, the molar ratio of isocyanate groups to amine groups (NCO:NH) is 1.09.

[0156] The isocyanate prepolymer is a compound of hexamethylene diisocyanate (HDI) trimer and isophorone diisocyanate (IPDI) in a mass ratio of 56:44.

[0157] The composite functional filler includes organo-modified bentonite, crown ether, and Cyanex 272. The crown ether is dicyclohexyl-18-crown-6 (DCH18C6), and the mass ratio of organo-modified bentonite, crown ether, and Cyanex 272 is 100:16:28.

[0158] The volume ratio of component A to component B is 1:1.

[0159] Its preparation method includes at least the following steps:

[0160] (1) Preparation of component A: Amine-terminated polydimethylsiloxane, modified polyaspartic acid ester resin, and diethyltoluene diamine were added to a dispersion vessel and stirred. Then, fumed silica, dispersant, defoamer and ethylene bis-12-hydroxystearamide were added and stirred. Finally, composite functional filler slurry was added and dispersed. After the fineness was tested to be ≤30μm, the material was discharged to obtain component A.

[0161] (2) Preparation of component B: Prepare an isocyanate prepolymer with an NCO content of 13%;

[0162] (3) Package components A and B separately and mix them according to the ratio during construction.

[0163] Example 5

[0164] This embodiment provides a two-component coating that combines radionuclide adsorption and peelability, characterized in that it includes component A and component B;

[0165] Component A comprises the following raw materials in parts by weight:

[0166] 64 parts of amino-terminated polydimethylsiloxane;

[0167] 24 parts of modified polyaspartic acid ester resin;

[0168] 7.5 parts of diethyltoluenediamine;

[0169] 24 parts of composite functional filler;

[0170] 2.5 parts of fumed silica;

[0171] 2.4 parts of ethylene bis-12-hydroxystearamide;

[0172] 1.5 parts dispersant;

[0173] 0.7 parts of defoamer;

[0174] Component B includes an isocyanate prepolymer; the NCO content of the isocyanate prepolymer is 15% by mass; after mixing components A and B, the molar ratio of isocyanate groups to amine groups (NCO:NH) is 1.1. The isocyanate prepolymer is compounded from hexamethylene diisocyanate (HDI) trimer and isophorone diisocyanate (IPDI) at a mass ratio of 59:41.

[0175] The composite functional filler includes organo-bentonite, crown ether, and Cyanex 272. The crown ether is dicyclohexyl-18-crown-6 (DCH18C6), and the mass ratio of organo-bentonite, crown ether, and Cyanex 272 is 100:25:30.

[0176] The volume ratio of component A to component B is 1:1.

[0177] Its preparation method includes at least the following steps:

[0178] (1) Preparation of component A: Amine-terminated polydimethylsiloxane, modified polyaspartic acid ester resin, and diethyltoluene diamine were added to a dispersion vessel and stirred. Then, fumed silica, dispersant, defoamer and ethylene bis-12-hydroxystearamide were added and stirred. Finally, composite functional filler slurry was added and dispersed. After the fineness was tested to be ≤30μm, the material was discharged to obtain component A.

[0179] (2) Preparation of component B: Prepare an isocyanate prepolymer with an NCO content of 15%;

[0180] (3) Package components A and B separately and mix them according to the ratio during construction.

[0181] The performance of Examples 1-5 and Comparative Examples 1-3 was tested, and the results are shown in the table below:

[0182]

[0183]

[0184] In the peelability test, the test substrate was a 304 stainless steel plate with dimensions of 150mm×70mm×1mm. The surface was sanded to Ra=0.8μm, cleaned with ethanol, and then dried.

[0185] As shown in Table 1, this invention successfully prepared a peelable coating with both excellent protective properties and radionuclide decontamination function through molecular structure innovation (polyurea-organosilicon hybridization) and functional composite innovation (bentonite-crown ether-Cyanex 272 composite functional filler), resolving the contradiction between strength and peelability. As shown in Example 1, the tensile strength reaches 15.2 MPa while maintaining 370% elongation at break and complete peelability, achieving efficient synergistic adsorption of multiple nuclides. Example 1 shows the effect on Cs... + 、Sr 2+ and UO2 2+ The adsorption rates reached 92.5%, 90.8%, and 92.8%, respectively, far exceeding those of Comparative Example 1 (<30%) and Comparative Example 3 (<40%, mainly due to strong adhesion). The adsorption rates of the three substances in the other examples were also significantly higher than those of Comparative Example 1. Comparative Example 2 could not be completely peeled off (due to the lack of a specific component), and Comparative Example 3 could not be peeled off using traditional polyurea coatings. This indicates a synergistic effect between bentonite, crown ether, and Cyanex 272, rather than a simple additive effect. Using organic bentonite as a carrier, simultaneously loading crown ether (Cs...) + 、Sr 2+ The combination of capture and Cyanex 272 has created an integrated solution for radionuclide adsorption and fixation that can be peeled off, solving the industry problems of large waste volume and high risk of secondary pollution from traditional decontamination technologies.

[0186] To further verify the synergistic effect of the composite functional filler, the present invention also conducted the following adsorption experiments:

[0187] Experimental solution: Prepared solution containing Cs + (1000mg / L), Sr 2+ (800mg / L), UO2 2+ A simulated radionuclide solution of (500 mg / L) was prepared, and the pH was adjusted to 6.0 ± 0.2 using HNO3 / NaOH.

[0188] Adsorption process: Take 50 mg of coating powder and add it to 50 mL of radionuclide solution, and shake at 25 °C for 96 hours.

[0189] Concentration determination: The changes in ion concentration before and after adsorption were determined by ICP-MS, and the results are shown in Table 2.

[0190] The adsorption rate is calculated using the formula: Adsorption rate = C0 - C e / C0×100%, where: C0 is the initial concentration, C eResidual concentration

[0191] Table 2: Adsorption test results of the three components in the composite functional packing.

[0192]

[0193] The data in Table 2 provide the following conclusions, which fully demonstrate the existence of the synergistic effect:

[0194] For Cs + Adsorption: The adsorption rate of the composite filler (92.5%) was significantly higher than the highest adsorption rate of any single component (crown ether, 68.5%), indicating that the presence of bentonite and Cyanex 272 significantly enhanced the adsorption of Cs by the crown ether. + Its capture capability.

[0195] For Sr 2+ and UO2 2+ Adsorption: Adsorption rates of the composite packing material (90.8% and 92.8%, respectively), Sr 2+ The adsorption rate exceeded the arithmetic sum of the adsorption rates of the three components, demonstrating significant synergistic performance.

[0196] In summary, the organic bentonite, crown ether, and Cyanex 272 are not simply a physical mixture, but rather a composite system with an extraordinary adsorption capacity for a variety of radionuclides through functional complementarity and interaction.

[0197] The above embodiments fully demonstrate the inventiveness and technological advancement of the present invention, and have broad application prospects in the fields of nuclear facility decommissioning, temporary surface and interface protection, contamination containment, and nuclear emergency response.

[0198] Rapid curing and workability: Examples 1-5 maintain the rapid curing characteristics of polyurea materials (surface dry in 10 minutes), which is due to the rapid AB component reaction characteristics of polyurea itself, meeting the needs of efficient construction.

[0199] Excellent mechanical properties and peelability: Examples 1-5 achieve a balance between high tensile strength and moderate elongation at break. Compared to Comparative Example 3, tensile strength and tear strength are significantly improved, which is attributed to the reinforcing effect formed by the microphase separation of silicone segments and polyurea hard segments.

[0200] The addition of the peelability modifier enabled complete peeling of the cured coating by forming a weak boundary layer at the coating-substrate interface (Comparative Example 2 showed poor peelability, and Comparative Example 3 showed complete non-peelability). In addition to ethylene bis-12-hydroxystearamide, the low surface energy of organosilicon also significantly contributed to this property.

[0201] Innovative radionuclide decontamination function: This is the core innovation of this design.

[0202] Example 1 on Cs + The adsorption rate reached 92.5%, Sr 2+ The adsorption rate was 90.8%, UO2 2+ The adsorption rate was 92.8%, demonstrating extremely high efficiency (the same applies to the other examples). This is entirely due to the addition of a specially designed adsorbent with high selectivity and capacity for the target ions. Comparative Example 1, lacking this functional material, exhibited no adsorption performance whatsoever, fully demonstrating the crucial role of the modified filler.

[0203] Environmentally friendly and practical: The dense and seamless coating formed after spraying can provide long-term protection and can be completely peeled off after maintenance or contamination. Radioactive nuclides are fixed in the coating and can be centrally treated as solid waste, which greatly reduces secondary pollution and waste liquid generation, and achieves the integration of decontamination, protection and waste minimization.

[0204] This design successfully developed a novel two-component silicone-modified polyurea peelable coating. Through molecular structure innovation and functional composite innovation, it effectively integrates four major functions: rapid curing, high strength, good peelability, and efficient removal of radionuclides.

[0205] Experimental data show that its overall performance is significantly superior to traditional polyurea materials (Comparative Example 3), and its decontamination function is entirely achieved by a creatively introduced special adsorbent (Comparative Example 2). This coating has extremely high application value in the surface protection, emergency decontamination, and radioactive waste minimization of equipment in facilities such as nuclear power plants, nuclear fuel processing plants, and medical radiology departments, providing a brand-new material solution for solving problems in the field of nuclear environmental protection.

[0206] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A two-component coating that combines radionuclide adsorption and peelability, characterized in that, Includes component A and component B; Component A comprises the following raw materials in parts by weight: 50-70 parts of amino-terminated polydimethylsiloxane; 20-30 parts of modified polyaspartic acid ester resin; 5-10 parts of diethyltoluenediamine; 20-40 parts of composite functional filler; 2-5 parts of fumed silica; 2-4 parts of ethylene bis-12-hydroxystearamide; 1-2 parts dispersant; 0.5-1 part defoamer; The composite functional filler includes organic bentonite, crown ether, and bis(2,4,4-trimethylpentyl)phosphonic acid; Component B includes isocyanate prepolymer.

2. The two-component coating with both radionuclide adsorption and peelable functions according to claim 1, characterized in that, 55-65 parts of amino-terminated polydimethylsiloxane; 22-28 parts of modified polyaspartic ester resin; 6-9 parts of diethyltoluenediamine; 25-35 parts of composite functional filler; 3-4 parts of fumed silica; Ethylene bis-12-hydroxystearamide 2.5-3.5 parts; Dispersant 1.2-1.8 parts; 0.6-0.9 parts of defoamer.

3. The two-component coating with both radionuclide adsorption and peelable functions according to claim 2, characterized in that, Component A comprises the following raw materials in parts by weight: 60 parts of amino-terminated polydimethylsiloxane; 25 parts of modified polyaspartic acid ester resin; 8 parts of diethyltoluenediamine; 30 parts of composite functional filler; 3.5 parts of fumed silica; 3 parts of ethylene bis-12-hydroxystearamide; 1.5 parts dispersant; 0.7 parts of defoamer.

4. The two-component coating with both radionuclide adsorption and peelable functions according to any one of claims 1-3, characterized in that: The volume ratio of component A to component B is 1:(0.5-2).

5. The two-component coating with both radionuclide adsorption and peelable functions according to any one of claims 1-3, characterized in that: The NCO content of the isocyanate prepolymer is 8%-16% by mass.

6. The two-component coating with both radionuclide adsorption and peelable functions according to any one of claims 1-3, characterized in that: After mixing components A and B, the molar ratio of isocyanate groups to amine groups (NCO:NH) is 1.05-1.

10.

7. The two-component coating with both radionuclide adsorption and peelable functions according to any one of claims 1-3, characterized in that: The crown ether is dicyclohexyl-18-crown-6 (DCH18C6), and the mass ratio of the organo-bentonite, crown ether and bis(2,4,4-trimethylpentyl)phosphonic acid is 100:(15-25):(20-30).

8. The two-component coating with both radionuclide adsorption and peelable functions according to any one of claims 1-3, characterized in that: The isocyanate prepolymer is composed of hexamethylene diisocyanate (HDI) trimer and isophorone diisocyanate (IPDI) in a mass ratio of (55-65):(45-35).

9. A method for preparing a two-component coating with both radionuclide adsorption and peelable functions as described in any one of claims 1-8, characterized in that, It should include at least the following steps: (1) Preparation of component A: Amine-terminated polydimethylsiloxane, modified polyaspartic acid ester resin, and diethyltoluene diamine were added to a dispersion vessel and stirred. Then, fumed silica, dispersant, defoamer and ethylene bis-12-hydroxystearamide were added and stirred. Finally, composite functional filler slurry was added and dispersed. After the fineness was tested to be ≤30μm, the material was discharged to obtain component A. (2) Preparation of component B: Prepare isocyanate prepolymer with NCO content of 8%-16%; (3) Package components A and B separately and mix them according to the ratio during construction.

10. The application of the two-component coating with radionuclide adsorption and enrichment and peelability as described in any one of claims 1-8 in the surface protection and radioactive contamination decontamination of nuclear facilities and equipment.

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