CN116837639A - Strippable decontamination composite film capable of being rapidly solidified under sunlight and preparation method - Google Patents

Abstract

The invention provides a peelable stain removal composite film capable of being quickly cured under sunlight and a preparation method thereof, wherein the peelable stain removal composite film comprises a peelable layer and a reinforcing layer, and the peelable layer consists of 1-9 mol of a monomer A, 1-9 mol of a monomer B, 0.2-3 mol of a cross-linking agent, 0.01-1 mol of a photoinitiator, 1-60 mol of deionized water, 0.2-4 mol of dimethyl silicone oil and 0.2-5 mol of a stain remover; the reinforcing layer is non-woven fabric or polyethylene mesh cloth. The preparation method of the strippable decontamination composite film comprises the following steps: uniformly mixing a monomer, a cross-linking agent, a photoinitiator, deionized water, dimethyl silicone oil and a detergent according to a certain proportion to obtain a solution with a peelable layer; spraying the solution of the strippable layer on the reinforcing layer, and irradiating with sunlight in the decontamination operation to obtain the strippable decontamination composite film. The strippable decontamination film provided by the invention has the characteristics of no need of an external light source, quick film formation, high strength, easy stripping, excellent tear resistance and high film formation stripping rate, can be sprayed and used at a low temperature, and is particularly suitable for the field of radioactive decontamination in alpine regions.

Description

A peelable decontamination composite film that can be quickly cured under sunlight and its preparation method

Technical field

The invention belongs to the technical field of radioactive decontamination, and specifically relates to a high-strength, low-temperature-resistant peelable decontamination composite film that can be quickly cured under sunlight and a preparation method.

Background technique

Nuclear technology is increasingly used in civilian power generation, military, medical testing and treatment, industrial flaw detection and many other fields, and has become an indispensable and important part of national defense and people's production and life. However, during the processing and application of nuclear materials, radioactive contamination will occur to varying degrees; existing radioactive decontamination materials mainly include dry removers, decontamination agents, chemical foam/gel decontamination agents and peelable films Materials etc. Among them, the decontamination of peelable membrane materials has the advantages of simple spraying, easy peeling and recycling, no waste liquid, and easy mechanized operation. It is suitable for rapid decontamination of buildings, roads, large equipment and devices.

At present, the more common peelable films are organic solvent type, water-soluble (emulsion) type and UV curing type. For example, Lin Xiaoyan's research group published in the Journal of Southwest University of Science and Technology in 2020 a peelable film that uses polyethylene acetate as the film main body and ethyl acetate as its organic solvent. The polyethylene acetate needs to be dissolved in ethyl acetate. In the ester, wait for the ethyl acetate to evaporate and then dry to form a film. The drying time is about 5-7 hours. Wang Shanqiang’s research group published a semi-continuous emulsion method to copolymerize vinyl acetate and acrylic acid in the Journal of Southwest University of Science and Technology in 2019. A water-soluble peelable decontamination film is prepared using three monomers: butyl ester and polyvinyl alcohol. The water-soluble film material has the advantages of being non-toxic, harmless, and environmentally friendly, but the drying time to form a film exceeds 12 hours. In addition, water-soluble (emulsion) When the temperature of the system is lower than the freezing point, the water-soluble (emulsion) system will freeze or the polymer emulsion will break, making the peelable film unable to be used below 0°C; the existing UV peelable composite film needs to be processed in an oven for a period of time After a period of high-temperature baking, ultraviolet light is used to form a film, but high-temperature baking cannot be achieved in outdoor decontamination sites.

In addition, there are two main problems with existing mechanized peelable films: poor peelability and tear resistance of the peelable film. Due to the strong adhesion between the peelable film and the ground, it is difficult to peel the film body from the ground surface through the device. In addition, if the ground is uneven, holes are easily formed during the curing process of the film. Since the peelable film itself has poor tear resistance, The existence of holes makes the membrane easily torn during the peeling process, and the torn membrane is left on the ground. Therefore, in actual mechanized operations, the overall peelability rate of the membrane is very low.

Contents of the invention

(1) Technical problems to be solved

The present invention proposes a peelable decontamination composite film that can be quickly cured under sunlight and a preparation method to solve the technical problems of poor tear resistance and low peeling rate of existing mechanized peelable films.

(2) Technical solutions

In order to solve the above technical problems, the present invention proposes a peelable decontamination composite film that can be quickly cured under sunlight. The peelable decontamination composite film includes a reinforcement layer and a peelable layer sprayed on the reinforcement layer; wherein, massage The raw material components of the peelable layer include: monomer A 1 to 9 mol, monomer B 1 to 9 mol, cross-linking agent 0.2 to 3 mol, photoinitiator 0.01 to 1 mol, deionized water 1 to 60 mol, dimethyl silicone oil 0.2 ~4mol, detergent 0.2~5mol; monomer A is one of acrylic acid, methacrylic acid, itaconic acid, trans-aconitic acid, and maleic anhydride; monomer B is acrylamide, methacrylamide, A kind of vinylimidazole.

Further, the molar ratio of monomer A to monomer B is (1:9) to (9:1).

Further, the cross-linking agent is zirconium oxychloride octahydrate, zirconium sulfate, aluminum chloride hexahydrate, ferric chloride hexahydrate, zinc perchlorate hexahydrate, zinc sulfate heptahydrate, zinc nitrate hexahydrate, zinc iodide, A kind of water copper chloride.

Further, the photoinitiator is a visible light initiator.

Further, the visible light initiator is two to three of camphorquinone, diphenylsilane, diphenyliodonium hexafluorophosphate, and 4-dimethylamino-ethyl benzoate.

Further, the detergent is one or more of ethylenediaminetetraacetic acid, citric acid, and sodium dodecylbenzene sulfonate.

Further, the reinforcing layer is non-woven fabric or polyethylene mesh.

In addition, the present invention also proposes a method for preparing a peelable and decontamination composite membrane, which is characterized in that the preparation method includes the following steps:

S1. Weigh the raw materials according to the above ratio, mix the monomer, cross-linking agent, photoinitiator, deionized water, dimethyl silicone oil and detergent in proportion to obtain a peelable layer solution;

S2. Spray the peelable layer solution on the reinforcement layer and irradiate it with sunlight during the decontamination operation to obtain a peelable decontamination composite film.

Further, the duration of sunlight exposure is 5 to 30 minutes.

(3) Beneficial effects

The invention proposes a peelable and decontamination composite film that can be quickly cured under sunlight and a preparation method. The peelable and decontamination composite film includes a peelable layer and a reinforcing layer. The peelable layer is composed of the following components: Monomer A1 ~9mol, monomer B1~9mol, cross-linking agent 0.2~3mol, photoinitiator 0.01~1mol, deionized water 1~60mol, dimethyl silicone 0.2~4mol, detergent 0.2~5mol; the reinforcing layer is non-woven cloth or polyethylene mesh. The preparation method of the peelable and decontamination composite membrane is as follows: mix the monomer, cross-linking agent, photoinitiator, deionized water, dimethyl silicone oil and detergent in a certain proportion to obtain a peelable layer solution; The solution of the peeling layer is sprayed on the reinforcing layer, and the decontamination composite film can be peeled off after being irradiated by sunlight during the decontamination operation. The peelable decontamination film provided by the present invention has the characteristics of no external light source, fast film formation, high strength, easy peeling, excellent tear resistance, high film formation and peeling rate, and can be sprayed and used under low temperature conditions. Especially suitable for radioactive decontamination in alpine areas.

The beneficial effects of the present invention are specifically as follows:

1. The peelable layer solution in the present invention maintains a low viscosity state at -20°C, so even at the extreme temperature of -20°C, the peelable layer solution can be sprayed by machine without roller coating, reducing the process and saving money. Human and material costs.

2. The peelable layer in the present invention can be cured only by sunlight, without the need for external light sources and heating devices (such as traditional high-energy mercury lamps, ultraviolet lamps, ovens, etc.). The curing time is shortened to 5 to 30 minutes, which is convenient for operation. Reduce processes, save energy and environmental protection, and save labor and material costs.

3. Based on the metal coordination effect and the mechanism of metal salts lowering the freezing point of the solution, the peelable layer prepared by the present invention still has excellent strength and toughness at low temperatures, so the peelable layer can be used under extreme outdoor conditions of -20°C.

4. The present invention uses the reinforcing layer as a carrier to form a sandwich structure (peelable layer - reinforcing layer - peelable layer) between the reinforcing layer and the peelable layer. When using a machine to peel off, the reinforcing layer can be removed simply by dragging it up. The peelable layer is completely separated from the ground, which improves the overall peelability of the membrane body. The peelability rate is above 99.9%. At the same time, it is supported by a high-strength reinforcement layer, which fundamentally solves the problem of easy tearing of the peelable film.

5. The peelable decontamination composite film provided by the present invention is particularly suitable for rapid radioactive decontamination in alpine areas. It can be sprayed even at -20°C without the need for external light sources and heating equipment, and only requires sunlight irradiation. It can form a film quickly, and the film body has the characteristics of high strength, high toughness, excellent tear resistance, easy peeling, and high film peeling rate at -20°C.

Detailed ways

In order to make the purpose, content and advantages of the present invention clearer, specific implementation modes of the present invention will be further described in detail below in conjunction with examples.

The present invention proposes a high-strength, low-temperature-resistant peelable and decontamination composite film that can be quickly cured under sunlight. The peelable and decontamination composite film includes a reinforcing layer and a peelable layer sprayed on the reinforcing layer; wherein, massage Number, the raw material components of the peelable layer include: monomer A1~9mol, monomer B1~9mol, cross-linking agent 0.2~3mol, photoinitiator 0.01~1mol, deionized water 1~60mol, dimethyl silicone oil 0.2~4mol , Detergent 0.2~5mol.

Monomer A is one of acrylic acid AAc, methacrylic acid MAAc, itaconic acid IAc, trans-aconitic acid ACAc, and maleic anhydride MAH. The selected monomers contain carboxylate groups that can coordinate with metal salts to provide high strength to the peelable layer. Monomer B is one of acrylamide AAm, methacrylamide MAAm, and vinylimidazole VI. The selected monomer contains a C=C double bond, which can be copolymerized with monomer A, and generates a The hydrogen bonding effect can further improve the strength of the peelable layer.

In the present invention, the molar ratio of monomer A to monomer B is (1:9) to (9:1). If the molar ratio of monomer A to monomer B is too low, the viscosity of the peelable layer solution will become high, which is not conducive to spraying; if the molar ratio of monomer A to monomer B is too high, the strength of the peelable layer will be too low.

In the present invention, the cross-linking agent is zirconium oxychloride octahydrate ZrOCl ₂ ·8H ₂ O, zirconium sulfate Zr(SO ₄ ) ₂ , aluminum chloride hexahydrate AlCl ₃ ·6H ₂ O, and ferric chloride hexahydrate FeCl ₃ ·6H ₂ O, zinc perchlorate hexahydrate Zn(ClO ₄ ) ₂ ·6H ₂ O, zinc sulfate heptahydrate ZnSO ₄ ·7H ₂ O, zinc nitrate hexahydrate Zn(NO ₃ ) ₂ ·6H ₂ O, zinc iodide ZnI _2. One of copper chloride dihydrate CuCl ₂ ·2H ₂ O. The selected monomer contains metal ions, which can coordinate with monomer A to provide high strength to the peelable layer. The selected metal salt can lower the freezing point of the solution, so that the peelable layer solution has good low-temperature flow sprayability at -20°C, and the prepared peelable layer still has excellent strength and toughness at -20°C. The cross-linking agent is 0.2~3mol. If the cross-linking agent content is too low, the degree of cross-linking between functional groups will be reduced, which will lead to a reduction in the strength of the peelable layer. If the cross-linking agent content is too high, it will lead to excessive cross-linking between functional groups, which will lead to The peelable layer becomes brittle and its mechanical properties decrease.

In the present invention, the photoinitiator is two to three of camphorquinone CQ, diphenylsilane DPS, diphenyliodonium hexafluorophosphate Iod, and 4-dimethylamino-ethyl benzoate EDB. The selected photoinitiators are all visible light initiators. The photoinitiator is 0.01~1 mol. If the photoinitiator content is too low, the growth rate of the free radical chain during the photopolymerization reaction will be much lower than the chain termination rate of oxygen-inhibited polymerization. As a result, the induction period of the photopolymerization reaction will increase and the reaction will The rate is slow or even no reaction occurs; if the photoinitiator content is too high, the molecular weight distribution of the polymerized product will become wider and the molecular weight will become lower.

In the present invention, the deionized water is 1 to 60 mol. If the content of the deionized water is too low, the viscosity of the peelable layer solution will become high, which is not conducive to spraying; if the content of the deionized water is too high, the strength of the peelable layer will be too high. Low.

In the present invention, dimethyl silicone oil is 0.2 to 4 mol. The content of dimethyl silicone oil is too low, which cannot reduce the surface energy of the membrane body and reduce the bonding strength between the membrane body and the medium, and thus cannot improve the peelability of the membrane. ; If the proportion of dimethyl silicone oil in the system is too high, it will hinder the cross-linking reaction between monomers, making it difficult to cure the system.

In the present invention, the detergent is one or more of ethylenediaminetetraacetic acid EDTA, citric acid CA, and sodium dodecylbenzene sulfonate SDBS. EDTA can form stable water-soluble chelates with any metal ions except K ⁺ , Rb ⁺ , and Cs ⁺ ; CA can ionize a certain amount of hydrogen ions and change the value of the decontamination sol, thus contributing to the complexing agent coordination, and its own polycarboxyl structure can form complex ions with metal ions; SDBS sodium dodecylbenzene sulfonate is an anionic surfactant. On the one hand, it can coordinate with metal ions to improve decontamination efficiency. On the other hand, it is beneficial to improve the peelability of the decontamination film and improve the stability of the decontamination agent. The detergent content is 0.2 to 5 mol. The detergent content is too low and cannot remove surface contamination. As the detergent concentration increases, the decontamination first gradually increases and then remains basically unchanged.

In the present invention, the reinforcing layer is non-woven fabric or polyethylene mesh.

The method for preparing the above-mentioned peelable dirt-removing composite membrane includes the following steps:

S1. Weigh the raw materials according to the proportion, mix the monomer, cross-linking agent, photoinitiator, deionized water, dimethyl silicone oil and detergent in proportion to obtain a peelable layer solution;

S2. Spray the peelable layer solution on the reinforcement layer and irradiate it with sunlight to obtain a peelable and decontamination composite film.

The raw materials used in Examples 1-3 are: acrylic acid (>99%, ALADDIN, CAS#79-10-7), methacrylic acid (=>99%, ALADDIN, CAS#79-41-4), Icon Acid (>99%, ALADDIN, CAS#97-65-4), acrylamide (>99%, ALADDIN, CAS#79-06-1), methacrylamide (>98%, ALADDIN, CAS#79- 39-0), vinylimidazole (>99%, ALADDIN, CAS#1072-63-5), zirconium oxychloride octahydrate (>99%, ALADDIN, CAS#13520-92-8), aluminum chloride hexahydrate (>97%, ALADDIN, CAS#7784-13-6), zinc perchlorate hexahydrate (>99%, ALADDIN, CAS#10025-54-6), camphorquinone (>98%, ALADDIN, CAS#10373 -78-1), diphenylsilane (>97%, ALADDIN, CAS#775-12-2), ethyl p-dimethylaminobenzoate (>97%, ALADDIN, CAS#775-12-2), Diphenyl iodonium hexafluorophosphate (>97%, TCI, CAS#58109-40-3), dimethicone (Greagent, CAS#63148-62-9), ethylenediaminetetraacetic acid (>98% , Aldrich, CAS#304695-78-1), citric acid (>99.5%, ALADDIN, CAS#77-92-9), sodium dodecylbenzene sulfonate (>95%, ALADDIN, CAS#25155-30 -0), uranyl nitrate hexahydrate (>99%, Bore, CAS#36478-76-9).

The method for measuring the tensile strength of the decontamination composite film is as follows: cut the peelable decontamination composite film into a rectangular sample with a width of 2cm and a length of 6cm, set the sample gauge length to 2cm on a computer-controlled electronic universal testing machine, and then Clamp the sample vertically and stretch it at a speed of 2mm/min until it breaks to obtain the tensile strength and elongation at break of the peelable decontamination composite film.

The method for measuring the decontamination rate of the decontamination composite membrane is as follows: spray the peelable decontamination composite membrane on the sample contaminated by uranyl nitrate and illuminate it to form a film. Then peel off the film, measure the remaining radioactivity of the sample after decontamination, and compare it with the radioactivity measured on the sample before decontamination. Calculate the decontamination rate eta according to the following formula.

In the formula, eta is the decontamination rate after decontamination of the coating film, A ₀ is the radioactivity of the original contamination, and A ₁ is the remaining radioactivity after the decontamination of the coating film.

Example 1

3 mol acrylic acid (AAc), 7 mol acrylamide (AAm), 1 mol zirconium oxychloride octahydrate (ZrOCl ₂ ·8H ₂ O), 0.05 mol camphorquinone (CQ), 0.05 mol diphenylsilane (DPS), 0.05 mol di Phenyliodonium hexafluorophosphate (Iod), 11 mol deionized water, 1 mol dimethyl silicone oil, 4 mol ethylenediaminetetraacetic acid (EDTA) and 2 mol sodium dodecylbenzene sulfonate (SDBS), mix evenly and spray On the ground covered with non-woven fabric, irradiate it under the winter noon sun for 6 minutes to obtain a peelable decontamination composite film. The tensile strength of the composite film was measured in a -20°C experimental box. It was determined that the strength of the decontamination composite film was 10.6±2.4MPa, the elongation at break was 20.0±14.4%, and the elastic modulus was 176.2±36.8%. . The decontamination rate of the decontamination composite film on the glass surface reaches 99.92%, and the decontamination rate on the cement surface reaches 86.67%. The peeling rate of the decontamination composite film is 100%.

Example 2

Mix 1 mol of itaconic acid (IAc), 9 mol of methacrylamide (MAAm), 0.2 mol of aluminum chloride hexahydrate (AlCl ₃ ·6H ₂ O), 0.01 mol of camphorquinone (CQ), 0.01 mol of 4-dimethylamino- Ethyl benzoate (EDB), 0.01 mol diphenyliodonium hexafluorophosphate (Iod), 60 mol deionized water, 0.2 mol dimethyl silicone oil, 5 mol citric acid (CA) and 0.2 mol dodecylbenzene sulfonate Sodium sulfate (SDBS), mix evenly, spray on the ground covered with polyethylene mesh, and irradiate it under sunlight at 8:00 in winter for 26 minutes to obtain a peelable decontamination composite film. The tensile strength of the composite film was measured in an experimental box at -20°C. It was determined that the strength of the decontamination composite film was 8.0±1.4MPa, the elongation at break was 68.9±18.2%, and the elastic modulus was 38.3±2.6%. . The decontamination rate of the decontamination composite film on the glass surface reaches 99.70%, and the decontamination rate on the cement surface reaches 86.45%. The peeling rate of the decontamination composite film is 100%.

Example 3

9mol methacrylic acid (MAAc), 1mol vinylimidazole (VI), 3mol zinc perchlorate hexahydrate (Zn(ClO ₄ ) ₂ ·6H ₂ O), 1mol camphorquinone (CQ), 1mol 4-dimethylamino - Ethyl benzoate (EDB), 1 mol deionized water, 4 mol dimethyl silicone oil and 1 mol ethylenediaminetetraacetic acid (EDTA), mix evenly, spray on the ground covered with non-woven fabric, at 10:00 in winter Exposed to sunlight for 10 minutes, a peelable decontamination composite film will be obtained. The tensile strength of the composite film was measured in an experimental box at -20°C. It was determined that the strength of the decontamination composite film was 7.0±0.7MPa, the elongation at break was 21.1±3.7%, and the elastic modulus was 44.7±1.2%. . The decontamination rate of the decontamination composite film on the glass surface reaches 97.37%, and the decontamination rate on the cement surface reaches 80.38%. The peeling rate of the decontamination composite film is 100%.

The above are only preferred embodiments of the present invention. It should be noted that those of ordinary skill in the art can also make several improvements and modifications without departing from the technical principles of the present invention. These improvements and modifications It should also be regarded as the protection scope of the present invention.

Claims (9)

1. A peelable stain removal composite film capable of rapidly curing in sunlight, characterized in that the peelable stain removal composite film comprises a reinforcing layer and a peelable layer sprayed on the reinforcing layer; wherein, the peelable layer comprises the following raw material components in mole number: 1 to 9mol of monomer A, 1 to 9mol of monomer B, 0.2 to 3mol of cross-linking agent, 0.01 to 1mol of photoinitiator, 1 to 60mol of deionized water, 0.2 to 4mol of simethicone and 0.2 to 5mol of detergent; the monomer A is one of acrylic acid, methacrylic acid, itaconic acid, trans-aconitic acid and maleic anhydride; the monomer B is one of acrylamide, methacrylamide and vinylimidazole.

2. The releasable stain removing composite film of claim 1, wherein the molar ratio of monomer a to monomer B is from (1:9) to (9:1).

3. The peelable stain removal composite film of claim 1, wherein the cross-linking agent is one of zirconium oxychloride octahydrate, zirconium sulfate, aluminum chloride hexahydrate, ferric chloride hexahydrate, zinc perchlorate hexahydrate, zinc sulfate heptahydrate, zinc nitrate hexahydrate, zinc iodide, copper chloride dihydrate.

4. The releasable stain-removing composite film of claim 1, wherein the photoinitiator is a visible light photoinitiator.

5. The releasable, stain-removing composite film of claim 4, wherein the visible light initiator is two to three of camphorquinone, diphenylsilane, diphenyliodonium hexafluorophosphate, ethyl 4-dimethylamino-benzoate.

6. The releasable stain-removing composite film of claim 1, wherein the stain remover is one or more of ethylenediamine tetraacetic acid, citric acid, sodium dodecyl benzene sulfonate.

7. The releasable stain-removing composite film of claim 1, wherein the reinforcing layer is a nonwoven fabric or a polyethylene scrim.

8. A method of preparing a peelable stain release composite film according to any one of claims 1 to 7, comprising the steps of:

s1, weighing raw materials according to the proportion of claim 1, and uniformly mixing a monomer, a cross-linking agent, a photoinitiator, deionized water, simethicone and a detergent according to a proportion to obtain a peelable layer solution;

s2, spraying the strippable layer solution on the reinforcing layer, and irradiating the reinforcing layer with sunlight in the decontamination operation to obtain the strippable decontamination composite film.

9. The releasable, decontaminating composite film of claim 8, wherein the irradiation of solar light is for a period of time of 5 to 30 minutes.