A linker, its preparation method and application

Abstract

This application discloses a bonding agent, its preparation method, and its application, belonging to the field of plexiglass technology. The bonding agent provided in this application is prepared by polymerization of the following raw materials in parts by weight: 90-95 parts by weight of methyl methacrylate; 5-10 parts by weight of modifier; 0.2-0.7 parts by weight of first initiator; and 0.05-0.2 parts by weight of second initiator. The modifier comprises an aromatic acrylate monomer, a piperidine scavenger, and a shielding agent. This application achieves excellent gamma-radiation resistance through the synergistic effect of energy absorption, free radical capture, and radiation shielding; and exhibits high bonding interface strength and no delamination. Plexiglass made with this bonding agent maintains excellent mechanical properties while having an initial light transmittance ≥91% and a yellowing index <1.2% after 10 kGy gamma irradiation, making its comprehensive performance suitable for various harsh application scenarios.

Description

Technical Field

[0001] This application belongs to the field of acrylic glass technology, and in particular relates to a binder, its preparation method and application. Background Technology

[0002] With the rapid development of the nuclear industry, the first batch of nuclear power plants, which have been in service for nearly 40 years, have entered a peak period of equipment replacement. Scenarios such as nuclear waste disposal and nuclear facility operation and maintenance place high demands on the comprehensive performance of protective materials. As a core facility for handling highly radioactive materials, the hot chamber's viewing window must possess characteristics such as high-efficiency radiation protection, long-term transparency and stability, and reliable mechanical properties, making it a key component for ensuring operational safety.

[0003] Existing technologies can modify polymethyl methacrylate (PMMA) by adding radiation-resistant agents, utilizing mechanisms such as energy transfer and free radical capture to absorb radiation energy, thereby reducing radiation damage to the matrix and effectively improving the radiation resistance of PMMA. However, the commonly used specification K709 for hot chamber viewing windows has a thickness of up to 34.5 cm, and such ultra-thick PMMA components require multi-layer bonding and composite molding.

[0004] Currently, modified PMMA still has significant shortcomings: (1) The curing conditions are harsh, requiring heating or ultraviolet irradiation, which makes it difficult to meet the requirements of on-site construction; (2) It has poor radiation resistance, and after γ-irradiation, it is prone to yellowing and embrittlement, and the light transmittance decreases significantly; (3) The interfacial bonding strength is low, and it is prone to delamination failure during long-term service. Summary of the Invention

[0005] This application discloses a bonding agent, its preparation method and application, aiming to solve the technical problems of harsh curing conditions, poor radiation resistance and low bonding strength of existing modified PMMA.

[0006] To achieve the above objectives, the technical solution of this application is: The first aspect of this application provides a bonding agent, which is prepared by polymerization reaction from raw materials comprising the following parts by weight: 90-95 parts by weight of methyl methacrylate; Modifier 5-10 parts by weight; 0.2-0.7 parts by weight of the first initiator; Second initiator: 0.05-0.2 parts by weight; The modifier is a compound of aromatic acrylate monomers, piperidine scavengers, and shielding agents.

[0007] Preferably, in conjunction with the first aspect, the mass ratio of the aromatic acrylate monomer, the piperidine scavenger, and the shielding agent is (5-8):(1-2):(0.5-1).

[0008] Preferably, in conjunction with the first aspect, the aromatic acrylate monomer includes one or more of benzyl methacrylate, benzyl acrylate, phenyl methacrylate, and phenyl acrylate; The piperidine-based scavenging agent includes one or more of 2,2,6,6-tetramethylpiperidine, 2,2,6,6-tetramethylpiperidine-1-oxy, and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxy. The shielding agent is prepared by compounding benzophenone and benzotriazole in a mass ratio of (1-2):(2-1).

[0009] Preferably, in conjunction with the first aspect, the benzophenone is selected from one or a combination of 2-hydroxy-4-n-octyloxybenzophenone and 2-hydroxy-4-methoxybenzophenone. The benzotriazoles are selected from one or a combination of 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole and 2-(2'-hydroxy-5'-methylphenyl)benzotriazole.

[0010] Preferably, in conjunction with the first aspect, the first initiator is benzoyl peroxide; The second initiator is N,N-dimethylaniline; The mass ratio of the first initiator to the second initiator is (3-14):1.

[0011] The second aspect of this application provides a method for preparing the binder described in the first aspect, the method comprising: Methyl methacrylate, aromatic acrylate monomers, piperidine scavengers, and shielding agents are mixed at 60-70 °C to obtain a prepolymer. At room temperature, the first initiator and the second initiator are added to the prepolymer to carry out a polymerization reaction, thereby obtaining the linker.

[0012] The third aspect of this application provides an plexiglass, which is obtained by curing and molding an adhesive prepared by the method described in the first aspect or the method described in the second aspect.

[0013] The fourth aspect of this application provides a method for preparing the plexiglass described in the third aspect, the method comprising: The binder is injected into the mold and allowed to stand at 20-28 ℃ for 6-24 h to cure. After demolding, the acrylic glass is obtained.

[0014] Preferably, in conjunction with the fourth aspect, the preparation method further includes: The bonding agent is injected between at least two plexiglass substrates, the plexiglass substrates having a thickness of 3-4 mm, and the interlayer thickness of the bonding agent after injection is 0.5-1 mm.

[0015] The fifth aspect of this application provides the application of the plexiglass described in the third aspect or the plexiglass prepared by the method described in the fourth aspect in nuclear industry viewing windows, nuclear waste treatment observation windows, medical irradiation consumables, and bonding and repair of PMMA components in radioactive environments.

[0016] Compared with the prior art, the advantages or beneficial effects of the embodiments of this application include at least the following: The binder provided in this application is prepared by polymerization initiated by an initiator at room temperature. The aromatic acrylate monomer contains polymerizable carbon-carbon double bonds, which can undergo free radical copolymerization with methyl methacrylate and integrate into the polymer backbone, absorbing and dissipating high-energy radiation energy and reducing direct damage to the backbone from radiation. Piperidine scavengers and shielding agents are uniformly dispersed in a physical blend. The piperidine scavengers can quickly capture peroxide and alkoxy radicals generated by irradiation, terminating the irradiation-induced chain oxidation reaction and inhibiting yellowing, embrittlement, and mechanical degradation of the material. The shielding agent can absorb ultraviolet and high-energy radiation and convert it into heat energy, further reducing radiation damage to the matrix and improving long-term optical stability. Through the triple synergistic effect of energy absorption, free radical capture, and radiation shielding, excellent gamma radiation resistance is achieved; and the bonding interface has high strength and no delamination. The plexiglass made with this binder maintains excellent mechanical properties while having an initial light transmittance of ≥91% and a yellowing index of <1.2% after 10 kGy gamma irradiation, making its comprehensive performance suitable for various harsh application scenarios. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a viscosity-time curve of A1-connector and A2-connector provided in the embodiments of this application. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0020] In the following description of this embodiment, the term "and / or" is used to describe the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, B existing alone, and A and B existing simultaneously. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0021] In the following description of this embodiment, the term "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0022] Those skilled in the art should understand that, in the following description of the embodiments of this application, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0023] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0024] It should be noted that all raw materials and / or reagents in the embodiments of this application were purchased on the market or prepared according to conventional methods known to those skilled in the art.

[0025] In a first aspect, embodiments of this application provide a bonding agent, which is prepared by polymerization reaction from raw materials comprising the following parts by weight: 90-95 parts by weight of methyl methacrylate; 5-10 parts by weight of modifier; 0.2-0.7 parts by weight of first initiator; and 0.05-0.2 parts by weight of second initiator; wherein the modifier comprises a compound of aromatic acrylate monomer, piperidine scavenger, and shielding agent.

[0026] In some specific embodiments, this application uses a modifier comprising an aromatic acrylate monomer, a piperidine scavenger, and a shielding agent. The PMMA binder's resistance to gamma radiation is improved through a triple synergistic mechanism of energy absorption, free radical capture, and radiation shielding. The mechanisms of action of each component are as follows: The aromatic acrylate monomer contains polymerizable carbon-carbon double bonds (C=C), which can undergo free radical copolymerization with methyl methacrylate (MMA) and integrate into the polymer backbone. It absorbs and dissipates high-energy radiation energy through its benzene ring structure, reducing direct damage to the backbone from radiation. The piperidine scavenger has high steric hindrance and is uniformly dispersed in a physical blend. It can rapidly capture peroxide and alkoxy free radicals generated by irradiation, terminating the irradiation-induced chain oxidation reaction and inhibiting yellowing, embrittlement, and mechanical degradation of the material. The benzophenone-benzotriazole composite shielding agent is dispersed in a physical blend. It can absorb ultraviolet and high-energy radiation and convert it into heat energy, further reducing radiation damage to the matrix and improving long-term optical stability. The three components work synergistically to achieve a combination of high light transmittance, low yellowing, strong adhesion, and radiation resistance, resulting in a significant improvement in overall performance.

[0027] It should be noted that the matrix used in this application is methyl methacrylate, accounting for 95.00-90.00 wt%; the sum of the mass percentages of all components is 100 wt%.

[0028] In some specific embodiments, the preferred mass ratio of the aromatic acrylate monomer, piperidine scavenger, and shielding agent is (5-8):(1-2):(0.5-1), more preferably 7:1.8:0.8. By limiting the above ratio range, the formulation within this range can achieve synergistic effects of energy absorption, free radical scavenging, and radiation shielding, maximizing the material's resistance to gamma radiation while ensuring high light transmittance. Exceeding this range can lead to insufficient radiation resistance, decreased light transmittance, poor system compatibility, and deteriorated storage stability. The optimal ratio of 7:1.8:0.8 corresponds to the best overall performance of the sample in Example 2, perfectly suited for demanding high-radiation service scenarios.

[0029] In some specific embodiments, the aromatic acrylate monomer preferably includes one or more of benzyl methacrylate, benzyl acrylate, phenyl methacrylate, and phenyl acrylate; these aromatic acrylate monomers contain polymerizable carbon-carbon double bonds, can undergo free radical copolymerization with methyl methacrylate and be incorporated into the polymer backbone, absorb and dissipate high-energy radiation energy, reduce direct damage to the backbone by radiation, and at the same time improve the compatibility between the binder and the plexiglass substrate.

[0030] In some specific embodiments, the piperidine-based scavenger preferably includes one or a combination of 2,2,6,6-tetramethylpiperidine, 2,2,6,6-tetramethylpiperidine-1-oxy, and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxy; it is uniformly dispersed in the binder system in a physical blend form, which can rapidly capture peroxide free radicals and alkoxy free radicals generated by irradiation, terminate the irradiation-induced chain oxidation reaction, and effectively inhibit the yellowing, embrittlement and mechanical degradation of the material.

[0031] In some specific embodiments, the shielding agent is prepared by compounding benzophenone-based substances and benzotriazole-based substances in a mass ratio of (1-2):(2-1). The benzophenone-based substances are preferably one or a combination of 2-hydroxy-4-n-octyloxybenzophenone (UV-531) and 2-hydroxy-4-methoxybenzophenone (UV-9); the benzotriazole-based substances are preferably one or a combination of 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole (UV-327) and 2-(2'-hydroxy-5'-methylphenyl)benzotriazole (UV-P), and the mass ratio is more preferably 1:1. The two substances work synergistically to absorb ultraviolet and high-energy rays and convert them into heat energy for release, further reducing radiation damage to the substrate and improving the long-term optical stability of the bonding agent and subsequent plexiglass.

[0032] In some specific embodiments, the first initiator is preferably benzoyl peroxide; the second initiator is preferably N,N-dimethylaniline; and the mass ratio of the first initiator to the second initiator is preferably (3-14):1. Benzoyl peroxide and N,N-dimethylaniline can achieve efficient initiation of polymerization at room temperature, generating free radicals and undergoing redox reactions, without the need for additional heating or UV curing equipment, while ensuring stable polymerization and improving product production stability. This not only significantly reduces energy consumption and production costs during the preparation process but also greatly shortens the polymerization time, achieving rapid curing at room temperature and effectively improving ease of use.

[0033] In some specific embodiments, the viscosity of the bonding agent is 800-1000 cp; this viscosity range can balance the flowability of the injection material and the bonding strength, which is convenient for the subsequent preparation and bonding of plexiglass.

[0034] Secondly, this application provides a method for preparing the linker described in the first aspect, the method comprising: mixing methyl methacrylate, aromatic acrylate monomer, piperidine scavenger and shielding agent at 60-70 °C to obtain a prepolymer; and adding a first initiator and a second initiator to the prepolymer at room temperature to obtain the linker.

[0035] It should be noted that the preparation method used in this application also includes: after polymerization is completed under room temperature initiation, naturally cooling to room temperature, filtering to remove any insoluble impurities that may exist in the system, improving the purity of the linker, and ensuring its subsequent performance.

[0036] Thirdly, this application provides an acrylic glass, which is obtained by curing and molding an adhesive prepared by the method described in the first aspect or the preparation method described in the second aspect. Based on the excellent comprehensive properties of the aforementioned adhesive, the acrylic glass possesses good gamma radiation resistance, optical properties, and mechanical properties, making it suitable for use in high-irradiation environments.

[0037] Fourthly, this application provides a method for preparing the plexiglass described in the third aspect, the method comprising: injecting the binder into a mold, allowing it to stand and cure at 20-28 ℃ for 6-24 h, and then demolding to obtain the plexiglass.

[0038] In some specific embodiments, the preparation method further includes: injecting the binder between at least two plexiglass substrates, wherein the thickness of the plexiglass substrates is 3-4 mm, and the interlayer thickness of the binder after injection is 0.5-1 mm.

[0039] It should be noted that the adhesive provided in this application can not only be used alone, i.e., directly cured and molded to prepare plexiglass, but also can be injected between at least two pieces of plexiglass for bonding glass, adapting to different application scenarios and having high practical value.

[0040] It should be noted that the binder and the plexiglass produced therefrom provided in this application have a simple and controllable preparation process. Through the synergistic effect of two initiators, polymerization can be initiated at room temperature without the need for high-temperature and high-pressure equipment, reducing energy consumption and process difficulty, and the product has stable performance. It has excellent gamma radiation resistance. Through the triple synergistic effect of aromatic acrylate monomers, piperidine scavengers, and shielding agents, energy absorption, free radical capture, and radiation shielding are synergistically enhanced, effectively inhibiting radiation-induced material degradation. It has excellent adhesion performance. The binder has good compatibility with the plexiglass substrate, high bonding interface strength, and no delamination, improving the service stability of the components. The plexiglass has excellent comprehensive performance, high light transmittance, slight yellowing after irradiation, and stable mechanical properties. It can be widely adapted to high-irradiation scenarios and has significant practical value and market application prospects.

[0041] Fifthly, this application provides the application of the plexiglass described in the third aspect or the plexiglass prepared by the method described in the fourth aspect in nuclear industry viewing windows, nuclear waste treatment observation windows, medical irradiation consumables, and bonding and repair of PMMA components in radioactive environments. Based on the aforementioned binder, the plexiglass of this application possesses excellent optical properties, with an initial light transmittance of over 91%, and a yellowing index of less than 1.2% after 10 kGy irradiation aging. Furthermore, it ensures tight interfacial bonding without delamination, high overall bonding strength, and excellent service stability, making its comprehensive performance suitable for various harsh application scenarios.

[0042] The technical solution of this application will be further described below with reference to specific embodiments.

[0043] Example 1 This embodiment provides a method for preparing A1-connector, specifically including: S101: A modifier consisting of 16.0 g of benzyl methacrylate, 4.0 g of 2,2,6,6-tetramethylpiperidin-1-oxy, and 5.0 g of UV-531 / UV-327 compounding agent (mass ratio approximately 6:1.5:1) was added to 462.5 g of methyl methacrylate and stirred. The mixture was heated to 65±5 ℃, and after the system became clear and transparent, it was cooled to room temperature to obtain the prepolymer. S102: At room temperature, 0.75 g of the first initiator benzoyl peroxide and 0.25 g of the second initiator N,N-dimethyl-p-toluidine are added sequentially to the above prepolymer system and stirred until completely dissolved to obtain A1-linker.

[0044] To verify further applications, the A1-bonding agent prepared above was directly poured into a mold and allowed to cure at room temperature for 10 hours to obtain A1-plexiglass.

[0045] Tests showed that the thickness of the A1-plexiglass was 9 mm.

[0046] Example 2 This embodiment provides a method for preparing A2-connector, specifically including: S201: A modifier consisting of 23.7 g of benzyl methacrylate, 6.1 g of 2,2,6,6-tetramethylpiperidin-1-oxy, and 2.7 g of UV-531 / UV-327 compounding agent (mass ratio approximately 7:1.8:0.8) was added to 455 g of methyl methacrylate and stirred. The mixture was heated to 65±5 ℃, and after the system became clear and transparent, it was cooled to room temperature to obtain the prepolymer. S202: At room temperature, 2 g of the first initiator benzoyl peroxide and 0.65 g of the second initiator N,N-dimethyl-p-toluidine are added sequentially to the above prepolymer system and stirred until completely dissolved to obtain A2-linker.

[0047] To verify further applications, the A2-bonding agent prepared above was directly poured into a mold and allowed to cure at room temperature for 8 hours to obtain A2-plexiglass.

[0048] Tests showed that the thickness of the A2-plexiglass was 9 mm.

[0049] Example 3 This embodiment provides a method for preparing A3-connector, specifically including: S301: A modifier consisting of 23.7 g of benzyl methacrylate, 6.1 g of 2,2,6,6-tetramethylpiperidin-1-oxy, and 2.7 g of UV-531 / UV-327 compounding agent (mass ratio approximately 7:1.8:0.8) was added to 455 g of methyl methacrylate and stirred. The mixture was heated to 65±5 ℃, and after the system became clear and transparent, it was cooled to room temperature to obtain the prepolymer. S302: At room temperature, 2 g of the first initiator benzoyl peroxide and 0.65 g of the second initiator N,N-dimethyl-p-toluidine are added sequentially to the above prepolymer system and stirred until completely dissolved to obtain A3-linker.

[0050] To verify further applications, the A3-bonding agent prepared above was directly injected into two plexiglass substrates with a thickness of 4 mm. After curing at room temperature for 10 h, the interlayer thickness of the bonding agent after injection was 1 mm, resulting in A3-plexiglass.

[0051] That is, the thickness of the A3-plexiglass is 9 mm.

[0052] Meanwhile, to verify the comprehensive performance of the plexiglass prepared in the above embodiments, this application provides the following comparative examples for detailed illustration.

[0053] Comparative Example 1 This comparative example provides a preparation method, component ratio, preparation operation, and process parameters for B1-linker that are basically the same as those in Example 3. The difference is that the raw material modifier used in this comparative example is only 32.5 g of benzyl methacrylate, which is prepared by continuing the preparation according to step S302 and is denoted as B1-linker.

[0054] Further static curing yields B1-plexiglass.

[0055] Comparative Example 2 This embodiment provides a method for preparing B2-connector, specifically including: S501: A modifier consisting of 16.6 g of benzyl methacrylate, 4.3 g of 2,2,6,6-tetramethylpiperidin-1-oxy, and 1.9 g of UV-531 / UV-327 compounding agent (mass ratio approximately 7:1.8:0.8) was added to 455 g of methyl methacrylate (mass ratio of MMA to modifier approximately 20:1) and stirred. The mixture was heated to 65±5 ℃, and after the system became clear and transparent, it was cooled to room temperature to obtain the prepolymer. S502: At room temperature, 2 g of the first initiator benzoyl peroxide and 0.65 g of the second initiator N,N-dimethyl-p-toluidine are added sequentially to the above prepolymer system and stirred until completely dissolved to obtain B2-linker.

[0056] To verify further applications, the B2-bonding agent prepared above was directly injected into two plexiglass substrates with a thickness of 4 mm. After curing at room temperature for 10 h, the interlayer thickness of the bonding agent after injection was 1 mm, resulting in B2-plexiglass.

[0057] Comparative Example 3 This embodiment provides a method for preparing B3-connector, specifically including: S601: A modifier consisting of 41.5 g of benzyl methacrylate, 10.7 g of 2,2,6,6-tetramethylpiperidin-1-oxy, and 4.7 g of UV-531 / UV-327 compounding agent (mass ratio approximately 8.8:2.3:1) was added to 455 g of methyl methacrylate (MMA to modifier mass ratio approximately 8:1) and stirred. The mixture was heated to 65±5 ℃, and after the system became clear and transparent, it was cooled to room temperature to obtain the prepolymer. S602: At room temperature, 2 g of the first initiator benzoyl peroxide and 0.65 g of the second initiator N,N-dimethyl-p-toluidine are added sequentially to the above prepolymer system and stirred until completely dissolved to obtain B3-linker.

[0058] To verify further applications, the B3-bonding agent prepared above was directly injected into two plexiglass substrates with a thickness of 4 mm. After curing at room temperature for 10 h, the interlayer thickness of the bonding agent after injection was 1 mm, resulting in B3-plexiglass.

[0059] Comparative Example 4 This comparative example uses a commercially available two-component acrylate adhesive, brand Ergo / model 9900, as the B4-bonding agent. After mixing the B4-bonding agent evenly according to the instructions, apply it uniformly to the surfaces of the two acrylic substrates to be bonded. Stack the substrates and secure them with clamps, ensuring a uniform adhesive layer thickness. Allow to cure at room temperature for up to 12 hours to fully cure, resulting in bonded B4-acrylic glass.

[0060] The viscosity of the binders prepared in Examples 1-3 and Comparative Examples 1-4 was tested, and the performance of the plexiglass, including impact strength, YI, light transmittance and curing conditions, was tested. The test results are shown in Tables 1 and 2.

[0061] Impact strength was tested according to the requirements of GB / T 1843-2008 "Determination of Impact Strength of Plastic Cantilever Beams".

[0062] YI and light transmittance are tested according to the requirements of GB / T 2410-2008 "Determination of light transmittance and haze of transparent plastics".

[0063] Viscosity was measured using an online viscometer. The binder system was dynamically measured in real time under constant temperature and normal pressure conditions of (25±1)℃. After the system value stabilized, the steady-state viscosity value was recorded.

[0064] Storage stability: The adhesive was sealed and stored at (25±1) ℃ for 30 days, and its viscosity change rate (compared to the initial viscosity) and whether layering or gelation occurred were tested.

[0065] Table 1 Comprehensive performance of the binder performance viscosity cp Storage stability A1 850 No gel, no layering, no yellowing, viscosity change rate of 7.8%. A2 980 No gel, no layering, no yellowing, viscosity change rate of 5.6%. A3 920 No gel, no layering, no yellowing, viscosity change rate of 6.3%. B1 720 Slight yellowing, viscosity increased by 18.2%. B2 760 No layering or gel formation, poor system compatibility, and trace precipitation. B3 2100 Slight layering occurred, and light transmittance decreased significantly. B4 3200 Layering occurred after 7 days of storage; usable period < 4 hours. Table 2 Comprehensive Performance of Acrylic Glass performance Initial transmittance / % Transmittance after 10kGy irradiation / % YI / % after 10kGy irradiation <![CDATA[Impact strength / (KJ / m 2 )]]> A1 91.31 90.1 0.49 15 A2 91.38 90.8 0.3 16 A3 91.3 86.3 1.2 13 B1 91.02 82.5 3.72 12 B2 88.5 85.1 1.58 11 B3 86.2 83.4 1.2 10 B4 87.1 82 1.5 14 The bonding agents prepared in Examples 1-3 of this application all have viscosity within the optimal range of 800-1000 cp, exhibit excellent storage stability, and fully meet the production requirements for injection and bonding.

[0066] The sample in Example 2 exhibits the best overall performance, with an initial transmittance ≥91%, a yellowing index as low as 0.3% after 10 kGy γ irradiation, and an impact strength of 16 kJ / m². This plexiglass possesses excellent γ irradiation resistance, optical properties, and mechanical properties, making it suitable for use in high-irradiation scenarios.

[0067] Comparative Example 1 used only one modifier, and Comparative Example 2 added too little modifier, both of which resulted in severe yellowing after irradiation and a significant decrease in optical and mechanical properties, demonstrating the necessity and ingenuity of the triple synergistic mechanism; Comparative Example 3 had excessive modifier, which led to poor system compatibility and a significant decrease in initial transmittance, failing to meet the usage requirements.

[0068] Comparative Example 4 shows that the transmittance, radiation resistance, and interface stability of commercially available adhesives are all far lower than those of the product in this application, and therefore cannot meet the long-term service requirements under high-radioactivity conditions.

[0069] In summary, the binder prepared in this application solves the three major pain points of existing technologies—harsh curing conditions, poor radiation resistance, and low bonding strength—through a triple radiation resistance synergistic mechanism and a room temperature redox initiation system. It has excellent comprehensive performance and significant industrial application value and market prospects.

[0070] according to Figure 1 The figure shows the viscosity-time curves of A1-bonding agent and A2-bonding agent. The horizontal axis represents curing time (unit: min), and the vertical axis represents system viscosity (unit: cp). The curves show that the viscosity of A1 and A2-bonding agents increases steadily with curing time, without any explosive polymerization. Among them, the viscosity increase rate of A2-bonding agent is more gradual, and the application period is longer, making it more suitable for on-site grouting and bonding construction.

[0071] Therefore, the binder prepared in this application is obtained by polymerization initiated by two initiators at room temperature. The aromatic acrylate monomer contains polymerizable carbon-carbon double bonds, which can undergo free radical copolymerization with methyl methacrylate and be incorporated into the polymer backbone, absorbing and dissipating high-energy ray energy, reducing the direct damage of radiation to the backbone. The piperidine scavenger and shielding agent are uniformly dispersed in a physical blend. The piperidine scavenger can quickly capture peroxide free radicals and alkoxy free radicals generated by irradiation, terminating the irradiation-induced chain oxidation reaction and inhibiting yellowing, embrittlement, and mechanical decay of the material. The shielding agent can absorb ultraviolet and high-energy rays and convert them into heat energy for release, further reducing radiation damage to the matrix and improving long-term optical stability. Through the triple synergistic effect of energy absorption, free radical capture, and ray shielding, excellent γ-radiation resistance is achieved; and the bonding interface has high strength and no delamination. The plexiglass made with this binder maintains excellent mechanical properties while having a light transmittance of ≥91% and a yellowing index of <1.2% after 10 kGy γ-radiation, making its comprehensive performance suitable for various harsh application scenarios.

[0072] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0073] This invention illustrates the detailed process equipment and process flow through the above embodiments. However, this invention is not limited to the detailed process equipment and process flow described above, meaning that this invention does not necessarily depend on the detailed process equipment and process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, addition of auxiliary components, and selection of specific methods, all fall within the protection scope and disclosure scope of this invention.

[0074] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A bonding agent, characterized in that, The binder is prepared by polymerization reaction from raw materials comprising the following parts by weight: 90-95 parts by weight of methyl methacrylate; Modifier 5-10 parts by weight; 0.2-0.7 parts by weight of the first initiator; Second initiator: 0.05-0.2 parts by weight; The modifier is a compound of aromatic acrylate monomers, piperidine scavengers, and shielding agents.

2. The binder according to claim 1, characterized in that, The mass ratio of the aromatic acrylate monomer, piperidine scavenger, and shielding agent is (5-8):(1-2):(0.5-1).

3. The connector according to claim 2, characterized in that, The aromatic acrylate monomers include one or more of benzyl methacrylate, benzyl acrylate, phenyl methacrylate, and phenyl acrylate; The piperidine-based scavenging agent includes one or more of 2,2,6,6-tetramethylpiperidine, 2,2,6,6-tetramethylpiperidine-1-oxy, and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxy. The shielding agent is prepared by compounding benzophenone and benzotriazole in a mass ratio of (1-2):(2-1).

4. The connector according to claim 3, characterized in that, The benzophenones are selected from one or a combination of 2-hydroxy-4-n-octyloxybenzophenone and 2-hydroxy-4-methoxybenzophenone. The benzotriazoles are selected from one or a combination of 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole and 2-(2'-hydroxy-5'-methylphenyl)benzotriazole.

5. The binder according to claim 1, characterized in that, The first initiator is benzoyl peroxide; The second initiator is N,N-dimethylaniline; The mass ratio of the first initiator to the second initiator is (3-14):

1.

6. A method for preparing the binder according to any one of claims 1-5, characterized in that, The preparation method includes: Methyl methacrylate, aromatic acrylate monomers, piperidine scavengers, and shielding agents are mixed at 60-70 °C to obtain a prepolymer. At room temperature, the first initiator and the second initiator are added to the prepolymer to carry out a polymerization reaction, thereby obtaining the linker.

7. An acrylic glass, characterized in that, The plexiglass is obtained by curing and molding the binder prepared by any one of claims 1-5 or the method described in claim 6.

8. A method for preparing the plexiglass according to claim 7, characterized in that, The preparation method includes: The binder is injected into the mold and allowed to stand at 20-28 ℃ for 6-24 h to cure. After demolding, the acrylic glass is obtained.

9. The method for preparing plexiglass according to claim 8, characterized in that, The preparation method further includes: The bonding agent is injected between at least two plexiglass substrates, the plexiglass substrates having a thickness of 3-4 mm, and the interlayer thickness of the bonding agent after injection is 0.5-1 mm.

10. The application of the plexiglass according to claim 7 or the plexiglass prepared by any one of claims 8-9 in nuclear industry viewing windows, nuclear waste treatment observation windows, medical irradiation consumables, and bonding and repair of PMMA components in radioactive environments.

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