Preparation method of photocuring plastic scintillator
The preparation of plastic scintillators through photocuring technology solves the complex and time-consuming problem of traditional preparation methods, and realizes the preparation of high-efficiency and low-energy-consuming plastic scintillators, improving the stability of optical and mechanical properties.
Patent Information
- Application Number
- CN202510193188.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-21
- Publication Date
- 2025-07-04
AI Technical Summary
In the prior art, the preparation process of plastic scintillator materials is complex, time-consuming, and energy consumption is high, and the optical and mechanical properties are easily affected by residual stress or impurities during the preparation process, resulting in a decrease in stability and service life.
The plastic scintillator is prepared by photocuring technology, and the scintillator is dissolved by organic solvent, photosensitive resin and photoinitiator are added, oxygen in the solution is removed and oxygen-free photopolymerization is carried out to obtain a photocured plastic scintillator.
The preparation of plastic scintillator is achieved with a short preparation cycle and environmentally friendly, which improves the stability of optical and mechanical properties, and reduces energy consumption and costs.
Smart Images
Figure CN120248239A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of plastic scintillator preparation, and specifically, to a preparation method of a photocurable plastic scintillator. Background Art
[0002] In recent years, plastic scintillator materials have shown extensive application potential in the field of high-energy radiation detection. Plastic scintillators, with their advantages of high light output, fast response, high mechanical strength, and easy processing, play an important role in the fields of nuclear physics, nuclear medicine, and radiation safety. However, traditional plastic scintillator materials are usually prepared by thermal polymerization methods, which have problems such as complex operation, long time consumption, and high energy consumption. In addition, the optical and mechanical properties of plastic scintillators are also easily affected by residual stress or impurities during the preparation process, resulting in a decrease in stability and service life. In recent years, due to its characteristics such as rapid prototyping, low-temperature operation, and environmental friendliness, photocuring technology has gradually become an efficient and convenient preparation method suitable for the manufacture of complex shapes. However, the current research on photocurable plastic scintillators is still in its infancy, and its performance optimization and large-scale industrial preparation still face challenges. Therefore, developing a plastic scintillator based on photocuring technology, with excellent optical, mechanical, and environmental stability, has become one of the important directions in the current material research field. Summary of the Invention
[0003] Aiming at the problems existing in the above-mentioned prior art, the present invention provides a preparation method of a photocurable plastic scintillator, which prepares the plastic scintillator by a method based on photocuring technology, and greatly shortens the preparation time on the basis of ensuring the excellent performance of the plastic scintillator itself.
[0004] To achieve the above object, the technical solution adopted by the present invention is as follows:
[0005] A preparation method of a photocurable plastic scintillator, comprising the following steps:
[0006] S1. Weigh an organic solvent and a scintillating substance and place them in an opaque sealed container, and perform a constant-temperature ultrasonic treatment on the obtained mixed solution to fully dissolve the scintillating substance in the organic solvent, obtaining a first precursor solution;
[0007] S2. Add a photosensitive resin and a photoinitiator to the first precursor solution, perform a constant-temperature ultrasonic treatment, and obtain a second precursor solution after mixing evenly;
[0008] S3. Fully introduce nitrogen into the second precursor solution to remove oxygen in the solution, and perform a vacuum pumping and sealing treatment on the sealed container to obtain a prepolymer;
[0009] S4. Transfer the prepolymer to a photocuring device for anaerobic photopolymerization to obtain a photocurable plastic scintillator.
[0010] Preferably, the organic solvent is a mixed solution of polystyrene and polymethyl methacrylate, and the mass ratio of polystyrene to polymethyl methacrylate is 4:1.
[0011] Preferably, the scintillating substance includes a main fluorescent dye PPO and a secondary fluorescent dye POPOP. The mass fraction of the main fluorescent dye PPO is not more than 12% of the mass of the plastic scintillator matrix, and the mass fraction of the secondary fluorescent dye POPOP is not more than 0.05% of the mass of the plastic scintillator matrix.
[0012] Preferably, the photosensitive resin is a mixture of 621A-80 and HDDA, and the mass ratio of 621A-80 to HDDA is 4:1 to 13:7.
[0013] Preferably, the photoinitiator is photoinitiator I184, and its mass fraction is 3-5% of the mass of the plastic scintillator matrix.
[0014] Preferably, when performing the constant-temperature ultrasonic treatment in steps S1 and S2, the temperature is 25-45°C, and the ultrasonic time does not exceed 30 min.
[0015] Preferably, the process of repeatedly introducing nitrogen and evacuating the closed container in step S3 is performed three times to finally obtain a prepolymer.
[0016] Preferably, when transferring the prepolymer to the photocuring device in step S4, first transfer the closed container to the closed photocuring device, then quantitatively transfer the prepolymer in the closed container to a pre-prepared mold, and finally place the mold containing the prepolymer on the workbench for photocuring.
[0017] Preferably, when performing anaerobic photopolymerization in step S4, the light source power is 20 W, the light source wavelength is 365 nm, the distance between the light source and the mold is 20 cm, and the curing time is 1.5 h.
[0018] Furthermore, after obtaining the photocured plastic scintillator in step S4, it is taken out and polished to meet the use standard.
[0019] Compared with the prior art, the present invention has the following beneficial effects:
[0020] (1) The present invention uses organic solvents PS and PMMA to dissolve the scintillating substances PPO and POPOP, and then incorporates them into the photosensitive resin for photocuring at room temperature to complete the preparation of the plastic scintillator. It has the characteristics of short preparation cycle and environmental friendliness, effectively overcoming the deficiencies of long time cycle and high energy consumption in the traditional thermal polymerization preparation process. The design of the present invention is simple and ingenious, the implementation is simple and reliable, and it is suitable for application in the preparation of plastic scintillators.
[0021] (2) The process steps of the present invention are few, and the equipment required for preparation are all conventional chemical equipment, with low cost; by controlling conditions such as the ratio of photosensitive resin, photoinitiator, and dosage of scintillating substance in the preparation process flow, the mechanical properties and optical properties of the plastic scintillator are controlled, and the process flow is simple and easy to implement.
[0022] (3) The preparation of the plastic scintillator of the present invention can be carried out at room temperature, with a short synthesis period and low energy consumption required. Compared with the traditional thermal polymerization process, it can effectively reduce energy consumption and save preparation costs.
[0023] (4) By introducing sufficient nitrogen and performing vacuum treatment in the precursor solution, the dissolved oxygen in the solution is reduced to ensure that the plastic scintillator is not oxidized during curing, and the preparation period of the plastic scintillator is reduced by controlling the distance of the light source, facilitating rapid and efficient preparation. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 It is a schematic process flow diagram of an embodiment of the present invention.
[0025] Figure 2 It is a schematic diagram of fluorescence spectrum comparison of Examples 1 - 3 of the present invention.
[0026] Figure 3 It is a schematic diagram of thermogravimetric analysis comparison of Examples 4 - 8 of the present invention.
[0027] Figure 4 is Figure 3 A partial comparison schematic diagram of the dashed box part (200 - 300 °C) in
[0028] Figure 5 It is a schematic diagram of Shore hardness comparison of Examples 4 - 8 of the present invention.
[0029] Figure 6 It is a schematic diagram of fluorescence spectrum comparison of Examples 9 - 11 of the present invention.
[0030] Figure 7 It is a schematic diagram of fluorescence spectrum comparison of Examples 10, 12, 13 and 1 of the present invention.
[0031] Figure 8 It is a schematic diagram of fluorescence spectrum comparison of Examples 14 - 16 and 12 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0032] The present invention will be further described below with reference to the drawings and embodiments. The embodiments of the present invention include but are not limited to the following examples.
[0033] Example 1
[0034] As Figure 1As shown, the preparation method of the photocurable plastic scintillator includes the following steps:
[0035] S1. Weigh 1.6 g of organic solvent polystyrene (PS), 0.4 g of polymethyl methacrylate (PMMA), 0.7 g of main fluorescent dye PPO as the scintillating substance, and 0.002 g of secondary fluorescent dye POPOP; at room temperature, in an opaque sealed container, dissolve the scintillating substances PPO and POPOP in the organic solvents PS and PMMA, and then perform a constant-temperature ultrasonic treatment on the obtained mixed solution at a temperature of 35 °C for 20 min to fully dissolve the scintillating substances in the organic solvent, obtaining a first precursor solution.
[0036] S2. Add 2.8 g of photosensitive resin 621A-80, 1.2 g of HDDA, and 0.24 g of photoinitiator I184 to the first precursor solution, and perform a constant-temperature ultrasonic treatment at a temperature of 35 °C for 20 min. After mixing evenly, a second precursor solution is obtained.
[0037] S3. Slowly introduce nitrogen into the second precursor solution to remove the oxygen in the solution, specifically, slowly introduce nitrogen for 5 min, evacuate the sealed container for 10 min, repeat three times and then seal it to obtain a prepolymer.
[0038] S4. Transfer the sealed container containing the prepolymer to a photocuring device, then quantitatively transfer the prepolymer to a mold, place it on the workbench, and perform anaerobic photopolymerization. The power of the light source used is 20 W, the wavelength of the light source is 365 nm, the distance between the light source and the mold is 20 cm, and the curing time is 1.5 h to obtain a photocurable plastic scintillator.
[0039] S5. Take out the obtained plastic scintillator, and use a metallographic polishing machine to polish it to obtain the final product.
[0040] Example 2
[0041] The difference between this example and Example 1 is only that: during the constant-temperature ultrasonic treatment in steps S1 and S2, the temperature is 25 °C.
[0042] Example 3
[0043] The difference between this example and Example 1 is only that: during the constant-temperature ultrasonic treatment in steps S1 and S2, the temperature is 45 °C.
[0044] Example 4
[0045] The difference between this example and Example 1 is that: in step S1, 0.4 g of the scintillating substance PPO is weighed; in step S2, 3.2 g of photosensitive resin 621A-80, 0.8 g of HDDA, and 0.18 g of photoinitiator I184 are added to the first precursor solution.
[0046] Example 5
[0047] The difference between this example and Example 1 is as follows: in step S1, 0.4 g of the scintillating substance PPO is weighed; in step S2, 3 g of photosensitive resin 621A-80, 1 g of HDDA, and 0.18 g of photoinitiator I184 are added to the first precursor solution.
[0048] Example 6
[0049] The difference between this example and Example 1 is as follows: in step S1, 0.4 g of the scintillating substance PPO is weighed; in step S2, 0.18 g of photoinitiator I184 is added to the first precursor solution.
[0050] Example 7
[0051] The difference between this example and Example 1 is as follows: in step S1, 0.4 g of the scintillating substance PPO is weighed; in step S2, 2.6 g of photosensitive resin 621A-80, 1.4 g of HDDA, and 0.18 g of photoinitiator I184 are added to the first precursor solution.
[0052] Example 8
[0053] The difference between this example and Example 1 is as follows: in step S1, 0.4 g of the scintillating substance PPO is weighed; in step S2, 2.4 g of photosensitive resin 621A-80, 1.6 g of HDDA, and 0.18 g of photoinitiator I184 are added to the first precursor solution.
[0054] Example 9
[0055] The difference between this example and Example 6 is only that: in step S4, the curing time for anaerobic photopolymerization is 2.5 h.
[0056] Example 10
[0057] The difference between this example and Example 1 is only that: in step S1, 0.4 g of the scintillating substance PPO is weighed.
[0058] Example 11
[0059] The difference between this example and Example 10 is as follows: in step S2, 0.3 g of photoinitiator I184 is added to the first precursor solution; in step S4, the curing time for anaerobic photopolymerization is 1 h.
[0060] Example 12
[0061] The difference between this example and Example 1 is only that: in step S1, 0.5 g of the scintillating substance PPO is weighed.
[0062] Example 13
[0063] The difference between this example and Example 1 is only that: in step S1, the weighed scintillating substance PPO is 0.6 g.
[0064] Example 14
[0065] The difference between this example and Example 12 is only that: in step S4, the curing time for anaerobic photopolymerization is 1 h.
[0066] Example 15
[0067] The difference between this example and Example 14 is only that: in step S4, the curing time for anaerobic photopolymerization is 2 h.
[0068] Example 16
[0069] The difference between this example and Example 14 is only that: in step S4, the curing time for anaerobic photopolymerization is 3 h.
[0070] Table 1 can more intuitively show the parameter comparison of the above Examples 1 - 16, where the temperature refers to the temperature of constant-temperature ultrasonic dissolution, Time refers to the curing time of anaerobic photopolymerization, and the experimental ratio comparisons of photoinitiator I184, main fluorescent dye PPO, secondary fluorescent dye POPOP, photosensitive resin 621A - 80 and HDDA, organic solvents PS and PMMA are listed.
[0071]
[0072]
[0073] Table 1 Parameter Comparison of Each Example
[0074] The plastic scintillators obtained from the above Examples 1 - 16 are respectively subjected to experimental performance tests and result analysis.
[0075] As Figure 2The fluorescence spectra comparison of the plastic scintillators obtained in Examples 1-3 is shown. It can be seen that the fluorescence intensity is the highest when the ultrasonic temperature is 35 °C. An increase or decrease in temperature on this basis will cause a certain degree of reduction in the fluorescence intensity. Analyzing the reasons, it can be known that under the condition that the ultrasonic temperature is 25-35 °C, appropriately increasing the temperature improves the dissolution and dispersion effects of the components, enhances the ultrasonic cavitation effect and the molecular diffusion efficiency, effectively reduces the agglomeration and quenching phenomena of the phosphor, and improves the fluorescence intensity. When the ultrasonic temperature is lower than 25 °C, the dissolution efficiency of the solvent for the fluorescent dye and monomer is relatively low, resulting in uneven dispersion or microscopic agglomeration of the fluorescent dye in the matrix, thus triggering the fluorescence quenching effect and reducing the luminescence efficiency. At the same time, the cavitation intensity at low temperature is relatively weak, which is not conducive to the uniform distribution of the fluorescent dye. When the ultrasonic temperature is 35-45 °C, the increase in temperature will cause the fluorescent dye molecules to start degrading, resulting in a decrease in the fluorescence intensity. And when the ultrasonic temperature exceeds 45 °C, the too high temperature further causes partial degradation of the fluorescent dye molecules or changes in their photophysical properties, resulting in a significant reduction in the fluorescence intensity.
[0076] As Figure 3 and Figure 4 The thermogravimetric analysis comparison of the plastic scintillators obtained in Examples 4-8 is shown. It can be seen that with the change of the ratio of 621A-80 to HDDA, the thermal decomposition behavior of the product shows significant differences. Examples 4 and 5 show relatively high thermal stability, and the initial temperature of mass loss is relatively high, indicating better heat resistance at high temperatures. In contrast, Examples 7 and 8 start to have mass loss at lower temperatures, showing poor thermal stability. In addition, the mass loss of Example 6 at 250 °C is only 5%, showing excellent heat resistance performance. As Figure 5 The Shore hardness test results comparison of the plastic scintillators obtained in Examples 4-8 is shown. It can be found that Example 6 has relatively good hardness performance, probably because the ratio of 621A-80 to HDDA of this plastic scintillator ensures a relatively high crosslinking density while maintaining a certain flexibility. The hardness of Example 5 is the second, indicating that the ratio of 3:1 can still better balance the crosslinking density and flexibility. In Example 4, the content of HDDA is too small, resulting in uneven surface and even cracks, so the hardness fluctuates greatly. In Examples 7 and 8, due to too much HDDA, the crosslinking density is insufficient, thus affecting the hardness performance. To sum up, when the mass ratio of 621A-80 to HDDA is in the range of 4:1 to 13:7, the thermal stability and hardness performance of the plastic scintillator can meet the basic application requirements. When the mass ratio of 621A-80 to HDDA is 7:3, the plastic scintillator shows the best comprehensive thermal stability and hardness performance.
[0077] As Figure 6The fluorescence spectra comparison of the plastic scintillators obtained in Examples 9 - 11 is shown. It can be seen that with the change of the proportion of photoinitiator, the fluorescence intensity of the product shows a trend of first increasing and then decreasing. The experimental results show that the plastic scintillator in Example 10 has relatively high fluorescence performance. In Example 9, due to the low proportion of photoinitiator, the curing process takes a long time, and the long-time light exposure causes the photosensitive resin to undergo an oxidation reaction in a high-temperature environment, resulting in yellowing of the plastic scintillator, and thus the fluorescence intensity decreases. In the plastic scintillator of Example 11, the proportion of photoinitiator is relatively high. Although the curing time is shortened, the photoinitiator decomposes incompletely, resulting in the formation of quenching centers in the plastic scintillator, increasing the energy loss during the light transmission process, and ultimately reducing the fluorescence intensity.
[0078] As Figure 7 The fluorescence spectra comparison of the plastic scintillators obtained in Examples 10, 12, 13 and 1 is shown. It can be seen that the change in the proportion of the main fluorescent dye also affects the fluorescence intensity of the plastic scintillator. In Example 12, the plastic scintillator has the highest fluorescence intensity with the proportion of the main fluorescent dye. The dye molecules at this proportion can effectively avoid non-radiative energy loss. An increase or decrease in the proportion of the main fluorescent dye on this basis will lead to a decrease in the fluorescence intensity of the product.
[0079] As Figure 8 The fluorescence spectra comparison of the plastic scintillators obtained in Examples 14 - 16 and 12 is shown. It can be seen that the fluorescence intensity of the product is the highest when the curing time is 1.5 h. Analyzing the reasons, it can be known that in Example 14, when the curing time is less than 1.5 h, there is still an uncured liquid part at the bottom of the plastic scintillator, and the fluorescence intensity gradually increases with the extension of the curing time; the plastic scintillator in Example 12 is completely cured, and the photoinitiator is basically decomposed completely. At this time, the energy transfer efficiency inside the scintillator reaches the highest, and the fluorescence intensity also reaches the peak; for the plastic scintillators in Examples 15 and 16, due to the long-time ultraviolet light irradiation, the cured photosensitive resin begins to undergo a decomposition reaction, or is oxidized due to high temperature, destroying the matrix structure, resulting in a decrease in the fluorescence intensity of the plastic scintillator with the extension of the curing time.
[0080] The above embodiments are only the preferred embodiments of the present invention, and do not limit the protection scope of the present invention. Any changes made by adopting the design principle of the present invention and non-creative labor on this basis shall fall within the protection scope of the present invention.
Claims
1. A preparation method of a photocurable plastic scintillator, characterized in that, It includes the following steps: S1. Weigh an organic solvent and a scintillating substance and place them in an opaque sealed container. Perform constant-temperature ultrasonic treatment on the obtained mixed solution to fully dissolve the scintillating substance in the organic solvent, obtaining a first precursor solution; S2. Add a photosensitive resin and a photoinitiator to the first precursor solution, perform constant-temperature ultrasonic treatment, and obtain a second precursor solution after mixing evenly; S3. Sufficiently introduce nitrogen into the second precursor solution to remove oxygen in the solution, and evacuate and seal the sealed container to obtain a prepolymer; S4. Transfer the prepolymer to a photocuring device for anaerobic photopolymerization to obtain a photocured plastic scintillator.
2. The preparation method of the photocurable plastic scintillator according to claim 1, characterized in that The organic solvent is a mixed solution of polystyrene and polymethyl methacrylate, and the mass ratio of polystyrene to polymethyl methacrylate is 4:
1.
3. The preparation method of the photocurable plastic scintillator according to claim 1, characterized in that, The scintillating substance includes a main fluorescent dye PPO and a secondary fluorescent dye POPOP. The mass fraction of the main fluorescent dye PPO is not more than 12% of the mass of the plastic scintillator matrix, and the mass fraction of the secondary fluorescent dye POPOP is not more than 0.05% of the mass of the plastic scintillator matrix.
4. The preparation method of the photocurable plastic scintillator according to claim 1, characterized in that, The photosensitive resin is a mixture of 621A-80 and HDDA, and the mass ratio of 621A-80 to HDDA is 4:1 to 13:
7.
5. The preparation method of the photocurable plastic scintillator according to claim 1, characterized in that, The photoinitiator is photoinitiator I184, and its mass fraction is 3-5% of the mass of the plastic scintillator matrix.
6. The preparation method of the photocurable plastic scintillator according to any one of claims 1 to 5, characterized in that, When performing constant-temperature ultrasonic treatment in steps S1 and S2, the temperature is 25-45°C, and the ultrasonic time does not exceed 30 min.
7. The preparation method of the photocurable plastic scintillator according to any one of claims 1 to 5, characterized in that, In step S3, the process of repeatedly introducing nitrogen and evacuating the sealed container is performed three times to finally obtain a prepolymer.
8. The preparation method of the photocurable plastic scintillator according to any one of claims 1 to 5, characterized in that, When transferring the prepolymer to the photocuring device in step S4, first transfer the sealed container to the sealed photocuring device, then quantitatively transfer the prepolymer in the sealed container to a pre-prepared mold, and finally place the mold containing the prepolymer on the workbench for photocuring.
9. The preparation method of the photocurable plastic scintillator according to claim 8, characterized in that, When performing anaerobic photopolymerization in step S4, the light source power used is 20 W, the light source wavelength is 365 nm, the distance between the light source and the mold is 20 cm, and the curing time is 1.5 h.
10. The preparation method of the photocurable plastic scintillator according to any one of claims 1 to 5, characterized in that, After obtaining the photocured plastic scintillator in step S4, take it out and polish it to meet the use standard.