PI-based anti-electron radiation composite material and preparation method thereof
By preparing PI-based electron radiation shielding composite materials, utilizing the low-density properties of boron carbide and polyimide, and combining the interface strength enhancement of silane coupling agents, the problem of high density in existing materials was solved, achieving lightweight and highly efficient radiation shielding effects.
Patent Information
- Application Number
- CN202512049664.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-31
- Publication Date
- 2026-03-17
AI Technical Summary
Existing radiation shielding materials have a high density in spacecraft applications, which limits the possibility of weight reduction and makes it difficult to simultaneously achieve low density and good electron radiation shielding performance.
The preparation method of PI-based electron radiation shielding composite material involves mixing boron carbide powder, silane coupling agent and organic solvent to form a uniform dispersion, adding 4,4'-diaminodiphenyl ether and pyromellitic dianhydride, stirring, filtering and degassing, and finally heating to form a polyimide precursor, thus forming a composite material with polyimide as the matrix.
The prepared composite material has low density and good electron radiation protection performance, which meets the lightweight requirements of spacecraft, while improving the radiation shielding effect of the material.
Smart Images
Figure CN121673829A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of radiation protection materials technology, and more specifically, to a PI-based radiation protection composite material and its preparation method. Background Technology
[0002] In recent years, the harmful effects of various types of radiation, especially electron radiation, on the human body and the environment have become increasingly recognized. Currently, researchers are conducting extensive development and research on electron radiation shielding materials, some of which are already being used in practical applications. Current materials for shielding electron radiation mainly include lead, lead alloys, copper, aluminum, and concrete. Although they possess good electron radiation shielding and mechanical properties, their relatively high density limits the possibility of weight reduction when applied to spacecraft. Therefore, obtaining materials with lower density and better electron radiation shielding performance has become a pressing technical problem to be solved. Summary of the Invention
[0003] The problem this invention addresses is how to obtain materials with low density and good protection against electron radiation.
[0004] To address the above problems, this invention provides a method for preparing a PI-based electron radiation shielding composite material, comprising: Step S1: After mixing boron carbide powder, silane coupling agent and organic solvent, the mixture is dispersed to obtain a dispersion. Step S2: Add 4,4-diaminodiphenyl ether and pyromellitic dianhydride to the dispersion, and then perform stirring, filtration and degassing treatment in sequence to obtain the composite adhesive solution; Step S3: Apply the composite adhesive to the mold and heat it to obtain the anti-electron radiation composite material.
[0005] Optionally, in step S3, the heating treatment includes: first heating to 85°C to 95°C and holding for 0.9h to 1.1h, then heating to 125°C to 135°C and holding for 0.4h to 0.6h, then heating to 165°C to 175°C and holding for 0.4h to 0.6h, then heating to 205°C to 215°C and holding for 0.4h to 0.6h, then heating to 255°C to 265°C and holding for 0.4h to 0.6h, then heating to 305°C to 315°C and holding for 0.4h to 0.6h, and finally heating to 355°C to 365°C and holding for 0.4h to 0.6h.
[0006] Optionally, the mass ratio of the boron carbide powder to the electron radiation shielding composite material is (10 to 30): 100.
[0007] Optionally, in step S2, the molar ratio of the 4,4-diaminodiphenyl ether to the pyromellitic dianhydride is 1:(1.01 to 1.02).
[0008] Optionally, in step S2, the stirring speed is 40 rpm to 60 rpm and the time is 2 h to 4 h.
[0009] Optionally, in step S2, the filter screen used for filtration has a mesh size of 190 to 210 mesh.
[0010] Optionally, in step S1, the mass ratio of the silane coupling agent to the boron carbide powder is 1% to 5%.
[0011] Optionally, in step S1, the silane coupling agent is γ-aminopropyltriethoxysilane.
[0012] Optionally, in step S1, the organic solvent is N,N-dimethylacetamide.
[0013] The present invention also provides a PI-based electron radiation shielding composite material, which is prepared by the method described above for preparing PI-based electron radiation shielding composite materials.
[0014] Compared with related technologies, the preparation process of this invention consists of three steps: First, boron carbide powder, silane coupling agent, and organic solvent are mixed and dispersed to form a uniform dispersion. The silane coupling agent acts as a "molecular bridge," with its inorganic-philic groups reacting with the surface of boron carbide and its organic-philic groups binding with the subsequent PI matrix, significantly improving interfacial strength and reducing internal defects. Second, 4,4'-diaminodiphenyl ether and pyromellitic dianhydride are added to the dispersion, and a polycondensation reaction occurs under stirring to generate a polyimide precursor (polyamic acid). After filtration to remove impurities and degassing, the purity of the adhesive is ensured, avoiding pores or stress concentration points in the finished product. Finally, the composite adhesive is coated onto a mold and heated to convert the polyimide precursor into polyimide. The composite material prepared by this invention uses polyimide (PI) as the matrix and introduces boron carbide to form the composite material. Since both polyimide and boron carbide have low densities, the resulting composite material has a low density. In addition, experiments have shown that the composite material prepared by the method of this invention has better electron radiation protection performance compared with polyimide. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the preparation method of the PI-based electron radiation shielding composite material in an embodiment of the present invention; Figure 2 These are scanning electron microscope (SEM) images of the electron radiation shielding composite materials prepared in Examples 1 to 3 of the present invention and the polyimide prepared in Comparative Example 1. Detailed Implementation
[0016] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.
[0017] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
[0018] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used to distinguish different objects, not to describe a specific order or hierarchy. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.
[0019] like Figure 1 As shown in the figure, an embodiment of the present invention provides a method for preparing a PI-based electron radiation shielding composite material, comprising: Step S1: After mixing boron carbide powder, silane coupling agent and organic solvent, the mixture is dispersed to obtain a dispersion. Step S2: Add 4,4-diaminodiphenyl ether and pyromellitic dianhydride to the dispersion, and then perform stirring, filtration and degassing treatment in sequence to obtain a composite adhesive solution; the main components of the composite adhesive solution are boron carbide and polyamic acid; Step S3: Apply the composite adhesive to the mold and heat it to imidize the polyamic acid to obtain the electron radiation shielding composite material.
[0020] The preparation process of this invention consists of three steps: First, boron carbide powder, silane coupling agent, and organic solvent are mixed and dispersed to form a uniform dispersion. The silane coupling agent acts as a "molecular bridge," with its inorganic-philic groups reacting with the surface of boron carbide and its organic-philic groups binding with the subsequent PI matrix, significantly improving interfacial strength and reducing internal defects. Second, 4,4'-diaminodiphenyl ether and pyromellitic dianhydride are added to the dispersion, and a polycondensation reaction occurs under stirring to generate a polyimide precursor (polyamic acid). After filtration to remove impurities and degassing, the purity of the adhesive is ensured, preventing pores or stress concentration points in the finished product. Finally, the composite adhesive is coated onto a mold and heated to convert the polyimide precursor into polyimide. The composite material prepared by this method uses polyimide (PI) as the matrix and introduces boron carbide to form the composite material. Since both polyimide and boron carbide have low densities, the resulting composite material has a low density. In addition, experiments have shown that the composite material prepared by the method of the present invention has better protection against electron radiation compared with polyimide.
[0021] In some embodiments of the present invention, in step S1, the mass ratio of the silane coupling agent to the boron carbide powder is 1% to 5%. Exemplarily, the silane coupling agent is γ-aminopropyltriethoxysilane (KH-550); exemplarily, the organic solvent is N,N-dimethylacetamide.
[0022] In some embodiments of the present invention, in step S2, the molar ratio of the 4,4-diaminodiphenyl ether to the pyromellitic dianhydride is 1:(1.01 to 1.02).
[0023] In some embodiments of the present invention, in step S2, the stirring speed is 40 rpm to 60 rpm and the time is 2 h to 4 h.
[0024] In some embodiments of the present invention, in step S2, the filter screen used for filtration has a mesh size of 190 to 210 mesh.
[0025] In some embodiments of the present invention, the heating treatment in step S3 includes: first heating to 85°C to 95°C and holding for 0.9h to 1.1h; then heating to 125°C to 135°C and holding for 0.4h to 0.6h; then heating to 165°C to 175°C and holding for 0.4h to 0.6h; then heating to 205°C to 215°C and holding for 0.4h to 0.6h; then heating to 255°C to 265°C and holding for 0.4h to 0.6h; then heating to 305°C to 315°C and holding for 0.4h to 0.6h; and finally heating to 355°C to 365°C and holding for 0.4h to 0.6h.
[0026] In some embodiments of the present invention, the mass ratio of the boron carbide powder to the electron radiation shielding composite material is (10 to 30): 100.
[0027] This invention also provides a PI-based electron radiation shielding composite material, which is prepared using the method described above for preparing PI-based electron radiation shielding composite materials.
[0028] The present invention will be further described below with reference to specific embodiments.
[0029] Example 1 A1. Boron carbide powder, silane coupling agent, and organic solvent are mixed and ultrasonically dispersed for 2 hours under stirring to obtain a dispersion; wherein the silane coupling agent is γ-aminopropyltriethoxysilane, the mass ratio of the silane coupling agent to the boron carbide powder is 5%, the organic solvent is N,N-dimethylacetamide, and the mass ratio of the boron carbide powder to the volume of the organic solvent is 0.1 g / mL.
[0030] A2. Add 4,4-diaminodiphenyl ether and pyromellitic dianhydride to the dispersion, stir first, then filter through a 200-mesh filter to remove large particles, and then degas by vacuuming to obtain a composite adhesive; the main components of the composite adhesive are boron carbide and polyamic acid; wherein, the molar ratio of 4,4-diaminodiphenyl ether to pyromellitic dianhydride is 1:1.01; the stirring speed is 50 rpm and the time is 3 hours.
[0031] A3. The composite adhesive is coated onto a mold and heated to imidize the polyamic acid, thereby obtaining an anti-electron radiation composite material; wherein the heating treatment includes: first heating to 90°C and holding for 1 hour, then heating to 130°C and holding for 0.5 hours, then heating to 170°C and holding for 0.5 hours, then heating to 210°C and holding for 0.5 hours, then heating to 260°C and holding for 0.5 hours, then heating to 310°C and holding for 0.5 hours, and finally heating to 360°C and holding for 0.5 hours. The mass ratio of the boron carbide powder added in step A1 to the electron radiation shielding composite material obtained in step A3 is 1:10.
[0032] Example 2 The difference from Example 1 is that the mass ratio of boron carbide powder added in step A1 to the electron radiation shielding composite material prepared in A3 is 2:10.
[0033] Example 3 The difference from Example 1 is that the mass ratio of boron carbide powder added in step A1 to the electron radiation shielding composite material prepared in A3 is 3:10.
[0034] Comparative Example 1 4,4-Diaminodiphenyl ether and pyromellitic dianhydride are added to the organic solvent N,N-dimethylacetamide. The mixture is first stirred, and then degassed by vacuuming to obtain a polyamic acid adhesive. The molar ratio of 4,4-diaminodiphenyl ether to pyromellitic dianhydride is 1:1.01.
[0035] The composite adhesive is coated onto a mold and heated to imidize the polyamic acid, thereby obtaining polyimide. The heating treatment includes: first heating to 90°C and holding for 1 hour, then heating to 130°C and holding for 0.5 hours, then heating to 170°C and holding for 0.5 hours, then heating to 210°C and holding for 0.5 hours, then heating to 260°C and holding for 0.5 hours, then heating to 310°C and holding for 0.5 hours, and finally heating to 360°C and holding for 0.5 hours.
[0036] Experimental Example The electron radiation shielding composite materials prepared in Examples 1 to 3 and the polyimide prepared in Comparative Example 1 were characterized by scanning electron microscopy. The results are shown in the figure. Figure 2 , Figure 2 Image (a) is a scanning electron microscope image of the polyimide prepared in Comparative Example 1. Figure 2 Image (b) is a scanning electron microscope image of the electron radiation shielding composite material prepared in Example 1. Figure 2 Image (c) is a scanning electron microscope image of the electron radiation shielding composite material prepared in Example 2. Figure 2 Image d is a scanning electron microscope image of the electron radiation shielding composite material prepared in Example 3.
[0037] The electron radiation shielding composite materials prepared in Examples 1 to 3 and the polyimide prepared in Comparative Example 1 were placed in an environment with an electron energy of 1 MeV and an irradiation dose of 2 × 10⁻⁶. 14 e / cm 2 Under radiation conditions, the electron radiation absorption dose of the electron radiation shielding composite materials prepared in Examples 1 to 3 and the polyimide shielding prepared in Comparative Example 1 was measured. The results are shown in Table 1. As can be seen from Table 1, compared with Comparative Example 1, the electron radiation absorption dose of the electron radiation shielding composite materials prepared in Examples 1 to 3 is smaller after shielding, indicating that the electron radiation shielding performance of the electron radiation shielding composite materials in Examples 1 to 3 is better.
[0038] Table 1
[0039] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.
Claims
1. A method for preparing a PI-based anti-electronic radiation composite material, characterized in that, The preparation method comprises the following steps: S1, mixing boron carbide powder, silane coupling agent and organic solvent, and then performing dispersion treatment to obtain a dispersion liquid; S2, adding 4,4-diamino diphenyl ether and pyromellitic dianhydride into the dispersion liquid, and then sequentially performing stirring treatment, filtration and defoaming treatment to obtain a composite glue solution; S3, coating the composite glue solution on a mold and performing heating treatment to obtain an anti-electronic radiation composite material.
2. The method for preparing the PI-based electron radiation shielding composite material according to claim 1, characterized in that, In the step S3, the heating treatment comprises the following steps: firstly, increasing the temperature to 85-95℃, maintaining for 0.9-1.1h; secondly, increasing the temperature to 125-135℃, maintaining for 0.4-0.6h; thirdly, increasing the temperature to 165-175℃, maintaining for 0.4-0.6h; fourthly, increasing the temperature to 205-215℃, maintaining for 0.4-0.6h; fifthly, increasing the temperature to 255-265℃, maintaining for 0.4-0.6h; sixthly, increasing the temperature to 305-315℃, maintaining for 0.4-0.6h; and seventhly, increasing the temperature to 355-365℃, maintaining for 0.4-0.6h.
3. The method for preparing the PI-based electron radiation shielding composite material according to claim 1, characterized in that, The mass ratio of the boron carbide powder to the anti-electronic radiation composite material is (10-30):
100.
4. The method for preparing the PI-based electron radiation shielding composite material according to claim 1, characterized in that, In the step S2, the molar ratio of the 4,4-diamino diphenyl ether to the pyromellitic dianhydride is 1:(1.01-1.02).
5. The method for preparing the PI-based electron radiation shielding composite material according to claim 1, characterized in that, In the step S2, the stirring treatment is performed at a rotating speed of 40-60rpm for 2-4h.
6. The method for preparing the PI-based electron radiation shielding composite material according to claim 1, characterized in that, In the step S2, the filter screen aperture used in the filtration is 190-210 mesh.
7. The method for preparing the PI-based electron radiation shielding composite material according to claim 1, characterized in that, In the step S1, the mass ratio of the silane coupling agent to the boron carbide powder is 1%-5%.
8. The method for preparing the PI-based electron radiation shielding composite material according to claim 1, characterized in that, In the step S1, the silane coupling agent is γ-aminopropyl triethoxysilane.
9. The method for preparing the PI-based electron radiation shielding composite material according to claim 1, characterized in that, In the step S1, the organic solvent is N,N-dimethylacetamide.
10. A PI-based anti-electronic radiation composite material, characterized in that, The PI-based anti-electronic radiation composite material is prepared by using the preparation method according to any one of claims 1-9.