CN115926074B - Preparation method of lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler - Google Patents
Preparation method of lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler Download PDFInfo
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- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims description 10
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- 230000007935 neutral effect Effects 0.000 claims description 3
- KWVGIHKZDCUPEU-UHFFFAOYSA-N 2,2-dimethoxy-2-phenylacetophenone Chemical group C=1C=CC=CC=1C(OC)(OC)C(=O)C1=CC=CC=C1 KWVGIHKZDCUPEU-UHFFFAOYSA-N 0.000 claims description 2
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- HALXZLZYPIVRNL-UHFFFAOYSA-N lead;prop-2-enoic acid Chemical compound [Pb].OC(=O)C=C HALXZLZYPIVRNL-UHFFFAOYSA-N 0.000 description 24
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- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 2
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- 229910052580 B4C Inorganic materials 0.000 description 1
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- DBYVFGSEJWZZCZ-UHFFFAOYSA-N borinothioic acid Chemical compound SB DBYVFGSEJWZZCZ-UHFFFAOYSA-N 0.000 description 1
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- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
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- Y02A30/00—Adapting or protecting infrastructure or their operation
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Abstract
The application provides a preparation method of lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler, which comprises the following steps: preparing hydroxylated boron nitride powder by ball milling boric acid and boron nitride, dispersing the hydroxylated boron nitride powder in ethanol solution, and adding gamma-mercaptopropyl triethoxysilane to obtain mercaptoboron nitride; then adding lead acrylate and an initiator to initiate reaction to obtain lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler; according to the method, the boron nitride inorganic filler with neutron shielding function and the lead acrylate organic filler with gamma ray shielding function are chemically bonded, so that the interface compatibility between the inorganic filler and the organic filler as well as between the inorganic filler and the polymer matrix is improved, the dispersion uniformity and the functional filler content of the radiation shielding functional filler in the composite material are effectively improved, the radiation shielding performance and the comprehensive mechanical performance of the composite material are improved, and the method has wide application prospects in the field of nuclear radiation protection.
Description
Technical Field
The invention relates to the field of nuclear radiation protection, in particular to a preparation method of lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler.
Background
The nuclear science technology is widely applied to the fields of national defense, energy sources, industry, medical treatment and the like, brings great economic and social benefits, and increases the opportunity of people to contact various radiations. The development of radiation protective materials to effectively reduce the harm of radiation to the human body, equipment and environment has become an important component of military and civilian radiation protection work. Concrete, lead products and the like, which are relatively low in price, have been widely used in the protection fields of stationary nuclear reactors, accelerators and the like, and have been playing an important role. However, in the occasions where special requirements on weight and volume are required, such as mobile nuclear power devices, nuclear waste transportation and storage containers, space vehicles and the like, the application of the traditional protective materials is limited, and a novel radiation protective material with light weight and high efficiency is needed.
Polymer matrix composite materials using micropowder with radiation shielding function as filler have become the research and development direction of novel radiation-proof materials because of the advantages of small density, easy processing and the like. The radiation shielding effect of the polymer-based radiation protection material is closely related to the type, content, dispersibility and the like of the functional filler. The radiation protection effect of the material can be improved due to the fact that the radiation shielding functional particle content is increased, but the mechanical property and fatigue property of the matrix material are often affected when the functional particle content is too high, and therefore the improvement space of the radiation protection effect is limited. Meanwhile, after the micro-nano particles are introduced into a polymer system, multiphase interfaces are generated, including organic-organic interfaces, inorganic-inorganic interfaces, organic-inorganic interfaces and the like, so that important influences on radiation protection effect and comprehensive performance are generated (More C V, alsed Z, badawi M S, et al, environ Chem Lett, 2021, 19:2057-2090).
The protection mechanism of neutrons and gamma rays has a large difference, and for the protection requirement of a mixed radiation field, various radiation shielding functional elements are required to be optimally designed and introduced. The natural abundance of the isotope B-10 is 19.8%, the thermal neutron capture cross section is large, and boron nitride, boron carbide and the like are widely applied to the field of neutron shielding. Lead has a high atomic number and good shielding effect on gamma rays. With the traditional physical blending method, inorganic filler containing boron and inorganic filler containing lead can be simultaneously introduced into the polymer matrix, and the problem of the interface between the inorganic filler and the polymeric matrix needs to be concerned. Chinese patent CN 113072752A discloses a rubber composite material with excellent nuclear protection and flexibility and a preparation method thereof, wherein particles with neutron and gamma-ray radiation protection function are introduced into a polymer matrix after being surface modified by a coupling agent, so that the composite material has radiation protection performance and comprehensive use performance; the method can improve the interface between the inorganic filler and the polymer matrix to a certain extent by carrying out surface modification on the inorganic functional filler, but has larger limitations. The mechanical property and the service behavior of the inorganic filler are affected due to the poor interface between the inorganic filler and the organic polymer matrix, so that the content and the dispersion uniformity of functional elements are limited, and the radiation shielding performance of the composite material is restricted from being improved. Therefore, how to improve the protection performance of the radiation protection material against the mixed radiation field is still a technical problem to be solved in the field.
Disclosure of Invention
In order to solve the protection requirement of a mixed radiation field (neutron and gamma-ray radiation), the application provides a preparation method of an acrylic acid lead-boron nitride organic-inorganic hybrid radiation shielding function filler, which is characterized in that a boron nitride inorganic filler with a neutron shielding function and a lead acrylic acid lead organic filler with a gamma-ray shielding function are used for chemical bonding, so that the interfacial compatibility between the boron nitride inorganic filler and the lead acrylic acid organic filler as well as between the boron nitride inorganic filler and a polymer matrix is improved, the dispersion uniformity and the content of the functional filler of the radiation shielding function filler in a composite material are effectively improved, and the radiation shielding performance and the comprehensive mechanical performance of the composite material are improved; the filler is simultaneously introduced with two radiation shielding functional elements of boron and lead, so that the dispersion uniformity among different functional elements is improved, the balanced protection of a neutron and gamma-ray mixed radiation field is realized, and the mechanical property of the boron nitride nanosheet can be improved by introducing the boron nitride nanosheet.
Specifically, the aim of the invention is achieved by the following technical scheme:
the preparation method of the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler comprises the following specific steps:
(a) Uniformly mixing boric acid and boron nitride to obtain a ball-milling sample, putting the ball-milling sample into a planetary ball-milling tank, adding a grinding ball, wherein the rotating speed is preferably 350 rpm, and after ball-milling is performed for about 24 and h, finishing ball-milling when the transverse size of the boron nitride in the ball-milling sample is about 100 nm, so as to obtain a ball-milling material; washing ball-milling materials with deionized water, carrying out suction filtration, repeating the steps until the eluate is neutral, and putting the solid obtained by suction filtration into a blast drying oven for drying at 80 ℃ to obtain hydroxylated boron nitride powder; in this step, the mass ratio of the grinding balls to the ball-milled sample is preferably 9:1.
(b) Dispersing the hydroxylated boron nitride powder obtained in the step (a) in ethanol water solution, carrying out ultrasonic treatment (450W, 1 h) to ensure that the hydroxylated boron nitride powder is dispersed uniformly, adding a stirrer, transferring the mixture into an oil bath, adding gamma-mercaptopropyl triethoxysilane, regulating the pH to 3 by adopting dilute hydrochloric acid (or acetic acid), continuously stirring and reacting at 30 ℃ and 50 rpm for 24h, washing by adopting deionized water, and drying in an oven at 80 ℃ to obtain the mercaptoboron nitride powder for later use; in this step, the volume percentage of the ethanol aqueous solution is preferably 95%, and the mass-volume ratio of the hydroxylated boron nitride to the ethanol aqueous solution is preferably 1:10, with the mass-volume ratio unit being g/mL.
(c) Adding absolute ethyl alcohol and acrylic acid into a three-neck flask, putting the three-neck flask into an oil bath kettle preheated to 65 ℃ and stirring, slowly adding lead oxide powder, heating to 70 ℃, refluxing until the lead oxide is completely dissolved, filtering while the three-neck flask is hot, cooling and crystallizing the filtrate, performing suction filtration, taking precipitate to wash with deionized water, putting the obtained white solid into a blast drying oven, and drying at 80 ℃ to obtain lead acrylate powder for later use; the volume ratio of the absolute ethyl alcohol to the acrylic acid added in the step is preferably 95:14;
(d) Dispersing the sulfhydrylated boron nitride prepared in the step (b) and the lead acrylate prepared in the step (c) in absolute ethyl alcohol, transferring the dispersion liquid into a three-neck flask, magnetically stirring and uniformly mixing at a rotating speed of 120rpm, adding an initiator, thermally or photo-initiating a 'mercaptan-alkene' click reaction under the protection of nitrogen, washing a precipitate with the hot alcohol, and then placing the washed precipitate into a blast drying oven for drying at 80 ℃ to obtain the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler; in this step, the initiator used includes two kinds of photoinitiators and thermal initiators; when a photoinitiator is used, the photoinitiating conditions are preferably magnetic stirring at room temperature while irradiating 18 h with a portable ultraviolet lamp of 32W, 365 nm; when a thermal initiator is used, it is preferably heated in a constant temperature oil bath with magnetic stirring at a reaction temperature of 60℃for a reaction time of 12 h-24 h.
Preferably, in the preparation method of the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler, the mass ratio of boric acid to boron nitride in the step (a) is 4:1.
Preferably, in the preparation method of the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler, the grinding balls used in the step (a) have diameters of 15 mm, 12 mm, 10 mm and 5 mm respectively; the mass ratio of the four grinding balls is preferably 3:2:1:1 in sequence.
Preferably, in the preparation method of the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler, the silane coupling agent used in the step (b) is gamma-mercaptopropyl triethoxysilane, and the addition amount of the silane coupling agent is 10 wt% of that of the hydroxylated boron nitride in the dispersion liquid.
Preferably, in the preparation method of the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler, in the step (c), the mass ratio of the acrylic acid to the lead oxide is 1:1.5.
Preferably, in the preparation method of the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler, in the step (d), the mass ratio of the mercapto boron nitride to the lead acrylate is 1:1.4.
preferably, in the preparation method of the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler, the photoinitiator used in the step (d) is 2, 2-dimethoxy-2-phenylacetophenone (DMPA), and the thermal initiator is 2, 2-Azobisisobutyronitrile (AIBN); the mass ratio of the initiator to the lead acrylate is 3: 1-35: 1.
the application carries out chemical bonding, rather than physical blending, on the boron nitride inorganic filler with neutron shielding function and the lead acrylate organic filler with gamma ray shielding function, and compared with the existing preparation method, the preparation method has the advantages that: through organic-inorganic hybridization, the interfacial compatibility among inorganic filler, organic filler and polymer matrix can be improved, the dispersion uniformity and the functional filler content of the radiation shielding functional filler in the composite material can be effectively improved, and the radiation shielding performance and the comprehensive mechanical property of the composite material can be improved; through organic-inorganic hybridization, various radiation shielding functional elements can be introduced, so that the dispersion uniformity among different functional elements is improved, and the balanced protection of a mixed radiation field is realized; the preparation process is simple, convenient, adjustable and controllable, has obvious effect, low dependence on processing equipment, is easy to realize, and has wide application prospect in the field of nuclear radiation protection.
Drawings
Fig. 1 is a schematic diagram of the preparation principle of lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler.
FIG. 2 is an infrared spectrum of boron nitride, lead acrylate, and lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler prepared in the examples.
FIG. 3 is an elemental distribution diagram of a lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler prepared in example 1.
Detailed Description
The present invention will be further illustrated by the following examples, wherein the raw materials, reagents, instruments, etc. used in the examples are commercially available products.
Example 1 preparation method of lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler
(a) Uniformly mixing 20 g boric acid and 5 g boron nitride to obtain a ball-milling sample; putting a ball-milling sample into a planetary ball-milling tank, adding a grinding ball, performing ball milling at the rotating speed of 350 rpm, and finishing ball milling when the transverse size of boron nitride is about 100 nm after ball milling is performed on 24 and h, so as to obtain a ball-milling material; washing ball-milling materials by adopting deionized water, and performing suction filtration; washing and suction-filtering for several times until the washing liquid is neutral, and putting the solid obtained by suction-filtering into a blast drying oven to be dried at 80 ℃ to obtain hydroxylated boron nitride powder;
in the embodiment, the mass ratio of the grinding balls to the ball milling sample is 9:1, and the diameters of the grinding balls are 15 mm, 12 mm, 10 mm and 5 mm respectively; the mass ratio of the grinding balls is 3:2:1:1 in sequence.
(b) Dispersing 20 g hydroxylated boron nitride powder in 200 mL of 95vol% ethanol water solution, and carrying out ultrasonic treatment (450W, 1 h) to uniformly disperse the powder; adding a stirrer, transferring to an oil bath, adding 2 g gamma-mercaptopropyl triethoxysilane, regulating the pH value to 3 by adopting 0.1 mol/L dilute hydrochloric acid, stirring and reacting for 24 hours at 30 ℃ and 50 rpm, washing by adopting deionized water, and drying in an oven at 80 ℃ to obtain mercaptoboron nitride powder for later use;
(c) Adding 95 mL absolute ethyl alcohol and 14 mL acrylic acid into a three-neck flask, putting the three-neck flask into an oil bath kettle preheated to 65 ℃ and stirring, slowly adding 22 g lead oxide powder, heating to 70 ℃, refluxing until the lead oxide is completely dissolved, filtering while the three-neck flask is hot, cooling and crystallizing the filtrate, carrying out suction filtration, taking precipitate and washing, putting the obtained white solid into a blast drying oven, and drying at 80 ℃ to obtain lead acrylate powder; standby;
(d) Dispersing 0.25 g of the sulfhydrylated boron nitride prepared in the step (c) and 3.5 g of the lead acrylate prepared in the step (c) in 75 mL absolute ethyl alcohol, transferring the dispersion liquid into a three-neck flask, magnetically stirring (120 rpm) and uniformly mixing, adding 0.1 g of initiator AIBN, magnetically stirring under the protection of nitrogen, heating in a constant-temperature oil bath at the reaction temperature of 60 ℃ for the reaction time of 12 h, washing the precipitate with hot ethanol, and drying in a blast drying oven at 80 ℃ to obtain the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler.
The lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler prepared in the embodiment is modified for a silicon rubber composite material (sy 34-3 of Anhui Ming Yi silicon industry Co., ltd.). The filler content was 40 phr, its thermal neutron shielding performance was tested using an Am-Be neutron source (moderation) and He-3 detector, and its gamma ray shielding performance was tested using a Ba-133 source and NaI detector.
The test result of the shielding performance of the mixed radiation field shows that after the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding function filler is modified, the thermal neutron shielding performance of the silicon rubber-based composite material is improved by 14%, and the gamma ray shielding performance is improved by 8%.
Example 2
(a) Uniformly mixing 20 g boric acid and 5 g boron nitride, putting the mixture into a planetary ball milling tank, adding grinding balls, wherein the mass ratio of the grinding balls to a sample is 9:1, the mass ratio of the grinding balls with diameters of 15: 15 mm, 12 mm, 10 mm and 5 mm is 3:2:1:1, the rotating speed is 350 rpm, the transverse size of the boron nitride after ball milling is 24: 24h is about 100 nm, adopting deionized washing and suction filtration to neutrality of washing liquid, and putting the obtained solid into a blast drying box for drying at 80 ℃ to obtain hydroxylated boron nitride powder;
(b) Dispersing 20 g hydroxylated boron nitride powder in 200 mL of 95vol% ethanol solution, carrying out ultrasonic treatment (450W, 1 h) to ensure that the powder is uniformly dispersed, adding a stirrer, transferring the mixture into an oil bath, adding 2 g gamma-mercaptopropyl triethoxysilane, adjusting pH to be 3 by adopting 0.1 mol/L dilute hydrochloric acid, stirring and reacting for 24h at 30 ℃ and 50 rpm, washing by adopting deionized water, and drying in an oven at 80 ℃ to obtain the thiolated boron nitride powder;
(c) Adding 95 mL absolute ethyl alcohol and 14 mL acrylic acid into a three-neck flask, putting the three-neck flask into an oil bath kettle preheated to 65 ℃ and stirring, slowly adding 22 g lead oxide powder, heating to 70 ℃, refluxing until the lead oxide is completely dissolved, filtering while the three-neck flask is hot, cooling and crystallizing the filtrate, carrying out suction filtration, taking precipitate and washing, and putting the obtained white solid into a blast drying box for drying at 80 ℃ to obtain lead acrylate powder.
(d) Dispersing 0.25 g sulfhydrylation boron nitride and 3.5 g lead acrylate in 75 mL absolute ethyl alcohol, transferring the dispersion liquid into a three-neck flask, magnetically stirring and uniformly mixing at a speed of 120rpm, adding 0.4 g initiator AIBN, magnetically stirring under the protection of nitrogen, heating in an oil bath at a constant temperature at a reaction temperature of 60 ℃ for 12 h, washing the precipitate with hot ethanol, and drying at 80 ℃ in a blast drying oven to obtain the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler.
The result of the mixed radiation field shielding performance test (the test method is the same as that of the embodiment 1) shows that after the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding function filler is modified, the thermal neutron shielding performance of the silicon rubber-based composite material is improved by 13%, and the gamma ray shielding performance is improved by 10%.
Example 3
(a) Uniformly mixing 20 g boric acid and 5 g boron nitride, putting the mixture into a planetary ball milling tank, adding grinding balls, wherein the mass ratio of the grinding balls to a sample is 9:1, the mass ratio of the grinding balls with diameters of 15: 15 mm, 12 mm, 10 mm and 5 mm is 3:2:1:1, the rotating speed is 350 rpm, the transverse size of the boron nitride after ball milling is 24: 24h is about 100 nm, adopting deionized washing and suction filtration to neutrality of washing liquid, and putting the obtained solid into a blast drying box for drying at 80 ℃ to obtain hydroxylated boron nitride powder;
(b) Dispersing 20 g hydroxylated boron nitride powder in 200 mL of 95vol% ethanol solution, carrying out ultrasonic treatment (450W, 1 h) to ensure that the powder is uniformly dispersed, adding a stirrer, transferring the mixture into an oil bath, adding 2 g gamma-mercaptopropyl triethoxysilane, adjusting pH to be 3 by adopting 0.1 mol/L dilute hydrochloric acid, stirring and reacting for 24h at 30 ℃ and 50 rpm, washing by adopting deionized water, and drying in an oven at 80 ℃ to obtain the thiolated boron nitride powder;
(c) Adding 95 mL absolute ethyl alcohol and 14 mL acrylic acid into a three-neck flask, putting the three-neck flask into an oil bath kettle preheated to 65 ℃ and stirring, slowly adding 22 g lead oxide powder, heating to 70 ℃, refluxing until the lead oxide is completely dissolved, filtering while the three-neck flask is hot, cooling and crystallizing the filtrate, carrying out suction filtration, taking precipitate and washing, putting the obtained white solid into a blast drying oven, and drying at 80 ℃ to obtain lead acrylate powder;
(d) Dispersing 0.25 g sulfhydrylation boron nitride and 3.5 g lead acrylate in 75 mL absolute ethyl alcohol, transferring the dispersion liquid into a three-neck flask, magnetically stirring and mixing uniformly, adding 0.4 g initiator AIBN, using nitrogen as a protective atmosphere, magnetically stirring at 120rpm, heating with constant temperature oil bath, reacting at 60 ℃ for 24h, washing precipitate with hot ethanol, and drying at 80 ℃ in a blast drying oven to obtain the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler.
The result of the mixed radiation field shielding performance test (the test method is the same as that of the embodiment 1) shows that after the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding function filler is modified, the thermal neutron shielding performance of the silicon rubber-based composite material is improved by 15%, and the gamma ray shielding performance is improved by 14%.
Example 4
(a) Uniformly mixing 20 g boric acid and 5 g boron nitride, putting the mixture into a planetary ball milling tank, adding grinding balls, wherein the mass ratio of the grinding balls to a sample is 9:1, the mass ratio of the grinding balls with diameters of 15: 15 mm, 12 mm, 10 mm and 5 mm is 3:2:1:1, the rotating speed is 350 rpm, the transverse size of the boron nitride after ball milling is 24: 24h is about 100 nm, adopting deionized washing and suction filtration to neutrality of washing liquid, and putting the obtained solid into a blast drying box for drying at 80 ℃ to obtain hydroxylated boron nitride powder;
(b) Dispersing 20 g hydroxylated boron nitride powder in 200 mL 95vol% ethanol solution, carrying out ultrasonic treatment (450W, 1 h) to ensure that the powder is uniformly dispersed, adding a stirrer, transferring the mixture into an oil bath, adding 2 g gamma-mercaptopropyl triethoxysilane, adjusting pH to be 3 by adopting 0.1 mol/L dilute hydrochloric acid, continuously stirring and reacting for 24h at 30 ℃ and 50 rpm, washing by adopting deionized water, and drying in an oven at 80 ℃ to obtain the mercaptoboron nitride powder;
(c) Adding 95 mL absolute ethyl alcohol and 14 mL acrylic acid into a three-neck flask, putting the three-neck flask into an oil bath kettle preheated to 65 ℃ and stirring, slowly adding 22 g lead oxide powder, heating to 70 ℃, refluxing until the lead oxide is completely dissolved, filtering while the three-neck flask is hot, cooling and crystallizing the filtrate, carrying out suction filtration, taking precipitate and washing, putting the obtained white solid into a blast drying oven, and drying at 80 ℃ to obtain lead acrylate powder;
(d) Dispersing 0.25 g sulfhydrylation boron nitride and 3.5 g lead acrylate in 75 mL absolute ethyl alcohol, transferring the dispersion liquid into a three-neck flask, magnetically stirring and mixing uniformly, adding 1.2 g initiator DMPA, magnetically stirring at room temperature and 120rpm under the protection of nitrogen, simultaneously irradiating 18 h by using 32W and 365 nm portable ultraviolet lamps, washing the precipitate by using hot ethanol, and drying in a blast drying oven at 80 ℃ to obtain the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler.
The result of the mixed radiation field shielding performance test (the test method is the same as that of the embodiment 1) shows that after the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding function filler is modified, the thermal neutron shielding performance of the silicon rubber-based composite material is improved by 16%, and the gamma ray shielding performance is improved by 18%.
FIG. 2 is an infrared spectrum of the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler prepared in examples 1-4. The IR spectra of examples 1, 2, 3, 4 and lead acrylate, it can be seen that the FTIR curves of examples 1, 2, 3, 4 are 1637cm -1 The absorption peak of unsaturated carbon-carbon double bond (c=c) in lead acrylate is lost or the relative intensity is reduced, at 1418 cm -1 And 1541 cm -1 Still in the presence of acrylate (COO) - ) Symmetrical and antisymmetric stretching vibration characteristic peaks of 1374 and 1374 cm -1 And 812 cm -1 Characteristic absorption peaks appear nearby, and respectively correspond to an in-plane stretching vibration peak of B-N and an out-of-plane bending vibration peak of B-N-B, which shows that all the examples 1, 2, 3 and 4 successfully prepare the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler.
The efficiency of bond hybridization is related to the preparation conditions. Comparing example 1 with example 2, the FTIR curve of example 1 was 1637cm, since the amount of initiator AIBN added in example 1 was less than that in example 2 -1 The absorption peak of unsaturated carbon-carbon double bond (c=c) in lead acrylate only appears to be reduced in relative strength, and a small amount of lead acrylate still exists, which indicates that boron nitride is not completely bonded with lead acrylate. The reaction time was relatively short in example 2, the FTIR profile of example 2 had more hetero peaks and the characteristic peaks were relatively weak compared to examples 2 and 3. Comparing example 3 with example 4, it can be seen that both thermal initiation and photoinitiation can successfully prepare the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler.
FIG. 3 is an elemental distribution diagram of a lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler prepared in example 1. In fig. 3, a is SEM detection result, B is Pb-MA distribution result, and C is N-KA distribution result, and it can be seen that the lead element from the lead acrylate and the nitrogen element from the boron nitride are uniformly distributed in the hybrid filler due to efficient hybridization between the lead acrylate and the boron nitride.
The above examples show that the preparation method adopts a boric acid-assisted ball milling process to graft hydroxyl on the surface of boron nitride, adopts a silane coupling agent to carry out sulfhydrylation modification on the boron nitride, and utilizes the principle of 'thiol-ene' click reaction to react the boron nitride containing sulfhydryl groups with lead acrylate with double bond structure, so that the lead acrylate-boron nitride organic-inorganic hybridization radiation shielding functional filler can be successfully prepared, and the preparation mechanism is shown in figure 1. The boron nitride inorganic filler with neutron shielding function and the lead acrylate organic filler with gamma ray shielding function are chemically bonded, so that the interfacial compatibility between the inorganic filler and the organic filler as well as between the inorganic filler and the polymer matrix can be improved, the dispersion uniformity and the functional filler content of the radiation shielding functional filler in the composite material can be effectively improved, various radiation shielding functional elements can be introduced, the dispersion uniformity of different functional elements can be improved, and the improvement of the radiation shielding performance and the comprehensive mechanical performance of the composite material and the balanced protection of a mixed radiation field can be realized. The preparation process is simple, convenient, adjustable and controllable, has obvious effect, is easy to realize, and has wide application prospect in the field of nuclear radiation protection.
The above embodiments are not intended to limit the present invention in any way, and any simple modification, equivalent variation and modification made to the above embodiments according to the technical substance of the present invention without departing from the technical scope of the present invention.
Claims (9)
1. The preparation method of the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler is characterized by comprising the following specific steps:
(a) Mixing boric acid and boron nitride according to a mass ratio of 4:1 to obtain a ball milling sample, putting the ball milling sample into a planetary ball milling tank, adding a grinding ball, and ball milling for 24 h; washing with deionized water, suction-filtering until the eluate is neutral, and drying the solid obtained by suction-filtering to obtain hydroxylated boron nitride;
(b) Dispersing hydroxylated boron nitride in ethanol water solution, performing ultrasonic dispersion, adding gamma-mercaptopropyl triethoxysilane, adjusting the pH to 3, stirring at 30 ℃ for reaction 24h, washing and drying to obtain mercaptoboron nitride;
(c) Dispersing sulfhydryl boron nitride and lead acrylate in absolute ethyl alcohol, adding an initiator, reacting in nitrogen atmosphere, washing and drying a precipitate obtained by the reaction to obtain the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler;
the initiator used includes photoinitiators and thermal initiators; when a photoinitiator is used, the reaction conditions are: the room temperature, 32W, 365 nm ultraviolet lamp irradiates 18 h; when a thermal initiator is used, the reaction conditions are: 60. reaction 12 h-24 h is heated.
2. The method for preparing the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler according to claim 1, wherein in the step (a), the mass ratio of the grinding balls to the ball milling sample is 9:1.
3. The method for preparing lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler according to claim 1, wherein the addition amount of gamma-mercaptopropyl triethoxysilane in the step (b) is 10% of the mass of the hydroxylated boron nitride.
4. The method for preparing a lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler according to claim 1, wherein the volume concentration of the ethanol aqueous solution in the step (b) is 95%.
5. The method for preparing a lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler according to claim 1, wherein the lead acrylate in the step (c) is obtained by the following method: uniformly mixing absolute ethyl alcohol and acrylic acid, stirring at 65 ℃, adding lead oxide, heating to 70 ℃, refluxing until the lead oxide is completely dissolved, filtering, cooling and crystallizing filtrate, filtering, taking precipitate, washing and drying to obtain lead acrylate; the mass ratio of the added acrylic acid to the lead oxide is 1:1.5.
6. The method for preparing the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler according to claim 1, wherein the mass ratio of the added mercaptoboron nitride to the lead acrylate in the step (c) is 1:1.4.
7. the method for preparing the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler according to claim 1, wherein in the step (c), the mass ratio of the initiator to the lead acrylate is 3: 1-35: 1.
8. the method for preparing lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler according to claim 1, wherein in the step (c), the photoinitiator is 2, 2-dimethoxy-2-phenylacetophenone, and the thermal initiator is 2, 2-azobisisobutyronitrile.
9. The method for preparing the lead acrylate-boron nitride organic-inorganic hybrid radiation shielding functional filler according to claim 2, wherein the diameters of grinding balls used in the step (a) are respectively 15 mm, 12 mm, 10 mm and 5 mm, and the mass ratio of the grinding balls is 3:2:1:1 in sequence.
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