CN104744945B - Neutron shielding material with anti-flaming thermal-insulation performance and preparation method thereof - Google Patents

Abstract

The present invention discloses a kind of neutron shielding material with anti-flaming thermal-insulation performance and preparation method thereof, and the material is made up of methyl ethylene silica gel, neutron absorber material, anti-flaming function filler, heat insulating function filler, vulcanizing agent double 25 and powder surface modifier；Its preparation method is after being plasticated in double two or the five addition mills of methyl ethylene silica gel and vulcanizing agent, with by banburying in neutron absorber material, anti-flaming function filler, heat insulating function filler, the public addition vacuum banbury of powder surface modifier mixed liquor, banburying product is finally added into vulcanizing press, that is, obtains the neutron shielding material with anti-flaming thermal-insulation performance；The material has the material of thermal neutron shielding properties, with good pliability, fire resistance, heat-proof quality, mechanical strength, can not only meet complex-shaped nuclear instrument equipment perimeter defense, is also that good NEUTRON PROTECTION takes core material.

Description

Neutron shielding material with flame-retardant and heat-insulating properties and preparation method thereof

technical field

The invention relates to a neutron shielding material with flame-retardant and heat-insulating properties and a preparation method thereof, belonging to the field of nuclear radiation protection and the technical field of preparation of nuclear radiation shielding materials.

technical background

As the application of nuclear technology plays an increasingly important role in energy conservation and environmental protection, resource exploration, radiation processing, medical diagnosis, and national defense and military affairs, the number of radioactive practitioners has also increased. But while bringing convenience and enjoyment to people, various rays also bring harm to human beings to some extent. Therefore, it is necessary to reduce the occupational exposure level of practitioners in various radioactive activities and ensure the life and health of radiation practitioners. extremely important.

The traditional neutron radiation protective clothing uses multi-layer neutron protective fiber cloth as the main material, which is heavy, poor in flexibility, weak in neutron shielding ability, and does not have flame retardancy and heat insulation performance. Fire protection requirements; traditional hard polymer shielding materials cannot change randomly with the size of the environment and the shape of the equipment, and do not have flame retardancy, which brings certain difficulties and risks to the protection of nuclear equipment. Therefore, developing a neutron shielding material with flame-retardant and heat-insulating properties has become a technical problem to be solved urgently in this field.

Contents of the invention

In order to solve the above problems, the present invention provides a material with thermal neutron shielding performance based on methyl vinyl silica gel, which has good flexibility, flame retardancy, heat insulation performance, mechanical strength, and thermal neutron shielding performance. The material with shielding performance has good flexibility, flame retardancy, heat insulation performance and mechanical strength, and the present invention is realized in this way:

A neutron shielding material with flame-retardant and heat-insulating properties, the specific components are as follows, in parts by mass: 100 parts of methyl vinyl silica gel, 30-90 parts of neutron absorber material, and 15.8-48 parts of flame-retardant functional filler , 2.7-8.2 parts of thermal insulation functional filler, 0.5-3 parts of vulcanizing agent Shuangerwu,

1~5 parts of powder surface modifier; wherein, the neutron absorber material is one or more of Sm ₂ O ₃ , Gd ₂ O ₃ , LiF or B ₄ C; the flame retardant functional filler It is one or more of aluminum hydroxide, magnesium hydroxide, zinc borate or red phosphorus; the thermal insulation functional filler is hollow microspheres;

The powder surface modifier is one or more of coupling agent KH-540, coupling agent KH-550, aminopropyltrimethoxysilane and coupling agent D-90.

Further, in the present invention, the hollow microspheres are one or more of TiO ₂ hollow microspheres, SiO ₂ hollow microspheres, Al ₂ O ₃ hollow microspheres or glass hollow microspheres.

Further, in the present invention, the hardness of the methyl vinyl silica gel is 5HA.

Further, in the present invention, the particle diameters of the neutron absorber material, flame retardant functional filler, and thermal insulation functional filler are 2.5um~50um.

According to the preparation method of the neutron shielding material with flame-retardant and heat-insulating properties according to the present invention, the specific steps are as follows:

(1) Adjust the speed of the two-roll mill to 45rpm, the distance between the two rollers to 2mm, the temperature to 30-50°C, add methyl vinyl silica gel for 3-5min, and then add the vulcanizing agent Shuangerwu to continue the mastication for 10-15min;

(2) After mixing the neutron absorber material, flame-retardant functional filler, heat-insulating functional filler, and powder surface modifier, add deionized water 0.3-0.5 times their total mass, and react at a temperature of 30-50°C 1-1.5h, to obtain the functional filler reaction solution;

(3) Add the masticated product obtained in step 1 and the functional filler reaction solution obtained in step 2 into a vacuum mixer, and banbury at 105-115°C for 20-30 minutes to obtain a silica gel-based mixture;

(5) The temperature of the upper and lower plates of the flat vulcanizer is 170-190°C, add the silica gel-based mixture obtained in step 3, vulcanize under 10-15MPa pressure for 15-20min, and obtain the neutron shielding with flame-retardant and heat-insulating properties after cooling Material.

The neutron shielding material obtained by the present invention through plasticizing of silica gel and vulcanizing agent, surface modification of functional filler, mixing of silica gel and functional filler, hot pressing of silica gel base material, etc., has good thermal neutron shielding performance and relatively high heat dissipation. Neutron absorption cross section, 4cm thick material can shield up to 72.2% of neutrons emitted by Am-Be neutron source; with methyl vinyl silica gel as the matrix, the polymer material obtained is soft and easy to curl after molding; flame retardant function When the filler component is heated, it can decompose crystal water to absorb heat or form a covering layer to insulate heat and oxygen, and has high flame retardancy; in addition, after testing, the material also has high mechanical strength and certain heat insulation performance. Not only can it meet the peripheral protection requirements of nuclear instruments and equipment with complex shapes, but it is also a good core material for neutron protective clothing.

detailed description

The present invention will be further described in conjunction with following specific examples:

Example 1:

The formula of the neutron shielding material with flame-retardant and heat-insulating properties is: 100g of methyl vinyl silica gel with a hardness of 5HA, 90g of B4C powder, 8.2g of _SiO2 hollow microspheres, _48g of zinc borate powder, and 0.5g of bis-pentasulfide , KH-540 coupling agent 1g. The B ₄ C powder has a particle size of 50um, the SiO ₂ hollow microbeads has a particle size of 25um, and the zinc borate powder has a particle size of 2.5um.

The steps of the preparation method of the neutron shielding material with flame-retardant and heat-insulating properties are as follows:

(1) Plastic refining of methyl vinyl silica gel matrix material: adjust the distance between the double rollers of the open mill to 2mm, and the rotation speed to 45r/min. Put it into the double roller room for masticating, and the masticating time is 3 minutes. Add 1g of vulcanizing agent Shuang25 to the above-mentioned methyl vinyl silica gel and continue masticating for 10 minutes, during which the rolling operation method is used for masticating.

(2) Surface modification process of functional fillers: Mix 75g of deionized water and 3g of KH-540 coupling agent with functional filler powder, and react at 30°C for 1.5 hours.

(3) Mixing of silica gel and functional filler powder: Add the above-mentioned silica gel that has been masticated, the functional powder that has been reacted, and the reaction liquid mixture into the vacuum mixer, adjust the processing temperature to 105°C, mix for 30 minutes, mix thoroughly and remove moisture.

(4) Thermal compression molding of silica gel matrix material: set the temperature of the upper and lower plates of the flat vulcanizer to 170°C, place the silica gel-based mixture mixed in the vacuum internal mixer in a flat cavity mold coated with a release agent, and place it on the flat plate Lay release cloth on the top and bottom of the mold, and then add 10MPa pressure to vulcanize for 20 minutes, take out the mold, and take out the sample after cooling.

Material mechanical properties:

Density (g/cm ³ ) Shore hardness (HA) Tensile strength (MPa) Tear strength (KN/m) Elongation at break (%) 1.34 22.5 0.363 3.54 311.5

Material heat insulation performance: thermal conductivity 0.681W/(m·k).

Material flame retardancy: oxygen index 28.3.

Neutron shielding performance: 4cm thick material can shield 72.2% of the neutrons emitted by the Am-Be neutron source.

Example 2:

The formula of the neutron shielding material with flame-retardant and heat-insulating properties is: 100g of methyl vinyl silica gel with a hardness of 5HA, 53.5g of B ₄ C powder, 4.8g of TiO ₂ hollow microspheres, 28.3g of zinc borate powder, and bis-pentasulfurizing agent 2g, KH-550 coupling agent 3g. Among them, the B ₄ C powder has a particle size of 50um, the TiO ₂ hollow microbead has a particle size of 20um, and the zinc borate powder has a particle size of 2.5um.

The steps of the preparation method of the neutron shielding material with flame-retardant and heat-insulating properties are as follows:

(1) Plastic refining of methyl vinyl silica gel matrix material: adjust the distance between the double rollers of the open mill to 2mm, and the speed of 45r/min. Carry out masticating between two rollers, the masticating time is 4 minutes. Add a certain amount of vulcanizing agent 225 to the methyl vinyl silica gel and continue masticating for 14 minutes, during which the rolling operation method is used for masticating.

(2) Surface modification process of functional fillers: Mix 80g of deionized water and 3g of KH-550 with functional filler powder, and react at 40°C for 1.2 hours.

(3) Mixing of silica gel and functional filler powder: Add the above-mentioned silica gel that has been masticated, the functional powder that has been reacted, and the reaction liquid mixture into the vacuum mixer, adjust the processing temperature to 110°C, knead for 25 minutes, mix thoroughly and remove moisture.

(4) Thermal compression molding of silica gel matrix material: set the temperature of the upper and lower plates of the flat vulcanizing machine to 180°C, place the silica gel-based mixture mixed in the vacuum internal mixer in a flat cavity mold coated with a release agent, and place it on the flat plate Lay release cloth on the top and bottom of the mold, and then add 13MPa pressure to vulcanize for 17 minutes, take out the mold, and take out the sample after cooling.

Material mechanical properties:

Density (g/cm ³ ) Shore hardness (HA) Tensile strength (MPa) Tear strength (KN/m) Elongation at break (%) 1.23 16.5 0.447 3.73 491.5

Material thermal insulation performance: thermal conductivity 0.533 W/(m·k).

Material flame retardancy: oxygen index 26.7.

Neutron shielding performance: 4cm thick material can shield 60.7% of the neutrons emitted by the Am-Be neutron source.

Example 3:

The formula of neutron shielding material with flame-retardant and heat-insulating properties is: 100g of methyl vinyl silica gel with hardness 5HA, 30g of B ₄ C powder, 2.7g of Al ₂ O ₃ hollow microspheres, 15.8g of zinc borate powder, bis-pentasulfide Agent 3g, aminopropyltrimethoxysilane 5g. Among them, the B ₄ C powder has a particle size of 50um, the Al ₂ O ₃ hollow microbeads have a particle size of 30um, and the zinc borate powder has a particle size of 2.5um.

The steps of the preparation method of the neutron shielding material with flame-retardant and heat-insulating properties are as follows:

(1) Plastic refining of methyl vinyl silica gel matrix material: adjust the distance between the double rollers of the open mill to 2mm, and the speed of 45r/min. Carry out mastication between the double rollers, and the mastication time is 5 minutes. Add a certain amount of vulcanizing agent bis-2-5 into the methyl vinyl silica gel and continue masticating for 15 minutes, during which the rolling operation method is used for masticating.

(2) Surface modification process of functional fillers: Mix 78.25g of deionized water and 5g of aminopropyltrimethoxysilane with functional filler powder, and react at 50°C for 1.5 hours.

(3) Mixing of silica gel and functional filler powder: Add the above-mentioned silica gel that has been masticated, the functional powder that has been reacted, and the reaction liquid mixture into the vacuum mixer, adjust the processing temperature to 115°C, mix for 30 minutes, mix thoroughly and remove moisture.

(4) Thermal compression molding of silica gel matrix material: set the temperature of the upper and lower plates of the flat vulcanizer to 190°C, place the silica gel-based mixture mixed in the vacuum internal mixer in the flat cavity mold coated with a release agent, and place it on the flat plate Lay release cloth on the top and bottom of the mold, and then add 15MPa pressure to vulcanize for 20 minutes, take out the mold, and take out the sample after cooling.

Material mechanical properties:

Density (g/cm ³ ) Shore hardness (HA) Tensile strength (MPa) Tear strength (KN/m) Elongation at break (%) 1.11 11 0.51 2.12 671.1

Material thermal insulation performance: thermal conductivity 0.412 W/(m·k).

Material flame retardant performance: oxygen index 24.5.

Neutron shielding performance: 4cm thick material can shield 48.9% of the neutrons emitted by the Am-Be neutron source.

The above are only several embodiments of the present invention, and are not intended to limit the scope of the present invention. In the specific operation process, the neutron absorber functional filler powder can be selected from Sm ₂ O ₃ , Gd ₂ O ₃ , LiF, B ₄ One or more of C, the flame retardant functional filler powder can choose one or more of aluminum hydroxide, magnesium hydroxide, zinc borate, red phosphorus, and the thermal insulation functional filler can be TiO ₂ hollow microbeads, SiO ₂ One or more of hollow microspheres, Al ₂ O ₃ hollow microspheres, glass hollow microspheres, powder surface modifier can choose coupling agent KH-540, coupling agent KH-550, aminopropyl One or more of trimethoxysilane and coupling agent D-90, these changes can all achieve the purpose of the present invention.

Claims (4)

1. A neutron shielding material with flame-retardant and heat-insulating properties, characterized in that, the specific components are as follows, in parts by mass: Methyl vinyl silica gel 100 parts, 30-90 parts of neutron absorber material, Flame retardant functional filler 15.8-48 parts, Heat insulation functional filler 2.7-8.2 parts, 0.5~3 parts of vulcanizing agent Shuangerwu, 1~5 parts of powder surface modifier; Wherein, the neutron absorber material is one or more of Sm ₂ O ₃ , Gd ₂ O ₃ , LiF or B ₄ C; The flame retardant functional filler is one or more of aluminum hydroxide, magnesium hydroxide, zinc borate or red phosphorus; The thermal insulation functional filler is hollow microspheres; The powder surface modifier is one or more of coupling agent KH-540, coupling agent KH-550, aminopropyltrimethoxysilane, and coupling agent D-90; The hollow microspheres are one or more of TiO ₂ hollow microspheres, SiO ₂ hollow microspheres, Al ₂ O ₃ hollow microspheres or glass hollow microspheres. 2. The neutron shielding material with flame-retardant and heat-insulating properties according to claim 1, wherein the methyl vinyl silica gel has a hardness of 5HA. 3 . The neutron shielding material with flame-retardant and heat-insulating properties according to claim 2 , wherein the particle diameter of the neutron absorber material, flame-retardant functional filler, and heat-insulating functional filler is 2.5 um to 50 um. 4. The preparation method of the neutron shielding material with flame-retardant and heat-insulating properties as claimed in any one of claims 1-3, characterized in that, the specific steps are as follows: (1) Adjust the speed of the two-roll mill to 45rpm, the distance between the two rollers to 2mm, the temperature to 30-50°C, add methyl vinyl silica gel for 3-5min, and then add the vulcanizing agent Shuangerwu to continue the mastication for 10-15min; (2) After mixing the neutron absorber material, flame-retardant functional filler, heat-insulating functional filler, and powder surface modifier, add deionized water 0.3-0.5 times their total mass, and react at a temperature of 30-50°C 1-1.5h, to obtain the functional filler reaction solution; (3) Add the masticated product obtained in step 1 and the functional filler reaction solution obtained in step 2 into a vacuum mixer, and banbury at 105-115°C for 20-30 minutes to obtain a silica gel-based mixture; (4) The temperature of the upper and lower plates of the flat vulcanizer is 170-190°C, add the silica gel-based mixture obtained in step 3, vulcanize under 10-15MPa pressure for 15-20min, and obtain the neutron shielding with flame-retardant and heat-insulating properties after cooling Material.