阅读说明：本技术 一种具有中子屏蔽效能和隔热效能的有机硅复合材料及制备工艺 (Organosilicon composite material with neutron shielding efficiency and heat insulation efficiency and preparation process thereof ) 是由 邓志华 邓建国 纪兰香 白小峰 于 2021-08-09 设计创作，主要内容包括：本发明公开了一种具有中子屏蔽效能和隔热效能的有机硅复合材料及制备工艺,具体包括以下步骤：A：低粘度乙烯基硅树脂合成：B：低粘度含氢硅油合成；C：硼硅树脂复合材料制备：D：真空脱泡；E：室温浇注固化成型。本发明在低粘度硅树脂及硅油中加入核电级碳化硼及无机氢氧化物粉体,在室温下浇注固化成型,具有含氢量高、密度适中、耐高温、抗燃烧和跌落等特点,可满足新式乏燃料干式贮存与运输对辐照屏蔽材料性能要求。(The invention discloses an organic silicon composite material with neutron shielding efficiency and heat insulation efficiency and a preparation process thereof, and the preparation process specifically comprises the following steps: a: synthesizing low-viscosity vinyl silicone resin: b: synthesizing low-viscosity hydrogen-containing silicone oil; c: preparing a borosilicate resin composite material: d: vacuum defoaming; e: and (5) casting, curing and molding at room temperature. The nuclear power grade boron carbide and inorganic hydroxide powder are added into the low-viscosity silicon resin and the silicon oil, and the mixture is cast, cured and formed at room temperature, has the characteristics of high hydrogen content, moderate density, high temperature resistance, combustion resistance, drop resistance and the like, and can meet the performance requirements of novel spent fuel dry storage and transportation on the radiation shielding material.)

1. A preparation process of an organic silicon composite material with neutron shielding effectiveness and heat insulation effectiveness is characterized by comprising the following steps:

a: synthesis of low-viscosity vinyl silicone resin: methyl silane, tetramethyl divinyl siloxane, water, organic alcohol, cyclohexane and acid are mixed according to the proportion of 100: 1: 50: 70: 50: 3-100: 30:20:30: 50:1, adding the mixture into a reaction container in proportion, uniformly stirring, reacting, washing with water to be neutral to obtain the low-viscosity vinyl silicone resin, wherein the viscosity of the product is 300-1000 mPa & s, and the volatile matter is less than or equal to 1%;

b: synthesizing low-viscosity hydrogen-containing silicone oil: methyl silane, tetramethyl siloxane, water, organic alcohol, cyclohexane and acid are mixed according to the weight ratio of 100: 1: 50: 70: 50: 3-100: 30:20:30: 50:1, adding the mixture into a reaction container in proportion, uniformly stirring, reacting, washing with water to be neutral to obtain low-viscosity hydrogen-containing silicone oil, wherein the viscosity of the product is 300-1000 mPa & s, and the volatile matter is less than or equal to 1%;

c: preparing a borosilicate resin composite material: adding B into a container filled with low-viscosity vinyl silicone resin and low-viscosity hydrogen-containing silicone oil₄C, shearing, stirring and mixing the inorganic hydroxide powder at a high speed to obtain a mixture;

d: vacuum defoaming: c, placing the mixture obtained in the step C into a vacuum oven at room temperature, vacuumizing to be more than 0.095MPa, and maintaining the pressure for 60-250 minutes until all gases in the mixture are completely removed;

e, pouring, curing and forming at room temperature: and D, adding a room-temperature curing organosilicon platinum catalyst into the product obtained in the step D, stirring at room temperature, pouring the mixture into a mold, and curing and molding at room temperature.

2. The preparation process of the organosilicon composite material with neutron shielding effectiveness and heat insulation effectiveness according to claim 1, wherein the stirring temperature is 55-95 ℃ and the reaction time is 3-16 hours.

3. The preparation process of the organosilicon composite material with neutron shielding effectiveness and heat insulation effectiveness according to claim 1, wherein the stirring temperature is 55-75 ℃ and the reaction time is 3-16 hours.

4. The process for preparing organosilicon composite material having neutron shielding and thermal insulation effects according to claim 1, wherein the acid in step a and step B is selected from any one of trifluoromethanesulfonic acid, glacial acetic acid, concentrated sulfuric acid, and strongly acidic cation exchange resin.

5. The preparation process of the organosilicon composite material with neutron shielding effect and heat insulation effect according to claim 1, wherein the raw materials in step C are in a ratio of 50:50:10: 90-50: 50:40:75, and the shearing, stirring and mixing time is 30-180 minutes.

6. The process of claim 1, wherein the inorganic hydroxide powder in step C is selected from one or more of magnesium hydroxide, aluminum hydroxide, iron hydroxide, and calcium hydroxide.

7. The preparation process of the organosilicon composite material with neutron shielding effectiveness and heat insulation effectiveness according to claim 1, wherein the stirring time in step E is 10-30 minutes, and the curing time is 60-180 minutes.

8. An organosilicon composite material with neutron shielding effectiveness and heat insulation effectiveness prepared according to any one of claims 1 to 7, which is characterized by comprising the following raw materials in parts by weight: 50 parts of phenyl vinyl silicone resin, 50 parts of phenyl hydrogen-containing silicone resin, 10-40 parts of boron carbide, 70-90 parts of inorganic hydroxide and 0.1-3 parts of organosilicon platinum catalyst.

Technical Field

The invention relates to preparation of a high-temperature-resistant material, in particular to an organic silicon composite material with neutron shielding efficiency and heat insulation efficiency and a preparation process thereof.

Background

Spent fuel, also known as irradiated nuclear fuel, is spent nuclear fuel that has been subjected to irradiation, typically produced by a nuclear reactor in a nuclear power plant. In the storage process of the spent fuel, slow nuclear fission reaction also occurs, and certain neutrons and gamma rays are generated and are accompanied with certain temperature rise. If not properly disposed of, it can cause serious harm to the surrounding environment and people.

With the development of new energy strategy in China, the proportion of nuclear energy in the energy structure in China is larger and larger, the number of units in operating nuclear power projects in China is increased gradually, and the spent fuel generated cumulatively by nuclear power plants in China by 2030 is estimated to reach 19500 tHM. The spent fuel dry storage and transportation provides a new subject for radiation safety, so that the development of a novel high-temperature-resistant long-service-life spent fuel dry storage and transportation radiation shielding material has great economic and social significance. According to the new requirements of spent fuel dry storage and transportation, Shanghai nuclear engineering research and design institute designs a radiation shielding material to have a service life of 20 years at 170 ℃, simultaneously meets neutron fluence of 4.0 x 1014n/cm2, accompanies 1.0 x 106 (Gy-air) gamma ray integral dose irradiation, and keeps the material appearance complete.

At present, the neutron shielding material for the dry storage and transportation of the spent fuel mainly adopts epoxy resin-B₄And C, a composite material. The material is cheap and easy to prepare. However, the maximum temperature resistance of the material is 160 ℃, and the material is easy to age and decompose under the temperature for a long time, so that the nuclear photon leakage risk exists.

Disclosure of Invention

The invention aims to provide an organic silicon composite material with neutron shielding effect and heat insulation effect and a preparation process thereof₄C, inorganic hydroxide powder and a room temperature curing platinum catalyst are mixed at room temperature to remove bubbles, and then the mixture is poured and cured at room temperature to form the catalyst. The spent fuel radiation shielding composite material has the service life of 20 years at 170 ℃ and can resist 4.0 multiplied by 10¹⁴n/cm²Neutron fluence associated with 1.0X 10⁶The (Gy-air) gamma ray integral dose irradiation, fuel resistance, drop resistance and the like, and the easy operation such as casting, room temperature curing and forming and the like.

In order to achieve the technical effects, the invention provides the following technical scheme:

a preparation process of an organic silicon composite material with neutron shielding effectiveness and heat insulation effectiveness comprises the following steps:

a: synthesis of low-viscosity vinyl silicone resin: methyl silane, tetramethyl divinyl siloxane, water, organic alcohol, cyclohexane and acid are mixed according to the proportion of 100: 1: 50: 70: 50: 3-100: 30:20:30: 50:1, adding the mixture into a reaction container, uniformly stirring, reacting, washing with water to be neutral to obtain the low-viscosity vinyl silicone resin, wherein the viscosity of the product is 300-1000 mPa & s, and the volatile matter is less than or equal to 1%;

b: synthesizing low-viscosity hydrogen-containing silicone oil: methyl silane, tetramethyl siloxane, water, organic alcohol, cyclohexane and acid are mixed according to the weight ratio of 100: 1: 50: 70: 50: 3-100: 30:20: 30:50: 1, adding the mixture into a reaction container, uniformly stirring, reacting, washing with water to be neutral to obtain low-viscosity hydrogen-containing silicone oil, wherein the viscosity of the product is 300-1000 mPa & s, and the volatile matter is less than or equal to 1%;

c: preparing a borosilicate resin composite material: adding B into a container filled with low-viscosity vinyl silicone resin and low-viscosity hydrogen-containing silicone oil₄C, shearing, stirring and mixing the inorganic hydroxide powder at a high speed to obtain a mixture;

d: vacuum defoaming: c, placing the mixture obtained in the step C into a vacuum oven at room temperature, vacuumizing to be more than 0.095MPa, and maintaining the pressure for 60-250 minutes until all gases in the mixture are completely removed;

e, pouring, curing and forming at room temperature: and D, adding a room-temperature curing platinum catalyst into the product obtained in the step D, stirring at room temperature, pouring the mixture into a mold, and curing and molding at room temperature.

The further technical scheme is that in the step A, the stirring temperature is 35-95 ℃, and the reaction time is 3-16 hours.

The further technical scheme is that in the step B, the stirring temperature is 35-75 ℃, and the reaction time is 3-16 hours.

The further technical scheme is that the acid in the step A and the step B is selected from any one of trifluoromethanesulfonic acid and strong-acid cation exchange resin.

The further technical scheme is that the raw materials in the step C are in a ratio of 50:50:10: 90-50: 50:40:75, and the shearing, stirring and mixing time is 30-180 minutes.

The further technical scheme is that in the step C, the inorganic hydroxide powder is selected from one or more of magnesium hydroxide, aluminum hydroxide and ferric hydroxide.

The further technical scheme is that in the step E, the stirring time is 10-30 minutes, and the curing time is 60-180 minutes.

An organosilicon composite material with neutron shielding effectiveness and heat insulation effectiveness is composed of the following raw materials in parts by weight: 50 parts of phenyl vinyl silicone resin, 50 parts of phenyl hydrogen-containing silicone resin, 10-30 parts of boron carbide, 70-90 parts of magnesium hydroxide and 0.1-1 part of organosilicon platinum catalyst.

The invention uses a certain amount of B₄And C, adding inorganic hydroxide into the organic silicon resin, and casting, curing and molding at room temperature. The material mainly uses a large amount of H atoms to slow down the neutron rate of the spent fuel, and then uses B atoms to absorb neutrons so as to achieve the neutron shielding effect.

Compared with the prior art, the invention has the following beneficial effects: the composite material not only endows the composite material with good neutron and gamma ray absorption capacity of 20-year spent fuel, but also has the characteristics of high temperature resistance and long service life, the composite material is continuously treated at the high temperature of 190 ℃ for 3000 hours, the loss rate is less than or equal to 5 percent, and the appearance of a sample is kept complete; the sample was passed through 4.0X 10¹⁴n/cm²Neutron fluence associated with 1.0X 10⁶The weight loss rate of the sample is less than or equal to 3 percent by (Gy-air) gamma ray integral dose irradiation, the appearance of the sample is kept complete, the weight ratio of hydrogen to boron in the material is respectively more than 5.5 percent and 5.4 percent, and the density of the material is more than 1.50g/cm³The thermal conductivity coefficient of the material is more than 0.4W/mK, and the thermal expansion coefficient is 10^-4m/K grade.

Detailed Description

Example 1

An organosilicon composite material with neutron shielding effectiveness and heat insulation effectiveness is composed of the following raw materials in parts by weight: 50 parts of phenyl vinyl silicone resin, 50 parts of phenyl hydrogen-containing silicone resin, 10 parts of boron carbide, 90 parts of magnesium hydroxide and 0.1 part of organosilicon platinum catalyst.

The preparation method comprises the following steps:

a: synthesis of low-viscosity vinyl silicone resin: the calculated amounts of methyltrimethoxysilane, tetramethyldivinylsiloxane, water, ethanol, cyclohexane, trifluoromethanesulfonic acid were calculated as 100: 1: 50: 70: 50: 3, adding the mixture into a three-neck flask, stirring the mixture at the temperature of between 35 and 75 ℃ for reaction for 8 hours, and washing the mixture to be neutral to obtain the vinyl silicone resin. The viscosity of the product is 300 mPas, and the volatile matter is 0.81%.

B: synthesizing low-viscosity hydrogen-containing silicone oil: mixing calculated amounts of methyltrimethoxysilane, tetramethylsiloxane, water, ethanol, cyclohexane and trifluoromethanesulfonic acid according to a ratio of 100: 1: 50: 70: 50: 3, adding the mixture into a three-neck flask, stirring the mixture at the temperature of between 35 and 75 ℃, and finishing the reaction after reacting for 6 hours to obtain the hydrogen-containing silicone oil, wherein the viscosity of the product is 420mPa & s, and the volatile component is 0.86 percent.

C: preparing a borosilicate resin composite material: adding 15 parts of B into 50 parts of A and B beakers at room temperature₄C and 80 parts of magnesium hydroxide are sheared, stirred and mixed for 120 minutes at a high speed, so that the organic silicon-inorganic powder is uniformly mixed.

D: vacuum defoaming: and (3) putting the mixture C into a vacuum oven at room temperature, vacuumizing to be more than 0.095MPa, and maintaining the pressure for 150 minutes until all gases in the mixture are completely removed.

E, pouring, curing and forming at room temperature: adding a certain amount of room temperature curing organosilicon platinum catalyst into the defoamed mixture D, stirring the mixture at room temperature for about 30 minutes, pouring the mixture into a mold, and curing and molding the mixture at room temperature for 120 minutes.

Example 2

An organosilicon composite material with neutron shielding effectiveness and heat insulation effectiveness is composed of the following raw materials in parts by weight: 50 parts of phenyl vinyl silicone resin, 50 parts of phenyl hydrogen-containing silicone resin, 20 parts of boron carbide, 80 parts of ferric hydroxide and 0.3 part of organosilicon platinum catalyst.

The preparation method comprises the following steps:

a: synthesis of low-viscosity vinyl silicone resin: calculated amounts of dimethyldiethoxysilane, tetramethyldivinylsiloxane, water, ethanol, cyclohexane, cation exchange resin were mixed in a 100:20:45:60: 50: 3, adding the mixture into a three-neck flask, stirring the mixture at the temperature of between 55 and 95 ℃ for reaction for 12 hours, filtering the mixture, and removing cation exchange resin to obtain the vinyl silicone resin. The product viscosity is 500 mPas, and the volatile matter is 0.95%.

B: synthesizing low-viscosity hydrogen-containing silicone oil: mixing dimethyl diethoxysilane, tetramethylsiloxane, water, ethanol, cyclohexane and cation exchange resin according to the weight ratio of 100:20:45:60: 50: 2.5, adding the mixture into a three-neck flask, stirring and reacting for 9 hours at the temperature of 55-95 ℃, and filtering to remove cation exchange resin to obtain the hydrogen-containing silicone oil. The viscosity of the product is 600 mPas, and the volatile matter is 0.80 percent

C: preparing a borosilicate resin composite material: to 50 parts each of A and B beakers were added 30 parts of B in fixed amounts₄C and 75 parts of aluminum hydroxide, shearing, stirring and mixing for 180 minutes at a high speed, and uniformly mixing by using organic silicon-inorganic powder.

D: vacuum defoaming: placing the mixed mixture C into a vacuum oven at room temperature, vacuumizing to more than 0.095MPa, and maintaining the pressure for 250 minutes to completely remove gas in the mixture

E, pouring, curing and forming at room temperature: adding a small amount of room temperature curing organosilicon platinum catalyst into the defoamed mixture D, stirring at room temperature for 10 minutes, pouring the mixture into a mold, and curing at room temperature for 60 minutes.

Example 3:

an organosilicon composite material with neutron shielding effectiveness and heat insulation effectiveness is composed of the following raw materials in parts by weight: 50 parts of phenyl vinyl silicone resin, 50 parts of phenyl hydrogen-containing silicone resin, 30 parts of boron carbide, 75 parts of aluminum hydroxide and 1 part of organosilicon platinum catalyst.

The preparation method comprises the following steps:

a: synthesis of low-viscosity vinyl silicone resin: the calculated amounts of methyltrimethoxysilane tetramethyldivinylsiloxane, water, methanol, cyclohexane, trifluoromethanesulfonic acid were calculated as a 100:20:40: adding the mixture into a three-neck flask in a ratio of 60:30:2, stirring the mixture at the temperature of between 35 and 95 ℃ for reaction for 16 hours, and washing the mixture to be neutral to obtain the vinyl silicone resin. The product viscosity is 750 mPa.s, and the volatile matter is 0.58%.

B: synthesizing low-viscosity hydrogen-containing silicone oil: adding calculated amount of dimethyl diethoxy silane, tetramethyl siloxane, water, methanol, cyclohexane and trifluoromethanesulfonic acid into a three-neck flask according to the proportion of 100:20:40:60:30:1.5, stirring and reacting at the temperature of 35-95 ℃ for 13 hours, and washing with room temperature water to be neutral to obtain the hydrogen-containing silicone oil. The viscosity of the product is 720 mPas, and the volatile matter is 0.64%.

C: preparing a borosilicate resin composite material: to 50 parts each of A and B beakers was added 25 parts of B₄C and 80 parts of ferric hydroxide, shearing, stirring and mixing for 120 minutes at a high speed, and uniformly mixing by using organic silicon-inorganic powder.

D: vacuum defoaming: and (3) placing the mixed mixture C into a vacuum oven at room temperature, vacuumizing to be more than 0.095MPa, and maintaining the pressure for 200 minutes until all gas in the mixture is completely removed.

E, pouring, curing and forming at room temperature: adding a small amount of room temperature curing organosilicon platinum catalyst into the defoamed mixture D, stirring at room temperature for 25 minutes, pouring the mixture into a mold, and curing at room temperature for 150 minutes.

Example 4:

the preparation method comprises the following steps:

an organosilicon composite material with neutron shielding effectiveness and heat insulation effectiveness is composed of the following raw materials in parts by weight: 50 parts of phenyl vinyl silicone resin, 50 parts of phenyl hydrogen-containing silicone resin, 40 parts of boron carbide, 75 parts of calcium hydroxide and 1 part of organosilicon platinum catalyst.

A: synthesis of low-viscosity vinyl silicone resin: mixing calculated amounts of methyltriethoxysilane, tetramethyldivinylsiloxane, water, ethanol, cyclohexane, and trifluoromethanesulfonic acid in a ratio of 100:30:20:30: 50: adding 1 proportion into a three-neck flask, stirring and reacting for 12 hours at the temperature of 35-95 ℃, and washing to be neutral at room temperature to obtain the vinyl silicone resin. The product viscosity is 960 mPas, and the volatile matter is 0.38%.

B: synthesizing low-viscosity hydrogen-containing silicone oil: mixing calculated amounts of methyltriethoxysilane, tetramethylsiloxane, water, ethanol, cyclohexane, and trifluoromethanesulfonic acid in a ratio of 100:30:20:30: 50:1 proportion is added into a three-neck flask, stirred and reacted for 16 hours at the temperature of 35-95 ℃, and then washed to be neutral to obtain the hydrogen-containing silicone oil. The product viscosity is 920 mPa.s, and the volatile matter is 0.41 percent.

C: preparing a borosilicate resin composite material: to 50 parts each of A and B beakers were added a fixed amount of 40 parts of B₄C and 75 parts of calcium hydroxide powder, shearing, stirring and mixing for 180 minutes at a high speed, and uniformly mixing by using organic silicon-inorganic powder.

D: vacuum defoaming: and (3) placing the mixed mixture C into a vacuum oven at room temperature, vacuumizing to be more than 0.095MPa, and maintaining the pressure for 250 minutes until all gases in the mixture are completely removed.

E, pouring, curing and forming at room temperature: adding a small amount of room temperature curing organosilicon platinum catalyst into the defoamed mixture D, stirring at room temperature for 10 minutes, pouring the mixture into a mold, and curing at room temperature for 60 minutes.

Although the present invention has been described herein with reference to the illustrated embodiments thereof, which are intended to be preferred embodiments of the present invention, it is to be understood that the invention is not limited thereto, and that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure.