Anti-radiation non-woven fabric fiber for shielding and filtering radiation substances and preparation method thereof

Abstract

The invention relates to the technical field of anti-radiation materials, and particularly discloses an anti-radiation non-woven fabric fiber for shielding and filtering radiation substances and a preparation method of the anti-radiation non-woven fabric fiber. The invention relates to an anti-radiation non-woven fabric fiber for shielding and filtering radiation substances. The anti-radiation non-woven fabric fiber is prepared from the following raw materials in parts by weight: 10 parts of polymer; 4-5 parts of modified rare earth salt; a preparation method of the modified rare earth salt comprises the following steps: adding unsaturated carboxylic acid and rare earth hydroxide into water, carrying out heating reaction and rotary evaporation, then adding 1-ethyl acetate group-3-methylimidazolium tetrafluoroborate, mixing, carrying out suction filtration to remove filtrate, and drying to obtain the modified rare earth salt. The weight ratio of the unsaturated carboxylic acid to the rare earth hydroxide is (1.3-1.5): 1. The anti-radiation non-woven fabric fiber for shielding and filtering radiation substances can be used for preparing anti-radiation materials, and has the advantages that the lead equivalent reaches 0.19 mmPb or above, and the anti-radiation effect is good.

Description

Technical Field

[0001] The present application relates to the technical field of radiation protection materials, and more specifically, to a radiation protection non-woven fabric fiber for shielding and filtering radiation substances and a preparation method thereof. Background Art

[0002] Radiation is mainly divided into ionizing radiation and non-ionizing radiation. Ionizing radiation has very high photosensitive energy, and they have a strong ability to penetrate any object, which is harmful. In recent years, researchers have conducted in-depth research on the research direction of radiation protection materials.

[0003] Radiation-proof composite fiber materials have radiation-proof properties by adding some modified compounds or monomers into the fibers. For example, polypropylene, polyurethane, polyester, polyacrylonitrile and other materials with excellent properties and spinnability can be used as polymer-based composite materials, while single or lanthanide rare earth compounds with large absorption cross-sections can be used as fillers for radiation-proof composite materials. The fiber products made from them have a wide range of applications in the field of radiation protection.

[0004] At present, there is a radiation-proof nonwoven fabric, which is prepared from polymer-compounded rare earth complexes as raw materials, wherein the rare earth complex is unsaturated carboxylic acid-modified rare earth hydroxide, and the dispersibility between the rare earth complex and the polymer is improved by unsaturated carboxylic acid modification. However, since the introduction of organic acid will reduce the electron cloud density around the rare earth particles, thereby reducing the probability of photoelectric efficiency, the lead equivalent of the prepared fiber is below 0.05 mmPb, and there is a problem of low lead equivalent and insufficient radiation protection effect. Summary of the invention

[0005] In order to improve the radiation protection effect of non-woven fabrics, the present application provides a radiation protection non-woven fabric fiber for shielding and filtering radioactive substances and a preparation method thereof, wherein the fiber raw material has a higher lead equivalent and has a better radiation protection effect.

[0006] In the first aspect, the present application provides a radiation-proof nonwoven fabric fiber for shielding and filtering radiation substances, using the following technical solution: A radiation-proof non-woven fabric fiber for shielding and filtering radiation substances, the preparation raw materials include the following components in parts by weight: 10 parts of polymer; 4-5 parts of modified rare earth salt; The preparation method of the modified rare earth salt is as follows: adding unsaturated carboxylic acid and rare earth hydroxide to water, heating the reaction, rotary evaporation, adding 1-ethyl acetate-3-methylimidazolium tetrafluoroborate, mixing, removing the filtrate by suction filtration, and drying to obtain the modified rare earth salt; The weight ratio of the unsaturated carboxylic acid to the rare earth hydroxide is 1.3-1.5:1.

[0007] By adopting the above technical solution: rare earth elements can form many energy level transitions due to their special electron layers, consuming a lot of energy, thereby weakening radiation. The present application controls the use of a relatively low amount of unsaturated carboxylic acid to modify rare earth hydroxides to reduce the impact of the introduction of organic acids on the radiation effect of rare earth salts, but the dispersibility decreases. Therefore, 1-ethyl acetate-3-methylimidazolium tetrafluoroborate is added at the same time to introduce an ester group, increase steric hindrance, and reduce the agglomeration of modified rare earth salts to compensate for the effect of low-content carboxylic acid on the dispersibility. The two jointly modify the rare earth hydroxide, not only to maximize the radiation protection performance of the rare earth salt, but also to improve the compatibility of the modified rare earth salt with the polymer and make the modified rare earth salt fully dispersed in the non-woven fabric, ensuring that the prepared fiber has a better radiation protection effect.

[0008] After testing, when the amount of modified rare earth salt is 40% of the amount of polymer, the lead equivalent of the fiber laminate using (unsaturated carboxylic acid, 1-ethyl acetate-3-methylimidazolium tetrafluoroborate) modified rare earth salt is 0.19mmPb, the lead equivalent of the fiber laminate using only unsaturated carboxylic acid modified rare earth salt is only 0.15mmPb, and the lead equivalent of the fiber laminate using the same amount of unsaturated carboxylic acid instead of 1-ethyl acetate-3-methylimidazolium tetrafluoroborate modified rare earth salt is 0.13mmPb. This shows that excessive unsaturated carboxylic acid will reduce the radiation protection effect, while using the same amount of unsaturated carboxylic acid and 1-ethyl acetate-3-methylimidazolium tetrafluoroborate to modify rare earth salt can effectively improve the fiber radiation protection effect.

[0009] Optionally, the unsaturated carboxylic acid is one of acrylic acid, methacrylic acid, crotonic acid, maleic acid and itaconic acid.

[0010] By adopting the above technical solution: the modified rare earth salt of the present application has low requirements on unsaturated carboxylic acids, and the above unsaturated carboxylic acids can all be used, and can be selected from the above substances according to process requirements.

[0011] Optionally, the weight volume ratio of the added amount of the rare earth hydroxide to water is 18-22g:100mL.

[0012] By adopting the above technical solution, the concentration of rare earth hydroxide is controlled to ensure that the prepared modified rare earth salt has a better radiation protection effect.

[0013] Optionally, the rare earth element of the rare earth hydroxide is one of lanthanum, yttrium, neodymium, praseodymium and gadolinium.

[0014] Optionally, the weight ratio of 1-ethyl acetate-3-methylimidazolium tetrafluoroborate to rare earth hydroxide is 0.37-0.42:1.

[0015] By adopting the above technical scheme: when the weight ratio of 1-ethyl acetate-3-methylimidazolium tetrafluoroborate to rare earth hydroxide is 0.3:1, the lead equivalent of the prepared fiber is 0.21 mmPb, and when the weight ratio is 0.37-0.42:1, the fiber lead equivalent is 0.23-0.25 mmPb, indicating that when the amount of 1-ethyl acetate-3-methylimidazolium tetrafluoroborate is within the above range, the radiation protection effect of the prepared fiber is better.

[0016] Optionally, the temperature-raising reaction condition is to raise the temperature to 75-85° C. and react for 6-8 hours.

[0017] By adopting the above technical solution: the forward progress of the reaction is promoted.

[0018] Optionally, the polymer is a mixture of polypropylene and thermoplastic polyurethane rubber in a weight ratio of 6:4.

[0019] By adopting the above technical solution: polypropylene has good heat resistance, low density, good mechanical properties, good chemical properties, and does not react with most chemicals; thermoplastic polyurethane rubber has the advantages of high elasticity, softness, high strength, toughness, high wear resistance, oil resistance, solvent resistance and chemical resistance, cold resistance, heat resistance, oxidation resistance, weather resistance, thermoplastic processability, transparency and gloss, environmental protection, biocompatibility, etc. The two are compounded to produce fibers with better performance.

[0020] In a second aspect, the present application provides a method for preparing radiation-proof non-woven fabric fibers for shielding and filtering radiation substances, using the following technical solution: A method for preparing radiation-proof nonwoven fabric fibers for shielding and filtering radiation substances comprises the following steps: S1, blending a polymer and a modified rare earth salt, granulating, and obtaining a mixture; S2, spinning the mixed material to obtain.

[0021] By adopting the above technical solution, there are fewer steps, the process is simple and efficient, it is conducive to large-scale preparation of fibers, and the prepared fibers have better radiation protection performance.

[0022] Optionally, the spinning process parameters are: temperature of 220° C., spinneret diameter of 0.1 mm, screw speed of 45 r / min, and winding rate of 6 m / min.

[0023] In summary, this application has the following beneficial effects: 1. The present application adopts modified rare earth salts. On the one hand, a low content of unsaturated carboxylic acid is used to improve the compatibility of the modified rare earth salts with polymers while reducing the impact on the radiation protection effect of the rare earth salts. At the same time, 1-ethyl acetate-3-methylimidazolium tetrafluoroborate is added to reduce the agglomeration of the modified rare earth salts, thereby compensating for the effect of insufficient dispersibility caused by the reduced amount of unsaturated carboxylic acid. Therefore, the two are modified together, so that the fiber with a lower dosage of the modified rare earth salt can still ensure that the lead equivalent is still above 0.19 mmPb; 2. The present application controls the weight ratio of 1-ethyl acetate-3-methylimidazolium tetrafluoroborate to rare earth hydroxide in the modified rare earth salt to improve the compounding effect and ensure that the modified rare earth salt effectively improves the radiation protection effect of the fiber; 3. The method of the present application has a simple process and fewer steps, which is conducive to industrial scale-up of fiber preparation and application in radiation-proof non-woven fabrics. DETAILED DESCRIPTION

[0024] The present application is further described in detail below in conjunction with the examples. The sources of the components are as follows, except for the following special instructions, the components are commercially available: Lanthanum hydroxide, sourced from Shengwanjia New Materials (Shandong) Co., Ltd.; 1-Ethyl acetate-3-methylimidazolium tetrafluoroborate was obtained from Xi'an Qiyue Biotechnology Co., Ltd.; Gadolinium hydroxide was purchased from Hubei Xinyuhong Biopharmaceutical Technology Co., Ltd., product number xyh001; Yttrium hydroxide, sourced from Shengwanjia New Materials (Shandong) Co., Ltd., particle size 325 mesh; Polypropylene, purchased from Dongguan Lerui Plastic Co., Ltd., model PH150; Thermoplastic polyurethane rubber, TPU, brand is BASF of Germany, grade 1198A.

[0025] Preparation Example 1 A modified rare earth salt is prepared by the following steps: Add 23.4 g of unsaturated carboxylic acid (methacrylic acid) and 18 g of rare earth hydroxide (lanthanum hydroxide) to 100 mL of water, heat to 80 ° C and react for 7 hours, remove most of the water by rotary evaporation, add 5.4 g of 1-ethyl acetate-3-methylimidazolium tetrafluoroborate, stir and mix at 200 rpm for 30 minutes, remove the filtrate by suction, and dry at 50 ° C for 1 hour.

[0026] Preparation Example 2 A modified rare earth salt is prepared by the following steps: Add 28 g of unsaturated carboxylic acid (acrylic acid) and 20 g of rare earth hydroxide (gadolinium hydroxide) to 100 mL of water, heat to 75 ° C and react for 8 hours, remove most of the water by rotary evaporation, add 6 g of 1-ethyl acetate-3-methylimidazolium tetrafluoroborate, stir and mix at 200 rpm for 30 minutes, remove the filtrate by suction, and dry at 50 ° C for 1 hour to obtain the product.

[0027] Preparation Example 3 A modified rare earth salt is prepared by the following steps: Add 33 g of unsaturated carboxylic acid (maleic acid) and 22 g of rare earth hydroxide (yttrium hydroxide) to 100 mL of water, heat to 85 ° C and react for 6 hours, remove most of the water by rotary evaporation, add 6.6 g of 1-ethyl acetate-3-methylimidazolium tetrafluoroborate, stir and mix at 200 rpm for 30 minutes, remove the filtrate by suction, and dry at 50 ° C for 1 hour.

[0028] Preparation Example 4-6 A modified rare earth salt, which is different from Preparation Example 2 in that the amount of 1-ethyl acetate-3-methylimidazolium tetrafluoroborate is different, specifically as follows: In Preparation Example 4, the weight ratio of the amount of 1-ethyl acetate-3-methylimidazolium tetrafluoroborate added to the rare earth hydroxide is 0.37:1.

[0029] In Preparation Example 5, the weight ratio of the amount of 1-ethyl acetate-3-methylimidazolium tetrafluoroborate added to the rare earth hydroxide is 0.4:1.

[0030] In Preparation Example 6, the weight ratio of the amount of 1-ethyl acetate-3-methylimidazolium tetrafluoroborate added to the rare earth hydroxide is 0.42:1.

[0031] Example 1 A radiation-proof nonwoven fabric fiber for shielding and filtering radiation substances is prepared by the following steps: S1, blending 10 kg of polymer (polypropylene and thermoplastic polyurethane rubber in a weight ratio of 6:4), 4 kg of modified rare earth salt (prepared in Preparation Example 1), and 0.25 kg of antioxidant 1010, and extruding and granulating at 200° C. and 260 rpm to obtain a mixture; S2, spinning the mixed material (spinning process parameters: temperature 220° C., spinneret diameter 0.1 mm, screw speed 45 r / min, winding rate 6 m / min).

[0032] Example 2 A radiation-proof nonwoven fabric fiber for shielding and filtering radiation substances is prepared by the following steps: S1, blending 10 kg of polymer (polypropylene and thermoplastic polyurethane rubber in a weight ratio of 6:4), 4.5 kg of modified rare earth salt (prepared in Preparation Example 1), and 0.25 kg of antioxidant 1010, and extruding and granulating at 200° C. and 260 rpm to obtain a mixture; S2, spinning the mixed material (spinning process parameters: temperature 220° C., spinneret diameter 0.1 mm, screw speed 45 r / min, winding rate 6 m / min).

[0033] Example 3 A radiation-proof nonwoven fabric fiber for shielding and filtering radiation substances is prepared by the following steps: S1, blending 10 kg of polymer (polypropylene and thermoplastic polyurethane rubber in a weight ratio of 6:4), 5 kg of modified rare earth salt (prepared in Preparation Example 1), and 0.25 kg of antioxidant 1010, and extruding and granulating at 200° C. and 260 rpm to obtain a mixture; S2, spinning the mixed material (spinning process parameters: temperature 220° C., spinneret diameter 0.1 mm, screw speed 45 r / min, winding rate 6 m / min).

[0034] Comparative Example 1 A non-woven fabric fiber is prepared by the following steps: S1, blending 10 kg of polymer (polypropylene and thermoplastic polyurethane rubber in a weight ratio of 6:4), 3.5 kg of modified rare earth salt (prepared in Preparation Example 1), and 0.25 kg of antioxidant 1010, and extruding and granulating at 200° C. and 260 rpm to obtain a mixture; S2, spinning the mixed material (spinning process parameters: temperature 220° C., spinneret diameter 0.1 mm, screw speed 45 r / min, winding rate 6 m / min).

[0035] Comparative Example 2 A non-woven fabric fiber is prepared by the following steps: S1, blending 10 kg of polymer (polypropylene and thermoplastic polyurethane rubber in a weight ratio of 6:4), 5.5 kg of modified rare earth salt (prepared in Preparation Example 1), and 0.25 kg of antioxidant 1010, and extruding and granulating at 200° C. and 260 rpm to obtain a mixture; S2, spinning the mixed material (spinning process parameters: temperature 220° C., spinneret diameter 0.1 mm, screw speed 45 r / min, winding rate 6 m / min).

[0036] Comparative Example 3 A non-woven fabric fiber, which differs from Example 2 in that an equal amount of lanthanum hydroxide is used instead of the modified rare earth salt.

[0037] Comparative Example 4 A non-woven fiber, which differs from Example 2 in that, in the preparation process of the modified rare earth salt, an equal amount of unsaturated carboxylic acid is used instead of 1-ethyl acetate-3-methylimidazole tetrafluoroborate, and the specific preparation method of the modified rare earth salt is: Add 28.8 g of unsaturated carboxylic acid (methacrylic acid) and 18 g of rare earth hydroxide (lanthanum hydroxide) to 100 mL of water, heat to 80°C and react for 7 h, remove most of the water by rotary evaporation, remove the filtrate by suction, and dry at 50°C for 1 h to obtain the product.

[0038] Comparative Example 5 A non-woven fabric fiber, which is different from Example 2 in that 1-ethyl acetate-3-methylimidazole tetrafluoroborate is not added during the preparation of the modified rare earth salt.

[0039] Embodiment 4-8 A radiation-proof non-woven fabric fiber for shielding and filtering radiation substances. The difference from Example 2 is that the usage of the modified rare earth salt refers to Table 1, but the amount of the modified rare earth salt remains unchanged.

[0040] Table 1 Usage of modified rare earth salts in Examples 4-8 Example 4 5 6 7 8 Preparation example of modified rare earth salt 2 3 4 5 6 Performance Testing The fibers prepared in the examples and comparative examples were subjected to the following performance tests, and the test results are recorded in Table 2.

[0041] Detection Methods 1. X-ray shielding performance: The fibers prepared in the examples and comparative examples were pressed into short fiber laminates (thickness 3 mm, unit area mass 0.46 g / cm 2 ), and the sample is obtained. The sample is tested using the MG324 high-stability X-ray machine of Philips of Germany and the PTWDCI-8500 precision integrating galvanometer of the Austrian Scientific Research Center (using 120kV, 2.5mmAl X-ray). The method is to take five points on the sheet (each point is a circle with a radius of 2.5cm) for testing, and then take the average value. The X-ray shielding performance is characterized by lead millimeter equivalent. The larger the lead equivalent value, the better the radiation protection effect.

[0042] 2. Elongation at break: The fibers prepared in the examples and comparative examples were subjected to conventional spinning, stretching, curling, drying and shaping to obtain nonwoven fabrics (weight 400 g / m 2 、Surface density 1150g / m 2), the elongation at break is tested according to GB / T3923.1-2013.

[0043] Table 2 Performance test results Referring to the data in Table 2, in Examples 1-3, the modified rare earth salt prepared in Preparation Example 1 was used, so that the lead equivalent value of the fiber (accounting for 40-50% of the polymer mass) at a lower dosage of the modified rare earth salt can still reach more than 0.19 mmPb; while in Comparative Example 3, unmodified lanthanum hydroxide was used instead of the modified rare earth salt, resulting in a lead equivalent of only 0.10 mmPb due to poor dispersibility; the modified rare earth salt used in Comparative Example 4 used a higher dosage of unsaturated carboxylic acid, which reduced the probability of photoelectric efficiency, resulting in a lead equivalent of 0.13 mmPb for the prepared fiber; the modified rare earth salt used in Comparative Example 5 did not add 1-ethyl acetate-3-methylimidazolium tetrafluoroborate, and the lead equivalent was 0.15 mmPb, indicating that only when unsaturated carboxylic acid and 1-ethyl acetate-3-methylimidazolium tetrafluoroborate were used for joint modification, the radiation protection effect of the fiber can be improved well; The possible reason is that: in the modified rare earth salt prepared in Comparative Example 4, only unsaturated carboxylic acid is used. Although the dispersibility is improved, the probability of photoelectric efficiency is reduced, resulting in the radiation protection effect. Therefore, in the preparation process of the modified rare earth salt, the amount of unsaturated carboxylic acid is appropriately reduced, and 1-ethyl acetate-3-methylimidazolium tetrafluoroborate is introduced to increase the steric hindrance of the modified rare earth salt and reduce the agglomeration of the modified rare earth salt. Therefore, not only the dispersibility is improved, but also the influence on the radiation protection effect of the rare earth salt is reduced, and the lead equivalent is significantly increased.

[0044] The difference between Example 4-5 and Example 2 is that the amounts of the components used in the preparation process of the modified rare earth salt are different, and the lead equivalent of the produced fibers is relatively high, indicating that when the components are within the range of Example 4-5, the produced fibers have better radiation protection properties.

[0045] The difference between Example 6-8 and Example 4 is that in the preparation process of the modified rare earth salt, the amount of 1-ethyl acetate-3-methylimidazole tetrafluoroborate is increased, and the lead equivalent of the prepared fiber can be increased from 0.21 mmPb to 0.25 mmPb at most.

[0046] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A radiation-proof nonwoven fabric fiber for shielding and filtering radiation substances, It is characterized in that The preparation raw materials include the following components in parts by weight: 10 parts of polymer; 4-5 parts of modified rare earth salt; The preparation method of the modified rare earth salt is as follows: adding unsaturated carboxylic acid and rare earth hydroxide to water, heating the reaction, rotary evaporation, adding 1-ethyl acetate-3-methylimidazolium tetrafluoroborate, mixing, filtering to remove the filtrate, and drying to obtain the modified rare earth salt; The weight ratio of the unsaturated carboxylic acid to the rare earth hydroxide is 1.3-1.5:

1.

2. The radiation-proof nonwoven fabric for shielding and filtering radiation substances according to claim 1, Features: The unsaturated carboxylic acid is one of acrylic acid, methacrylic acid, crotonic acid, maleic acid and itaconic acid.

3. The radiation-proof nonwoven fabric for shielding and filtering radiation substances according to claim 1, Features: The weight volume ratio of the added amount of the rare earth hydroxide to water is 18-22g:100mL.

4. The radiation-proof nonwoven fabric for shielding and filtering radiation substances according to claim 3, Features: The rare earth element of the rare earth hydroxide is one of lanthanum, yttrium, neodymium, praseodymium and gadolinium.

5. The radiation-proof nonwoven fabric fiber for shielding and filtering radiation substances according to claim 1, Features: The weight ratio of the 1-ethyl acetate-3-methylimidazolium tetrafluoroborate to the rare earth hydroxide is 0.37-0.42:

1.

6. The radiation-proof nonwoven fabric fiber for shielding and filtering radiation substances according to claim 1, Features: The temperature-raising reaction condition is to raise the temperature to 75-85° C. and react for 6-8 hours.

7. The radiation-proof nonwoven fabric fiber for shielding and filtering radiation substances according to claim 1, Features: The polymer is a mixture of polypropylene and thermoplastic polyurethane rubber in a weight ratio of 6:

4.

8. A method for preparing the radiation-proof nonwoven fabric fiber for shielding and filtering radiation substances according to any one of claims 1 to 7, It is characterized in that The following steps are involved: S1, blending a polymer and a modified rare earth salt, granulating, and obtaining a mixture; S2, spinning the mixed material to obtain.

9. The method for preparing the radiation-proof nonwoven fabric fiber for shielding and filtering radiation substances according to claim 8, Features: The spinning process parameters are as follows: temperature of 220° C., spinneret diameter of 0.1 mm, screw speed of 45 r / min, and winding speed of 6 m / min.

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