Anti-ionizing radiation core-sheath composite staple fiber and preparation method thereof

Abstract

The application discloses a kind of anti-ionizing radiation skin-core composite short fibers and preparation method thereof, belong to nuclear radiation shielding material production technical field, including core layer and skin layer, core layer and skin layer are prepared using thermoplastic resin and radiation protection material mixture is formed.The anti-ionizing radiation skin-core composite short fiber of the application is made of thermoplastic resin and radiation protection material, and the carbon nanotube with surface grafted organic polymer molecular chain is used as radiation protection material, the unique structure of carbon nanotube itself makes it can be used as free radical scavenger to eliminate the free radical generated by product through radiation, so as to have radiation protection performance;The organic polymer molecular layer on the surface of carbon nanotube can effectively improve the compatibility of carbon nanotube and thermoplastic resin matrix, promote its dispersion in thermoplastic resin, while it will not have negative impact on the mechanical properties of short fiber;The organic polymer molecular chain contains benzene ring, and rigid benzene ring can improve the mechanical strength of short fiber to a certain extent, improve the durability of short fiber product.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of nuclear radiation shielding material production, and particularly relates to a kind of anti-ionizing radiation sheath-core composite short fiber and its preparation method. BACKGROUND

[0002] With the wide application of nuclear technology in various fields, nuclear radiation (such as neutron, gamma radiation) cannot be ignored for people's health and property safety. For wearable shielding materials, traditional shielding materials are mainly rubber composites, which have poor air permeability and are heavy, causing inconvenience to on-site personnel in wearing and working. In view of this, the present application relates to an anti-ionizing radiation sheath-core composite short fiber, which can produce convenient shielding clothing by combining short fiber processing technology with non-woven preparation process.

[0003] In addition, the fillers currently used to improve the structural mechanical properties of polyethylene-based shielding materials mainly include glass beads and glass fibers, but such fillers are inorganic substances, have poor compatibility with organic polymer materials, and do not have both performance enhancement and shielding performance. SUMMARY

[0004] The present application aims to overcome the defects of the prior art and provide an anti-ionizing radiation sheath-core composite short fiber and its preparation method.

[0005] The anti-ionizing radiation sheath-core composite short fiber of the present application is made of a thermoplastic resin and a radiation protection material. The radiation protection material is a carbon nanotube with a surface grafted with an organic polymer molecular chain. The unique structure of the carbon nanotube allows it to act as a free radical scavenger to eliminate free radicals generated during the radiation of the product, thereby providing radiation protection. The dimethylaminoethyl methacrylate molecule contains a carbon-carbon double bond, which undergoes a polymerization reaction with the carbon-carbon double bond on the surface of the carbon nanotube to form an organic polymer molecular layer on the surface of the carbon nanotube. On the one hand, the organic polymer molecular layer is a high molecular polymer containing ester groups and amide bonds, which can effectively improve the compatibility of the carbon nanotube with the thermoplastic resin matrix, improve the interfacial bonding performance, and promote the dispersion of the carbon nanotube in the thermoplastic resin without negatively affecting the mechanical properties of the short fiber. On the other hand, the organic polymer molecular chain contains benzene rings, which can improve the mechanical strength of the short fiber to some extent and improve the durability of the short fiber product.

[0006] The object of the present application can be achieved by the following technical solutions:

[0007] An anti-ionizing radiation sheath-core composite short fiber includes a core layer and a sheath layer, both of which are made of a thermoplastic resin and a radiation protection material.

[0008] The mass ratio of the thermoplastic resin to the radiation protection material in the core layer is 3:0-1.

[0009] The mass ratio of the thermoplastic resin and the anti-radiation material in the skin layer is 1:1.

[0010] Further, the thermoplastic resin is one or more of the following: spinnable PET, PBT, PA6, PA66 and PP, mixed in any ratio.

[0011] Further, the anti-radiation material is prepared by the following steps:

[0012] S1, place carbon nanotubes in a three-necked flask, slowly add a mixture of concentrated sulfuric acid and concentrated nitric acid, ultrasonic dispersion while stirring for 60-90 min, 60°C oil bath condensation reflux, stirring reaction for 3h, the reaction solution is naturally cooled to room temperature, suction filtration, washed with deionized water until the washing liquid is neutral, finally put the filter cake into a 80°C drying oven to dry to constant weight, grind and sieve to obtain acidified carbon nanotubes; the ratio of the amount of carbon nanotubes, concentrated sulfuric acid, concentrated nitric acid is 5g:210mL:70mL;

[0013] Under the action of concentrated sulfuric acid and concentrated nitric acid, the carbon nanotubes are acidified, thereby introducing -COOH on the surface of the carbon nanotubes, laying the reaction site for the subsequent reaction;

[0014] S2, add DIC (N,N-diisopropylcarbodiimide) and dichloromethane into a round-bottom flask, dissolve, then under nitrogen protection, add acidified carbon nanotubes, 4-vinylaniline and triethylamine into the flask, stir at room temperature under N2 protection for 3h, after the reaction is completed, centrifugal separation, and then wash with ethanol and deionized water for 3-4 times, finally put the filter cake into a 60°C drying oven to dry to constant weight, grind and sieve to obtain double bond modified carbon nanotubes; the ratio of the amount of acidified carbon nanotubes, 4-vinylaniline, triethylamine, DIC and dichloromethane is 5g:11.9g:10.1g:6.3g:300mL;

[0015] Under the action of DIC and triethylamine, -COOH on the surface of the acidified carbon nanotubes chemically reacts with -NH2 on the 4-vinylaniline molecule, thereby grafting carbon-carbon double bond on the surface of the carbon nanotubes, laying the reaction site for the subsequent coating reaction;

[0016] S3, the double bond modified carbon nanotube is ultrasonically dispersed in anhydrous ethanol, distilled water and FeSO4.7H2O are sequentially added, under magnetic stirring at room temperature, dimethylaminoethyl methacrylate is added to the system, after nitrogen is passed, the system is sealed, irradiation is carried out for 28h, after irradiation, the reaction solution is transferred to a centrifugal tube, diluted with oxalic acid aqueous solution (0.2mol / L), centrifugal separation is carried out, and ethanol is used for washing 2-3 times, finally, the product is placed in a 50℃ drying box and dried to constant weight, grinding and sieving are carried out, and the anti-radiation material is obtained; the ratio of the amounts of the double bond modified carbon nanotube, anhydrous ethanol, distilled water, FeSO4.7H2O and dimethylaminoethyl methacrylate is 3g:100mL:100mL:1.4g:20mL.

[0017] The unique structure of the carbon nanotube itself enables the carbon nanotube to eliminate free radicals generated by radiation of a product as a free radical scavenger, thereby having the anti-radiation performance; the dimethylaminoethyl methacrylate molecule contains a carbon-carbon double bond, and a polymerization reaction occurs between the carbon-carbon double bond on the surface of the carbon nanotube and the carbon-carbon double bond on the dimethylaminoethyl methacrylate molecule, thereby forming an organic polymer molecular layer on the surface of the carbon nanotube; on one hand, the organic polymer molecular layer belongs to a high polymer, contains ester groups and amide bonds, can effectively improve the compatibility of the carbon nanotube with a thermoplastic resin matrix, improve the interface bonding performance, promote dispersion of the carbon nanotube in the thermoplastic resin, and does not have a negative impact on the mechanical performance of the short fiber; on the other hand, the organic polymer molecular chain contains benzene rings, and the rigid benzene rings can improve the mechanical strength of the short fiber to a certain extent and improve the durability of a short fiber product.

[0018] A preparation method of an ionizing radiation resistant sheath-core composite short fiber, comprising the following steps: after bundling a filament drum, sequentially passing through a tension frame, a five-roller drafting machine, a steam preheating box, a crimping machine, a drying and setting box, a cutting machine and a packaging machine.

[0019] In the method, the maximum linear speed of drafting and crimping is 150 m / min, the maximum linear speed of cutting is 165 m / min, the steam preheating temperature is 100-140 DEG C, and the drying and setting temperature is 80-100 DEG C.

[0020] The method has the following beneficial effects:

[0021] The anti-ionizing radiation sheath-core composite short fiber of the present application is made of a thermoplastic resin and an anti-radiation material, and the anti-radiation material is a carbon nanotube with a surface grafted with an organic polymer molecular chain. The unique structure of the carbon nanotube enables it to act as a free radical scavenger to eliminate free radicals generated by radiation, thereby having the anti-radiation performance. The dimethylaminoethyl methacrylate molecule contains a carbon-carbon double bond, which is polymerized with the carbon-carbon double bond on the surface of the carbon nanotube to form an organic polymer molecular layer on the surface of the carbon nanotube. On the one hand, the organic polymer molecular layer is a high polymer containing ester groups and amide bonds, which can effectively improve the compatibility of the carbon nanotube with the thermoplastic resin matrix, improve the interfacial bonding performance, promote the dispersion of the carbon nanotube in the thermoplastic resin, and at the same time, will not have a negative impact on the mechanical properties of the short fiber. On the other hand, the organic polymer molecular chain contains benzene rings, and the rigid benzene rings can improve the mechanical strength of the short fiber to some extent and improve the durability of the short fiber product. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0023] Embodiment 1

[0024] The anti-radiation material is prepared by the following steps:

[0025] S1, 5g of carbon nanotubes is placed in a three-necked flask, and a mixture of 210mL of concentrated sulfuric acid and 70mL of concentrated nitric acid is slowly added, and stirred while ultrasonically dispersed for 60min, and then condensed and refluxed at 60℃ in an oil bath, and stirred for 3h, and then the reaction solution is naturally cooled to room temperature, and then filtered, and washed with deionized water until the washing liquid is neutral, and finally the filter cake is placed in a 80℃ drying oven to dry to constant weight, and then ground and sieved to obtain acidified carbon nanotubes;

[0026] S2, 6.3g of DIC (N,N-diisopropyl carbodiimide) and 300mL of dichloromethane are added to a round-bottomed flask, and after dissolution, 5g of acidified carbon nanotubes, 11.9g of 4-vinylaniline and 10.1g of triethylamine are added to the flask, and stirred at room temperature under N2 protection for 3h, and then centrifuged, and washed with ethanol and deionized water three times in turn, and finally the filter cake is placed in a 60℃ drying oven to dry to constant weight, and then ground and sieved to obtain double bond modified carbon nanotubes;

[0027] S3, 3g of double bond modified carbon nanotubes were ultrasonically dispersed in 100mL of anhydrous ethanol, 100mL of distilled water and 1.4g of FeSO4·7H2O were sequentially added, 20mL of dimethylaminoethyl methacrylate was added to the system under magnetic stirring at room temperature, sealed after nitrogen was passed, irradiated for 28h, after irradiation, the reaction solution was transferred to a centrifuge tube, diluted with 150mL of oxalic acid aqueous solution (0.2mol / L), centrifuged, washed with ethanol for 2 times, finally the product was placed in a 50℃ drying oven to dry to constant weight, ground and sieved to obtain a radiation protection material.

[0028] Example 2

[0029] A radiation protection material was prepared by the following steps:

[0030] S1, 10g of carbon nanotubes were placed in a three-necked flask, a mixture of 420mL of concentrated sulfuric acid and 140mL of concentrated nitric acid was slowly added, ultrasonic dispersion was performed while stirring for 90min, 60℃ oil bath condensation reflux was performed, stirring reaction was performed for 3h, the reaction solution was naturally cooled to room temperature, filtration was performed, deionized water was washed until the washing liquid was neutral, finally the filter cake was placed in an 80℃ drying oven to dry to constant weight, ground and sieved to obtain acidified carbon nanotubes;

[0031] S2, 12.6g of DIC (N,N-diisopropyl carbodiimide) and 600mL of dichloromethane were added to a round-bottomed flask, after dissolution, 10g of acidified carbon nanotubes, 23.8g of 4-vinylaniline and 20.2g of triethylamine were added to the flask, stirring reaction was performed at room temperature under N2 protection for 3h, after the reaction was completed, centrifugal separation was performed, and ethanol and deionized water were sequentially washed for 4 times, finally the filter cake was placed in a 60℃ drying oven to dry to constant weight, ground and sieved to obtain double bond modified carbon nanotubes;

[0032] S3, 6g of double bond modified carbon nanotubes were ultrasonically dispersed in 200mL of anhydrous ethanol, 200mL of distilled water and 2.8g of FeSO4·7H2O were sequentially added, 40mL of dimethylaminoethyl methacrylate was added to the system under magnetic stirring at room temperature, sealed after nitrogen was passed, irradiated for 28h, after irradiation, the reaction solution was transferred to a centrifuge tube, diluted with 300mL of oxalic acid aqueous solution (0.2mol / L), centrifuged, washed with ethanol for 3 times, finally the product was placed in a 50℃ drying oven to dry to constant weight, ground and sieved to obtain a radiation protection material.

[0033] Example 3

[0034] An ionizing radiation resistant core-sheath composite staple fiber comprises a core layer and a sheath layer, both of which are prepared by mixing a thermoplastic resin and a radiation protection material;

[0035] Among them, only the thermoplastic resin is in the core layer;

[0036] The mass ratio of the thermoplastic resin and the anti-radiation material in the sheath layer is 1:1.

[0037] The thermoplastic resin is a spinning grade PET.

[0038] Example 4

[0039] A core-sheath composite staple fiber for preventing ionizing radiation includes a core layer and a sheath layer, both of which are prepared by mixing a thermoplastic resin and an anti-radiation material.

[0040] The mass ratio of the thermoplastic resin and the anti-radiation material in the core layer is 3:0.5.

[0041] The mass ratio of the thermoplastic resin and the anti-radiation material in the sheath layer is 1:1.

[0042] The thermoplastic resin is a spinning grade PBT.

[0043] Example 5

[0044] A core-sheath composite staple fiber for preventing ionizing radiation includes a core layer and a sheath layer, both of which are prepared by mixing a thermoplastic resin and an anti-radiation material.

[0045] The mass ratio of the thermoplastic resin and the anti-radiation material in the core layer is 3:1.

[0046] The mass ratio of the thermoplastic resin and the anti-radiation material in the sheath layer is 1:1.

[0047] The thermoplastic resin is a spinning grade PA6.

[0048] The quality indexes of the staple fibers obtained in Examples 3-5 are as follows: linear density 4.1-4.3 dtex, breaking strength 3.0-3.2 cN / dtex, elongation at break 45-48%, and cut length 51-52 mm.

[0049] In the description of the specification, the description of the terms "one embodiment", "an example", "a specific example", and the like means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0050] The above is only an example and a description of the present application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or use similar ways to replace, as long as they do not deviate from the invention or exceed the scope defined by the present claims, which shall belong to the protection scope of the present application.

Claims

1. An ionizing radiation shielding core-sheath composite staple fiber, characterized by, The core layer and the skin layer are both prepared by mixing a thermoplastic resin and a radiation protection material; The radiation protection material is prepared by the following steps: S1, carbon nanotubes are placed in a three-necked flask, and a mixture of concentrated sulfuric acid and concentrated nitric acid is slowly added, and the mixture is stirred and ultrasonically dispersed for 60-90 min, and then the mixture is condensed and refluxed in an oil bath at 60 DEG C, and the mixture is stirred for 3 h, and then the mixture is naturally cooled to room temperature, and then the mixture is filtered, and then the mixture is washed with deionized water until the washing liquid is neutral, and finally the filter cake is dried in a drying oven at 80 DEG C until the weight is constant, and then the mixture is ground and sieved to obtain acidified carbon nanotubes; S2, N, N-diisopropyl carbodiimide DIC and dichloromethane are added to a round-bottom flask, and then the mixture is dissolved, and then acidified carbon nanotubes, 4-vinylaniline and triethylamine are added to the flask under nitrogen protection, and then the mixture is stirred at room temperature under N2 protection for 3 h, and then the mixture is centrifuged and washed with ethanol and deionized water for 3-4 times in sequence, and finally the filter cake is dried in a drying oven at 60 DEG C until the weight is constant, and then the mixture is ground and sieved to obtain double bond modified carbon nanotubes; S3, the double bond modified carbon nanotubes are ultrasonically dispersed in anhydrous ethanol, and then distilled water and FeSO4·7H2O are added in sequence, and then methyl methacrylate is added to the system under magnetic stirring at room temperature, and then the system is sealed after nitrogen is passed, and then the system is irradiated for 28 h, and then the reaction liquid is transferred to a centrifuge tube after irradiation, and then the mixture is diluted with an oxalic acid aqueous solution, and then the mixture is centrifuged and washed with ethanol for 2-3 times, and finally the product is dried in a drying oven at 50 DEG C until the weight is constant, and then the mixture is ground and sieved to obtain a radiation protection material.

2. The ionizing radiation shielding sheath-core composite staple fiber according to claim 1, wherein, The amount ratio of carbon nanotubes, concentrated sulfuric acid and concentrated nitric acid in step S1 is 5g:210mL:70mL.

3. The ionizing radiation shielding sheath-core composite staple of claim 1 wherein, The amount ratio of acidified carbon nanotubes, 4-vinylaniline, triethylamine, DIC and dichloromethane in step S2 is 5g:11.9g:10.1g:6.3g:300mL.

4. The ionizing radiation shielding sheath-core composite staple of claim 1 wherein, The amount ratio of double bond modified carbon nanotubes, anhydrous ethanol, distilled water, FeSO4·7H2O, methyl methacrylate in step S3 is 3g:100mL:100mL:1.4g:20mL.

5. The ionizing radiation shielding sheath-core composite staple of claim 1 wherein, The mass ratio of the thermoplastic resin and the radiation protection material in the core layer is 3:0-1, and the mass ratio of the thermoplastic resin and the radiation protection material in the skin layer is 1:

1.

6. The ionizing radiation shielding sheath-core composite staple of claim 1 wherein, The thermoplastic resin is one or more of spinning grade PET, PBT, PA6, PA66 and PP mixed in any ratio.

7. The method for preparing a core-sheath composite short fiber for ionizing radiation protection according to claim 1, characterized in that, After the filament drum is bundled, the bundled filament drum is sequentially passed through a tension frame, a five-roller drafting machine, a steam preheating box, a crimping machine, a drying and setting box, a cutting machine and a packing machine.

8. A method of producing an ionizing radiation shielding core-sheath composite staple fiber according to claim 7, characterized by, The maximum linear speed of drafting and crimping is 150 m / min, the maximum linear speed of cutting is 165 m / min, the steam preheating temperature is 100-140 DEG C, and the drying and setting temperature is 80-100 DEG C.