Ethylene propylene rubber for nuclear radiation prevention clothes and preparation method thereof

Abstract

The invention relates to the technical field of materials for anti-nuclear radiation clothes, in particular to ethylene propylene rubber for anti-nuclear radiation clothes and a preparation method of the ethylene propylene rubber. A composite multi-walled carbon nanotube subjected to pretreatment; an accelerant; a fiber; a plasticizer; an anti-aging agent; stearic acid; through an innovative raw material formula and a corresponding preparation process, the novel ethylene propylene rubber material for the nuclear radiation prevention clothing is mainly researched and developed. In the aspect of raw materials, the radiation shielding performance of the ethylene propylene rubber is remarkably improved by introducing the specially pretreated composite multi-walled carbon nanotubes and reasonably matching the nano zinc oxide. Meanwhile, the specific dosage ratio of the ethylene propylene rubber, the accelerant, the fiber, the plasticizer and other raw materials ensures that the product has excellent shielding performance and also has good weather resistance, flexibility and comfort.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nuclear radiation protection clothing materials, in particular to an ethylene propylene rubber for nuclear radiation protection clothing and a preparation method thereof. BACKGROUND

[0002] With the development of society, the application of nuclear energy is also more and more extensive, such as the continuous operation of nuclear power plants, the rapid development of nuclear medicine and the increasing frequency of nuclear scientific research activities, which greatly promotes the progress of society. However, at the same time, the potential harm caused by nuclear radiation is also increasingly prominent. Long-term exposure to a nuclear radiation environment can cause serious damage to human cells and DNA, greatly increasing the risk of cancer and possibly causing various other health problems.

[0003] Therefore, nuclear radiation protection clothing, as an important equipment to protect the health and safety of relevant personnel, has great significance.

[0004] Ethylene propylene rubber (EPDM) is a high-performance synthetic rubber that has been widely used in many fields due to its excellent weather resistance, chemical corrosion resistance, electrical insulation, and flexibility. In the field of nuclear radiation protection clothing, ethylene propylene rubber has shown great potential due to its unique molecular structure and physical properties. On the one hand, its stable chemical properties help resist the erosion of various harmful substances in the radiation environment; on the other hand, its good flexibility ensures the comfort and flexibility of the clothing during wear.

[0005] Currently, the nuclear radiation protection clothing on the market still has deficiencies in radiation shielding performance, and the shielding rate of traditional nuclear radiation protection clothing is relatively low. Therefore, the development of ethylene propylene rubber materials for nuclear radiation protection clothing is of great significance to improve the shielding rate of nuclear radiation protection clothing. SUMMARY

[0006] In view of the problems in the prior art, the present application provides an ethylene propylene rubber for nuclear radiation protection clothing and a preparation method thereof.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0008] An ethylene propylene rubber for nuclear radiation protection clothing, consisting of the following raw materials in parts by weight: ethylene propylene rubber 100 parts; pretreated composite multi-walled carbon nanotubes 4-6 parts; accelerator 1.5-2.2 parts; fiber 13-15 parts; plasticizer 6-8 parts; antioxidant 1.2-1.8 parts; stearic acid 1.2-1.8 parts;

[0009] The plasticizer is a polyester plasticizer with an acid value less than 0.8 mgKOH / g, a number average molecular weight of 2000-2500 g / mol, a density of 1.1-1.2 g / cm 3 , and a flash point not less than 200℃.

[0010] As a further technical solution, the ethylene-propylene rubber is a terpolymer ethylene-propylene rubber, the third monomer is dicyclopentadiene, and the content is 5-6wt%, and the Mooney viscosity (ML1+4, 125℃) is 55-60.

[0011] As a further technical solution, the accelerator is a thiuram accelerator;

[0012] The specific thiuram accelerator is tetramethylthiuram disulfide, and the melting point is between 138-140℃.

[0013] As a further technical solution, the antioxidant is a diphenylamine antioxidant;

[0014] The diphenylamine antioxidant is specifically N-phenyl-β-naphthylamine, and the heat reduction is not more than 0.3%.

[0015] As a further technical solution, the saponification value of the stearic acid is between 208-210mgKOH / g. As a further technical solution, the pretreatment method of the composite multi-walled carbon nanotube is as follows:

[0016] The nano zinc oxide is dispersed in a 10-12wt% hydrochloric acid solution at a mass ratio of 1:20-22, ultrasonic dispersion for 40-50 minutes to form a zinc oxide dispersion;

[0017] The multi-walled carbon nanotube is added to the above zinc oxide dispersion at a mass ratio of 1:10-12, and stirred at 85-95℃ for 2.5-3.5 hours; then repeatedly washed with deionized water until the pH value is 6.5-6.8, and vacuum dried at 120-125℃ for 8-9 hours to obtain the multi-walled carbon nanotube loaded with zinc oxide;

[0018] Subsequently, the multi-walled carbon nanotube loaded with zinc oxide is dispersed in a xylene solution containing 5.5-6.5% aluminate coupling agent, and stirred at 65-75℃ for 5.5-6.5 hours, and then filtered and vacuum dried at 120-125℃ for 8-9 hours to obtain.

[0019] As a further technical solution, the ultrasonic dispersion power is 350W, and the frequency is 40kHz.

[0020] As a further technical solution, the fiber is basalt fiber, the silica content is between 47-50%, and the single filament diameter is 10-12μm.

[0021] The preparation method of the ethylene-propylene rubber for nuclear radiation protection clothing comprises the following steps:

[0022] Raw material drying pretreatment step: dry the ethylene-propylene rubber in a vacuum drying oven at 60-70 DEG C for 2-3 hours to remove moisture; at the same time, dry the fiber at 80-90 DEG C for 1-2 hours to ensure that the raw materials are in a dry state;

[0023] Premixing step: the plasticizer, antioxidant and stearic acid are pre-mixed and stirred at 55-65 DEG C for 20-30 minutes to form a premix;

[0024] Mixing step: the dried ethylene-propylene rubber is put into the internal mixer and plasticized at 105-115 DEG C for 9-11 minutes; the pretreated multi-walled carbon nanotube, the premix, the accelerator, and the dried fiber are sequentially added and mixed at 150-160 DEG C for 15-18 minutes; during the mixing process, the glue is discharged and cooled every 3-5 minutes to ensure uniform mixing, and the mixed rubber is obtained;

[0025] Vulcanization step: the mixed rubber is vulcanized on a flat vulcanization machine, the vulcanization temperature is 185-195 DEG C, the vulcanization pressure is 15-18 MPa, and the vulcanization time is 22-26 minutes, and the vulcanized rubber is obtained;

[0026] Post-processing step: the vulcanized rubber is soaked in warm water at 40-50 DEG C for 1-2 hours to remove surface residues, and then aged at 45-50 DEG C for 24-30 hours to obtain the ethylene-propylene rubber for anti-nuclear radiation clothing.

[0027] Compared with the prior art, the beneficial effects of the present application are:

[0028] The present application develops a new type of ethylene-propylene rubber material for anti-nuclear radiation clothing through innovative raw material formula and corresponding preparation process. In terms of raw materials, the present application introduces a special pretreated composite multi-walled carbon nanotube and reasonably matches nano zinc oxide, which significantly improves the radiation shielding performance of ethylene-propylene rubber. At the same time, the specific amount of ethylene-propylene rubber, accelerator, fiber, plasticizer and other raw materials is matched to ensure that the product not only has excellent shielding performance, but also has good weather resistance, flexibility and comfort.

[0029] In terms of raw material selection and matching, the specific ternary ethylene-propylene rubber principle not only ensures that the material has good fluidity during processing, which is beneficial to the uniform dispersion of other components, but also gives the finished product excellent flexibility, greatly improving the wearing comfort of anti-nuclear radiation clothing. At the same time, after being loaded with nano zinc oxide, the unique pretreated composite multi-walled carbon nanotube forms an efficient nuclear radiation shielding network. The multi-walled carbon nanotube has a nanoscale hollow tubular structure with a large specific surface area, which can anchor nano zinc oxide particles and make them uniformly dispersed in the rubber matrix. This dispersion method not only avoids the agglomeration of zinc oxide, but also widens the shielding dimension, effectively blocking various nuclear radiation.

[0030] The introduction of the accelerator tetramethylthiuram disulfide can rapidly decompose to generate free radicals, accelerate the crosslinking reaction between rubber molecular chains, and greatly increase the crosslinking density of the rubber. The increase of the crosslinking density significantly enhances the physical properties such as tensile strength and wear resistance of the material, and prolongs the actual service life of the product.

[0031] The basalt fiber not only provides excellent mechanical strength to the material, but also enhances the dimensional stability, ensuring that the anti-nuclear radiation clothing can maintain good protective performance in complex environments.

[0032] In summary, through the synergistic innovation of raw materials and process, the anti-nuclear radiation performance is greatly improved, and the weather resistance, durability and comfort are comprehensively optimized, fully meeting the stringent requirements of anti-nuclear radiation clothing in long-term and high-intensity use scenarios. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only a 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.

[0034] The raw materials or reagents used in the following examples are commercially available.

[0035] Example 1

[0036] Raw material preparation: take ethylene-propylene rubber 100 parts; pretreated composite multi-walled carbon nanotubes 4 parts; accelerator 1.5 parts; fiber 13 parts; plasticizer 6 parts; antioxidant 1.2 parts; stearic acid 1.2 parts.

[0037] Plasticizer: polyester plasticizer, acid value 0.6 mgKOH / g, number average molecular weight 2000 g / mol, density 1.1 g / cm 3 , flash point 205℃.

[0038] Ethylene-propylene rubber: ternary ethylene-propylene rubber, third monomer dicyclopentadiene content 5wt%, Mooney viscosity (ML1+4, 125℃) 55.

[0039] Accelerator: tetramethylthiuram disulfide, melting point 138℃.

[0040] Antioxidant: N-phenyl-β-naphthylamine, heating loss 0.2%.

[0041] Stearic acid: saponification value 208 mgKOH / g.

[0042] Composite multi-walled carbon nanotube pretreatment: Nanometer zinc oxide was dispersed in a 10% mass fraction hydrochloric acid solution at a mass ratio of 1:20, and ultrasonic dispersion was performed at a power of 350 W and a frequency of 40 kHz for 40 minutes to form a zinc oxide dispersion liquid; multi-walled carbon nanotubes were added to the above zinc oxide dispersion liquid at a mass ratio of 1:10, and stirring reaction was performed at 85°C for 2.5 hours; then repeated washing with deionized water was performed until the pH value was 6.5, and vacuum drying was performed at 120°C for 8 hours to obtain zinc oxide-loaded multi-walled carbon nanotubes; then the zinc oxide-loaded multi-walled carbon nanotubes were dispersed in a dimethylbenzene solution containing 5.5% aluminate coupling agent, stirring reaction was performed at 65°C for 5.5 hours, and vacuum drying was performed at 120°C for 8 hours after filtration.

[0043] Fiber: basalt fiber, silica content 47%, single filament diameter 10 μm.

[0044] Preparation process:

[0045] Raw material drying pretreatment: ethylene-propylene rubber was dried in a vacuum drying oven at 60°C for 2 hours to remove water; at the same time, the fiber was dried at 80°C for 1 hour to ensure that the raw materials were in a dry state.

[0046] Premixing: the plasticizer, antioxidant and stearic acid were pre-mixed and stirred at 55°C for 20 minutes to form a premix.

[0047] Mixing: the dried ethylene-propylene rubber was put into a mixer, plasticized at 105°C for 9 minutes; the pretreated multi-walled carbon nanotubes, the premix, the accelerator, and the dried fiber were sequentially added, and mixed at 150°C for 15 minutes; during the mixing process, glue discharge and heat dissipation were performed every 3 minutes to obtain a mixed rubber.

[0048] Post-treatment: the vulcanized rubber was soaked in warm water at 40°C for 1 hour to remove surface residual impurities, and then aged at 45°C for 24 hours to obtain the ethylene-propylene rubber for anti-nuclear radiation clothing.

[0049] Example 2

[0050] Raw material preparation: ethylene-propylene rubber 100 parts; pretreated composite multi-walled carbon nanotubes 5 parts; accelerator 1.8 parts; fiber 14 parts; plasticizer 7 parts; antioxidant 1.5 parts; stearic acid 1.5 parts.

[0051] Plasticizer: acid value 0.7 mgKOH / g, number average molecular weight 2200 g / mol, density 1.15 g / cm 3 , flash point 210°C.

[0052] Ethylene propylene rubber: third monomer dicyclopentadiene content 5.5 wt%, Mooney viscosity (ML 1+4, 125°C) 57.

[0053] Accelerator: tetramethylthiuram disulfide, melting point 139°C.

[0054] Antioxidant: N-phenyl-β-naphthylamine, heat reduction 0.25%.

[0055] Stearic acid: saponification value 209 mg KOH / g.

[0056] Composite multi-walled carbon nanotube pretreatment: nanometer zinc oxide was dispersed in a 11% mass fraction hydrochloric acid solution at a mass ratio of 1:21, ultrasonic dispersion for 45 minutes to form a zinc oxide dispersion liquid; multi-walled carbon nanotubes were added to the above zinc oxide dispersion liquid at a mass ratio of 1:11, and stirred and reacted at 90°C for 3 hours; then repeatedly washed with deionized water until the pH value was 6.6, and vacuum dried at 122°C for 8.5 hours to obtain zinc oxide loaded multi-walled carbon nanotubes; then the zinc oxide loaded multi-walled carbon nanotubes were dispersed in a dimethylbenzene solution containing 6% aluminate coupling agent, stirred and reacted at 70°C for 6 hours, and vacuum dried at 122°C for 8.5 hours after filtration.

[0057] Fiber: basalt fiber, silica content 48%, single filament diameter 11 μm.

[0058] Preparation process:

[0059] Raw material drying pretreatment: ethylene propylene rubber was dried in a vacuum drying oven at 65°C for 2.5 hours, and the fiber was dried at 85°C for 1.5 hours.

[0060] Premixing: the plasticizer, antioxidant and stearic acid were stirred at 60°C for 25 minutes to form a premix. Mixing: the dried ethylene propylene rubber was plasticized at 110°C for 10 minutes; the pretreated multi-walled carbon nanotubes, the premix, the accelerator, and the dried fiber were sequentially added, and mixed at 155°C for 16 minutes, with glue removal and heat dissipation every 4 minutes.

[0061] Vulcanization: vulcanization was carried out at a vulcanization temperature of 190°C, a vulcanization pressure of 16 MPa, and a vulcanization time of 24 minutes.

[0062] Post-treatment: the vulcanized rubber was soaked in warm water at 45°C for 1.5 hours, and then aged at 47°C for 27 hours.

[0063] Example 3

[0064] Raw material preparation: ethylene propylene rubber 100 parts; pretreated composite multi-walled carbon nanotubes 6 parts; accelerator 2.2 parts; fiber 15 parts; plasticizer 8 parts; antioxidant 1.8 parts; stearic acid 1.8 parts.

[0065] Plasticizer: acid value 0.8 mg KOH / g, number average molecular weight 2500 g / mol, density 1.2 g / cm3 3 , flash point 220 °C. Ethylene propylene rubber: third monomer dicyclopentadiene content 6 wt%, Mooney viscosity (ML 1+4, 125 °C) 60. Accelerator: tetramethyl thiuram disulfide, melting point 140 °C.

[0066] Antioxidant: N-phenyl-β-naphthylamine, heat reduction 0.3%.

[0067] Stearic acid: saponification value 210 mg KOH / g.

[0068] Composite multi-walled carbon nanotube pretreatment: nanometer zinc oxide was dispersed in a 12% mass fraction hydrochloric acid solution at a mass ratio of 1:22, ultrasonic dispersion for 50 minutes to form a zinc oxide dispersion liquid; multi-walled carbon nanotubes were added to the above zinc oxide dispersion liquid at a mass ratio of 1:12, and stirred and reacted at 95 °C for 3.5 hours; then repeatedly washed with deionized water until the pH value was 6.8, and vacuum dried at 125 °C for 9 hours to obtain zinc oxide loaded multi-walled carbon nanotubes; then the zinc oxide loaded multi-walled carbon nanotubes were dispersed in a dimethylbenzene solution containing 6.5% aluminate coupling agent, stirred and reacted at 75 °C for 6.5 hours, and vacuum dried at 125 °C for 9 hours after filtration.

[0069] Fiber: basalt fiber, silica content 50%, monofilament diameter 12 μm.

[0070] Preparation process:

[0071] Raw material drying pretreatment: ethylene propylene rubber was dried in a vacuum drying oven at 70 °C for 3 hours, and the fiber was dried at 90 °C for 2 hours.

[0072] Premixing: the plasticizer, antioxidant and stearic acid were stirred at 65 °C for 30 minutes to form a premix. Mixing: the dried ethylene propylene rubber was plasticized at 115 °C for 11 minutes; the pretreated multi-walled carbon nanotubes, the premix, the accelerator, and the dried fiber were sequentially added, and mixed at 160 °C for 18 minutes, with glue removal and heat dissipation every 5 minutes.

[0073] Vulcanization: vulcanization was carried out at a vulcanization temperature of 195 °C, a vulcanization pressure of 18 MPa, and a vulcanization time of 26 minutes.

[0074] Post-treatment: the vulcanized rubber was soaked in warm water at 50 °C for 2 hours, and then aged at 50 °C for 30 hours.

[0075] Comparative Example 1

[0076] On the basis of example 1, distinguished from example 1 is that the composite multi-walled carbon nanotubes are not pretreated, and the multi-walled carbon nanotubes are directly used.

[0077] Comparative example 2

[0078] On the basis of example 1, distinguished from example 1 is that the fiber is replaced with an equal amount of ordinary glass fiber. Test:

[0079] The anti-nuclear radiation performance test uses professional nuclear radiation shielding test equipment to simulate common nuclear radiation scenes, and the ethylene-propylene rubber prepared by the examples and comparative examples is subjected to anti-nuclear radiation performance test, and the radiation shielding rates of materials under different formulations and processes are compared, and the results are shown in Table 1:

[0080] Table 1

[0081] Radiation shielding rate / % Example 1 89 Example 2 90 Example 3 87 Comparative Example 1 61 Comparative Example 2 85

[0082] As can be seen from Table 1, the ethylene-propylene rubber prepared in the present application has excellent anti-nuclear radiation performance.

[0083] Mechanical property test, the tensile strength and elongation at break of the ethylene-propylene rubber of the examples and comparative examples are tested according to GB / T 528-2009 “Determination of Tensile Stress-Strain Properties of Vulcanized Rubber or Thermoplastic Rubber”, as shown in Table 2:

[0084] Table 2

[0085] Tensile strength MPa Elongation at break % Example 1 25.5 450 Example 2 26.3 470 Example 3 26.0 460 Comparative Example 1 23.7 420 Comparative Example 2 20.3 400

[0086] As can be seen from Table 2, the ethylene-propylene rubber prepared in the present application has good mechanical properties.

[0087] The preferred embodiments of the present application disclosed above are only used to help illustrate the present application. The preferred embodiments do not describe all the details, nor limit the present application to the specific embodiments described. Obviously, many modifications and changes can be made according to the content of the present application.

Claims

1. An EPDM rubber for nuclear radiation protection clothing, characterized in that: The composition is composed of the following raw materials in parts by weight: 100 parts of ethylene propylene rubber; 4-6 parts of pretreated composite multi-walled carbon nanotubes; 1.5-2.2 parts of accelerator; 13-15 parts of fiber; 6-8 parts of plasticizer; 1.2-1.8 parts of antioxidant; 1.2-1.8 parts of stearic acid; The plasticizer is a polyester plasticizer with an acid value lower than 0.8 mgKOH / g, a number average molecular weight of 2000-2500 g / mol, and a density of 1.1-1.2 g / cm 3 , the flash point is not less than 200℃.

2. The EPDM rubber for nuclear radiation protection clothing according to claim 1, characterized in that: The EPDM rubber is EPDM, the third monomer is dicyclopentadiene, the content of which is 5-6 wt %, and the Mooney viscosity (ML1+4, 125° C.) is 55-60.

3. The EPDM rubber for nuclear radiation protection clothing according to claim 1, characterized in that: The accelerator is a thiuram accelerator; The specific one is tetramethylthiuram disulfide, which has a melting point between 138-140°C.

4. The EPDM rubber for nuclear radiation protection clothing according to claim 1, characterized in that: The antioxidant is a diphenylamine antioxidant; The diphenylamine antioxidant is specifically N-phenyl-β-naphthylamine, and the heating loss does not exceed 0.3%.

5. The EPDM rubber for nuclear radiation protection clothing according to claim 1, characterized in that: The saponification value of the stearic acid is between 208 and 210 mgKOH / g.

6. The EPDM rubber for nuclear radiation protection clothing according to claim 1, characterized in that: The pretreatment method of the composite multi-walled carbon nanotubes is as follows: Dispersing nano zinc oxide in a 10-12% by mass hydrochloric acid solution at a mass ratio of 1:20-22, and ultrasonically dispersing for 40-50 minutes to form a zinc oxide dispersion; Add multi-walled carbon nanotubes to the zinc oxide dispersion at a mass ratio of 1:10-12, and stir at 85-95°C for 2.5-3.5 hours; then repeatedly rinse with deionized water until the pH is 6.5-6.8, and vacuum dry at 120-125°C for 8-9 hours to obtain zinc oxide-loaded multi-walled carbon nanotubes; Subsequently, the multi-walled carbon nanotubes loaded with zinc oxide are dispersed in a xylene solution containing 5.5-6.5% aluminate coupling agent, stirred and reacted at 65-75° C. for 5.5-6.5 hours, filtered, and vacuum dried at 120-125° C. for 8-9 hours to obtain the product.

7. The EPDM rubber for nuclear radiation protection clothing according to claim 6, characterized in that: The ultrasonic dispersion power is 350W and the frequency is 40kHz.

8. The EPDM rubber for nuclear radiation protection clothing according to claim 1, characterized in that: The fiber is basalt fiber, the silicon dioxide content of the fiber is between 47-50%, and the diameter of the single fiber is 10-12 μm.

9. A method for preparing EPDM rubber for nuclear radiation protection clothing according to any one of claims 1 to 8, characterized in that: The following steps are involved: Raw material drying pretreatment step: Dry the EPDM rubber in a vacuum drying oven at 60-70°C for 2-3 hours to remove moisture; at the same time, dry the fiber at 80-90°C for 1-2 hours to ensure that the raw material is in a dry state; Premixing step: premix the plasticizer, antioxidant and stearic acid, and stir at 55-65°C for 20-30 minutes to form a premix; Mixing steps: adding the dried EPDM rubber into an internal mixer and masticating at 105-115°C for 9-11 minutes; adding the pretreated multi-walled carbon nanotubes, premix, accelerator, and dried fiber in sequence, and mixing at 150-160°C for 15-18 minutes; during the mixing process, performing rubber removal and heat dissipation every 3-5 minutes to ensure mixing uniformity, thereby obtaining a mixed rubber; Vulcanization step: vulcanizing the mixed rubber on a flat vulcanizer at a vulcanization temperature of 185-195°C, a vulcanization pressure of 15-18 MPa, and a vulcanization time of 22-26 minutes to obtain vulcanized rubber; Post-processing step: soaking the vulcanized rubber in warm water at 40-50°C for 1-2 hours to remove residual impurities on the surface, and then performing aging treatment at 45-50°C for 24-30 hours to obtain nuclear radiation-proof EPDM rubber for clothing.