Gamma ray radiation resistant medical protective apparel fabric and method of making same

Abstract

The application provides a medical protective clothing fabric resistant to gamma radiation and a preparation method thereof. The fabric of the application has excellent radiation resistance by using the synergistic effect of specific radiation-resistant stabilizers, light stabilizers, antioxidants, acid absorbents and the like. Further, the polypropylene is modified by the irradiation method, so that the prepared fabric has good flexibility.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of functional fiber manufacturing, D01F1 / 00, and in particular to a medical protective clothing fabric resistant to gamma ray radiation and a preparation method thereof. BACKGROUND

[0002] Medical protective clothing needs to be sterilized before and after use. In the prior art, protective clothing is mainly sterilized by using ethylene oxide, but ethylene oxide has a stimulating odor and toxicity, which pollutes the environment and harms human health. Moreover, it needs to be left for 7 days to resolve toxicity after sterilization, and the sterilization process is time-consuming. Irradiation sterilization is a sterilization method that uses electric power radiation to kill microorganisms and is increasingly widely used. Although irradiation sterilization can solve some defects caused by ethylene oxide sterilization, irradiation sterilization can affect the performance of the protective clothing fabric (especially polypropylene), which can easily cause a decrease in mechanical properties, yellowing, and can also cause post-irradiation effects (i.e., the performance of the fabric decreases more and more obviously as the storage time increases after irradiation).

[0003] Chinese patent CN108930075A discloses a radiation-proof fabric that enhances the radiation-proof performance of the fabric by adding an attempt oxide. Chinese patent CN111675856 discloses a polypropylene composite material that increases the radiation resistance of polypropylene by using a nucleating agent, a C12-C30 fatty acid salt, and a radiation stabilizer. Chinese patent CN114891271A discloses a composite additive and a preparation method thereof. The composite additive includes an antioxidant, a light stabilizer, a modified nucleating agent, and a C12-C30 fatty acid salt. The medical product prepared by mixing the composite additive with polypropylene has no significant changes in various performance indicators after irradiation.

[0004] However, the technology in the above patents cannot meet the needs of protective clothing that is exposed to radiation for a long time and also needs to be sterilized by radiation. Therefore, it is of great significance to prepare a protective clothing fabric that is resistant to radiation, has stable performance after radiation, and is excellent. SUMMARY

[0005] To solve the above technical problems, the present application first provides a medical protective clothing fabric resistant to gamma ray radiation. The fabric is a composite fiber non-woven fabric prepared from modified polypropylene masterbatch and modified polyethylene terephthalate.

[0006] Further, the modified polypropylene masterbatch is formed by melting polypropylene resin, a light stabilizer, an antioxidant, a C12-C30 fatty acid salt, and a radiation stabilizer.

[0007] Further, the modified polypropylene masterbatch component comprises, by weight parts, 80-90 parts of polypropylene resin, 0.5-2 parts of light stabilizer, 1-3 parts of antioxidant, 0.1-0.5 parts of C12-C30 fatty acid salt, and 0.3-0.8 parts of radiation stabilizer.

[0008] Further, the polypropylene resin is a homopolymer polypropylene resin with a melt index of 25-43 g / 10 min (230 °C / 2.16 kg, ASTM D1238L).

[0009] Preferably, the polypropylene resin is a homopolymer polypropylene resin with a melt index of 35-40 g / 10 min.

[0010] Further, the light stabilizer is selected from the group consisting of hindered amine light stabilizer, triazine light stabilizer, benzophenone; preferably a combination of hindered amine light stabilizer and benzophenone.

[0011] Further, the hindered amine light stabilizer includes, but is not limited to, at least one of UV-622, UV-944, UV-2020, UV-3853.

[0012] In a preferred embodiment, the light stabilizer is UV-944 and benzophenone in a mass ratio of (0.5-2): 1.

[0013] Further, the antioxidant is selected from the group consisting of at least one of tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester, tris(2,4-di-tert-butylphenyl) phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid octadecyl ester, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate.

[0014] Preferably, the antioxidant is 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate.

[0015] Further, the C12-C30 fatty acid salt is preferably a C18 fatty acid salt, which can be selected from any one of calcium stearate, zinc stearate, sodium stearate, magnesium stearate.

[0016] Further, the radiation stabilizer is selected from the group consisting of at least one of barium salt, barium oxide, strontium salt, strontium oxide, bismuth salt, bismuth oxide, samarium salt, samarium oxide, neodymium salt, neodymium oxide, erbium salt, erbium oxide.

[0017] Further, the radiation stabilizer includes at least one of barium salt, barium oxide, bismuth salt, bismuth oxide, samarium salt, samarium oxide.

[0018] Preferably, the radiation stabilizer comprises barium salts and bismuth oxides, specifically barium sulfate and bismuth trioxide.

[0019] Furthermore, the weight ratio of barium salt to bismuth oxide in the radiation stabilizer is (1-4):1; preferably (2-3):1.

[0020] Furthermore, the bismuth oxide must be modified by a modifier; the modifier is an organosilicon molecule containing unsaturated groups, and may be at least one of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, vinyltris(2-methoxyethoxy)silane, and vinyltriethoxysilane.

[0021] The addition of solid bismuth oxide to a system increases the impact strength of the fabric, but the resulting decrease in fabric flexibility is more pronounced. To address this issue, this application uses organosilicon molecules with unsaturated groups to modify the surface of bismuth oxide. The organosilicon molecules are connected to the bismuth oxide through intermolecular forces, acting as a bridge to improve the dispersion performance and stability of bismuth oxide in polypropylene. Most importantly, this application uses irradiation crosslinking technology to treat the polypropylene in the subsequent process. On the one hand, this causes a small number of polypropylene molecular chains to break, which, together with the higher molecular weight polypropylene, improves the flexibility of the polypropylene system. On the other hand, the unsaturated groups in the organosilicon molecules crosslink with the polypropylene under irradiation. The crystals of the organosilicon molecules insert into the crystals of the polypropylene, increasing the incompleteness of the spherulite morphology of the latter and causing the polypropylene spherulites to develop into a crystalline structure, thereby improving the flexibility of the polypropylene and effectively solving the problem of poor fabric flexibility caused by the addition of bismuth oxide. In addition, the fabric has the best flexibility only when γ-(2,3-epoxypropoxy)propyltrimethoxysilane is used in this application, possibly because the degree of crystal insertion produced by γ-(2,3-epoxypropoxy)propyltrimethoxysilane can better refine the microcrystals of polypropylene.

[0022] More preferably, the modifier is γ-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0023] Furthermore, the amount of the modifier is 10-25% of the weight of bismuth oxide; more preferably, it is 15-20% of the weight of bismuth oxide.

[0024] Furthermore, the modification method for bismuth oxide is as follows: after mixing isopropanol and water, add the modifier, stir and disperse, add bismuth oxide and continue stirring, then dry at 70-85℃, and then grind.

[0025] Furthermore, the average particle diameter of the bismuth oxide is 500-1200 nm.

[0026] Furthermore, the method for preparing the modified polypropylene masterbatch is as follows:

[0027] S1. Place polypropylene resin, light stabilizer, antioxidant, C12-C30 fatty acid salt and radiation stabilizer in a high-speed mixer and mix at 1200-1500 r / min for 5-8 min.

[0028] S2. Add the mixture to a melt extruder for extrusion granulation and pelletizing;

[0029] S3. Under nitrogen protection, using Co 60 - The S2 particles were irradiated by a gamma-ray source at a dose of 6-15 kGy.

[0030] Generally, polypropylene exhibits increased impact strength but decreased flexibility after irradiation. This application strictly adheres to an irradiation dose of 6-15 kGY to re-crosslink the modified polypropylene, causing appropriate molecular chain breakage and specific crosslinking with the modifier on the bismuth oxide surface. When the irradiation dose is too high, the number of molecular chain breaks is excessive, leading to a decrease in the strength of the polypropylene and the fabric prepared from it. When the irradiation dose is too low, the insertion effect of the organosilicon molecular modifier into the polypropylene grains is insufficient, failing to achieve the effect of improving the flexibility of the polypropylene and the fabric prepared from it.

[0031] Furthermore, in S2, the extruder temperature is 220-250℃, the die head temperature is 230-245℃, and the screw speed is 180-260rpm.

[0032] Furthermore, the modified polyethylene terephthalate is formed by melt blending aminated boron nitride and polyethylene terephthalate. The amount of aminated boron nitride is 2-5% of the weight of polyethylene terephthalate.

[0033] Further, the preparation of the amino boron nitride is as follows: γ-aminopropyltriethoxysilane or γ-aminopropyltrimethoxysilane is dispersed in a mixed solution of isopropanol and water and stirred, then boron nitride is added and stirred for 2-6 hours, filtered and dried.

[0034] Furthermore, the amount of γ-aminopropyltriethoxysilane or γ-aminopropyltrimethoxysilane used is 6-8% of the weight of boron nitride.

[0035] Furthermore, the average particle diameter of the aminated boron nitride is 300-1000 nm.

[0036] Preferably, the boron nitride is hexagonal boron nitride.

[0037] Furthermore, the raw materials for preparing the fabric include: 5-30 parts by weight of modified polypropylene masterbatch and 10-50 parts by weight of modified polyethylene terephthalate.

[0038] Secondly, the present invention also provides a method for preparing the gamma-ray resistant medical protective clothing fabric, comprising the following steps:

[0039] (1) In a high-temperature and high-pressure reaction environment of 200-240℃ and 2-6MPa, the modified polypropylene masterbatch and the modified polyethylene terephthalate are dissolved in an organic solvent to obtain the spinning solution.

[0040] (2) Spinning solution is ejected from the spinneret of a flash spinning machine and flash spinning is carried out at a certain temperature to obtain composite fibers with a diameter of 0.2-10 micrometers.

[0041] (3) The obtained composite fibers are thermally bonded to obtain nonwoven fabric.

[0042] Furthermore, the organic solvent is a mixed solution of dichloromethane and ethanol.

[0043] Furthermore, the weight of the organic solvent is 40-60% of the total weight of the modified polypropylene masterbatch and the modified polyethylene terephthalate.

[0044] Furthermore, the temperature in step (2) is 40-60℃.

[0045] Furthermore, in step (2), the spinning speed is 16000-20000 m / min.

[0046] Advantages

[0047] 1. This application combines radiation-resistant materials that absorb free radicals and have a shielding effect to effectively reduce the impact of radiation on composite fibers. It optimizes the relative amounts of radiation-resistant materials to simultaneously achieve advantages such as low cost, optimal radiation resistance, light weight, and fabric compatibility. Barium salts, bismuth oxides, and boron nitride all have good radiation resistance properties and can effectively absorb the energy generated by radiation to prevent its impact on composite fibers. This application combines these three materials to achieve the optimal radiation resistance effect. Barium sulfate is inexpensive, but its use in spinning solutions increases the crystallinity of polypropylene in the fibers, so its dosage should not be excessive. Boron nitride not only has excellent shielding effects but also high thermal conductivity to improve the high-temperature stability of composite fibers and fabrics. Boron nitride has a structure similar to graphene and can absorb free radicals, but its high hardness may reduce the mechanical strength of composite fibers if used excessively, and its cost is also relatively high. Therefore, it is necessary to strictly control the relative amounts of these three materials to make the fabric more suitable for industrial use.

[0048] 2. This application modifies the radiation-resistant material and readjusts the crosslinking state of polypropylene through subsequent irradiation treatment, which not only solves the problem of the effects of adding solid radiation-resistant materials, but also improves the flexibility of the composite fiber and its fabric.

[0049] 3. This application selects different types of light stabilizers to effectively capture free radicals generated by irradiation, thereby stabilizing the composite fibers. It also uses antioxidants to improve the heat resistance and durability of the composite fibers and fabrics. Through the synergistic effect of light stabilizers, antioxidants, and radiation-resistant materials, the radiation resistance of the composite fibers and their fabrics is improved in multiple ways.

[0050] 4. The gamma-ray resistant medical protective fabric prepared in this application has excellent radiation protection performance. After being irradiated with a dose of 40KGy gamma rays, the strength of the fabric does not decrease significantly, and the increase in yellowness index is also very small. Detailed Implementation

[0051] Example

[0052] Example 1

[0053] This embodiment provides a medical protective clothing fabric resistant to gamma radiation. The preparation method of the fabric includes the following steps:

[0054] (1) In a high-temperature and high-pressure reaction environment of 220℃ and 4MPa, 10 parts by weight of modified polypropylene masterbatch and 20 parts by weight of modified polyethylene terephthalate (Jiangsu Sanfangxiang, CZ5011) were dissolved in a mixed solution of dichloromethane and ethanol with a volume ratio of 1:1 to obtain a spinning solution; the weight of the mixed solution was 50% of the total weight of modified polypropylene masterbatch and modified polyethylene terephthalate.

[0055] (2) The spinning solution is ejected from the spinneret of the flash spinning machine and flash spinning is carried out at 55°C. The spinning speed is 18000m / min to obtain composite fibers with a diameter of 5.5 micrometers.

[0056] (3) The obtained composite fibers are thermally bonded to obtain nonwoven fabric.

[0057] The preparation method of modified polypropylene masterbatch is as follows:

[0058] S1. By weight, place 85 parts of polypropylene resin, 1.2 parts of light stabilizer, 1.5 parts of antioxidant, 0.2 parts of zinc stearate and 0.6 parts of radiation stabilizer in a high-speed mixer and mix at 1300 r / min for 6 min.

[0059] S2. Add the mixture to a melt extruder for extrusion granulation and pelletizing; the extruder temperature is 240℃, the die head temperature is 235℃, and the screw speed is 200rpm;

[0060] S3. Under nitrogen protection, using Co 60 - The S2 particles were irradiated by a gamma-ray source at a dose of 10 kGy.

[0061] The polypropylene resin has a melt index of 38 g / 10 min (Ryander Basel, HP563S); the light stabilizer is UV-944 and benzophenone in a mass ratio of 1:1; the antioxidant is 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid; and the radiation stabilizer is barium sulfate and bismuth trioxide in a weight ratio of 2.5:1.

[0062] The bismuth trioxide was modified with a modifier and prepared as follows: Isopropanol and water were mixed in a volume ratio of 2:1, and then the modifier γ-(2,3-epoxypropoxy)propyltrimethoxysilane was added. After stirring and dispersing, bismuth trioxide was added and stirring continued. The mixture was then dried at 80°C and ground. The amount of the modifier was 18% of the weight of the bismuth trioxide. The weight of the isopropanol and water mixture was equal to the weight of the bismuth trioxide. The average particle diameter of the bismuth trioxide was 800 nm.

[0063] The modified polyethylene terephthalate (PET) is formed by melt blending aminated boron nitride and PET, with the amount of aminated boron nitride being 4% of the weight of PET. The preparation of aminated boron nitride involves dispersing γ-aminopropyltriethoxysilane in a 1:1 volume ratio of isopropanol and water, stirring, then adding boron nitride and stirring for 5 hours, followed by filtration and drying. The amount of γ-aminopropyltriethoxysilane is 7% of the weight of boron nitride. The weight of the mixed solution is four times the weight of boron nitride. The average particle diameter of the aminated boron nitride is 500 nm. The boron nitride is hexagonal boron nitride, purchased from Zhengzhou Taixin Chemical Products Co., Ltd.

[0064] Example 2

[0065] This embodiment provides a medical protective clothing fabric resistant to gamma radiation. The preparation method of the fabric includes the following steps:

[0066] (1) In a high-temperature and high-pressure reaction environment of 240℃ and 6MPa, 5 parts by weight of modified polypropylene masterbatch and 50 parts by weight of modified polyethylene terephthalate were dissolved in a mixed solution of dichloromethane and ethanol with a volume ratio of 1:1 to obtain a spinning solution; the weight of the mixed solution was 40% of the total weight of modified polypropylene masterbatch and modified polyethylene terephthalate.

[0067] (2) The spinning solution is ejected from the spinneret of the flash spinning machine and flash spinning is carried out at 60°C. The spinning speed is 20000m / min to obtain composite fibers with a diameter of 2 micrometers.

[0068] (3) The obtained composite fibers are thermally bonded to obtain nonwoven fabric.

[0069] The preparation method of modified polypropylene masterbatch is as follows:

[0070] S1. By weight, place 80 parts of polypropylene resin, 0.5 parts of light stabilizer, 3 parts of antioxidant, 0.5 parts of zinc stearate and 0.3 parts of radiation stabilizer into a high-speed mixer and mix at 1200 r / min for 8 min.

[0071] S2. Add the mixture to a melt extruder for extrusion granulation and pelletizing; the extruder temperature is 250℃, the die head temperature is 245℃, and the screw speed is 180rpm;

[0072] S3. Under nitrogen protection, using Co 60 - The S2 particles were irradiated by a gamma-ray source at a dose of 6 kGy.

[0073] The polypropylene resin has a melt index of 38 g / 10 min (Ryander Basel, HP563S); the light stabilizer is UV-944 and benzophenone in a mass ratio of 1.8:1; the antioxidant is 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid; and the radiation stabilizer is barium sulfate and bismuth trioxide in a weight ratio of 3:1.

[0074] The bismuth trioxide was modified with a modifier and prepared as follows: Isopropanol and water were mixed in a volume ratio of 2:1, and then the modifier γ-(2,3-epoxypropoxy)propyltrimethoxysilane was added. After stirring and dispersing, bismuth trioxide was added and stirring continued. The mixture was then dried at 70°C and ground. The amount of the modifier was 20% of the weight of bismuth trioxide. The weight of the isopropanol and water mixture was equal to the weight of the bismuth trioxide. The average particle diameter of the bismuth trioxide was 500 nm.

[0075] The modified polyethylene terephthalate (PET) is formed by melt blending aminated boron nitride and PET; the amount of aminated boron nitride is 2% of the weight of PET. The preparation of aminated boron nitride is as follows: γ-aminopropyltrimethoxysilane is dispersed in a 1:1 volume ratio of isopropanol and water and stirred; then boron nitride is added and stirred for 6 hours, filtered, and dried. The amount of γ-aminopropyltrimethoxysilane is 8% of the weight of boron nitride. The weight of the mixed solution is 4 times the weight of boron nitride. The average particle diameter of the aminated boron nitride is 300 nm. The boron nitride is hexagonal boron nitride, purchased from Zhengzhou Taixin Chemical Products Co., Ltd.

[0076] Example 3

[0077] This embodiment provides a medical protective clothing fabric resistant to gamma radiation. The preparation method of the fabric includes the following steps:

[0078] (1) In a high-temperature and high-pressure reaction environment of 200℃ and 2MPa, 30 parts by weight of modified polypropylene masterbatch and 15 parts by weight of modified polyethylene terephthalate were dissolved in a mixed solution of dichloromethane and ethanol with a volume ratio of 1:1 to obtain a spinning solution; the weight of the mixed solution was 60% of the total weight of modified polypropylene masterbatch and modified polyethylene terephthalate.

[0079] (2) The spinning solution is ejected from the spinneret of the flash spinning machine and flash spinning is carried out at 40°C. The spinning speed is 16000m / min to obtain composite fibers with a diameter of 10 micrometers.

[0080] (3) The obtained composite fibers are thermally bonded to obtain nonwoven fabric.

[0081] The preparation method of modified polypropylene masterbatch is as follows:

[0082] S1. By weight, place 90 parts of polypropylene resin, 2 parts of light stabilizer, 1 part of antioxidant, 0.1 parts of zinc stearate and 0.8 parts of radiation stabilizer into a high-speed mixer and mix at 1500 r / min for 5 min.

[0083] S2. Add the mixture to a melt extruder for extrusion granulation and pelletizing; the extruder temperature is 220℃, the die head temperature is 245℃, and the screw speed is 260rpm;

[0084] S3. Under nitrogen protection, using Co 60 - The S2 particles were irradiated by a gamma-ray source at a dose of 15 kGy.

[0085] The polypropylene resin has a melt index of 38 g / 10 min (Ryander Basel, HP563S); the light stabilizer is UV-944 and benzophenone in a mass ratio of 0.5:1; the antioxidant is 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid; and the radiation stabilizer is barium sulfate and bismuth trioxide in a weight ratio of 2:1.

[0086] The bismuth trioxide was modified with a modifier and prepared as follows: Isopropanol and water were mixed in a volume ratio of 2:1, and then the modifier γ-(2,3-epoxypropoxy)propyltrimethoxysilane was added. After stirring and dispersing, bismuth trioxide was added and stirring continued. The mixture was then dried at 85°C and ground. The amount of the modifier was 15% of the weight of bismuth trioxide. The weight of the isopropanol and water mixture was equal to the weight of the bismuth trioxide. The average particle diameter of the bismuth trioxide was 1200 nm.

[0087] The modified polyethylene terephthalate (PET) is formed by melt blending aminated boron nitride and PET; the amount of aminated boron nitride is 5% of the weight of PET. The preparation of aminated boron nitride is as follows: γ-aminopropyltriethoxysilane or γ-aminopropyltrimethoxysilane is dispersed in a 1:1 volume ratio of isopropanol and water and stirred; then boron nitride is added and stirred for 2 hours, filtered, and dried. The amount of γ-aminopropyltriethoxysilane or γ-aminopropyltrimethoxysilane is 6% of the weight of boron nitride. The weight of the mixed solution is 3 times the weight of boron nitride. The average particle diameter of the aminated boron nitride is 1000 nm. The boron nitride is hexagonal boron nitride, purchased from Zhengzhou Taixin Chemical Products Co., Ltd.

[0088] Comparative Example 1

[0089] It is basically the same as Example 1, except that: the bismuth trioxide is modified with a modifier, which is γ-(methacryloyloxy)propyltrimethoxysilane.

[0090] Comparative Example 2

[0091] It is basically the same as Example 1, except that the amount of the modifier used is 35% of the weight of bismuth trioxide.

[0092] Comparative Example 3

[0093] It is basically the same as Example 1, except that the melt index of the polypropylene resin at 230℃ / 2.16kg is 25g / 10min (Sinopec, Z30S).

[0094] Comparative Example 4

[0095] It is basically the same as Example 1, except that in the preparation method of the modified polypropylene masterbatch, the irradiation dose of S3 is 18kGy.

[0096] Comparative Example 5

[0097] It is basically the same as Example 1, except that the radiation stabilizer is barium sulfate and bismuth trioxide in a weight ratio of 4:1.

[0098] Comparative Example 6

[0099] It is basically the same as Example 1, except that the boron nitride is cubic boron nitride, which was purchased from Zhengzhou Taixin Chemical Products Co., Ltd.

[0100] Comparative Example 7

[0101] It is basically the same as Example 1, except that the light stabilizer is UV-944 and benzophenone in a mass ratio of 1:3.

[0102] Comparative Example 8

[0103] It is basically the same as Example 1, except that the amount of aminated boron nitride used is 10% of the weight of polyethylene terephthalate.

[0104] Performance testing methods:

[0105] 1. Fabric breaking elongation: Tested according to GB / T 24218.18-2014 standard, and the average of its transverse and longitudinal breaking elongation is recorded as the fabric breaking elongation (X1); the fabric is irradiated with 50kGy and its breaking elongation is measured again (X2).

[0106] 2. Yellow Index: The initial yellow index (Y1) of the fabric is tested according to the test specifications of GB / T 2409; the fabric is then irradiated with an irradiation dose of 40 kGy and placed under conditions of 85°C and 85% humidity for 2 months, and its yellow index (Y2) is measured again.

[0107] Performance test results:

[0108] The test results are shown in Table 1.

[0109] Table 1

[0110]

[0111]

[0112] Analysis of the above data shows that the fabrics prepared in Examples 1-3 of this application have excellent radiation resistance. After irradiation treatment with 50kGy, the breaking strength will decrease less and the yellowing index will not increase much.

[0113] Comparing Example 1 and Comparative Example 1, it can be seen that when the modifier is γ-(methacryloyloxy)propyltrimethoxysilane, the radiation resistance of the fabric decreases. This may be because the absorption of free radicals by methacryloyloxy is lower than that of the epoxy group in γ-(2,3-epoxypropoxy)propyltrimethoxysilane, and its effect on refining polypropylene grains is also poor.

[0114] Comparing Example 1 and Comparative Example 2, it can be seen that the cross-linking effect of the modifier with polypropylene improves the dispersion performance of bismuth trioxide in polypropylene. However, when the amount of modifier is too large, the radiation resistance of the fabric is not significantly improved, and the raw material cost is also increased. This may be because only an appropriate amount of modifier can be effectively incorporated into the microcrystals of polypropylene to refine the grains and achieve the toughening effect.

[0115] Comparing Example 1 and Comparative Example 3, it can be seen that the melt index of polypropylene reflects its molecular weight. When the melt index is low, its molecular weight is relatively high, and the dispersion performance of solid radiation stabilizer is low. At the same time, during the polypropylene modification process, the relative amounts of high molecular weight polypropylene and low molecular weight polypropylene exceed the optimal range, resulting in a decrease in the fabric's flexibility.

[0116] Comparing Example 1 and Comparative Example 4, it can be seen that when the irradiation dose is too high, molecular breakage is more obvious, and the fabric strength is not high.

[0117] Comparing Example 1 and Comparative Example 5, it can be seen that only radiation stabilizers at specific dosages can produce better radiation resistance. On the contrary, when there is too much barium salt, it will increase the crystal formation in the composite fiber, resulting in a decrease in the breaking elongation of the fabric.

[0118] Comparing Example 1 and Comparative Example 6, it can be seen that hexagonal boron nitride has a stronger radiation resistance than cubic boron nitride, possibly because the crystal structure of hexagonal boron nitride enables it to absorb more radiation energy in the vertical direction.

[0119] Comparing Examples 1 and 7, it can be seen that only light stabilizers of specific types and contents can work synergistically with radiation stabilizers to achieve the best anti-radiation effect.

[0120] Comparing Example 1 and Comparative Example 8, it can be seen that increasing the amount of aminated boron nitride can improve radiation resistance, but the high hardness of boron nitride also affects the tensile properties and softness of the fabric.

Claims

1. A medical protective garment fabric resistant to gamma radiation, characterized in that, The fabric is a composite fiber non-woven fabric prepared from modified polypropylene masterbatch and modified polyethylene terephthalate; the modified polypropylene masterbatch component comprises, by weight fraction, 80-90 parts of polypropylene resin, 0.5-2 parts of light stabilizer, 1-3 parts of antioxidant, 0.1-0.5 parts of C12-C30 fatty acid salt and 0.3-0.8 parts of radiation stabilizer; The radiation stabilizer comprises barium salt and bismuth oxide, with a weight ratio of (1-4):1; the bismuth oxide must be modified by a modifier; the modifier is at least one of γ―(2,3-epoxypropoxy) propyl trimethoxysilane, γ-(methacryloyloxy) propyl trimethoxysilane, vinyl tri(2-methoxyethoxy) silane and vinyl triethoxysilane; the amount of the modifier is 10-25% of the weight of the bismuth oxide; The preparation method of the modified polypropylene masterbatch comprises the following steps: S1, mixing the polypropylene resin, light stabilizer, antioxidant, C12-C30 fatty acid salt and radiation stabilizer in a high-speed mixer at 1200-1500 r / min for 5-8 min; S2, extruding and granulating the mixture in a melt extruder, and then cutting the granules; S3, under the protection of nitrogen, irradiating the granules of S2 by a Co60-gamma ray radiation source, with a radiation dose of 6-15 kGy.

2. The medical protective apparel fabric of claim 1, wherein, The modified polyethylene terephthalate is prepared by melt blending aminated boron nitride and polyethylene terephthalate; the preparation of the aminated boron nitride comprises the following steps: dispersing γ-aminopropyl triethoxysilane or γ-aminopropyl trimethoxysilane in a mixed solution of isopropyl alcohol and water, stirring, placing boron nitride in the mixed solution and stirring for 2-6 h, filtering and drying.

3. The medical protective apparel fabric of claim 2, wherein, The amount of the γ-aminopropyl triethoxysilane or γ-aminopropyl trimethoxysilane is 6-8% of the weight of the boron nitride.

4. The medical protective apparel fabric of claim 1 wherein, The light stabilizer is a combination of histamine-based light stabilizer and benzophenone.

5. The medical protective apparel fabric of claim 1 wherein, The antioxidant is at least one of tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester, tris(2,4-di-tert-butylphenyl) phosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid octadecyl ester and 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanuric acid.

6. The method of making a medical protective apparel fabric according to any of claims 1-5, characterized in that, The method comprises the following steps: (1) dissolving the modified polypropylene masterbatch and the modified polyethylene terephthalate in an organic solvent in a high-temperature and high-pressure reaction environment at 200-240℃ and 2-6 MPa to obtain a spinning dope; (2) spraying the spinning dope from the spinneret of a flash spinning machine, and performing flash spinning at a certain temperature to obtain composite fibers with a diameter of 0.2-10 microns; (3) performing thermal bonding treatment on the obtained composite fibers to obtain a non-woven fabric.

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