A polypropylene composite material and a gamma-ray irradiation-resistant nonwoven fabric

Abstract

This invention discloses a polypropylene composite material and a gamma-ray irradiation-resistant nonwoven fabric. The raw materials of the polypropylene composite material include, by weight, 100 parts polypropylene, 5-15 parts radiation-resistant masterbatch, 5-20 parts thermoplastic elastomer, and 0.05-1 parts antioxidant. The radiation-resistant masterbatch is obtained by mixing polypropylene, hindered amine light stabilizer, and initiator in a weight ratio of 100:2-6:0.1-1.2 and granulating. The polypropylene composite material of this invention has good radiation resistance, maintaining good mechanical properties and yellowing resistance after irradiation. When used in nonwoven fabrics, the resulting nonwoven fabric also has good radiation resistance; for example, after irradiation, the nonwoven fabric is not prone to yellowing and maintains good mechanical properties.

Description

Technical Field

[0001] This invention belongs to the field of polypropylene material technology, and particularly relates to a polypropylene composite material and a gamma-ray irradiation-resistant nonwoven fabric. Background Technology

[0002] Polypropylene is one of the most widely used polymer materials both domestically and internationally. Its advantages, including affordability, odorlessness, non-toxicity, wide availability, excellent mechanical strength, and good chemical stability, have led to its widespread application in numerous fields, such as the medical field. For example, nonwoven fabrics made from polypropylene can be further processed into products such as drapes, surgical packs, surgical gowns, and sterilization drapes. All of these medical supplies require sterilization before use.

[0003] Traditional sterilization methods include high-temperature, high-pressure steam sterilization, ethylene oxide fumigation, and irradiation sterilization. High-temperature, high-pressure methods suffer from incomplete sterilization and are unsuitable for heat-sensitive polymers, while ethylene oxide sterilization requires prolonged desorption and may leave chemical residues. These two methods have significant drawbacks. Currently, the sterilization of medical materials is increasingly trending towards irradiation technology. Irradiation sterilization uses high-energy rays (such as gamma rays) to directly irradiate medical products and kill microorganisms. It offers many advantages, such as energy saving, thorough sterilization, no pollution, rapid sterilization, and continuous operation. Furthermore, irradiation sterilization is a "cold sterilization" method, capable of sterilization at room temperature, making it particularly suitable for some heat-sensitive materials.

[0004] However, ordinary medical-grade polypropylene nonwoven fabrics have poor irradiation stability. After irradiation, the mechanical properties of the product deteriorate, and it is prone to yellowing, eventually losing its usability. This is mainly because the hydrogen atoms on the tertiary carbon atoms in the polypropylene molecular chain are highly reactive and easily generate free radicals when irradiated, leading to chain-splitting reactions, causing the surface to yellow, fade, and degrade, reducing performance. Further degradation can occur after a period of storage following irradiation. Therefore, polypropylene used for irradiation sterilization requires special formulation design to produce medical products that can withstand the high-energy radiation during sterilization.

[0005] Patent CN111393745A discloses a method of using acetone-thiourea to eliminate free radicals generated after polypropylene irradiation; and a combination of phenolic antioxidants, thioester antioxidants, and phosphite antioxidants to prevent or slow down the generation of free radicals during oxidative aging. The resulting polypropylene resin composition exhibits excellent radiation resistance and can meet the requirements for electron beam sterilization of medical nonwoven fabrics. However, in reality, phenolic antioxidants are easily oxidized by free radicals generated during irradiation into quinones and methylquinones, which exacerbate the discoloration of the material. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a polypropylene composite material and a gamma-ray irradiation-resistant nonwoven fabric. The polypropylene composite material exhibits excellent radiation resistance, maintaining good mechanical properties and yellowing resistance even after irradiation. When used in nonwoven fabrics, the resulting nonwoven fabrics also possess excellent radiation resistance; for example, after irradiation, the nonwoven fabrics are not prone to yellowing and exhibit good mechanical properties.

[0007] The present invention proposes a polypropylene composite material, the raw materials of which, by weight, include: 100 parts polypropylene, 5-15 parts radiation-resistant masterbatch, 5-20 parts thermoplastic elastomer, and 0.05-1 parts antioxidant.

[0008] The radiation-resistant masterbatch is obtained by mixing and granulating polypropylene, hindered amine light stabilizer, and initiator in a mass ratio of 100:2-6:0.1-1.2. The structural formula of the hindered amine light stabilizer is shown below:

[0009]

[0010] n is an integer between 1 and 5.

[0011] In this invention, the hindered amine light stabilizer is blended with polypropylene and then thermally crosslinked with an initiator. Since the hindered amine light stabilizer contains unsaturated terminal alkenyl groups, the hindered amine groups can be grafted onto the polypropylene molecular chain via thermal initiation technology. On the one hand, this makes it difficult for the light stabilizer to migrate to the material surface or dissolve and leach out, resulting in a significant enhancement of the light stability of the polypropylene composite material, which plays a role in shielding and absorbing gamma rays (i.e., γ rays). On the other hand, the thermally initiated crosslinking modification also causes the polypropylene to crosslink and form a three-dimensional spatial network structure, stabilizing the molecular chain. At the same time, the generated crosslinked branches can also absorb and convert radiation energy, further improving the radiation resistance of the material.

[0012] Preferably, the polypropylene is homopolymer polypropylene or copolymer polypropylene, and preferably, under conditions of 230°C and 2.16 kg, the melt index is 1-100 g / 10 min.

[0013] Preferably, the hindered amine light stabilizer is prepared by the following method: first, cyanuric chloride and N-n-butyl-2,2,6,6-tetramethyl-4-piperidinamine undergo a nucleophilic substitution reaction, then a nucleophilic substitution reaction is carried out with diallyltriamine, followed by an electrophilic substitution reaction with a terminal alkenyl halide, thereby obtaining the hindered amine light stabilizer.

[0014] Preferably, the structural formula of the terminal alkenyl haloalkane is as follows:

[0015]

[0016] X is Br or Cl, and n is an integer from 1 to 5;

[0017] Preferably, the terminal alkenyl halide is at least one selected from 3-bromo-1-propene, 3-chloro-1-propene, 4-bromo-1-butene, 4-chloro-1-butene, 5-bromo-1-pentene, 5-chloro-1-pentene, 6-bromo-1-hexene, or 6-chloro-1-hexene.

[0018] Preferably, the initiator is at least one selected from dicumyl peroxide, di-tert-butyl peroxide, benzoyl peroxide, or 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0019] Preferably, the radiation-resistant masterbatch is obtained by mixing polypropylene, hindered amine light stabilizer and initiator in a high-speed mixer, and then melt-extruding and granulating it in a twin-screw extruder.

[0020] Preferably, the high-speed mixer has a rotational speed of 800-1000 r / min and a mixing time of 5-10 min; the twin-screw extruder has a screw speed of 100-200 r / min, a feed section temperature of 100-120℃, a melting section temperature of 150-170℃, and a conveying section temperature of 170-190℃.

[0021] Preferably, the thermoplastic elastomer is at least one of hydrogenated polystyrene-butadiene-styrene triblock copolymer, hydrogenated polyethylene-polyisoprene-polystyrene triblock copolymer, ethylene-octene copolymer, or ethylene-propylene copolymer.

[0022] Preferably, the antioxidant is a phosphite antioxidant, and more preferably at least one of antioxidant 168, antioxidant 626, or antioxidant 627.

[0023] Preferably, the polypropylene composite material raw material further includes, by weight: 0.1-1 parts lubricant and 0.05-0.5 parts acid absorber;

[0024] Preferably, the lubricant is at least one of ethylene bis-stearamide, polyethylene wax, oleamide or erucamide, and the acid absorber is at least one of calcium stearate or magnesium aluminum hydrotalcite.

[0025] Preferably, the preparation method of the polypropylene composite material includes: adding polypropylene, radiation-resistant masterbatch, thermoplastic elastomer and antioxidant into a high-speed mixer and mixing them evenly, then adding them into a twin-screw extruder for melt extrusion granulation, and drying them to obtain the polypropylene composite material.

[0026] Preferably, the high-speed mixer has a rotation speed of 1000-1200 r / min and a mixing time of 5-10 min; the twin-screw extruder has a screw speed of 100-200 r / min, a feed section temperature of 120-140℃, a melting section temperature of 150-170℃, and a conveying section temperature of 180-200℃; the drying temperature is 80-100℃, and the drying time is 4-6 h.

[0027] The present invention also proposes a gamma-ray resistant nonwoven fabric, which is made of the above-mentioned polypropylene composite material.

[0028] Compared with the prior art, the present invention has the following technical effects:

[0029] (1) The polypropylene composite material of the present invention includes polypropylene, radiation-resistant masterbatch, thermoplastic elastomer and antioxidant. Since the radiation-resistant masterbatch is obtained by blending and modifying polypropylene with hindered amine light stabilizer under the initiator, combined with thermoplastic elastomer and polypropylene, and with the synergistic effect of antioxidant, the polypropylene composite material has good radiation resistance. After irradiation, it still maintains good mechanical properties and yellowing resistance.

[0030] (2) The polypropylene composite material of the present invention, after being irradiated with 50KGy dose of gamma rays, has a tensile yield strength (MPa) that decreases by no more than 2%, a flexural modulus (MPa) that increases by no more than 2% after irradiation, and a yellow index that increases by no more than 20% after irradiation.

[0031] (3) When the polypropylene composite material described in this invention is applied to nonwoven fabric, the nonwoven fabric has good radiation resistance. For example, after irradiation, the nonwoven fabric is not easy to yellow and has good mechanical properties, which is beneficial to the use of nonwoven fabric in the medical field. Attached Figure Description

[0032] Figure 1 This is a synthetic route diagram of the hindered amine light stabilizer described in the embodiments of the present invention. Detailed Implementation

[0033] The present invention will now be described in detail through specific embodiments. However, these embodiments are clearly provided for illustrative purposes and are not intended to limit the scope of the present invention.

[0034] In the embodiments, the hindered amine light stabilizer is prepared by the following method:

[0035] Reference Figure 1The synthetic route involved dissolving cyanuric chloride (18.44 g, 100 mmol) in toluene (200 mL), slowly adding N-n-butyl-2,2,6,6-tetramethyl-4-piperidinamine (42.46 g, 200 mmol) under an ice-water bath, stirring for 2 h, then adding dropwise 20 mL of an aqueous solution containing sodium hydroxide (8.00 g, 200 mmol), heating to 70 °C and stirring for 12 h, cooling to room temperature, and extracting three times with water and ethyl acetate. The organic phases were combined, dried, and the solvent was removed by rotary evaporation to obtain compound A.

[0036] Compound A was dissolved in toluene (200 mL), and an aqueous solution (1500 mL) containing sodium hydroxide (400.0 g, 10 mol) was added. Then, diallyltriamine (6.56 g, 50 mmol) was added. The mixture was heated to 110 °C under nitrogen protection and stirred for 16 h. After cooling to room temperature, the mixture was separated, the solvent was removed by rotary evaporation, washed with water, and dried to obtain compound B.

[0037] Compound B was dissolved in dichloromethane (150 mL), and 3-bromo-1-propene (6.05 g, 50 mmol) and triethylamine (7.59 g, 75 mmol) were added. The mixture was heated to 45 °C and stirred for 2 h. After cooling to room temperature, water was added, the mixture was separated, the solvent was removed by rotary evaporation, washed with water, dried, and purified by column chromatography with hexane / ethyl acetate to obtain compound TM, which is the hindered amine light stabilizer.

[0038] The proton NMR spectra of the above-mentioned hindered amine light stabilizers are as follows: 1 H NMR(400MHz, CDCl3)δ5.87(s,1H),5.17(m,2H),5.05-5.01(m,4H),4.09-4.03(m,2H),3.37-3.32 (m,8H),3.06(m,12H),2.30(m,10H),1.66-1.59(m,24H),1.29-1.12(m,52H),0.95-0.90(m,12H).

[0039] Example 1

[0040] This embodiment proposes a polypropylene composite material, the raw materials of which, by weight, include: 100 parts of polypropylene (LG R6400), 10 parts of radiation-resistant masterbatch, and ethylene-octene copolymer (Dow ENGAGE). TM 7447) 10 parts and antioxidant 1680.1 parts;

[0041] The radiation-resistant masterbatch is prepared by mixing polypropylene (LG R6400), hindered amine light stabilizer, and dicumyl peroxide in a mass ratio of 100:4:0.5 in a high-speed mixer at a speed of 900 r / min for 8 min, followed by melt extrusion granulation in a twin-screw extruder at a screw speed of 150 r / min, a feed section temperature of 110°C, a melt section temperature of 160°C, and a conveying section temperature of 180°C.

[0042] The preparation method of the polypropylene composite material includes: mixing 100 parts of polypropylene (LG R6400), 10 parts of radiation-resistant masterbatch, and ethylene-octene copolymer (Dow ENGAGE). TM 10 parts of 7447 and 1680.1 parts of antioxidant were added to a high-speed mixer and mixed evenly. The high-speed mixer speed was 1100 r / min and the mixing time was 8 min. Then, the mixture was added to a twin-screw extruder for melt extrusion granulation. The screw speed of the twin-screw extruder was 150 r / min, the feed section temperature was 130℃, the melt section temperature was 160℃, and the conveying section temperature was 190℃. After drying at 90℃ for 5 h, the polypropylene composite material was obtained.

[0043] Example 2

[0044] This embodiment proposes a polypropylene composite material, the raw materials of which include, by weight: 100 parts of polypropylene (LG R6400), 5 parts of radiation-resistant masterbatch, 20 parts of hydrogenated polystyrene-butadiene-styrene triblock copolymer (Kerteng G1652) and 6261 parts of antioxidant.

[0045] The radiation-resistant masterbatch is prepared by mixing polypropylene (LG R6400), hindered amine light stabilizer, and dicumyl peroxide in a mass ratio of 100:6:1.2 in a high-speed mixer at a speed of 800 r / min for 10 min, followed by melt extrusion granulation in a twin-screw extruder at a screw speed of 100 r / min, a feed section temperature of 120°C, a melt section temperature of 150°C, and a conveying section temperature of 190°C.

[0046] The preparation method of the polypropylene composite material includes: adding 100 parts of polypropylene (LG R6400), 5 parts of radiation-resistant masterbatch, 20 parts of hydrogenated polystyrene-butadiene-styrene triblock copolymer (Kerteng G1652) and 6261 parts of antioxidant to a high-speed mixer and mixing them evenly. The high-speed mixer speed is 1000 r / min and the mixing time is 10 min. Then, the mixture is added to a twin-screw extruder for melt extrusion granulation. The twin-screw extruder screw speed is 200 r / min, the feed section temperature is 120℃, the melt section temperature is 170℃, and the conveying section temperature is 200℃. After drying at 80℃ for 6 h, the polypropylene composite material is obtained.

[0047] Example 3

[0048] This embodiment proposes a polypropylene composite material, the raw materials of which include, by weight: 100 parts of polypropylene (LG R6400), 15 parts of radiation-resistant masterbatch, 5 parts of ethylene-octene copolymer (Dow ENGAGE™ 7447), 0.05 parts of antioxidant 627, 0.5 parts of oleamide and 0.1 parts of calcium stearate;

[0049] The radiation-resistant masterbatch is prepared by mixing polypropylene (LG R6400), hindered amine light stabilizer, and dicumyl peroxide in a mass ratio of 100:2:0.1 in a high-speed mixer at a speed of 1000 r / min for 5 min, followed by melt extrusion granulation in a twin-screw extruder at a screw speed of 200 r / min, a feed section temperature of 100°C, a melt section temperature of 170°C, and a conveying section temperature of 190°C.

[0050] The preparation method of the polypropylene composite material includes: adding 100 parts of polypropylene (LG R6400), 15 parts of radiation-resistant masterbatch, 5 parts of ethylene-octene copolymer (Dow ENGAGE™ 7447), 0.05 parts of antioxidant 627, 0.5 parts of oleamide, and 0.1 parts of calcium stearate to a high-speed mixer and mixing them evenly. The high-speed mixer speed is 1200 r / min, and the mixing time is 5 min. Then, the mixture is added to a twin-screw extruder for melt extrusion granulation. The screw speed of the twin-screw extruder is 200 r / min, the feed section temperature is 140℃, the melt section temperature is 150℃, and the conveying section temperature is 180℃. After drying at 100℃ for 4 h, the polypropylene composite material is obtained.

[0051] Comparative Example 1

[0052] This comparative example presents a polypropylene composite material, the raw materials of which, by weight, include: 100 parts polypropylene (LG R6400), 9440.4 parts light stabilizer, and ethylene-octene copolymer (Dow ENGAGE). TM 7447) 10 parts and antioxidant 1680.1 parts.

[0053] The preparation method of the polypropylene composite material includes: 100 parts of polypropylene (LG R6400), 9440.4 parts of light stabilizer, and ethylene-octene copolymer (Dow ENGAGE). TM10 parts of 7447 and 1680.1 parts of antioxidant were added to a high-speed mixer and mixed evenly. The high-speed mixer speed was 1100 r / min and the mixing time was 8 min. Then, the mixture was added to a twin-screw extruder for melt extrusion granulation. The screw speed of the twin-screw extruder was 150 r / min, the feed section temperature was 130℃, the melt section temperature was 160℃, and the conveying section temperature was 190℃. After drying at 90℃ for 5 h, the polypropylene composite material was obtained.

[0054] Comparative Example 2

[0055] This comparative example presents a polypropylene composite material, the raw materials of which, by weight, include: 100 parts polypropylene (LG R6400), 10 parts radiation-resistant masterbatch, and ethylene-octene copolymer (Dow ENGAGE). TM 7447) 10 parts and antioxidant 1680.1 parts;

[0056] The radiation-resistant masterbatch is prepared by mixing polypropylene (LG R6400), light stabilizer 119, and dicumyl peroxide in a mass ratio of 100:4:0.5 in a high-speed mixer at a speed of 900 r / min for 8 min, followed by melt extrusion granulation in a twin-screw extruder at a screw speed of 150 r / min, a feed section temperature of 110°C, a melt section temperature of 160°C, and a conveying section temperature of 180°C.

[0057] The preparation method of the polypropylene composite material includes: mixing 100 parts of polypropylene (LG R6400), 10 parts of radiation-resistant masterbatch, and ethylene-octene copolymer (Dow ENGAGE). TM 10 parts of 7447 and 1680.1 parts of antioxidant were added to a high-speed mixer and mixed evenly. The high-speed mixer speed was 1100 r / min and the mixing time was 8 min. Then, the mixture was added to a twin-screw extruder for melt extrusion granulation. The screw speed of the twin-screw extruder was 150 r / min, the feed section temperature was 130℃, the melt section temperature was 160℃, and the conveying section temperature was 190℃. After drying at 90℃ for 5 h, the polypropylene composite material was obtained.

[0058] Comparative Example 3

[0059] This comparative example presents a polypropylene composite material, the raw materials of which, by weight, include: 100 parts polypropylene (LG R6400), 10 parts radiation-resistant masterbatch, and ethylene-octene copolymer (Dow ENGAGE). TM 7447) 10 parts and antioxidant 1680.1 parts;

[0060] The radiation-resistant masterbatch is prepared by mixing polypropylene (LG R6400), compound B, and dicumyl peroxide in a mass ratio of 100:4:0.5 in a high-speed mixer at a speed of 900 r / min for 8 min, followed by melt extrusion granulation in a twin-screw extruder at a screw speed of 150 r / min, a feed section temperature of 110°C, a melt section temperature of 160°C, and a conveying section temperature of 180°C.

[0061] The preparation method of the polypropylene composite material includes: mixing 100 parts of polypropylene (LG R6400), 10 parts of radiation-resistant masterbatch, and ethylene-octene copolymer (Dow ENGAGE). TM 10 parts of 7447 and 1680.1 parts of antioxidant were added to a high-speed mixer and mixed evenly. The high-speed mixer speed was 1100 r / min and the mixing time was 8 min. Then, the mixture was added to a twin-screw extruder for melt extrusion granulation. The screw speed of the twin-screw extruder was 150 r / min, the feed section temperature was 130℃, the melt section temperature was 160℃, and the conveying section temperature was 190℃. After drying at 90℃ for 5 h, the polypropylene composite material was obtained.

[0062] The polypropylene composite materials obtained in Examples 1-3 and Comparative Examples 1-3 were injection molded at high speed using an injection molding machine (standard plates with a thickness of 1 mm and mechanical specimens of standard dimensions). The properties before and after irradiation in a cobalt source (absorbed dose of 30 kGy, dose rate of 0.114 kGy / min) were tested. The results are shown in Table 1 below.

[0063] Table 1. Radiation resistance of the polypropylene composite materials described in the examples and comparative examples.

[0064]

[0065]

[0066] In Table 1 above, tensile yield strength was measured according to ISO 527-1 standard; flexural modulus was measured according to ISO-178 standard; cantilever beam impact strength was measured according to GB / T 1843-2008 standard; yellow index was measured according to GB / T 2409-1998 standard; and haze was measured according to GB / T 2410-2008 standard.

[0067] The test data above show that, due to the optimized formulation, the polypropylene composite material described in this invention still exhibits excellent mechanical properties and resistance to yellowing after being irradiated with a large dose of gamma rays.

[0068] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A polypropylene composite material, characterized in that, Its raw materials, by weight, include: 100 parts polypropylene, 5-15 parts radiation-resistant masterbatch, 5-20 parts thermoplastic elastomer, and 0.05-1 parts antioxidant; The radiation-resistant masterbatch is obtained by mixing and granulating polypropylene, hindered amine light stabilizer, and initiator in a mass ratio of 100:2-6:0.1-1.

2. The structural formula of the hindered amine light stabilizer is shown below: n is an integer between 1 and 5.

2. The polypropylene composite material according to claim 1, characterized in that, The polypropylene is homopolymer polypropylene or copolymer polypropylene, and the homopolymer polypropylene or copolymer polypropylene has a melt index of 1-100 g / 10 min under the conditions of 230℃ and 2.16 kg.

3. The polypropylene composite material according to claim 1 or 2, characterized in that, The hindered amine light stabilizer was prepared by the following method: first, cyanuric chloride and N-n-butyl-2,2,6,6-tetramethyl-4-piperidinamine were subjected to a nucleophilic substitution reaction, then a nucleophilic substitution reaction was carried out with diallyltriamine, and then an electrophilic substitution reaction was carried out with a terminal alkenyl halide, thereby obtaining the hindered amine light stabilizer. The structural formula of the terminal alkenyl haloalkane is shown below: X is Br or Cl, and n is an integer from 1 to 5.

4. The polypropylene composite material according to claim 3, characterized in that, The terminal alkenyl halide is at least one of 3-bromo-1-propene, 3-chloro-1-propene, 4-bromo-1-butene, 4-chloro-1-butene, 5-bromo-1-pentene, 5-chloro-1-pentene, 6-bromo-1-hexene, or 6-chloro-1-hexene.

5. The polypropylene composite material according to claim 1 or 2, characterized in that, The initiator is at least one of dicumyl peroxide, di-tert-butyl peroxide, benzoyl peroxide, or 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

6. The polypropylene composite material according to claim 1 or 2, characterized in that, The radiation-resistant masterbatch is obtained by mixing polypropylene, hindered amine light stabilizer and initiator in a high-speed mixer, and then melt-extruding and granulating it in a twin-screw extruder.

7. The polypropylene composite material according to claim 6, characterized in that, The high-speed mixer operates at 800-1000 r / min and has a mixing time of 5-10 min; the twin-screw extruder operates at 100-200 r / min, with a feed section temperature of 100-120℃, a melting section temperature of 150-170℃, and a conveying section temperature of 170-190℃.

8. The polypropylene composite material according to claim 1 or 2, characterized in that, The thermoplastic elastomer is at least one of hydrogenated polystyrene-butadiene-styrene triblock copolymer, hydrogenated polyethylene-polyisoprene-polystyrene triblock copolymer, ethylene-octene copolymer, or ethylene-propylene copolymer.

9. The polypropylene composite material according to claim 1 or 2, characterized in that, The antioxidant is at least one of antioxidant 168, antioxidant 626, or antioxidant 627.

10. The polypropylene composite material according to claim 1 or 2, characterized in that, Its raw materials, by weight, also include: 0.1-1 parts lubricant and 0.05-0.5 parts acid absorbent.

11. The polypropylene composite material according to claim 10, characterized in that, The lubricant is at least one of ethylene bis-stearamide, polyethylene wax, oleamide or erucamide, and the acid absorber is at least one of calcium stearate or magnesium aluminum hydrotalcite.

12. The polypropylene composite material according to claim 1 or 2, characterized in that, The preparation method of the polypropylene composite material includes: adding polypropylene, radiation-resistant masterbatch, thermoplastic elastomer and antioxidant into a high-speed mixer and mixing them evenly, then adding them into a twin-screw extruder for melt extrusion granulation, and drying them to obtain the polypropylene composite material.

13. The polypropylene composite material according to claim 12, characterized in that, The high-speed mixer operates at 1000-1200 r / min, with a mixing time of 5-10 min; the twin-screw extruder operates at 100-200 r / min, with a feed section temperature of 120-140℃, a melting section temperature of 150-170℃, and a conveying section temperature of 180-200℃; the drying temperature is 80-100℃, and the drying time is 4-6 h.

14. A gamma-ray irradiation-resistant nonwoven fabric, characterized in that, It is made of the polypropylene composite material according to any one of claims 1-13.

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