Radiation-resistant polypropylene composite material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of composite materials, in particular to an irradiation-resistant polypropylene composite material as well as a preparation method and application thereof, and the composite material comprises the following raw materials in percentage by weight: 59.2-79.8% of polypropylene, 10.0-20.0% of thermoplastic elastomer, 10.0-20.0% of an irradiation-resistant auxiliary agent, 0.1-0.5% of an antioxidant and 0.1-0.3% of an acid neutralizer. Wherein the antioxidant is a benzofuranone type antioxidant. By adding the benzofuranone antioxidant, the radiation-resistant auxiliary agent and the thermoplastic elastomer, the problems that the polypropylene material is not resistant to radiation and poor in toughness are solved, and meanwhile, the problem of yellowing of polypropylene is also solved.

Description

Technical Field

[0001] This invention relates to the field of composite material technology, and in particular to a radiation-resistant polypropylene composite material, its preparation method, and its application. Background Technology

[0002] Polypropylene (PP) is a semi-crystalline thermoplastic polymer made from propylene monomers through an addition polymerization reaction. PP is widely used in the medical device field due to its good biocompatibility, mechanical strength, light weight, low cost, and non-toxicity. The medical industry has high requirements for the radiation resistance, low-temperature resistance, and mechanical properties of PP materials. Unmodified PP has poor radiation resistance, which limits its application in the medical industry to some extent. To improve the radiation resistance of PP materials, commonly used methods include adding hindered amine antioxidants, phosphite antioxidants, and ultraviolet absorbers to the PP system.

[0003] Patent CN103834099A discloses a radiation-resistant medical-grade polypropylene material, which is composed of polypropylene powder, phosphite antioxidants, complex hindered amine light stabilizers, acid removers, and nucleating agents. After being sterilized by irradiation with a high-energy electron accelerator with a radiation dose of 25kGy, it still has high mechanical strength, good transparency, and maintains good whiteness, and can be widely used in the preparation of disposable medical device products.

[0004] Patent CN101967247A discloses a medical polypropylene material, which is based on an ethylene-octene-propylene terpolymer random copolymer, and is made by adding toughening agents, gamma shielding agents, transparent nucleating agents, antioxidants, lubricants, whitening agents and molecular weight regulators in a certain proportion.

[0005] Patent CN102585381A discloses a polypropylene upright soft bottle material for fully enclosed infusion, which has moderate toughness and rigidity, good heat-sealing properties, excellent radiation resistance, good transparency, and high processing efficiency. The material is made by blending polypropylene, polyethylene, radiation-resistant additives, toughening agents, and nucleating agents in a certain proportion, and then extruding the mixture using an extruder to obtain the polypropylene upright soft bottle material for fully enclosed infusion.

[0006] The radiation-resistant PP prepared above can improve the material's radiation resistance, but the radiation-resistant additives are all hindered amine or hindered phenolic additives, which are antioxidants or ultraviolet absorbers. Antioxidants can prevent material degradation and improve radiation resistance under radiation conditions, but hindered phenolic additives will form phenolic products when exposed to radiation, leading to yellowing of the material. Ultraviolet absorbers can absorb energy from certain wavelengths, thus preventing material degradation, but their protective effect is poor for shorter wavelengths in the near-ultraviolet region and even shorter wavelengths of electron beams. The above-mentioned additives have limited effectiveness against electron beam irradiation. Summary of the Invention

[0007] In view of this, the purpose of this invention is to provide a radiation-resistant polypropylene composite material, its preparation method and application, so as to solve the problems of polypropylene material's poor radiation resistance and toughness, and also to solve the problem of polypropylene yellowing.

[0008] To achieve the above objectives, the present invention provides a radiation-resistant polypropylene composite material comprising the following raw materials by weight percentage:

[0009] Polypropylene 59.2-79.8%

[0010] Thermoplastic elastomers 10.0-20.0%

[0011] Radiation-resistant additives 10.0-20.0%

[0012] Antioxidant 0.1-0.5%

[0013] Acid neutralizer 0.1-0.3%;

[0014] The antioxidant is a benzofuranone antioxidant.

[0015] The radiation-resistant additive is styrene-ethylene-butene-styrene.

[0016] The polypropylene is one or both of atactic polypropylene and homopolymer polypropylene.

[0017] The thermoplastic elastomer is one or both of ethylene octene copolymer and styrene-butadiene-styrene copolymer.

[0018] The benzofuranone antioxidants include 5,7-di-tert-butyl-3-(3,4-dimethyl)benzofuran-2(3H)-one.

[0019] The acid neutralizing agent is one or both of calcium stearate and hydrotalcite.

[0020] The present invention also provides a method for preparing the radiation-resistant polypropylene composite material, wherein the method comprises melting and extruding polypropylene, thermoplastic elastomer, radiation-resistant additive, antioxidant and acid neutralizer in accordance with the formula and then granulating to obtain the radiation-resistant polypropylene composite material.

[0021] Preferably, the granulation is carried out by melt extrusion using a twin-screw extruder, with the following temperature conditions: Zone 1: no heating; Zone 2: 170–190°C; Zone 3: 210–230°C; Zones 4–8: 240–260°C; Zones 9–10: 210–230°C; Zones 11–14: 190–210°C; Die head: 170–190°C; Main extruder speed: 400–600 rpm.

[0022] The present invention also provides the application of the radiation-resistant polypropylene composite material in medical device products.

[0023] The beneficial effects of this invention are as follows: By adding benzofuranone antioxidants, radiation-resistant additives, and thermoplastic elastomers, this invention solves the problems of poor radiation resistance and toughness in polypropylene materials, while also addressing the yellowing issue. The prepared material exhibits significantly increased yellowing resistance and toughness, while retaining the good transparency characteristic of atactic polypropylene. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A schematic diagram illustrating the preparation of the sample for Comparative Example 1;

[0026] Figure 2 This is a schematic diagram of the sample preparation in Example 3 of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0028] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects.

[0029] Example 1

[0030] A radiation-resistant polypropylene composite material comprising the following raw materials by weight percentage:

[0031] Polypropylene 79.7%, ethylene octene copolymer 10%, styrene-ethylene-butene-styrene 10%, 5,7-di-tert-butyl-3-(3,4-dimethylyl)benzofuran-2(3H)-one 0.1% and calcium stearate 0.2%.

[0032] The method for preparing the radiation-resistant polypropylene composite material in this embodiment is to melt-extrude and granulate polypropylene, ethylene-octene copolymer, styrene-ethylene-butene-styrene, 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one, and calcium stearate according to the above formula. The temperature conditions are as follows: Zone 1: no heating; Zone 2: 180±10℃; Zone 3: 220±10℃; Zones 4-8: 250±10℃; Zones 9-10: 220±10℃; Zones 11-14: 200±10℃; Die head: 180±10℃; Main engine speed: 500±100 rpm.

[0033] Examples 2-5 and Comparative Example 1 were carried out according to the raw material components and formulation amounts in Table 1 below.

[0034] Table 1

[0035] The polypropylene blends of Examples 1-5 and Comparative Example 1 were injection molded into samples for performance testing. The testing methods are as follows: tensile strength and elongation at break were performed according to DIN EN ISO 527-2 standard at a speed of 50 mm / min; cantilever beam notched impact strength was performed according to DIN EN ISO 180 standard; and the change in yellow index of the color sample after irradiation with a 30 kGy electron beam was performed according to GB / T2409-1998 standard.

[0036] The test results are shown in Table 2 below:

[0037] Table 2

[0038] The performance results from the above examples and comparative examples show that the addition of 5,7-di-tert-butyl-3-(3,4-xylyl)benzofuran-2(3H)-one antioxidant, styrene-ethylene-butene-styrene copolymer, and ethylene-octene copolymer significantly increases the impact strength and significantly reduces the yellowing index of the blends. Therefore, the addition of radiation-resistant additives, antioxidants, and thermoplastic elastomers improves the toughness and radiation resistance of the blends.

[0039] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity. Any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A radiation-resistant polypropylene composite material, characterized in that, The raw materials include the following weight percentages: Polypropylene 59.2-79.8% Thermoplastic elastomers 10.0-20.0% Radiation-resistant additives 10.0-20.0% Antioxidant 0.1-0.5% Acid neutralizer 0.1-0.3%; The antioxidant is a benzofuranone antioxidant.

2. The radiation-resistant polypropylene composite material according to claim 1, characterized in that, The radiation-resistant additive is styrene-ethylene-butene-styrene.

3. The radiation-resistant polypropylene composite material according to claim 1, characterized in that, The polypropylene is one or both of atactic polypropylene and homopolymer polypropylene.

4. The radiation-resistant polypropylene composite material according to claim 1, characterized in that, The thermoplastic elastomer is one or both of ethylene octene copolymer and styrene-butadiene-styrene copolymer.

5. The radiation-resistant polypropylene composite material according to claim 1, characterized in that, The benzofuranone antioxidants include 5,7-di-tert-butyl-3-(3,4-dimethyl)benzofuran-2(3H)-one.

6. The radiation-resistant polypropylene composite material according to claim 1, characterized in that, The acid neutralizing agent is one or both of calcium stearate and hydrotalcite.

7. The method for preparing the radiation-resistant polypropylene composite material according to any one of claims 1-6, characterized in that, The preparation method involves melting and extruding polypropylene, thermoplastic elastomer, radiation-resistant additives, antioxidants, and acid neutralizers according to the formula to obtain a radiation-resistant polypropylene composite material.

8. The method for preparing the radiation-resistant polypropylene composite material according to claim 7, characterized in that, The pellets are melt-extruded using a twin-screw extruder with the following temperature conditions: Zone 1: no heating; Zone 2: 170–190℃; Zone 3: 210–230℃; Zones 4–8: 240–260℃; Zones 9–10: 210–230℃; Zones 11–14: 190–210℃; Die head: 170–190℃; Main extruder speed: 400–600 rpm.

9. The use of the radiation-resistant polypropylene composite material according to any one of claims 1-6 in medical device products.

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