Preparation method and application of hydrophobic radiation-resistant polypropylene

Abstract

The invention relates to hydrophobic radiation-resistant polypropylene, which is prepared from the following raw materials in parts by mass: 70 to 90 parts of polypropylene resin, 5 to 15 parts of elastomer, 0 to 5 parts of cross-linking agent and 0.05 to 0.2 part of antioxidant. The elastomer, the cross-linking agent and the antioxidant are added in the formula, and the super-hydrophobic property is achieved on the basis of irradiation sterilization in an irradiation cross-linking mode, so that the hydrophobic property is greatly improved. The problem that the medical polypropylene material has super-hydrophobic performance while being subjected to irradiation sterilization is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a preparation method of super-hydrophobic radiation-resistant polypropylene and application thereof. Background Art

[0002] Inspired by the biological characteristics of lotus leaves and cicada wings, new functional materials with special wettability have attracted extensive attention in many fields such as biology, physics, chemistry and mechanics. Due to their hydrophobic surface wetting properties, they have shown great application prospects in self-cleaning, fluid drag reduction, oil-water separation, waterproofing and anti-icing.

[0003] Polypropylene (PP) is a thermoplastic resin made by polymerization of propylene. It is one of the most widely used synthetic resins at home and abroad, with the fastest production growth. It has the advantages of wide source, light weight and low price, non-toxic and odorless, high strength, good thermal stability and chemical stability, and is widely used in various fields. However, the surface chemical energy of pure PP material is relatively high, resulting in its poor hydrophobicity. In addition, polypropylene, as a raw material for the synthesis of some medical products, needs to be effectively sterilized before use. The most common sterilization methods include high temperature sterilization, ethylene oxide sterilization (EO), etc. for effective sterilization, but the disadvantages are also extremely obvious. At the same time, the method of irradiation sterilization has gradually been valued by people, using high-energy rays generated by electrical radiation such as gamma rays, X-rays and electron beams to achieve the purpose of sterilization.

[0004] When some medical products are used, they not only need to have excellent radiation resistance, but also super-hydrophobic function. Therefore, the preparation of super-hydrophobic radiation-resistant medical products has broad application prospects. In existing patents, there have been certain studies on the radiation resistance and super-hydrophobic function of polypropylene, such as patent publication number CN111518356A, but there is no medical polypropylene material that is both super-hydrophobic and radiation-resistant. Summary of the invention

[0005] In view of the above-mentioned super-hydrophobic radiation-resistant new polypropylene material, the present invention provides a method for preparing a hydrophobic radiation-resistant polypropylene material. The method improves the hydrophobicity while performing radiation sterilization by adding an elastomer, a cross-linking agent, etc., and changing the ratio of reactant raw materials and process conditions, and using different irradiation doses to improve the hydrophobicity, thereby achieving the preparation of a hydrophobic radiation-resistant polypropylene material.

[0006] To achieve the above object, the present invention adopts the following technical solution: A hydrophobic radiation-resistant polypropylene, the raw materials of which include polypropylene resin, elastomer, crosslinking agent and antioxidant, and the mass fractions of each raw material are: Polypropylene resin: 70-90 parts Polyolefin elastomer: 5-15 parts Cross-linking agent: 0-5 parts Antioxidant: 0.05-0.2 parts According to the present invention, the selected polypropylene is any one or more of copolymer polypropylene (PPR or PPB) and homopolypropylene (PPH), and the polypropylene melt flow index is in the range of 10-30 g / 10 min.

[0007] According to the present invention, the selected polyolefin elastomer is any one of SEBS, TPE and TPV.

[0008] According to the present invention, the cross-linking agent is any one of TAIC (triallyl isocyanate), HEA (2-hydroxyethyl acrylate), and HPA (hydroxypropyl acrylate).

[0009] According to the present invention, the ratio of the selected elastomer and the cross-linking agent is preferably 1:1 to 4:1 by mass.

[0010] According to the present invention, the antioxidant selected is a combination of a main antioxidant and an auxiliary antioxidant, and the main antioxidant is selected from any one of antioxidant 1010 (pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate) and antioxidant 702 (4,4'-methylenebis(2,6-di-tert-butylphenol)); The auxiliary antioxidant is selected from any one of the antioxidants DSTP (distearyl thiodipropionate), antioxidant 168 (tris(2,4-di-tert-butyl)phenyl phosphite), and antioxidant 9228 (bis(2,4-dicumylphenyl)pentaerythritol-diphosphite).

[0011] The present invention also provides a method for preparing the hydrophobic radiation-resistant polypropylene, which comprises an extrusion granulation process and an injection molding process.

[0012] According to the present invention, the extrusion granulation process is as follows: Add polypropylene resin, elastomer, crosslinking agent and antioxidant in a high-speed mixer in a certain ratio and mix them evenly to obtain a mixture. Add the mixture into the feeding hopper of the twin-screw extruder, set the temperature of each zone and the screw speed, and extrude and granulate.

[0013] Preferably, the aspect ratio of the twin-screw extruder is 40, and the temperatures of the zones are: 60-80°C in zone 1, 100-160°C in zone 2, 190-210°C in zone 3, 200-220°C in zone 4, 200-220°C in zone 5, 200-220°C in zone 6, 200-220°C in zone 7, 190-210°C in zone 8, 190-210°C in zone 9, 200-220°C in zone 10, and 190-210°C in die head. The screw speed is 200-400r / min, and the main feeding speed is 20-30Hz.

[0014] According to the present invention, the injection molding process is as follows: The extruded particles are injection molded in a single-screw injection molding machine at set temperature, injection pressure and speed to obtain a hydrophobic radiation-resistant polypropylene product.

[0015] Preferably, the injection molding machine sets the temperature of each zone as follows: zone 1 170-190° C., zone 2 170-190° C., zone 3 170-190° C., and nozzle 170-190° C. The injection pressure is 20-30 MPa, and the injection speed is 40-50%.

[0016] According to the present invention, the hydrophobic radiation-resistant polypropylene can be applied to biological pipettes and storage plates.

[0017] According to the present invention, the product has excellent water-repellent performance after being irradiated with 25-100 kGy high-energy rays.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention adds an elastomer, a cross-linking agent and an antioxidant to the formula, and uses radiation cross-linking to achieve super-hydrophobicity on the basis of radiation sterilization, thereby greatly improving the hydrophobicity. This solves the problem of medical polypropylene materials having super-hydrophobicity while being irradiated and sterilized. DETAILED DESCRIPTION

[0019] The essential contents of the present invention are further described below through specific embodiments.

[0020] Embodiments 1 to 13 Add polypropylene resin, elastomer, crosslinking agent and antioxidant to a high-speed mixer in a certain ratio and mix them evenly to obtain a mixture. Add the mixture to the main feeding hopper of the twin-screw extruder, set the temperature of each zone to 60-80℃ for zone 1, 100-160℃ for zone 2, 190-210℃ for zone 3, 200-220℃ for zone 4, 200-220℃ for zone 5, 200-220℃ for zone 6, 200-220℃ for zone 7, 190-210℃ for zone 8, 190-210℃ for zone 9, 200-220℃ for zone 10, and 190-210℃ for die head. The screw speed is 200-400r / min, the main feeding speed is 20-30Hz, and extrusion granulation is carried out.

[0021] The brands of main raw materials are: PPR-160 from Hongji Petrochemical; SEBS-G1643M from Kraton, USA, TPE-5280 from M. Holland; TPV-8281 from Santoping, USA; and the rest are commercially available.

[0022] The extruded particles are processed and molded by a single screw injection molding machine, and the temperature of each zone is set to 170-190°C for zone 1, 170-190°C for zone 2, 170-190°C for zone 3, 170-190°C for nozzle, 20-30MPa for injection pressure, and 40-50% for injection speed.

[0023] The above products were irradiated with a 5MeV electron accelerator at irradiation doses of 25 kGy, 50 kGy, and 100 kGy. After the irradiation, hydrophobic radiation-resistant polypropylene products were obtained and tested.

[0024] The raw material composition is calculated by weight, as shown in Table 1:

[0025] The raw material composition of Comparative Example 1 is the same as that of Example 1, except that no elastomer is added; the preparation method of Comparative Example 1 is exactly the same as that of Example.

[0026] The raw material composition of Comparative Example 2 is the same as that of Example 1, except that no crosslinking agent is added; the preparation method of Comparative Example 2 is exactly the same as that of Example 1.

[0027] The raw material composition of Comparative Example 3 is the same as that of Example 1, except that no antioxidant is added; the preparation method of Comparative Example 3 is exactly the same as that of Example 1.

[0028] The raw material composition of Comparative Example 4 is exactly the same as that of Example 1, and the preparation method of Comparative Example 4 is the same as that of Example 1, except that no irradiation is performed.

[0029] The products prepared in the above examples and comparative examples were tested for water contact angle (WCA) and yellowness index (YI). The test results are listed in Table 2.

[0030]

[0031] According to the results in Table 2, it can be seen from Examples 1 to 13 that the formulation provided by the present invention has a good hydrophobic radiation resistance effect.

[0032] By comparing Comparative Example 1 and Example 1, it can be seen that the contact angle without adding the elastomer is significantly lower than that with adding the elastomer. The addition of the elastomer allows the cross-linking agent to cross-link the resin matrix and the elastomer to form a three-network structure with a special structure, thereby improving the hydrophobic effect.

[0033] By comparing Comparative Example 2 and Example 1, it can be seen that without adding a crosslinking agent, the contact angle is significantly lower than that with adding a crosslinking agent. Without the addition of a crosslinking agent, the elastomer and the resin matrix do not produce a good crosslinking synergistic effect, resulting in a decrease in the contact angle.

[0034] By comparing Comparative Example 3 and Example 1, it can be seen that the contact angle of the material with the addition of antioxidant increases and the yellowness index decreases; the addition of antioxidant enhances the radiation resistance of the material, but reduces the hydrophobicity.

[0035] By comparing Comparative Example 4 and Example 1, it can be seen that the contact angle of the unirradiated material is lower than that of the irradiated sample. Due to the irradiation effect, the crosslinking agent crosslinks the resin matrix and the elastomer to each other, thereby improving the hydrophobic effect. The preparation method of the hydrophobic radiation-resistant polypropylene material provided by the present invention adds an elastomer, a crosslinking agent and an antioxidant to the resin, and irradiates it under certain irradiation conditions, so that its hydrophobicity is greatly improved while having radiation resistance. The polypropylene material has both hydrophobicity and radiation resistance.

Claims

1. A hydrophobic radiation-resistant polypropylene, characterized in that: The composition and content of raw materials (by mass) are as follows: Polypropylene resin: 70-90 parts Polyolefin elastomer: 5-15 parts Cross-linking agent: 0-5 parts Antioxidant: 0.05-0.2 parts.

2. The hydrophobic radiation-resistant polypropylene according to claim 1, characterized in that: The polypropylene resin grade is any one or more of copolymer polypropylene (PPR or PPB) and homopolypropylene (PPH); the polypropylene melt flow index is in the range of 10-30g / 10min.

3. The hydrophobic radiation-resistant polypropylene according to claim 1, characterized in that: The polyolefin elastomer is any one of SEBS, TPE and TPV; the density of the selected polyolefin elastomer is 0.85-0.95g / cm 3 scope.

4. The hydrophobic radiation-resistant polypropylene according to claim 1, characterized in that: The crosslinking agent is any one of TAIC (triallyl isocyanate), HEA (2-hydroxyethyl acrylate), and HPA (hydroxypropyl acrylate).

5. The hydrophobic radiation-resistant polypropylene according to claim 1, characterized in that: The antioxidant is a combination of a main antioxidant and an auxiliary antioxidant; the main antioxidant is selected from any one of antioxidant 1010 (tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester) and antioxidant 702 (4,4'-methylenebis(2,6-di-tert-butylphenol)); the auxiliary antioxidant is selected from any one of antioxidant DSTP (distearyl thiodipropionate), antioxidant 168 (tris(2,4-di-tert-butyl)phenyl phosphite) and antioxidant 9228 (bis(2,4-dicumylphenyl)pentaerythritol-diphosphite).

6. The hydrophobic radiation-resistant polypropylene according to claim 1, characterized in that: The mass ratio of the elastomer to the cross-linking agent is 1:1 to 4:

1.

7. A method for preparing the hydrophobic radiation-resistant polypropylene according to any one of claims 1 to 6, characterized in that: The preparation method of the hydrophobic radiation-resistant polypropylene comprises an extrusion granulation process and an injection molding process.

8. The method for preparing the hydrophobic radiation-resistant polypropylene according to claim 7, characterized in that: The extrusion granulation process is as follows: polypropylene resin, elastomer, crosslinking agent and antioxidant are added to a high-speed mixer in a certain ratio and mixed evenly to obtain a mixture. The mixture is added to the feeding hopper of the twin-screw extruder, and the temperature and screw speed of each zone are set for extrusion granulation; the aspect ratio of the twin-screw extruder is 40, and the temperatures of each zone are: 60-80°C in zone 1, 100-160°C in zone 2, 190-210°C in zone 3, 200-220°C in zone 4, 200-220°C in zone 5, 200-220°C in zone 6, 200-220°C in zone 7, 190-210°C in zone 8, 190-210°C in zone 9, 200-220°C in zone 10, and the die head is 190-210°C. The screw speed is 200-400r / min, and the main feeding speed is 20-30Hz; The injection molding process is as follows: the extruded particles are dried and then injection molded in a single screw injection molding machine at a set temperature, injection pressure and speed to obtain a hydrophobic radiation-resistant polypropylene product; the temperature of each zone of the injection molding machine is: 170-190°C for zone 1, 170-190°C for zone 2, 170-190°C for zone 3, and 170-190°C for the nozzle. The injection pressure is 20-30MPa, and the injection speed is 40-50%.

9. The hydrophobic radiation-resistant polypropylene material according to any one of claims 1 to 6, characterized in that: The polypropylene material can be applied to biological pipettes and biological storage plates.

10. The hydrophobic radiation-resistant biological pipette and biological storage plate according to claim 9, characterized in that: The product is irradiated before use, with the irradiation dose ranging from 25-100kGy.

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