A low-precipitation medical polypropylene material and its preparation method

Abstract

This application belongs to the technical field of medical material preparation, and specifically relates to a low-leaching medical polypropylene material and a preparation method thereof. A low-leaching medical polypropylene material comprises the following components in parts by mass: 80-95 parts of polypropylene, 6-12 parts of modified reinforcing filler, 15-23 parts of phosphoric acid hyperbranched polyester, 0.3-0.5 part of compound antioxidant, 2-7 parts of plasticizer, 1-3 parts of nucleating agent, and 1-3 parts of antibacterial agent. Among them, the modified reinforcing filler comprises nano silicon carbide whiskers and modified graphene carbon nanotubes. This application improves the problem that medical polypropylene materials are prone to leaching during long-term use, causing potential safety hazards in drug use, and prepares a low-leaching medical polypropylene material, thereby meeting the requirements of medical polypropylene materials, improving the weather resistance and long-term usability of polypropylene materials, preventing aging and leaching, and also preventing drugs such as fungi in dilute solutions.

Description

Technical Field

[0001] This application belongs to the technical field of medical material preparation, and specifically relates to a low-leaching medical polypropylene material and a preparation method thereof. Background Art

[0002] The medical plastics field is one of the most promising markets in the plastics industry at present. In the field of respiratory systems, plastic products related to ventilators are one of the most concentrated application areas of plastics in medical devices. Plastic caps are one of the most used plastic products in the medical device field, and most of these products are prepared from materials such as polyethylene, polyvinyl chloride, polypropylene, and rubber. This type of product is a consumable with a large clinical usage volume. The annual consumption value of such products in China is about hundreds of millions of yuan, and the market is very large. Among them, polypropylene material is a thermoplastic synthetic resin with excellent properties. It is a colorless, translucent thermoplastic lightweight general-purpose plastic with excellent properties. Through modification, it has been widely used in the medical field as a raw material for the preparation of medical devices, infusion bags, syringes, etc.

[0003] Due to the need to contact with medicinal liquids or the human body, the basic requirements for polypropylene materials are chemical stability and biological safety. When using polypropylene medical materials to prepare medical materials, there are also many disadvantages, such as poor mechanical properties and easy precipitation of some low-particle substances, which can be absorbed by humans and cause harm to human health. For example, when pharmaceutical factories inject plastic caps, the containers used for temporary packaging often use modified polypropylene. During the process, it is necessary to prevent the precipitation of plastic caps from causing the precipitation of particulate contaminants and entering the medicinal liquid or the human body, causing toxicity and damage to tissues and organs. It is an urgent technical problem in this field to provide a medical plastic material with low leaching and high safety. Summary of the Invention

[0004] In order to solve the problem that medical polypropylene materials are prone to leaching during long-term use, posing a potential safety hazard to medication, this application provides a low-leaching medical polypropylene material and a preparation method thereof.

[0005] In the first aspect, this application provides a low-leaching medical polypropylene material, adopting the following technical solution:

[0006] A low-leaching medical polypropylene material, comprising the following components in parts by mass: 80 - 95 parts of polypropylene, 6 - 12 parts of modified reinforcing filler, 15 - 23 parts of phosphoric acid hyperbranched polyester, 0.3 - 0.5 part of compound antioxidant, 2 - 7 parts of plasticizer, 1 - 3 parts of nucleating agent, and 1 - 3 parts of antibacterial agent. Among them, the modified reinforcing filler includes nano-silicon carbide whiskers and modified graphene carbon nanotubes.

[0007] By adopting the above technical solutions, through high-temperature melt blending of polypropylene, modified reinforcing filler, and phosphoric acid hyperbranched polyester, the tensile strength and elongation at break of the low-bleeding medical polypropylene material obtained are significantly improved. By modifying the reinforcing filler, the branched structure of the phosphoric acid hyperbranched polyester further disperses the reinforcing filler, preventing material bleeding. The phosphoric acid hyperbranched polyester can enhance the compatibility between polypropylene and the modified reinforcing filler. The branched structure of the phosphoric acid hyperbranched polyester serves as the backbone of the main structure and can further prevent polypropylene from bleeding during long-term use and polluting drugs. The modified reinforcing filler is modified graphene carbon nanotube composite nano-silicon carbide whiskers. Graphene carbon nanotubes are mainly composed of sp2 hybridized carbon atoms, and their crystal region size can reach dozens of micrometers. Therefore, it can more effectively promote the excellent properties of graphene at the microscale to be demonstrated at the macroscale, further improving mechanical properties such as tensile strength. Moreover, graphene carbon nanotubes themselves have dispersibility, and mixing with nano-silicon carbide whiskers with few defects improves the dispersibility of nano-silicon carbide whiskers, thereby improving the filling performance and making the polypropylene material have quite good high-temperature resistance and high strength. The thermal expansion coefficient of nano-silicon carbide whiskers is different from that of polypropylene, which can promote interfacial adhesion in a high-temperature environment and bear greater stress. After microcracks occur in the polypropylene material, closing stress can be applied to the cracked surface to prevent the further expansion of microcracks, thus playing a strengthening role and having a certain anti-aging effect at the same time.

[0008] The flexibility and impact resistance of polypropylene and the overall material are enhanced by a plasticizer to improve the weather resistance of the polypropylene material; by adding a composite antioxidant, antibacterial agent, and nucleating agent, the long-term usability of the polypropylene material is further increased, preventing aging and bleeding, and also preventing contamination by dilute fungi, etc., which may further contaminate drugs.

[0009] In a specific feasible embodiment, the mass ratio of the nano-silicon carbide whiskers to the modified graphene carbon nanotubes is (2 - 5):1.

[0010] By adopting the above technical solutions, through a certain range ratio of nano-silicon carbide whiskers and modified graphene carbon nanotubes, it can more effectively promote the excellent properties of graphene at the microscale to be demonstrated at the macroscale, further improving mechanical properties such as tensile strength. The nano-silicon carbide whiskers can bear greater stress and prevent microcracks from occurring in the polypropylene material. If the content of nano-silicon carbide whiskers is too low, it may make the cracks in the polypropylene material deeper, resulting in chipping and precipitation of fine particles, which may further contaminate drugs.

[0011] Preferably, the mass ratio of polypropylene, modified reinforcing filler, and phosphoric acid hyperbranched polyester is (8 - 9):1:2.

[0012] In a specific feasible embodiment, the preparation method of the phosphorous hyperbranched polyester comprises the following steps: adding nitrilotrimethylenephosphonic acid into water, stirring, and then adding itaconic anhydride, and carrying out stirring and refluxing at a temperature of 100-110°C for 8-14 h to obtain the phosphorous hyperbranched polyester.

[0013] In a specific feasible embodiment, the mass ratio of the nitrilotrimethylenephosphonic acid to the itaconic anhydride is (1.8-2.6):1.

[0014] By adopting the above technical solution, through the reaction of nitrilotrimethylenephosphonic acid and itaconic anhydride, the polymer is further branched, and the branches are rich in hydroxyl groups, which can further interact with the modified reinforcing filler, further disperse the modified filler, and enhance the overall performance of the material. Both ends of the hyperbranched polyester have unsaturated double bonds, which have good compatibility with the flexible chain segments in the structure and can effectively improve the thermodynamic properties of the polypropylene material. Compared with the pure polypropylene material, the tensile strength, flexural strength and impact strength are improved. If there is too much nitrilotrimethylenephosphonic acid, the mechanical properties of the polypropylene material will be affected; if there is too little, the hyperbranching efficiency will be too low, resulting in the precipitation of the reinforcing filler particles.

[0015] In a specific feasible embodiment, the plasticizer is one or both of tributyl acetylcitrate and tricresyl phosphate.

[0016] By adopting the above technical solution, both tributyl citrate and tricresyl phosphate have good compatibility with the polypropylene material. Tributyl citrate has high plasticizing efficiency, excellent cold resistance, light resistance and water resistance; low volatility, and has mildew resistance, and has certain environmental protection performance, and can adjust the properties such as tensile strength, hardness and toughness of the material.

[0017] In a specific feasible embodiment, the antibacterial agent is one or both of nano-titanium dioxide and ammonium dihydrogen phosphate.

[0018] By adopting the above technical solution, the addition of the antibacterial agent can effectively inhibit the growth and reproduction of bacteria, fungi and viruses, and meet the requirements of safety, cleanliness and environmental protection of medical rubber.

[0019] In a specific feasible embodiment, the compound antioxidant comprises antioxidant 627A and antioxidant 1010 with a mass ratio of 1:(1.2-1.8).

[0020] By adopting the above technical solution, through the use of phosphite antioxidant 627A, the stability of the polymer during compounding, production and use can be improved, the degradation of the polymer during processing can be reduced, and the color of the polymer can be well protected. When compounded with phenolic main antioxidants such as antioxidant 1010, the thermal stability of the polymer during processing can be improved.

[0021] In a second aspect, the present application provides a method for preparing a low-bleeding medical polypropylene material, adopting the following technical solution:

[0022] A method for preparing a low-bleeding medical polypropylene material includes the following steps: taking polypropylene, phosphoric acid hyperbranched polyester, and modified reinforcing filler in proportion, mixing them evenly, adding them into a screw extruder, and performing melt kneading at a temperature of 145 - 180 °C; adding a compound antioxidant, a plasticizer, and an antibacterial agent into the screw extruder for continuous extrusion, and water cooling to obtain the low-bleeding medical polypropylene material.

[0023] In summary, the present application has the following beneficial effects:

[0024] 1. By performing high-temperature melt blending of polypropylene, modified reinforcing filler, and phosphoric acid hyperbranched polyester, both the tensile strength and elongation at break of the obtained low-bleeding medical polypropylene material are significantly improved. Through modification of the reinforcing filler, the branched structure of the phosphoric acid hyperbranched polyester further disperses the reinforcing filler, preventing material bleeding. The phosphoric acid hyperbranched polyester can enhance the compatibility between polypropylene and the modified reinforcing filler. The branched structure of the phosphoric acid hyperbranched polyester serves as the framework of the main structure, and further can also prevent polypropylene from bleeding during long-term use and polluting drugs. By adding a plasticizer, the flexibility and impact resistance of polypropylene and the overall material are enhanced, and the weather resistance of the polypropylene material is improved; by adding a compound antioxidant and an antibacterial agent, the long-term usability of the polypropylene material is further increased, preventing aging and bleeding, and also preventing contamination by fungi and the like, thereby polluting drugs.

[0025] 2. Through the reaction of nitrilotrimethylenephosphonic acid and itaconic anhydride, the polymer is further branched, and its branches contain abundant hydroxyl groups that can further interact with the modified reinforcing filler, further dispersing the modified filler and enhancing the overall performance of the material. The two ends of the hyperbranched polyester have unsaturated double bonds and thus have good compatibility with the flexible chain segments in the structure, effectively improving the thermodynamic properties of the polypropylene material. Compared with pure polypropylene materials, the tensile strength, flexural strength, and impact strength are improved. If there is too much nitrilotrimethylenephosphonic acid, it will affect the mechanical properties of the polypropylene material; if there is too little, the hyperbranched efficiency will be too low, and then the reinforcing filler particles will precipitate. Specific Embodiments

[0026] The following further elaborates on the present application in conjunction with embodiments.

[0027] Raw Materials

[0028] Some of the raw materials used in the preparation examples and embodiments:

[0029] Polypropylene (melt index 35 g / 10 min) was purchased from Macklin, the nucleating agent di - O - (benzylidene) - sorbitol was purchased from Hefei Tianjian Chemical Co., Ltd.; nano - silicon carbide whiskers (particle size 50 - 100 nm) were purchased from Hubei Xinyuhong Biomedical Technology Co., Ltd.; graphene carbon nanotubes were purchased from Jinan Jinqianrun New Materials Co., Ltd.; nano - titanium dioxide model: KND - TH100.

[0030] For the related raw materials not specified in the examples and comparative examples, they are all conventional products that can be obtained through market purchase.

[0031] Preparation Example 1

[0032] Preparation of modified graphene carbon nanotubes: Take 50 g of graphene carbon nanotubes, first oxidize the fibers with hot air at 550 - 680 °C for 2 h, then impregnate and activate with 2% titanate coupling agent for 1 h and dry at 120 °C.

[0033] Preparation Example 2

[0034] Preparation of phosphorous acid hyperbranched polyester: Add 18 g of nitrilotrimethylenephosphonic acid to 80 ml of water and stir, then add 10 g of itaconic anhydride, and reflux with stirring at 100 °C for 14 h to obtain phosphorous acid hyperbranched polyester.

[0035] Preparation Example 3

[0036] Preparation of phosphorous acid hyperbranched polyester: Add 18 g of nitrilotrimethylenephosphonic acid to 80 ml of water and stir, then add 10 g of itaconic anhydride, and reflux with stirring at 110 °C for 8 h to obtain phosphorous acid hyperbranched polyester.

[0037] Preparation Example 4

[0038] Preparation of phosphorous acid hyperbranched polyester: Add 30 g of nitrilotrimethylenephosphonic acid to 80 ml of water and stir, then add 10 g of itaconic anhydride, and reflux with stirring at 110 °C for 8 h to obtain phosphorous acid hyperbranched polyester.

[0039] Preparation Example 5

[0040] Preparation of phosphorous acid hyperbranched polyester: Add 15 g of nitrilotrimethylenephosphonic acid to 80 ml of water and stir, then add 10 g of itaconic anhydride, and reflux with stirring at 110 °C for 8 h to obtain phosphorous acid hyperbranched polyester.

[0041] Examples

[0042] Example 1

[0043] A low-precipitation medical polypropylene material comprises the following components: 85 g of polypropylene, 10 g of modified reinforcing filler, 20 g of phosphoric acid hyperbranched polyester prepared in Preparation Example 2, 0.3 g of compound antioxidant, 7 g of plasticizer, 3 g of nucleating agent, and 1 g of antibacterial agent. Among them, the modified reinforcing filler is nano silicon carbide whiskers and modified graphene carbon nanotubes prepared in Preparation Example 1 with a mass ratio of 2:1; the compound antioxidant is antioxidant 627A and antioxidant 1010 with a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; the antibacterial agent is nano titanium dioxide.

[0044] Take polypropylene, phosphoric acid hyperbranched polyester prepared in Preparation Example 2, and modified reinforcing filler in proportion and mix them evenly. Add them into a screw extruder and melt-knead at a temperature of 145 °C; add compound antioxidant, plasticizer, and antibacterial agent into the screw extruder for continuous extrusion, and cool with water to obtain the low-precipitation medical polypropylene material.

[0045] Example 2

[0046] A low-precipitation medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of modified reinforcing filler, 20 g of phosphoric acid hyperbranched polyester prepared in Preparation Example 2, 0.5 g of compound antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent. Among them, the modified reinforcing filler is nano silicon carbide whiskers and modified graphene carbon nanotubes prepared in Preparation Example 1 with a mass ratio of 2:1; the compound antioxidant is antioxidant 627A and antioxidant 1010 with a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; the antibacterial agent is nano titanium dioxide.

[0047] Take polypropylene, phosphoric acid hyperbranched polyester prepared in Preparation Example 2, and modified reinforcing filler in proportion and mix them evenly. Add them into a screw extruder and melt-knead at a temperature of 180 °C; add compound antioxidant, plasticizer, and antibacterial agent into the screw extruder for continuous extrusion, and cool with water to obtain the low-precipitation medical polypropylene material.

[0048] Example 3

[0049] A low-precipitation medical polypropylene material comprises the following components: 95 g of polypropylene, 6 g of modified reinforcing filler, 23 g of phosphoric acid hyperbranched polyester prepared in Preparation Example 2, 0.5 g of compound antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent. Among them, the modified reinforcing filler is nano silicon carbide whiskers and modified graphene carbon nanotubes prepared in Preparation Example 1 with a mass ratio of 2:1; the compound antioxidant is antioxidant 627A and antioxidant 1010 with a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; the antibacterial agent is nano titanium dioxide.

[0050] Take polypropylene, the phosphoric acid hyperbranched polyester prepared in Preparation Example 2, and the modified reinforcing filler in proportion, mix them evenly, add them into a screw extruder, and carry out melt kneading at a temperature of 180 °C; add a compound antioxidant, a plasticizer, and an antibacterial agent into the screw extruder for continuous extrusion, and cool with water to obtain a low-bleed medical polypropylene material.

[0051] Example 4

[0052] A low-bleed medical polypropylene material comprises the following components: 95 g of polypropylene, 16 g of modified reinforcing filler, 13 g of phosphoric acid hyperbranched polyester prepared in Preparation Example 2, 0.5 g of compound antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent. Among them, the modified reinforcing filler is nano-silicon carbide whiskers and modified graphene carbon nanotubes prepared in Preparation Example 1 with a mass ratio of 2:1; the compound antioxidant is antioxidant 627A and antioxidant 1010 with a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; the antibacterial agent is nano-titanium dioxide.

[0053] Take polypropylene, the phosphoric acid hyperbranched polyester prepared in Preparation Example 2, and the modified reinforcing filler in proportion, mix them evenly, add them into a screw extruder, and carry out melt kneading at a temperature of 180 °C; add a compound antioxidant, a plasticizer, and an antibacterial agent into the screw extruder for continuous extrusion, and cool with water to obtain a low-bleed medical polypropylene material.

[0054] Example 5

[0055] A low-bleed medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of modified reinforcing filler, 20 g of phosphoric acid hyperbranched polyester prepared in Preparation Example 2, 0.5 g of compound antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent. Among them, the modified reinforcing filler is nano-silicon carbide whiskers and modified graphene carbon nanotubes prepared in Preparation Example 1 with a mass ratio of 5:1; the compound antioxidant is antioxidant 627A and antioxidant 1010 with a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; the antibacterial agent is nano-titanium dioxide.

[0056] Take polypropylene, the phosphoric acid hyperbranched polyester prepared in Preparation Example 2, and the modified reinforcing filler in proportion, mix them evenly, add them into a screw extruder, and carry out melt kneading at a temperature of 180 °C; add a compound antioxidant, a plasticizer, and an antibacterial agent into the screw extruder for continuous extrusion, and cool with water to obtain a low-bleed medical polypropylene material.

[0057] Example 6

[0058] A low-precipitation medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of modified reinforcing filler, 20 g of phosphoric acid hyperbranched polyester prepared in Preparation Example 2, 0.5 g of compound antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent. Among them, the modified reinforcing filler is a nanosilicon carbide whisker and modified graphene carbon nanotube prepared in Preparation Example 1 with a mass ratio of 1:1; the compound antioxidant is antioxidant 627A and antioxidant 1010 with a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; the antibacterial agent is nanometer titanium dioxide.

[0059] Take polypropylene, phosphoric acid hyperbranched polyester prepared in Preparation Example 2, and modified reinforcing filler in proportion and mix them evenly. Add them into a screw extruder and melt-knead at a temperature of 180 °C; add compound antioxidant, plasticizer, and antibacterial agent into the screw extruder for continuous extrusion, and cool with water to obtain the low-precipitation medical polypropylene material.

[0060] Example 7

[0061] A low-precipitation medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of modified reinforcing filler, 20 g of phosphoric acid hyperbranched polyester prepared in Preparation Example 2, 0.5 g of compound antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent. Among them, the modified reinforcing filler is a nanosilicon carbide whisker and modified graphene carbon nanotube prepared in Preparation Example 1 with a mass ratio of 2:1; the compound antioxidant is antioxidant 627A and antioxidant 1010 with a mass ratio of 1:1.2, the plasticizer is tributyl acetylcitrate and tricresyl phosphate with a mass ratio of 2:1; the antibacterial agent is nanometer titanium dioxide.

[0062] Take polypropylene, phosphoric acid hyperbranched polyester prepared in Preparation Example 2, and modified reinforcing filler in proportion and mix them evenly. Add them into a screw extruder and melt-knead at a temperature of 180 °C; add compound antioxidant, plasticizer, and antibacterial agent into the screw extruder for continuous extrusion, and cool with water to obtain the low-precipitation medical polypropylene material.

[0063] Example 8

[0064] A low-precipitation medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of modified reinforcing filler, 20 g of phosphoric acid hyperbranched polyester prepared in Preparation Example 3, 0.5 g of compound antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent. Among them, the modified reinforcing filler is a nanosilicon carbide whisker and modified graphene carbon nanotube prepared in Preparation Example 1 with a mass ratio of 2:1; the compound antioxidant is antioxidant 627A and antioxidant 1010 with a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; the antibacterial agent is nanometer titanium dioxide.

[0065] Take polypropylene, the phosphoric acid hyperbranched polyester prepared in Preparation Example 3, and the modified reinforcing filler in proportion, mix them evenly, add them into a screw extruder, and carry out melt kneading at a temperature of 180°C; add a compound antioxidant, a plasticizer, and an antibacterial agent into the screw extruder for continuous extrusion, and then cool with water to obtain a low-bleeding medical polypropylene material.

[0066] Example 9

[0067] A low-bleeding medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of modified reinforcing filler, 20 g of phosphoric acid hyperbranched polyester prepared in Preparation Example 4, 0.5 g of compound antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent. Among them, the modified reinforcing filler is nano-silicon carbide whiskers and modified graphene carbon nanotubes prepared in Preparation Example 1 with a mass ratio of 2:1; the compound antioxidant is antioxidant 627A and antioxidant 1010 with a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; the antibacterial agent is nano-titanium dioxide.

[0068] Take polypropylene, the phosphoric acid hyperbranched polyester prepared in Preparation Example 4, and the modified reinforcing filler in proportion, mix them evenly, add them into a screw extruder, and carry out melt kneading at a temperature of 180°C; add a compound antioxidant, a plasticizer, and an antibacterial agent into the screw extruder for continuous extrusion, and then cool with water to obtain a low-bleeding medical polypropylene material.

[0069] Example 10

[0070] A low-bleeding medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of modified reinforcing filler, 20 g of phosphoric acid hyperbranched polyester prepared in Preparation Example 5, 0.5 g of compound antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent. Among them, the modified reinforcing filler is nano-silicon carbide whiskers and modified graphene carbon nanotubes prepared in Preparation Example 1 with a mass ratio of 2:1; the compound antioxidant is antioxidant 627A and antioxidant 1010 with a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; the antibacterial agent is nano-titanium dioxide.

[0071] Take polypropylene, the phosphoric acid hyperbranched polyester prepared in Preparation Example 5, and the modified reinforcing filler in proportion, mix them evenly, add them into a screw extruder, and carry out melt kneading at a temperature of 180°C; add a compound antioxidant, a plasticizer, and an antibacterial agent into the screw extruder for continuous extrusion, and then cool with water to obtain a low-bleeding medical polypropylene material.

[0072] Comparative Example

[0073] Comparative Example 1

[0074] A low-precipitation medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of modified reinforcing filler, 20 g of phosphoric acid hyperbranched polyester prepared in Preparation Example 2, 0.5 g of compound antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent. Among them, the reinforcing filler is nano silicon carbide whiskers and graphene carbon nanotubes with a mass ratio of 2:1; the compound antioxidant is antioxidant 627A and antioxidant 1010 with a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; the antibacterial agent is nano titanium dioxide.

[0075] Take polypropylene, phosphoric acid hyperbranched polyester prepared in Preparation Example 2, and reinforcing filler in proportion, mix them evenly, add them into a screw extruder, and carry out melt kneading at a temperature of 180 °C; add compound antioxidant, plasticizer, and antibacterial agent into the screw extruder for continuous extrusion, and cool with water to obtain the low-precipitation medical polypropylene material.

[0076] Comparative Example 2

[0077] A low-precipitation medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of reinforcing filler, 20 g of phosphoric acid hyperbranched polyester prepared in Preparation Example 2, 0.5 g of compound antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent. Among them, the reinforcing filler is nano silicon carbide whiskers; the compound antioxidant is antioxidant 627A and antioxidant 1010 with a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; the antibacterial agent is nano titanium dioxide.

[0078] Take polypropylene, phosphoric acid hyperbranched polyester prepared in Preparation Example 2, and reinforcing filler in proportion, mix them evenly, add them into a screw extruder, and carry out melt kneading at a temperature of 180 °C; add compound antioxidant, plasticizer, and antibacterial agent into the screw extruder for continuous extrusion, and cool with water to obtain the low-precipitation medical polypropylene material.

[0079] Comparative Example 3

[0080] A low-precipitation medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of modified reinforcing filler, 20 g of phosphoric acid hyperbranched polyester prepared in Preparation Example 2, 0.5 g of compound antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent. Among them, the modified reinforcing filler is modified graphene carbon nanotubes; the compound antioxidant is antioxidant 627A and antioxidant 1010 with a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; the antibacterial agent is nano titanium dioxide.

[0081] Take polypropylene, phosphoric acid hyperbranched polyester prepared in Preparation Example 2, and modified reinforcing filler in proportion, mix them evenly, add them into a screw extruder, and carry out melt kneading at a temperature of 180 °C; add compound antioxidant, plasticizer, and antibacterial agent into the screw extruder for continuous extrusion, and cool with water to obtain the low-precipitation medical polypropylene material.

[0082] Comparative Example 4

[0083] A low-bleeding medical polypropylene material comprises the following components: 110 g of polypropylene, 10 g of modified reinforcing filler, 0.5 g of compound antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent. Among them, the modified reinforcing filler is nanosilicon carbide whiskers and modified graphene carbon nanotubes prepared in Preparation Example 1 with a mass ratio of 2:1; the compound antioxidant is antioxidant 627A and antioxidant 1010 with a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; the antibacterial agent is nano-titanium dioxide.

[0084] Take polypropylene and modified reinforcing filler in proportion and mix them evenly, then add them into a screw extruder and melt-knead at a temperature of 180 °C; add compound antioxidant, plasticizer, and antibacterial agent to the screw extruder for continuous extrusion, and cool with water to obtain the low-bleeding medical polypropylene material.

[0085] Comparative Example 5

[0086] A low-bleeding medical polypropylene material comprises the following components: 100 g of polypropylene, 20 g of phosphoric acid hyperbranched polyester prepared in Preparation Example 2, 0.5 g of compound antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent. Among them, the compound antioxidant is antioxidant 627A and antioxidant 1010 with a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; the antibacterial agent is nano-titanium dioxide.

[0087] Take polypropylene and phosphoric acid hyperbranched polyester prepared in Preparation Example 2 in proportion and mix them evenly, then add them into a screw extruder and melt-knead at a temperature of 180 °C; add compound antioxidant, plasticizer, and antibacterial agent to the screw extruder for continuous extrusion, and cool with water to obtain the low-bleeding medical polypropylene material.

[0088] Performance Testing

[0089] The performance of the medical polypropylene materials prepared in Examples 1-10 and Comparative Examples 1-5 was tested by the following methods:

[0090] a. Tensile strength test: Sample preparation and testing were carried out in accordance with ISO 527 requirements;

[0091] b. Elongation at break test: Sample preparation and testing were carried out in accordance with ISO 527 requirements;

[0092] c. Bleeding test: Appearance change of the medical polypropylene materials prepared in Examples and Comparative Examples after heating in a forced-air drying oven at 80 °C for 24 h; The performance is shown in Table 1:

[0093] Table 1 Performance Test Results

[0094]

[0095]

[0096] As can be seen from Table 1, by comparing Examples 2-4, Examples 8-10 and Comparative Examples 4-5, it can be known that by performing high-temperature melt blending of polypropylene, modified reinforcing filler, and phosphoric acid hyperbranched polyester, the tensile strength and elongation at break of the low-precipitation medical polypropylene material obtained are both significantly improved. By modifying the reinforcing filler, the branched structure of the phosphoric acid hyperbranched polyester further disperses the reinforcing filler to prevent material precipitation. The phosphoric acid hyperbranched polyester can enhance the compatibility between polypropylene and the modified reinforcing filler. The branched structure of the phosphoric acid hyperbranched polyester serves as the backbone of the main structure and can further prevent the precipitation of polypropylene during long-term use and contamination of drugs. When polypropylene, modified reinforcing filler, and phosphoric acid hyperbranched polyester are within a specific proportion range, the modified reinforcing filler and phosphoric acid hyperbranched polyester can play a cross-linking role, and the phosphoric acid hyperbranched polyester forms complex three-dimensional structures such as dendrites, which have a strong physical adsorption and retention effect on easily precipitated components such as polypropylene, thus effectively preventing the precipitation of microparticles from the material surface.

[0097] By comparing Example 2, Examples 5-6 and Comparative Examples 1-3, it can be known that through a certain range of proportions of nano-silicon carbide whiskers and modified graphene carbon nanotubes, it is possible to more effectively promote the excellent properties of graphene at the microscale to be demonstrated at the macroscale, further improving mechanical properties such as tensile strength. The nano-silicon carbide whiskers can withstand greater stress and prevent the generation of microcracks in the polypropylene material. If the content of nano-silicon carbide whiskers is too low, it may cause deeper cracks in the polypropylene material, resulting in flaking and precipitation of microparticles, and further contaminating drugs.

[0098] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A low precipitation medical polypropylene material, characterized in that: The invention comprises the following components in parts by weight: 80-95 parts of polypropylene, 6-12 parts of modified reinforcing filler, 15-23 parts of phosphoric acid hyperbranched polyester, 0.3-0.5 parts of composite antioxidant, 2-7 parts of plasticizer, 1-3 parts of nucleating agent and 1-3 parts of antibacterial agent, wherein the modified reinforcing filler comprises nano silicon carbide whisker and modified graphene carbon nanotubes, nitrilo trimethylene phosphonic acid is added into water and stirred, then itaconic anhydride is added, stirred and refluxed for 8-14 hours at a temperature of 100-110°C to obtain phosphoric acid hyperbranched polyester, wherein the mass ratio of nitrilo trimethylene phosphonic acid to itaconic anhydride is (1.8-2.6): 1; the preparation method of modified graphene carbon nanotubes is as follows: 50g of graphene carbon nanotubes are firstly oxidized by hot air at 550-680°C for 2 hours, then impregnated and activated by 2% titanate coupling agent for 1 hour and then dried at 120°C.

2. The low precipitation medical polypropylene material according to claim 1, characterized in that: The mass ratio of the nano silicon carbide whiskers to the modified graphene carbon nanotubes is (2-5):

1.

3. The low precipitation medical polypropylene material according to claim 1, characterized in that: The plasticizer is one or both of acetyl tributyl citrate and tricresyl phosphate.

4. The low precipitation medical polypropylene material according to claim 1, characterized in that: The antibacterial agent is one or both of nano titanium dioxide and ammonium dihydrogen phosphate.

5. The low precipitation medical polypropylene material according to claim 1, characterized in that: The composite antioxidant comprises antioxidant 627A and antioxidant 1010 in a mass ratio of 1:(1.2-1.8).

6. The method for preparing a low-precipitation medical polypropylene material according to any one of claims 1 to 5, characterized in that: The following steps are involved: Polypropylene, phosphoric acid hyperbranched polyester and modified reinforcing filler are mixed evenly in proportion, added into a screw extruder, and melt-kneaded at a temperature of 145-180°C; a composite antioxidant, a plasticizer and an antibacterial agent are added into the screw extruder for continuous extrusion, and water-cooling is performed to obtain a low-precipitation medical polypropylene material.

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