Low-precipitation medical polypropylene material and preparation method thereof

Abstract

The invention belongs to the technical field of medical material preparation, and particularly relates to a low-precipitation medical polypropylene material and a preparation method thereof. The low-precipitation medical polypropylene material comprises the following components in parts by mass: 80-95 parts of polypropylene, 6-12 parts of a modified reinforcing filler, 15-23 parts of phosphoric acid hyperbranched polyester, 0.3-0.5 part of a composite antioxidant, 2-7 parts of a plasticizer, 1-3 parts of a nucleating agent and 1-3 parts of an antibacterial agent, and the modified reinforcing filler comprises nano silicon carbide whiskers and modified graphene carbon nanotubes. The problem that the medical polypropylene material is easy to separate out in the long-term use process and causes potential safety hazards of medication is solved, and the low-separation medical polypropylene material is prepared, so that the requirements of the medical polypropylene material are met, the weather resistance and long-term usability of the polypropylene material are improved, aging separation is prevented, and medicines such as diluted fungi are also prevented.

Description

Technical Field

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

[0002] The field of medical plastics is one of the most promising markets in the current plastics industry. In the field of respiratory systems, plastic products related to ventilators are one of the most concentrated areas of plastic application in medical devices. Plastic covers are one of the most used plastic products in the field of medical devices. Most of these products are made of polyethylene, polyvinyl chloride, polypropylene, rubber and other materials. This type of product is a consumable item with a large clinical dosage. The annual average consumption of this type of product in my country is about several hundred million yuan, and the market is huge. Among them, polypropylene material is a thermoplastic synthetic resin with excellent performance. It is a colorless, translucent, thermoplastic, lightweight general-purpose plastic with excellent performance. Through modification, it has been widely used in the medical field as a raw material for the preparation of medical equipment, infusion bags, syringes, etc.

[0003] Since polypropylene materials need to be in contact with liquid medicine or the human body, the basic requirements are chemical stability and biological safety. Polypropylene medical materials also have many disadvantages in the preparation of medical materials, such as poor mechanical properties and easy precipitation of some low-particle substances, which are absorbed by humans and cause harm to human health. For example, when pharmaceutical factories are injection molding plastic caps, containers used for temporary packaging are often made of modified polypropylene. In the process, the precipitation of plastic caps is avoided to prevent particulate contamination components from precipitating and entering the liquid medicine or the human body, causing toxicity and damage to tissues and organs. It is urgent to provide a medical plastic material with low precipitation and high safety, which is a technical problem that needs to be solved in this field. Summary of the invention

[0004] In order to solve the problem that medical polypropylene materials are prone to precipitation during long-term use, causing hidden dangers in medication safety, the present application provides a low-precipitation medical polypropylene material and a preparation method thereof.

[0005] In the first aspect, the present application provides a low-precipitation medical polypropylene material, which adopts the following technical solution: A low-precipitation medical polypropylene material 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 whiskers and modified graphene carbon nanotubes.

[0006] By adopting the above technical scheme, by high-temperature melt blending of polypropylene, modified reinforcing filler and phosphoric acid hyperbranched polyester, the tensile strength and elongation at break of the obtained low precipitation medical polypropylene material are significantly improved. By modifying the reinforcing filler, the branched structure of phosphoric acid hyperbranched polyester further disperses the reinforcing filler to prevent the material from precipitating. The phosphoric acid hyperbranched polyester can enhance the compatibility of polypropylene and reinforcing modified filler. The phosphoric acid hyperbranched polyester branched structure as the skeleton of the main structure can further prevent the precipitation of polypropylene during long-term use and contaminate the medicine. The modified reinforcing filler modified graphene carbon nanotube composite nano silicon carbide whisker, graphene carbon nanotube is mainly composed of sp2 hybridized carbon atoms, and its crystal area size can reach tens of microns, therefore, it can more effectively promote the excellent properties of graphene microscale to be displayed on the macro scale, so that the mechanical properties such as tensile strength are further improved, and the graphene carbon nanotube itself has dispersibility, and the mixing with nano silicon carbide whisker with few defects improves the dispersibility of nano silicon carbide whisker, thereby improving the filling performance, so that the polypropylene material has quite good high temperature resistance and very high strength. Nano-silicon carbide whiskers have a different thermal expansion coefficient from polypropylene, which can promote interfacial bonding in high temperature environments and withstand greater stress. After microcracks occur in polypropylene materials, closing stress can be added to the cracked surface to prevent further expansion of the microcracks, thereby playing a reinforcing role while also having a certain anti-aging effect.

[0007] The flexibility and impact resistance of polypropylene and the overall material are enhanced by plasticizers, and the weather resistance of polypropylene materials is improved. The long-term usability of polypropylene materials is further increased by adding composite antioxidants, antibacterial agents and nucleating agents, preventing aging precipitation, and preventing contamination such as rare fungi, which in turn contaminates the drugs.

[0008] In a specific implementation manner, the mass ratio of the nano-silicon carbide whiskers to the modified graphene carbon nanotubes is (2-5):1.

[0009] By adopting the above technical scheme, through a certain range of proportions of nano-silicon carbide whiskers and modified graphene carbon nanotubes, the excellent properties of graphene at the microscopic scale can be more effectively promoted to be manifested at the macroscopic scale, so that mechanical properties such as tensile strength are further improved. Nano-silicon carbide whiskers can withstand greater stress and prevent polypropylene materials from generating microcracks. If the content of nano-silicon carbide whiskers is too low, the cracks of the polypropylene material may become deeper, and chips may fall off and particles may be precipitated, thereby contaminating the medicines.

[0010] Preferably, the mass ratio of polypropylene, modified reinforcing filler and phosphoric acid hyperbranched polyester is (8-9):1:2.

[0011] In a specific embodiment, the preparation method of the phosphoric acid hyperbranched polyester comprises the following steps: adding nitrilotrimethylenephosphonic acid into water and stirring, then adding itaconic anhydride, stirring and refluxing at a temperature of 100-110°C for 8-14 hours to obtain the phosphoric acid hyperbranched polyester.

[0012] In a specific embodiment, the mass ratio of the nitrilotrimethylenephosphonic acid to itaconic anhydride is (1.8-2.6):1.

[0013] By adopting the above technical scheme, the polymer is further branched through the reaction of nitrilotrimethylenephosphonic acid and itaconic anhydride, and the rich hydroxyl groups on the side chains can further interact with the modified reinforcing filler, further disperse the modified filler, and enhance the overall performance of the material. The hyperbranched polyester has unsaturated double bonds at both ends, which has good compatibility with the flexible segments in the structure, and can effectively improve the thermodynamic properties of polypropylene materials. Compared with pure polypropylene materials, the tensile strength, bending strength and impact strength are improved. Too much nitrilotrimethylenephosphonic acid will affect the mechanical properties of the polypropylene material, and too little will lead to too low hyperbranching efficiency, which will cause the precipitation of reinforcing filler particles.

[0014] In a specific embodiment, the plasticizer is one or both of acetyl tributyl citrate and tricresyl phosphate.

[0015] By adopting the above technical scheme, tributyl citrate and tricresyl phosphate are both compatible with polypropylene materials, and tributyl citrate has high plasticizing efficiency and excellent cold resistance, light resistance and water resistance; it has low volatility and mildew resistance, has certain environmental protection performance, and can adjust the tensile strength, hardness, toughness and other properties of the material.

[0016] In a specific embodiment, the antibacterial agent is one or both of nano titanium dioxide and ammonium dihydrogen phosphate.

[0017] By adopting the above technical solution, the addition of antibacterial agents can effectively inhibit the growth and reproduction of bacteria, fungi and viruses, ensuring the safety, cleanliness and environmental protection of medical rubber.

[0018] In a specific embodiment, the composite antioxidant includes antioxidant 627A and antioxidant 1010 in a mass ratio of 1:(1.2-1.8).

[0019] By adopting the above technical solution and using the phosphite antioxidant 627A, the stability of the polymer during the batching, production and use process can be improved, the degradation of the polymer during the processing process can be reduced, and the color of the polymer can be well protected. When used in combination with phenolic main antioxidants such as antioxidant 1010, the thermal stability of the polymer processing process can be improved.

[0020] In a second aspect, the present application provides a method for preparing a low-precipitation medical polypropylene material, using the following technical solution: A preparation method of a low-precipitation medical polypropylene material comprises the following steps: taking polypropylene, phosphoric acid hyperbranched polyester and modified reinforcing filler in proportion, mixing them uniformly, adding them into a screw extruder, and melting and kneading them at a temperature of 145-180 DEG C; adding a composite antioxidant, a plasticizer and an antibacterial agent into the screw extruder for continuous extrusion, and water cooling to obtain the low-precipitation medical polypropylene material.

[0021] In summary, this application has the following beneficial effects: 1. By high-temperature melt blending of polypropylene, modified reinforcing filler, and hyperbranched polyester phosphate, the tensile strength and elongation at break of the low-precipitation medical polypropylene material are significantly improved. By modifying the reinforcing filler, the branched structure of the hyperbranched polyester phosphate will further disperse the reinforcing filler to prevent the precipitation of the material. The hyperbranched polyester phosphate can enhance the compatibility of polypropylene and the reinforcing modified filler. The branched structure of the hyperbranched polyester phosphate serves as the skeleton of the main structure, which can further prevent the precipitation of polypropylene during long-term use and contamination of drugs. The flexibility and impact resistance of polypropylene and the overall material are enhanced by plasticizers, and the weather resistance of polypropylene materials is improved; by adding composite antioxidants and antibacterial agents, the long-term use of polypropylene materials is further increased to prevent aging precipitation, and also prevent contamination such as rare fungi, which in turn contaminates drugs.

[0022] 2. Through the reaction of nitrilotrimethylenephosphonic acid and itaconic anhydride, the polymer is further branched. The rich hydroxyl groups on the side chains can further interact with the modified reinforcing filler, further disperse the modified filler, and enhance the overall performance of the material. The hyperbranched polyester has unsaturated double bonds at both ends, which is compatible with the flexible segments in the structure and can effectively improve the thermodynamic properties of polypropylene materials. Compared with pure polypropylene materials, the tensile strength, bending strength and impact strength are improved. Too much nitrilotrimethylenephosphonic acid will affect the mechanical properties of polypropylene materials, and too little will lead to too low hyperbranching efficiency, which will cause the precipitation of reinforcing filler particles. DETAILED DESCRIPTION

[0023] The present application is further described in detail below with reference to the embodiments.

[0024] raw material Some of the raw materials used in the preparation examples and embodiments: Polypropylene (melt index 35 g / 10 min) was purchased from McLean, and 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 Biomedicine Technology Co., Ltd.; graphene carbon nanotubes were purchased from Jinan Jinqianrun New Materials Co., Ltd.; nano-titanium dioxide model: KND-TH100.

[0025] The raw materials used in the examples and comparative examples that are not otherwise specified are all conventional products that can be purchased from the market.

[0026] Preparation Example 1 Preparation of modified graphene carbon nanotubes: 50 g of graphene carbon nanotubes were first oxidized with hot air at 550-680° C. for 2 h, then impregnated and activated with 2% titanate coupling agent for 1 h and dried at 120° C.

[0027] Preparation Example 2 Preparation of phosphoric acid hyperbranched polyester: 18 g of nitrilotrimethylenephosphonic acid was added to 80 ml of water and stirred, followed by addition of 10 g of itaconic anhydride. The mixture was stirred and refluxed at 100° C. for 14 h to obtain phosphoric acid hyperbranched polyester.

[0028] Preparation Example 3 Preparation of phosphoric acid hyperbranched polyester: 18 g of nitrilotrimethylenephosphonic acid was added to 80 ml of water and stirred, followed by adding 10 g of itaconic anhydride. The mixture was stirred and refluxed at 110° C. for 8 h to obtain phosphoric acid hyperbranched polyester.

[0029] Preparation Example 4 Preparation of phosphoric acid hyperbranched polyester: 30 g of nitrilotrimethylenephosphonic acid was added to 80 ml of water and stirred, followed by adding 10 g of itaconic anhydride. The mixture was stirred and refluxed at 110° C. for 8 h to obtain phosphoric acid hyperbranched polyester.

[0030] Preparation Example 5 Preparation of phosphoric acid hyperbranched polyester: 15 g of nitrilotrimethylenephosphonic acid was added to 80 ml of water and stirred, followed by addition of 10 g of itaconic anhydride. The mixture was stirred and refluxed at 110° C. for 8 h to obtain phosphoric acid hyperbranched polyester. Example

[0031] Example 1 A low-precipitation medical polypropylene material comprises the following components: 85 g of polypropylene, 10 g of a modified reinforcing filler, 20 g of a phosphoric acid hyperbranched polyester obtained in Preparation Example 2, 0.3 g of a composite antioxidant, 7 g of a plasticizer, 3 g of a nucleating agent, and 1 g of an antibacterial agent, wherein the modified reinforcing filler is a nano silicon carbide whisker and a modified graphene carbon nanotube obtained in Preparation Example 1 in a mass ratio of 2:1; the composite antioxidant is an antioxidant 627A and an antioxidant 1010 in a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; and the antibacterial agent is nano titanium dioxide.

[0032] Take polypropylene, the hyperbranched phosphate polyester prepared in Preparation Example 2, and the modified reinforcing filler in proportion, mix them evenly, add them to a screw extruder, and melt-knead them at a temperature of 145°C; add a composite antioxidant, a plasticizer, and an antibacterial agent to the screw extruder for continuous extrusion, and water-cooling to obtain a low-precipitation medical polypropylene material.

[0033] Example 2 A low-precipitation medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of a modified reinforcing filler, 20 g of a phosphoric acid hyperbranched polyester obtained in Preparation Example 2, 0.5 g of a composite antioxidant, 2 g of a plasticizer, 1 g of a nucleating agent, and 3 g of an antibacterial agent, wherein the modified reinforcing filler is a nano silicon carbide whisker and a modified graphene carbon nanotube obtained in Preparation Example 1 in a mass ratio of 2:1; the composite antioxidant is an antioxidant 627A and an antioxidant 1010 in a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; and the antibacterial agent is nano titanium dioxide.

[0034] Take polypropylene, the hyperbranched phosphate polyester prepared in Preparation Example 2, and the modified reinforcing filler in proportion, mix them evenly, add them to a screw extruder, and melt-knead them at a temperature of 180°C; add a composite antioxidant, a plasticizer, and an antibacterial agent to the screw extruder for continuous extrusion, and water-cooling to obtain a low-precipitation medical polypropylene material.

[0035] Example 3 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 composite antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent, wherein the modified reinforcing filler is nano silicon carbide whiskers and modified graphene carbon nanotubes prepared in Preparation Example 1 in a mass ratio of 2:1; the composite antioxidant is antioxidant 627A and antioxidant 1010 in a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; and the antibacterial agent is nano titanium dioxide.

[0036] Take polypropylene, the hyperbranched phosphate polyester prepared in Preparation Example 2, and the modified reinforcing filler in proportion, mix them evenly, add them to a screw extruder, and melt-knead them at a temperature of 180°C; add a composite antioxidant, a plasticizer, and an antibacterial agent to the screw extruder for continuous extrusion, and water-cooling to obtain a low-precipitation medical polypropylene material.

[0037] Example 4 A low-precipitation medical polypropylene material comprises the following components: 95 g of polypropylene, 16 g of a modified reinforcing filler, 13 g of a phosphoric acid hyperbranched polyester obtained in Preparation Example 2, 0.5 g of a composite antioxidant, 2 g of a plasticizer, 1 g of a nucleating agent, and 3 g of an antibacterial agent, wherein the modified reinforcing filler is a nano silicon carbide whisker and a modified graphene carbon nanotube obtained in Preparation Example 1 in a mass ratio of 2:1; the composite antioxidant is an antioxidant 627A and an antioxidant 1010 in a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; and the antibacterial agent is nano titanium dioxide.

[0038] Take polypropylene, the hyperbranched phosphate polyester prepared in Preparation Example 2, and the modified reinforcing filler in proportion, mix them evenly, add them to a screw extruder, and melt-knead them at a temperature of 180°C; add a composite antioxidant, a plasticizer, and an antibacterial agent to the screw extruder for continuous extrusion, and water-cooling to obtain a low-precipitation medical polypropylene material.

[0039] Example 5 A low-precipitation medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of a modified reinforcing filler, 20 g of a phosphoric acid hyperbranched polyester obtained in Preparation Example 2, 0.5 g of a composite antioxidant, 2 g of a plasticizer, 1 g of a nucleating agent, and 3 g of an antibacterial agent, wherein the modified reinforcing filler is a nano silicon carbide whisker and a modified graphene carbon nanotube obtained in Preparation Example 1 in a mass ratio of 5:1; the composite antioxidant is an antioxidant 627A and an antioxidant 1010 in a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; and the antibacterial agent is nano titanium dioxide.

[0040] Take polypropylene, the hyperbranched phosphate polyester prepared in Preparation Example 2, and the modified reinforcing filler in proportion, mix them evenly, add them to a screw extruder, and melt-knead them at a temperature of 180°C; add a composite antioxidant, a plasticizer, and an antibacterial agent to the screw extruder for continuous extrusion, and water-cooling to obtain a low-precipitation medical polypropylene material.

[0041] Example 6 A low-precipitation medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of a modified reinforcing filler, 20 g of a phosphoric acid hyperbranched polyester obtained in Preparation Example 2, 0.5 g of a composite antioxidant, 2 g of a plasticizer, 1 g of a nucleating agent, and 3 g of an antibacterial agent, wherein the modified reinforcing filler is a nano silicon carbide whisker and a modified graphene carbon nanotube obtained in Preparation Example 1 in a mass ratio of 1:1; the composite antioxidant is an antioxidant 627A and an antioxidant 1010 in a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; and the antibacterial agent is nano titanium dioxide.

[0042] Take polypropylene, the hyperbranched phosphate polyester prepared in Preparation Example 2, and the modified reinforcing filler in proportion, mix them evenly, add them to a screw extruder, and melt-knead them at a temperature of 180°C; add a composite antioxidant, a plasticizer, and an antibacterial agent to the screw extruder for continuous extrusion, and water-cooling to obtain a low-precipitation medical polypropylene material.

[0043] Example 7 A low-precipitation medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of a modified reinforcing filler, 20 g of a phosphoric acid hyperbranched polyester obtained in Preparation Example 2, 0.5 g of a composite antioxidant, 2 g of a plasticizer, 1 g of a nucleating agent, and 3 g of an antibacterial agent, wherein the modified reinforcing filler is a nano silicon carbide whisker and a modified graphene carbon nanotube obtained in Preparation Example 1 in a mass ratio of 2:1; the composite antioxidant is an antioxidant 627A and an antioxidant 1010 in a mass ratio of 1:1.2; the plasticizer is acetylcitrate tributyl and tricresyl phosphate in a mass ratio of 2:1; and the antibacterial agent is nano titanium dioxide.

[0044] Take polypropylene, the hyperbranched phosphate polyester prepared in Preparation Example 2, and the modified reinforcing filler in proportion, mix them evenly, add them to a screw extruder, and melt-knead them at a temperature of 180°C; add a composite antioxidant, a plasticizer, and an antibacterial agent to the screw extruder for continuous extrusion, and water-cooling to obtain a low-precipitation medical polypropylene material.

[0045] Example 8 A low-precipitation medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of a modified reinforcing filler, 20 g of a phosphoric acid hyperbranched polyester obtained in Preparation Example 3, 0.5 g of a composite antioxidant, 2 g of a plasticizer, 1 g of a nucleating agent, and 3 g of an antibacterial agent, wherein the modified reinforcing filler is a nano silicon carbide whisker and a modified graphene carbon nanotube obtained in Preparation Example 1 in a mass ratio of 2:1; the composite antioxidant is an antioxidant 627A and an antioxidant 1010 in a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; and the antibacterial agent is nano titanium dioxide.

[0046] Take polypropylene, the hyperbranched phosphate polyester prepared in Preparation Example 3, and the modified reinforcing filler in proportion, mix them evenly, add them to a screw extruder, and melt-knead them at a temperature of 180°C; add a composite antioxidant, a plasticizer, and an antibacterial agent to the screw extruder for continuous extrusion, and water-cooling to obtain a low-precipitation medical polypropylene material.

[0047] Example 9 A low-precipitation medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of a modified reinforcing filler, 20 g of a phosphoric acid hyperbranched polyester obtained in Preparation Example 4, 0.5 g of a composite antioxidant, 2 g of a plasticizer, 1 g of a nucleating agent, and 3 g of an antibacterial agent, wherein the modified reinforcing filler is a nano silicon carbide whisker and a modified graphene carbon nanotube obtained in Preparation Example 1 in a mass ratio of 2:1; the composite antioxidant is an antioxidant 627A and an antioxidant 1010 in a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; and the antibacterial agent is nano titanium dioxide.

[0048] Take polypropylene, the hyperbranched phosphate polyester prepared in Preparation Example 4, and the modified reinforcing filler in proportion, mix them evenly, add them to a screw extruder, and melt-knead them at a temperature of 180°C; add a composite antioxidant, a plasticizer, and an antibacterial agent to the screw extruder for continuous extrusion, and water-cooling to obtain a low-precipitation medical polypropylene material.

[0049] Example 10 A low-precipitation medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of a modified reinforcing filler, 20 g of a phosphoric acid hyperbranched polyester obtained in Preparation Example 5, 0.5 g of a composite antioxidant, 2 g of a plasticizer, 1 g of a nucleating agent, and 3 g of an antibacterial agent, wherein the modified reinforcing filler is a nano silicon carbide whisker and a modified graphene carbon nanotube obtained in Preparation Example 1 in a mass ratio of 2:1; the composite antioxidant is an antioxidant 627A and an antioxidant 1010 in a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; and the antibacterial agent is nano titanium dioxide.

[0050] Take polypropylene, the hyperbranched phosphate polyester prepared in Preparation Example 5, and the modified reinforcing filler in proportion, mix them evenly, add them to a screw extruder, and melt-knead them at a temperature of 180°C; add a composite antioxidant, a plasticizer, and an antibacterial agent to the screw extruder for continuous extrusion, and water-cooling to obtain a low-precipitation medical polypropylene material.

[0051] Comparative Example Comparative Example 1 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 obtained in Preparation Example 2, 0.5 g of composite antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent, wherein the reinforcing filler is nano silicon carbide whiskers and graphene carbon nanotubes in a mass ratio of 2:1; the composite antioxidant is antioxidant 627A and antioxidant 1010 in a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; and the antibacterial agent is nano titanium dioxide.

[0052] Take polypropylene, the hyperbranched phosphate polyester prepared in Preparation Example 2, and the reinforcing filler in proportion, mix them evenly, add them to a screw extruder, and melt-knead them at a temperature of 180°C; add a composite antioxidant, a plasticizer, and an antibacterial agent to the screw extruder for continuous extrusion, and water-cooling to obtain a low-precipitation medical polypropylene material.

[0053] Comparative Example 2 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 obtained in Preparation Example 2, 0.5 g of composite antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent, wherein the reinforcing filler is nano silicon carbide whisker; the composite antioxidant is antioxidant 627A and antioxidant 1010 in a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; and the antibacterial agent is nano titanium dioxide.

[0054] Take polypropylene, the hyperbranched phosphate polyester prepared in Preparation Example 2, and the reinforcing filler in proportion, mix them evenly, add them to a screw extruder, and melt-knead them at a temperature of 180°C; add a composite antioxidant, a plasticizer, and an antibacterial agent to the screw extruder for continuous extrusion, and water-cooling to obtain a low-precipitation medical polypropylene material.

[0055] Comparative Example 3 A low-precipitation medical polypropylene material comprises the following components: 90 g of polypropylene, 10 g of a modified reinforcing filler, 20 g of a phosphoric acid hyperbranched polyester obtained in Preparation Example 2, 0.5 g of a composite antioxidant, 2 g of a plasticizer, 1 g of a nucleating agent, and 3 g of an antibacterial agent, wherein the modified reinforcing filler is a modified graphene carbon nanotube; the composite antioxidant is an antioxidant 627A and an antioxidant 1010 in a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; and the antibacterial agent is nano titanium dioxide.

[0056] Take polypropylene, the hyperbranched phosphate polyester prepared in Preparation Example 2, and the modified reinforcing filler in proportion, mix them evenly, add them to a screw extruder, and melt-knead them at a temperature of 180°C; add a composite antioxidant, a plasticizer, and an antibacterial agent to the screw extruder for continuous extrusion, and water-cooling to obtain a low-precipitation medical polypropylene material.

[0057] Comparative Example 4 A low-precipitation medical polypropylene material comprises the following components: 110 g of polypropylene, 10 g of modified reinforcing filler, 0.5 g of composite antioxidant, 2 g of plasticizer, 1 g of nucleating agent, and 3 g of antibacterial agent, wherein the modified reinforcing filler is nano silicon carbide whiskers and modified graphene carbon nanotubes prepared in Preparation Example 1 in a mass ratio of 2:1; the composite antioxidant is antioxidant 627A and antioxidant 1010 in a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate; and the antibacterial agent is nano titanium dioxide.

[0058] Polypropylene and modified reinforcing filler are mixed evenly in proportion, added into a screw extruder, and melt-kneaded at a temperature of 180° C. Composite antioxidant, plasticizer, and antibacterial agent are added into the screw extruder for continuous extrusion, and water-cooled to obtain a low-precipitation medical polypropylene material.

[0059] Comparative Example 5 A low-precipitation medical polypropylene material comprises the following components: 100 g of polypropylene, 20 g of phosphoric acid hyperbranched polyester obtained in Preparation Example 2, 0.5 g of a composite antioxidant, 2 g of a plasticizer, 1 g of a nucleating agent, and 3 g of an antibacterial agent, wherein the composite antioxidant is an antioxidant 627A and an antioxidant 1010 in a mass ratio of 1:1.2, the plasticizer is tricresyl phosphate, and the antibacterial agent is nano titanium dioxide.

[0060] Take polypropylene and the hyperbranched phosphate polyester prepared in Preparation Example 2 in proportion, mix them evenly, add them into a screw extruder, and melt-knead them at a temperature of 180°C; add a composite antioxidant, a plasticizer, and an antibacterial agent into the screw extruder for continuous extrusion, and water-cooling to obtain a low-precipitation medical polypropylene material.

[0061] Performance Testing The performance test of the medical polypropylene materials obtained in Examples 1-10 and Comparative Examples 1-5 was performed using the following method: a. Tensile strength test: Prepare samples and test them according to ISO 527 requirements; b. Elongation at break test: Prepare samples and test them according to ISO 527 requirements; c. Precipitation test: The appearance changes of the medical polypropylene materials obtained in the examples and comparative examples after being heated in a blast drying oven at 80°C for 24 hours; the properties are shown in Table 1: Table 1 Performance test results As can be seen from Table 1, by comparing Examples 2-4 and Examples 8-10 and Comparative Examples 4-5, it can be known that by 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 significantly improved. By modifying the reinforcing filler, the branched structure of the phosphoric acid hyperbranched polyester further disperses the reinforcing filler to prevent the material from precipitating. The phosphoric acid hyperbranched polyester can enhance the compatibility of polypropylene and the reinforcing modified filler. The phosphoric acid hyperbranched polyester branched structure as the skeleton of the main structure can further prevent the precipitation of polypropylene during long-term use and contaminate the medicine. Within a specific ratio range of polypropylene, modified reinforcing filler, and phosphoric acid hyperbranched polyester, the modified reinforcing filler and phosphoric acid hyperbranched polyester can play a cross-linking role, and the phosphoric acid hyperbranched polyester forms a complex three-dimensional structure such as a branch, which has a strong physical adsorption and retention effect on easy-to-precipitate components such as polypropylene, thereby effectively preventing the precipitation of particles from the surface of the material.

[0062] By comparing Example 2 with Examples 5-6 and Comparative Examples 1-3, it can be seen that by using a certain range of proportions of nano-silicon carbide whiskers and modified graphene carbon nanotubes, the excellent properties of graphene at the microscopic scale can be more effectively displayed at the macroscopic scale, so that mechanical properties such as tensile strength are further improved. Nano-silicon carbide whiskers can withstand greater stress and prevent polypropylene materials from generating microcracks. If the content of nano-silicon carbide whiskers is too low, the cracks of the polypropylene material may be deeper, and chips may fall off and particles may be precipitated, thereby contaminating the medicine.

[0063] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in 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 whiskers and modified graphene carbon nanotubes.

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 preparation method of the phosphoric acid hyperbranched polyester comprises the following steps: adding nitrilotrimethylenephosphonic acid into water and stirring, then adding itaconic anhydride, stirring and refluxing at a temperature of 100-110° C. for 8-14 hours to obtain the phosphoric acid hyperbranched polyester.

4. The low precipitation medical polypropylene material according to claim 3, characterized in that: The mass ratio of the nitrilotrimethylenephosphonic acid to itaconic anhydride is (1.8-2.6):

1.

5. 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.

6. 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.

7. 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).

8. The method for preparing a low-precipitation medical polypropylene material according to any one of claims 1 to 7, 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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