Self-lubricating PEBAX / TPU material suitable for medical catheter and preparation process of self-lubricating PEBAX / TPU material

Abstract

The invention relates to the technical field of medical materials, in particular to a self-lubricating PEBAX / TPU material suitable for a medical catheter and a preparation process of the self-lubricating PEBAX / TPU material. 8-15 parts of a self-lubricating modified material; 1.5 to 3 parts of an antioxidant complexing agent; and 3-5 parts of a compatilizer. According to the self-lubricating PEBAX / TPU material, fluorocarbon chains are enriched on the surface to form a long-acting low-friction layer through fluorinated polyethylene and hydrophobic nano silicon dioxide, an external coating is not needed, an antioxidant Irganox 1010 and carbodiimide synergistically inhibit oxidation and hydrolysis, the chemical stability is remarkably improved, the compatibility of PEBAX / TPU is improved through maleic anhydride grafted POE, and the self-lubricating PEBAX / TPU material has the advantages that the self-lubricating performance is good; the rigid gradient of the conduit is optimized by combining a multi-layer co-extrusion process, the protein adsorption resistance of the surface is further enhanced through plasma treatment and perfluorosilane grafting, the integrity of the material is guaranteed through accurately controlled low-temperature extrusion and low-dose gamma sterilization, and the material is more stable and reliable while the biological safety is maintained. The synergistic improvement of the lubrication durability, the mechanical property and the aging resistance is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of medical materials, and specifically to a self-lubricating PEBAX / TPU material applicable to medical catheters and its preparation process. Background Technique

[0002] A medical catheter is a flexible tubular instrument inserted into the body cavity or blood vessels of the human body, used for delivering drugs, draining body fluids or assisting in interventional surgeries. The core requirements include biocompatibility, flexibility and surface lubricity to reduce the risk of tissue damage. The PEBAX / TPU material is a polymer material composed of polyether block amide (PEBAX) and thermoplastic polyurethane (TPU). Among them, PEBAX provides excellent low-temperature elasticity and flexibility, while TPU endows the material with tear resistance and mechanical strength. The combination of the two is widely used in the main structure of the catheter, but its traditional form relies on an external coating to achieve lubrication and has insufficient long-term chemical stability.

[0003] The main defects of traditional PEBAX / TPU catheters are that the lubricity depends on a temporary coating that is easily peeled off, resulting in an increase in the friction coefficient over time. The ether bonds of PEBAX are easily oxidized and degraded, and TPU is easily hydrolyzed in body fluids, leading to material embrittlement or biocompatibility risks. In addition, the polarity difference between PEBAX and TPU results in defects at the blend interface, affecting the burst resistance of the catheter.

[0004] Based on this, the present invention provides a self-lubricating PEBAX / TPU material applicable to medical catheters and its preparation process to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a self-lubricating PEBAX / TPU material applicable to medical catheters and its preparation process to solve the problems mentioned in the above background technique.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A self-lubricating PEBAX / TPU material applicable to medical catheters, which is composed of the following raw materials in parts by weight:

[0008] Matrix material: 90 - 110 parts;

[0009] Self-lubricating modification material: 8 - 15 parts;

[0010] Antioxidant composite agent: 1.5 - 3 parts;

[0011] Compatibilizer: 3 - 5 parts;

[0012] The self-lubricating modification material is composed of fluorinated polyethylene and hydrophobically modified nano-silica. The fluorinated polyethylene: 5 - 10 parts, and the hydrophobically modified nano-silica: 3 - 5 parts.

[0013] Preferably, the matrix material is composed of PEBAX 7233 and ether-based TPU, with 60-70 parts of PEBAX 7233 and 30-40 parts of ether-based TPU.

[0014] Preferably, the antioxidant compound is composed of Irganox 1010 and carbodiimide, with 0.5-1.0 parts of Irganox 1010 and 1.0-2.0 parts of carbodiimide.

[0015] Preferably, the compatibilizer is maleic anhydride grafted POE.

[0016] The present invention also provides a preparation process for a self-lubricating PEBAX / TPU material suitable for medical catheters, comprising the following steps:

[0017] S1. Pretreat the raw materials;

[0018] S2. Melt and co-extrude;

[0019] S3. Treat the material surface by argon plasma with a power of 100W for 30 seconds to activate the surface, promote the migration of fluorinated segments to the surface, and enhance hydrophobic lubricity;

[0020] S4. Immerse the material in an ethanol solution containing 1% perfluorooctyltriethoxysilane and react at 60°C for 2 hours to form a covalently bonded perfluoroalkyl surface layer, further improving the anti-protein adsorption ability;

[0021] S5. Perform catheter forming and sterilization.

[0022] Preferably, the implementation steps of step S1 are as follows:

[0023] S1.1. Vacuum dry PEBAX and TPU particles at 80°C for 4 hours to ensure that the water content is less than 0.05%;

[0024] S1.2. Bake nano-silica at 120°C for 2 hours to reduce the surface hydroxyl activity to enhance hydrophobicity;

[0025] S1.3. Pre-mix PFE, nano-silica, antioxidant, hydrolysis stabilizer and compatibilizer into a masterbatch to improve the subsequent dispersion uniformity.

[0026] Preferably, the implementation steps of step S2 are as follows:

[0027] S2.1. Use a co-rotating twin-screw extruder with a length-to-diameter ratio of 40:1, control the screw speed at 200-300 rpm, and set the temperature zones as follows:

[0028] The feeding section is at 160 - 170 °C to prevent premature melting of TPU and cause bridging;

[0029] The melting section is at 190 - 200 °C to fully melt PEBAX / TPU and achieve shear dispersion;

[0030] The mixing section is at 200 - 210 °C to ensure uniform dispersion of nano-fillers in the matrix;

[0031] The die head temperature is at 180 - 190 °C to avoid decomposition of PFE, and its thermal decomposition temperature is higher than 220 °C;

[0032] S2.2. Apply a vacuum degassing of -0.08 MPa at the end of the extruder to remove residual volatiles.

[0033] Preferably, the implementation steps of step S5 are as follows:

[0034] S5.1. Adopt the multi-layer co-extrusion technology. The inner layer uses the modified PEBAX / TPU composite material, and the outer layer is covered with pure PEBAX to improve the adhesion to the blood vessel wall;

[0035] S5.2. In the sterilization stage, use a gamma irradiation dose of ≤25 kGy to avoid the decrease in mechanical properties caused by the breakage of PEBAX molecular chains.

[0036] Compared with the prior art, the beneficial effects of the present invention are:

[0037] The self-lubricating PEBAX / TPU material of the present invention forms a long-lasting low-friction layer by fluorinated polyethylene and hydrophobic nano-silica, making the fluorocarbon chains enrich on the surface without relying on external coatings. The antioxidant Irganox1010 and carbodiimide synergistically inhibit oxidation and hydrolysis, significantly improving chemical stability. Maleic anhydride grafted POE improves the compatibility of PEBAX / TPU. Combining with the multi-layer co-extrusion process optimizes the catheter rigidity gradient. Further strengthening the surface anti-protein adsorption ability through plasma treatment and perfluorosilane grafting. The precisely controlled low-temperature extrusion and low-dose gamma sterilization ensure the material integrity. While maintaining biosecurity, it realizes the synergistic improvement of lubrication durability, mechanical properties and aging resistance, providing a reliable material for high-performance medical catheters. Specific Embodiments

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0039] In the present invention, unless otherwise specified, the materials are commercially available. The present invention provides a self-lubricating PEBAX / TPU material suitable for medical catheters, which is composed of the following raw materials in parts by weight: matrix material: 90 - 110 parts; self-lubricating modification material: 8 - 15 parts; antioxidant composite: 1.5 - 3 parts; compatibilizer: 3 - 5 parts. The self-lubricating modification material is composed of fluorinated polyethylene and hydrophobically modified nano-silica, fluorinated polyethylene: 5 - 10 parts, hydrophobically modified nano-silica: 3 - 5 parts.

[0040] Among them, it should also be noted that the matrix material is composed of PEBAX 7233 and ether-based TPU, PEBAX 7233: 60 - 70 parts, ether-based TPU: 30 - 40 parts. The antioxidant composite is composed of Irganox 1010 and carbodiimide, Irganox 1010: 0.5 - 1.0 part, carbodiimide: 1.0 - 2.0 parts. The compatibilizer is maleic anhydride grafted POE.

[0041] Example: Based on the above self-lubricating PEBAX / TPU material suitable for medical catheters, the present invention also provides a preparation process for the self-lubricating PEBAX / TPU material suitable for medical catheters. Specifically, it includes the following steps:

[0042] S1. Raw material pretreatment:

[0043] S1.1. Pretreatment of PEBAX and TPU particles: For PEBAX7233, take 60 - 70 parts by weight of particles, vacuum dry at 80°C for 4 hours, and the moisture content < 0.05%.

[0044] For ether-based TPU, take 30 - 40 parts by weight of particles and perform synchronous drying treatment under the same conditions as PEBAX.

[0045] S1.2. Pretreatment of nano-silica: For hydrophobically modified nano-SiO2, take 3 - 5 parts by weight, bake at 120°C for 2 hours to reduce the surface hydroxyl activity.

[0046] S1.3. Premixing of masterbatch:

[0047] Premix the following raw materials in proportion: fluorinated polyethylene, PFE: 5 - 10 parts by weight;

[0048] Hydrophobically modified nano-SiO2: 3 - 5 parts by weight;

[0049] Antioxidant composite:

[0050] Irganox1010: 0.5 - 1.0 part by weight;

[0051] Carbodiimide, StabaxolCD: 1.0 - 2.0 parts by weight;

[0052] Compatibilizer, POE-g-MAH: 3-5 parts by weight;

[0053] After mixing evenly, granulate to form masterbatch for standby;

[0054] S2. Melting and blending extrusion:

[0055] S2.1. Process parameters of twin-screw extrusion Matrix material: Dried PEBAX, 60-70 parts, and TPU, 30-40 parts;

[0056] Masterbatch addition: Premixed masterbatch, containing 5-10 parts of PFE, 3-5 parts of nano-SiO2, 0.5-1.0 + 1.0-2.0 parts of antioxidant, and 3-5 parts of compatibilizer;

[0057] Temperature zones:

[0058] Feeding section: 160-170 °C to prevent TPU bridging;

[0059] Melting section: 190-200 °C to melt PEBAX / TPU;

[0060] Mixing section: 200-210 °C to disperse nano-fillers;

[0061] Die head: 180-190 °C to avoid PFE decomposition;

[0062] Screw speed: 200-300 rpm;

[0063] Vacuum devolatilization: -0.08 MPa to remove volatiles;

[0064] S2.2. Composition of blended material:

[0065] Total weight parts of the final extruded material are:

[0066] Matrix material: 90-110 parts, PEBAX + TPU;

[0067] Self-lubricating modification material: 8-15 parts, PFE + nano-SiO2;

[0068] Antioxidant compound: 1.5-3 parts, Irganox1010 + carbodiimide;

[0069] Compatibilizer: 3-5 parts, POE-g-MAH;

[0070] S3. Surface functionalization treatment Argon plasma treatment: 100 W power, 30 seconds, to activate the material surface and promote the migration of the fluorocarbon chains of PFE: 5-10 parts, to the surface to form a low-friction layer;

[0071] S4. Perfluoroalkylsilane grafting. Optionally, immerse the material in an ethanol solution containing 1% perfluorooctyltriethoxysilane (PFOTES) and react at 60 °C for 2 hours to enhance the surface protein adsorption resistance performance, synergistically with 5 - 10 parts of PFE premixed in step S1.3;

[0072] S5. Catheter forming and sterilization

[0073] S5.1. Multilayer co - extrusion forming Inner layer: modified PEBAX / TPU composite material;

[0074] Outer layer: pure PEBAX7233: 60 - 70 parts, to improve the adhesion to the blood vessel wall;

[0075] S5.2. Gamma irradiation sterilization dose ≤ 25 kGy, to avoid the breakage of PEBAX molecular chains, based on the antioxidant protection of 0.5 - 1.0 parts of Irganox1010 in the formulation;

[0076] Verification of the correspondence between the formulation and the process Matrix material ratio: PEBAX7233: 60 - 70 parts, ether - based TPU: 30 - 40 parts;

[0077] Self - lubricating modification material ratio: PFE: 5 - 10 parts, nano - SiO2: 3 - 5 parts;

[0078] Antioxidant composite agent ratio: Irganox1010: 0.5 - 1.0 parts, carbodiimide: 1.0 - 2.0 parts, meeting claim 3;

[0079] Compatibilizer ratio: POE - g - MAH: 3 - 5 parts.

[0080] Example 1. In this example, the components of the self - lubricating PEBAX / TPU material applicable to medical catheters are shown in Table 1:

[0081] Table 1 Components of the self - lubricating PEBAX / TPU material in Example 1

[0082] Component Parts by weight Process parameters PEBAX7233 65 Vacuum drying at 80 °C for 4 hours (moisture < 0.05%) Ether-based TPU 35 Synchronous drying treatment Fluorinated polyethylene (PFE) 8 Premixed masterbatch granulation <![CDATA[Hydrophobic nano-SiO2]]> 4 Baking at 120 °C for 2 hours Irganox1010 0.8 Premixed masterbatch granulation Carbodiimide 1.5 Premixed masterbatch granulation POE-g-MAH 4 Premixed masterbatch granulation

[0083] Prepare the self - lubricating PEBAX / TPU material according to the following preparation process;

[0084] In this example, the extrusion parameters:

[0085] Twin - screw extruder (L / D = 40:1), rotation speed 250 rpm; Temperature zones: feeding section 165 °C, melting section 195 °C, mixing section 205 °C, die head 185 °C; Vacuum devolatilization: - 0.08 MPa.

[0086] Surface treatment parameters: argon plasma (100 W, 30 s); perfluorooctylsilane grafting (1% PFOTES solution, 60 °C / 2 h).

[0087] Sterilization parameters: gamma irradiation dose 25 kGy.

[0088] Comparative Example 1. In this comparative example, the self-lubricating PEBAX / TPU material components applicable to medical catheters are shown in Table 2:

[0089] Table 2 Self-lubricating PEBAX / TPU material components of Comparative Example 1

[0090] Component Parts by weight Process parameters PEBAX7233 65 Same as Example 1 Ether-based TPU 35 Same as Example 1 Fluorinated polyethylene (PFE) 0 Variable <![CDATA[Hydrophobic nano-SiO2]]> 4 Same as Example 1 Irganox1010 0.8 Same as Example 1 Carbodiimide 1.5 Same as Example 1 POE-g-MAH 4 Same as Example 1

[0091] Prepare the self-lubricating PEBAX / TPU material according to the following preparation process;

[0092] In this comparative example, the extrusion parameters are the same as those in Example 1; surface treatment parameters: only argon plasma, no silane grafting, and no covalent layer can be formed due to the absence of PFE;

[0093] The sterilization parameters are the same as those in Example 1;

[0094] Comparative Example 2. In this comparative example, the self-lubricating PEBAX / TPU material components applicable to medical catheters are shown in Table 3:

[0095] Table 3 Self-lubricating PEBAX / TPU material components of Comparative Example 2

[0096]

[0097]

[0098] Prepare the self-lubricating PEBAX / TPU material according to the following preparation process;

[0099] In this comparative example, the extrusion parameters: the temperature of the mixing section is increased to 210 °C (enhanced dispersion); the rest is the same as in Example 1.

[0100] Comparative Example 3. In this comparative example, the self-lubricating PEBAX / TPU material components applicable to medical catheters are shown in Table 4:

[0101] Table 4 Self-lubricating PEBAX / TPU material components of Comparative Example 3

[0102] Component Parts by weight Process parameters PEBAX7233 65 Same as Example 1 Ether-based TPU 35 Same as Example 1 Fluorinated polyethylene (PFE) 8 Same as Example 1 <![CDATA[Hydrophobic nano-SiO2]]> 4 Same as Example 1 Irganox1010 0 Variable Carbodiimide 1.5 Same as Example 1 POE-g-MAH 4 Same as Example 1

[0103] Prepare the self-lubricating PEBAX / TPU material according to the following preparation process;

[0104] In this comparative example, the extrusion parameters: the same as in Example 1;

[0105] Sterilization parameter: Gamma irradiation dose is 25 kGy.

[0106] Comparative Example 4. In this comparative example, the self-lubricating PEBAX / TPU material components applicable to medical catheters are the same as those in Example 1.

[0107] Prepare the self-lubricating PEBAX / TPU material according to the following preparation process;

[0108] Extrusion parameters: The temperature of the melting section is raised to 210 °C; the temperature of the die head is raised to 200 °C; the rest is the same as in Example 1.

[0109] Comparative Example 5. In this comparative example, the self-lubricating PEBAX / TPU material components applicable to medical catheters are the same as those in Example 1.

[0110] Prepare the self-lubricating PEBAX / TPU material according to the following preparation process;

[0111] Sterilization parameter: Gamma irradiation dose is 35 kGy.

[0112] Prepare self-lubricating PEBAX / TPU material samples according to the material components and processes in the above Example 1 and Comparative Examples 1 to 5, and conduct friction coefficient, PEBAX oxidation index, tensile strength, and burst resistance pressure tests on the samples, and record the results in Table 5:

[0113] Table 5 Performance comparison table of Example 1 and Comparative Examples 1 to 5

[0114]

[0115]

[0116] It can be seen from Table 5 that PFE in Comparative Example 1 and nano-SiO2 in Comparative Example 2 are the cores of lubricity and mechanical properties. The antioxidant in Comparative Example 3 is crucial for chemical stability. Among them, the extrusion temperature in Comparative Example 4 needs to be strictly controlled below 200 °C, and a sterilization dose exceeding 25 kGy in Comparative Example 5 will cause irreversible damage. Therefore, combined with Table 5, it can be seen that in the present invention, in Example 1, through the precise matching of components and processes, the optimal balance of performance is achieved. Therefore, Example 1 is the best example.

[0117] In the description of this specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0118] The preferred embodiments of the present invention disclosed above are only used to assist in the description of the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. Self-lubricating PEBAX / TPU material suitable for medical catheters, characterized by: It is composed of the following raw materials in parts by weight: Base material: 90-110 parts; Self-lubricating modified material: 8-15 parts; Antioxidant compound: 1.5-3 parts; Compatibilizer: 3-5 parts; The self-lubricating modified material is composed of fluorinated polyethylene and hydrophobically modified nano-silicon dioxide, wherein the fluorinated polyethylene is 5-10 parts and the hydrophobically modified nano-silicon dioxide is 3-5 parts.

2. The self-lubricating PEBAX / TPU material suitable for medical catheters according to claim 1, characterized in that: The matrix material is composed of PEBAX 7233 and ether-based TPU, wherein the PEBAX 7233 accounts for 60-70 parts and the ether-based TPU accounts for 30-40 parts.

3. The self-lubricating PEBAX / TPU material suitable for medical catheters according to claim 2, characterized in that: The antioxidant composite agent is composed of Irganox 1010 and carbodiimide, wherein the Irganox 1010 is 0.5-1.0 part, and the carbodiimide is 1.0-2.0 part.

4. The self-lubricating PEBAX / TPU material suitable for medical catheters according to claim 3, characterized in that: The compatibilizer is maleic anhydride grafted POE.

5. The process for preparing the self-lubricating PEBAX / TPU material suitable for medical catheters according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Pre-treating the raw materials; S2. Melt and blend extrusion; S3. Activate the material surface by treating with argon plasma at 100W power for 30 seconds, promote the migration of fluorinated segments to the surface, and enhance the hydrophobic lubricity; S4. Immerse the material in an ethanol solution containing 1% perfluorooctyltriethoxysilane and react at 60°C for 2 hours to form a covalently bonded perfluoroalkyl surface layer to further enhance the ability to resist protein adsorption; S5. Perform catheter molding and sterilization.

6. The process for preparing the self-lubricating PEBAX / TPU material suitable for medical catheters according to claim 5, characterized in that: The implementation steps of step S1 are: S1.

1. PEBAX and TPU pellets were vacuum dried at 80°C for 4 hours to ensure that the water content was less than 0.05%; S1.

2. Nano-silica was baked at 120 °C for 2 hours to reduce the activity of surface hydroxyl groups and enhance hydrophobicity; S1.

3. Pre-mix PFE, nano-silica, antioxidant, hydrolysis stabilizer and compatibilizer into a masterbatch to improve subsequent dispersion uniformity.

7. The process for preparing the self-lubricating PEBAX / TPU material suitable for medical catheters according to claim 5, characterized in that: The implementation steps of step S2 are: S2.

1. Use a co-rotating twin-screw extruder with a length-to-diameter ratio of 40:1, the screw speed is controlled at 200-300 rpm, and the temperature zone is set as follows: The feeding section is 160-170℃, which is used to prevent TPU from melting prematurely and causing bridging; Melting stage 190-200℃, used to fully melt PEBAX / TPU and achieve shear dispersion; The mixing section is 200-210°C, which is used to ensure that the nanofillers are evenly dispersed in the matrix; The head temperature is 180-190℃ to avoid the decomposition of PFE, whose thermal decomposition temperature is higher than 220℃; S2.

2. Apply -0.08MPa vacuum devolatilization at the end of the extruder to remove residual volatiles.

8. The process for preparing the self-lubricating PEBAX / TPU material suitable for medical catheters according to claim 5, characterized in that: The implementation steps of step S5 are: S5.

1. Multi-layer co-extrusion technology is used, with the inner layer using modified PEBAX / TPU composite material and the outer layer covered with pure PEBAX to improve adhesion to the blood vessel wall; S5.

2. Use a gamma irradiation dose of ≤25 kGy during the sterilization stage to avoid the degradation of mechanical properties caused by the breakage of the PEBAX molecular chain.

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