Dustproof antibacterial thermoplastic polyurethane elastomer material as well as preparation method and application thereof

Abstract

The invention discloses a dustproof antibacterial thermoplastic polyurethane elastomer material as well as a preparation method and application thereof. The dustproof antibacterial thermoplastic polyurethane elastomer material is prepared from the following components in parts by mass: 60 to 70 parts of fluorine-containing polyether glycol, 20 to 30 parts of diisocyanate, 2 to 5 parts of N-TiO2-coated PEG-PDMS and 0.5 to 2 parts of silver zinc zeolite. Through molecular-level collaborative design of four functional components including fluorine-containing polyether glycol (F-PEG), dynamic crosslinking diisocyanate (SSDI), core-shell structure N-TiO2 (at) PEG-PDMS and silver zinc zeolite, improvement of antibacterial performance in different environments is realized, and the fluorine-containing polyether glycol-based antibacterial material is suitable for preparing medical catheters and / or guide wires. And meanwhile, the problem that the antibacterial property and the stability are reduced due to the addition of excessive additives is also solved.

Description

Technical Field

[0001] This invention relates to the field of medical materials technology, and in particular to a dustproof and antibacterial thermoplastic polyurethane elastomer material, its preparation method, and its application. Background Technology

[0002] In the field of interventional devices such as medical catheters and guidewires, thermoplastic polyurethane (TPU) has become a core material due to its excellent flexibility and biocompatibility. However, bacteria can easily grow and form biofilms on the surface of catheters that have been left in place for a long time, leading to the risk of infection.

[0003] Traditional solutions often achieve antibacterial properties through physical blending of silver ions or nano-zinc oxide, but these methods have significant drawbacks. For example, simple compounding of hydrophobic and antibacterial agents leads to interfacial delamination, and the hydrophobic properties of the material rapidly degrade after immersion in bodily fluids. Furthermore, high concentrations of antibacterial particles (8%-12%) cause localized stress concentration, making the catheter prone to cracking or even breakage when bent. Existing technologies lack a systematic design for long-term antibacterial and mechanical durability of materials in complex human environments (such as high blood humidity, tissue fluid penetration, and darkness), making it difficult to meet clinical needs.

[0004] To address the aforementioned contradictions, there is an urgent need to develop a thermoplastic polyurethane elastomer material solution to improve the antibacterial effect of polyurethane elastomer materials in different environments. Summary of the Invention

[0005] In view of this, this application provides a dustproof and antibacterial thermoplastic polyurethane elastomer material, its preparation method and application, to solve the problem of how to improve the antibacterial effect of polyurethane elastomer materials in different environments.

[0006] To achieve the above technical objectives, this application adopts the following technical solution: In a first aspect, this application provides a dustproof and antibacterial thermoplastic polyurethane elastomer material, comprising the following components in parts by weight: 60-70 parts of fluorinated polyether diol, 20-30 parts of diisocyanate, 2-5 parts of N-TiO2@PEG-PDMS, and 0.5-2 parts of silver-zinc zeolite. The fluorinated polyether diol is prepared from polyethylene glycol and perfluorooctyl ethanol as raw materials.

[0007] Secondly, this application provides a method for preparing a dustproof and antibacterial thermoplastic polyurethane elastomer material, comprising the following steps: S1. Using polyethylene glycol and perfluorooctyl ethanol as raw materials, a heating reaction is carried out to obtain a fluorinated polyether diol; S2. Under the action of a chain extender, a polymerization reaction is carried out using fluorinated polyether diol and diisocyanate as raw materials to obtain TPU prepolymer; S3. Dissolve N-TiO2 and PEG-PDMS in supercritical CO2, then inject the TPU prepolymer melt and depressurize to obtain a TPU melt containing N-TiO2@PEG-PDMS; S4. Mix silver-zinc zeolite with TPU melt containing N-TiO2@PEG-PDMS and perform melt blending extrusion to obtain dustproof and antibacterial thermoplastic polyurethane elastomer material.

[0008] Preferably, in step S1, the molecular weight of polyethylene glycol is 2000; the molar ratio of polyethylene glycol to perfluorooctyl ethanol is 1:2-4.

[0009] Preferably, in step S2, the chain extender is 1,4-butanediol and cystamine hydrochloride in a mass ratio of 2-4:1.

[0010] Preferably, in step S3, the depressurization rate is 8-10 MPa / s; the pressure of supercritical CO2 is 10-20 MPa, and the temperature is 50-60℃.

[0011] Preferably, in step S4, the temperature program for melt blending extrusion is: 170°C in zone 1, 180°C in zone 2, 185°C in zone 3, and 190°C at the die.

[0012] Preferably, in step S4, the silver-zinc zeolite is prepared by immersing the zeolite in a mixture of AgNO3 and Zn(NO3)2 for ion exchange, thereby obtaining the silver-zinc zeolite.

[0013] Preferably, the PDMS segment content in PEG-PDMS is 60-80 wt%.

[0014] Preferably, the molar ratio of AgNO3 to Zn(NO3)2 is 1:1-2.

[0015] Thirdly, this application provides the application of a dustproof and antibacterial thermoplastic polyurethane elastomer material in medical catheters and / or guidewires.

[0016] The beneficial effects of this application are as follows: This application achieves improved antibacterial performance under different environments through the molecular-level synergistic design of four functional components: fluorinated polyether diol (F-PEG), dynamically cross-linked diisocyanate (SSDI), core-shell structured N-TiO2@PEG-PDMS, and silver-zinc zeolite. It is suitable for the preparation of medical catheters and / or guidewires, and also solves the problem of decreased antibacterial performance and stability caused by adding too many additives. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0018] This application provides a dustproof and antibacterial thermoplastic polyurethane elastomer material, comprising the following components in parts by weight: 60-70 parts of fluorinated polyether diol, 20-30 parts of diisocyanate, 2-5 parts of N-TiO2@PEG-PDMS, and 0.5-2 parts of silver zinc zeolite.

[0019] This application provides a method for preparing a dustproof and antibacterial thermoplastic polyurethane elastomer material, comprising the following steps: S1. Using polyethylene glycol and perfluorooctyl ethanol as raw materials, a heating reaction is carried out to obtain a fluorinated polyether diol; S2. Under the action of a chain extender, a polymerization reaction is carried out using fluorinated polyether diol and diisocyanate as raw materials to obtain TPU prepolymer; S3. Dissolve N-TiO2 and PEG-PDMS in supercritical CO2, then inject the TPU prepolymer melt and depressurize to obtain a TPU melt containing N-TiO2@PEG-PDMS; S4. Mix silver-zinc zeolite with TPU melt containing N-TiO2@PEG-PDMS and perform melt blending extrusion to obtain dustproof and antibacterial thermoplastic polyurethane elastomer material.

[0020] This application achieves enhanced multi-mode antibacterial performance through the molecular-level synergistic design of four functional components: fluorinated polyether diol (F-PEG), dynamically cross-linked diisocyanate (SSDI), core-shell structured N-TiO2@PEG-PDMS, and silver-zinc zeolite.

[0021] In this structure, the F-PEG fluorinated backbone serves as the structural framework, with its two ends consisting of perfluorooctyl segments (-CF3) forming a hydrophobic barrier through strong dipole interactions, inhibiting the adhesion of dust and microorganisms in dry environments. The ether bond oxygen atoms in the backbone interact with the Ag supported by the silver-zinc zeolite. + / Zn 2+ The formation of dynamic coordination bonds serves both as anchoring points for the dispersion of antibacterial agents and as a means of controlling the migration rate of metal ions through ion slow-release equilibrium.

[0022] The disulfide bonds (-SS-) in the SSDI dynamic crosslinking network endow the material with reversible decrosslinking properties at high temperatures, ensuring the stability of antimicrobial agent distribution during recycling.

[0023] The N-TiO2@PEG-PDMS core-shell structure achieves antibacterial properties under different environments: when the ambient humidity increases, the hydrophilic segments of PEG in the core-shell structure swell with water molecules, while the hydrophobic segments of PDMS shrink towards the core, leading to increased exposure of N-TiO2. N-TiO2 promotes increased generation of reactive oxygen species (ROS), achieving rapid oxidation and killing of surface-attached bacteria. Simultaneously, the hydrophilic microenvironment formed by the swelling of PEG segments accelerates the oxidation of Ag in silver-zinc zeolite. + / Zn 2+ ion exchange, Ag + Zn disrupts the integrity of bacterial membrane proteins by binding to their sulfhydryl groups. 2+ This competitively inhibits the activity of microbial metalloenzymes, forming a synergistic killing effect. Additionally, under high humidity, the F-PEG ether bond interacts with Ag... + The coordination strength of Ag weakens, prompting some Ag to + The PDMS molecules migrate to the material surface, replenishing the local antibacterial concentration, while the elastic deformation of the SSDI crosslinked network provides a diffusion path for this process. Under low humidity or dark conditions, PDMS segments extend outward to form a dense hydrophobic shell. Nitrogen-doped sites on the N-TiO2 surface capture free electrons from the environment, forming a local negative potential region under dark conditions. This interferes with electron transport in the bacterial respiratory chain, reducing the ATP synthesis efficiency of aerobic bacteria such as Staphylococcus aureus. Furthermore, the PDMS shell compresses the ion release channels of silver-zinc zeolite, causing Ag... + The migration rate is reduced, which continuously inhibits biofilm formation and avoids cytotoxicity caused by high concentrations of silver ions. In addition, the superhydrophobic surface formed by the synergistic effect of F-PEG fluorinated segments and PDMS significantly reduces the physical adsorption of microorganisms.

[0024] Meanwhile, the fluorinated segments of the F-PEG in this application anchor the silver-zinc zeolite in the hard segment region of the polymer through strong dipole interaction, avoiding the stress concentration problem caused by the enrichment of antibacterial agents in the soft segment in the traditional blending method, and ultimately achieving a reduction in the amount of antibacterial agent added and an increase in tensile strength.

[0025] In some embodiments, in step S1, the molecular weight of polyethylene glycol is 2000; the molar ratio of polyethylene glycol to perfluorooctyl ethanol is 1:2-4.

[0026] This application utilizes the formation of fluorinated segments (HO-(CF3-PEG-CF3)-OH) at both ends of PEG modified with perfluorooctyl groups. This results in a low surface energy main chain (replacing the need for external hydrophobic agents) and directional adsorption onto the silver-zinc zeolite surface. Stable anchoring of the antibacterial agent is achieved through electrostatic-dipole synergy. The chemical bonding method of this application avoids the phase separation problem of traditional physical blending. Specifically, the F-PEG ether bond oxygen and the silver-zinc zeolite ions (Ag... + / Zn 2+The formation of reversible coordination bonds enables uniform dispersion of the antibacterial agent during melt processing. During high-temperature processing, the dynamic coordination bonds undergo reversible dissociation and recombination. In this embodiment, selecting a polyethylene glycol molecular weight of 2000 ensures sufficient heating reaction with perfluorooctyl ethanol while avoiding a decrease in material rigidity due to excessively long molecular chains. Controlling the molar ratio of polyethylene glycol to perfluorooctyl ethanol is beneficial for improving the degree of fluorination.

[0027] In some embodiments, in step S2, the chain extender is 1,4-butanediol and cystamine hydrochloride in a mass ratio of 2-4:1.

[0028] This range of proportions can balance the material's processing fluidity, strength in use, and recyclability.

[0029] In some embodiments, in step S3, the depressurization rate is 8-10 MPa / s; the pressure of supercritical CO2 is 10-20 MPa, and the temperature is 50-60°C.

[0030] By controlling the depressurization rate, this application allows PEG-PDMS to be properly coated onto N-TiO2, which is beneficial for exposing N-TiO2 when humidity or light conditions change.

[0031] In some embodiments, in step S4, the temperature program for melt blending extrusion is: 170°C in zone 1, 180°C in zone 2, 185°C in zone 3, and 190°C at the die.

[0032] In this embodiment, limiting the temperature of melt blending extrusion can prevent molecular chain degradation and also facilitate the peeling and dispersion of silver-zinc zeolite particles.

[0033] In some embodiments, in step S4, the silver-zinc zeolite is prepared by immersing the zeolite in a mixture of AgNO3 and Zn(NO3)2 for ion exchange, thereby obtaining the silver-zinc zeolite.

[0034] In some embodiments, the PDMS segments in PEG-PDMS account for 60-80 wt%.

[0035] In this embodiment, controlling the proportion of PDMS segments is beneficial for the core-shell structure to exhibit a significant conformational response when humidity changes: a higher PDMS content makes the hydrophobic barrier denser in a dry environment, while the retained PEG segments can still trigger a sufficient swelling effect under high humidity conditions.

[0036] In some embodiments, the molar ratio of AgNO3 to Zn(NO3)2 is 1:1-2.

[0037] In this embodiment, Ag is formed in the ion-exchanged silver-zinc zeolite. + With Zn 2+The gradient distribution can leverage the rapid contact sterilization advantage of silver ions and utilize the specific adsorption of zinc ions on biofilm polysaccharides to achieve long-lasting antibacterial effect.

[0038] This application provides the use of a dustproof and antibacterial thermoplastic polyurethane elastomer material in medical catheters and / or guidewires.

[0039] The following specific embodiments further illustrate this solution.

[0040] Example 1 A method for preparing a dustproof and antibacterial thermoplastic polyurethane elastomer material includes the following steps: S1. Take 100g of polyethylene glycol (PEG) with a molecular weight of 2000 and add it to a dry four-necked flask. Purge with nitrogen three times, heat to 60℃ to melt, add 236g of perfluorooctyl ethanol, then add 0.5g of catalyst 4-dimethylaminopyridine, and add toluene solution (10ml) of DCC dropwise while stirring. Control the temperature at 70℃ and react for 8 hours. After the reaction is completed, the organic phase is dried with anhydrous sodium sulfate and the solvent is removed by rotary evaporation to obtain waxy fluorinated polyether diol F-PEG. S2. Add 65g of F-PEG and 25g of diphenylmethane diisocyanate (MDI) to a reaction vessel, add 10g of chain extender mixture (1,4-butanediol and cystamine hydrochloride in a mass ratio of 3:1), and react at 85℃ for 4 hours under nitrogen protection to obtain a transparent viscous TPU prepolymer. S3. Add 3g of N-TiO2 and 5g of PEG-PDMS (PDMS content 70wt%) to a supercritical CO2 reactor, adjust the system to 15MPa and 55℃, maintain for 2 hours to allow the materials to fully dissolve and disperse, inject the above mixed fluid into the TPU prepolymer melt at 180℃, hold the pressure for 5 minutes, and then depressurize to atmospheric pressure at a rate of 9MPa / s to form a TPU melt containing N-TiO2@PEG-PDMS; S4. Immerse 10g of zeolite in a mixture of AgNO3 and Zn(NO3)2 with a molar ratio of 1:1.5 (total concentration 0.5mol / L), perform ion exchange at 60℃ for 8 hours, wash and dry to obtain 1.5g of silver-zinc zeolite. Mix the silver-zinc zeolite with the melt obtained in step S3 and feed it into a twin-screw extruder. Set the temperature program as follows: Zone 1 170℃, Zone 2 180℃, Zone 3 185℃, Die 190℃, and Screw speed 120rpm. The extruded strips are water-cooled and pelletized, and then vacuum dried at 60℃ for 12 hours to obtain a dustproof and antibacterial thermoplastic polyurethane elastomer material.

[0041] Example 2 A method for preparing a dustproof and antibacterial thermoplastic polyurethane elastomer material is the same as in Example 1, except that the molar ratio of polyethylene glycol to perfluorooctyl ethanol is 1:2.

[0042] Example 3 A method for preparing a dustproof and antibacterial thermoplastic polyurethane elastomer material is the same as that in Example 1, except that the pressure relief rate in step S3 is 10 MPa / s.

[0043] Comparative Example 1 A method for preparing a dustproof and antibacterial thermoplastic polyurethane elastomer material is the same as in Example 1, except that F-PEG is replaced with polyethylene glycol 2000.

[0044] Comparative Example 2 A method for preparing a dustproof and antibacterial thermoplastic polyurethane elastomer material is the same as in Example 1, except that PEG-PDMS is not added.

[0045] Comparative Example 3 A method for preparing a dustproof and antibacterial thermoplastic polyurethane elastomer material is the same as in Example 1, except that silver zinc zeolite is replaced with pure silver zeolite.

[0046] Comparative Example 4 A method for preparing a dustproof and antibacterial thermoplastic polyurethane elastomer material is the same as that in Example 1, except that the pressure relief rate in step S3 is 5 MPa / s.

[0047] Comparative Example 5 A method for preparing a dustproof and antibacterial thermoplastic polyurethane elastomer material is the same as that in Example 1, except that the PDMS segment of PEG-PDMS accounts for 50wt% in step S3.

[0048] Testing and Evaluation The performance of the materials obtained in different embodiments and comparative examples was tested, and the results are shown in Table 1: Hydrophobicity test: The static water contact angle was measured using a contact angle meter (Dataphysics OCA20) according to GB / T 30693-2014 standard.

[0049] Antibacterial properties: High humidity conditions (RH>85%): The 24-hour inhibition rate against Escherichia coli was tested according to ISO 22196; Dark and dry conditions (RH<30%): The 7-day inhibition rate against Aspergillus niger was tested according to GB / T 21510-2008.

[0050] Mechanical properties: Tensile strength and elongation at break were tested according to ASTM D638 standard.

[0051] Recyclability: The performance retention rate of the material is tested after three melt extrusion cycles.

[0052] Table 1 Test Results

[0053] As shown in Table 1, the polyurethane elastomer material obtained in this application exhibits excellent performance in all aspects. However, compared to Example 1, Comparative Example 1, due to the lack of anchoring effect from the fluorinated segments, experienced severe agglomeration of silver-zinc zeolite, leading to decreased mechanical strength, reduced antibacterial rate, and increased surface contamination adsorption due to loss of hydrophobicity. Comparative Example 2, lacking PEG-PDMS, resulted in the absence of a core-shell structure, preventing N-TiO2 from responding to humidity changes and reducing antibacterial activity under high humidity conditions. Comparative Example 3 used pure silver zeolite as an antibacterial agent, which lacks Zn... 2+ Synergistic effect of metabolic enzyme inhibition, reduced antibacterial rate in the dark, excessive Ag + Release leads to surface cytotoxicity. In Comparative Example 4, the reduced depressurization rate and excessively slow depressurization resulted in excessive N-TiO2 encapsulation by PDMS, leading to a decrease in antibacterial rate under high humidity conditions. Shell inhomogeneity also reduced the strength retention rate after recovery. In Comparative Example 5, the reduced PDMS content and increased hydrophilicity led to deterioration in drying and dustproof performance. Simultaneously, uncontrolled swelling of PEG segments reduced the stability of the shell structure, resulting in a low antibacterial rate after recovery.

[0054] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A dustproof and antibacterial thermoplastic polyurethane elastomer material, characterized in that, The product comprises the following components in parts by weight: 60-70 parts of fluorinated polyether diol, 20-30 parts of diisocyanate, 2-5 parts of N-TiO2@PEG-PDMS, and 0.5-2 parts of silver-zinc zeolite; wherein the fluorinated polyether diol is prepared from polyethylene glycol and perfluorooctyl ethanol.

2. A method for preparing the dustproof and antibacterial thermoplastic polyurethane elastomer material as described in claim 1, characterized in that, Includes the following steps: S1. Using polyethylene glycol and perfluorooctyl ethanol as raw materials, a heating reaction is carried out to obtain a fluorinated polyether diol; S2. Under the action of a chain extender, a polymerization reaction is carried out using fluorinated polyether diol and diisocyanate as raw materials to obtain TPU prepolymer; S3. Dissolve N-TiO2 and PEG-PDMS in supercritical CO2, then inject the TPU prepolymer melt and depressurize to obtain a TPU melt containing N-TiO2@PEG-PDMS; S4. Mix the silver-zinc zeolite with the TPU melt containing N-TiO2@PEG-PDMS and perform melt blending extrusion to obtain the dustproof and antibacterial thermoplastic polyurethane elastomer material.

3. The method for preparing the dustproof and antibacterial thermoplastic polyurethane elastomer material according to claim 2, characterized in that, In step S1, the molecular weight of the polyethylene glycol is 2000; the molar ratio of the polyethylene glycol to perfluorooctyl ethanol is 1:2-4.

4. The method for preparing the dustproof and antibacterial thermoplastic polyurethane elastomer material according to claim 2, characterized in that, In step S2, the chain extender is 1,4-butanediol and cystamine hydrochloride in a mass ratio of 2-4:

1.

5. The method for preparing the dustproof and antibacterial thermoplastic polyurethane elastomer material according to claim 2, characterized in that, In step S3, the depressurization rate is 8-10 MPa / s; the pressure of the supercritical CO2 is 10-20 MPa, and the temperature is 50-60℃.

6. The method for preparing the dustproof and antibacterial thermoplastic polyurethane elastomer material according to claim 2, characterized in that, In step S4, the temperature program for the melt blending extrusion is: 170°C in zone 1, 180°C in zone 2, 185°C in zone 3, and 190°C at the die.

7. The method for preparing the dustproof and antibacterial thermoplastic polyurethane elastomer material according to claim 2, characterized in that, In step S4, the silver-zinc zeolite is prepared by immersing the zeolite in a mixture of AgNO3 and Zn(NO3)2 for ion exchange, thereby obtaining the silver-zinc zeolite.

8. The method for preparing the dustproof and antibacterial thermoplastic polyurethane elastomer material according to claim 2, characterized in that, In the PEG-PDMS, the PDMS segment accounts for 60-80 wt%.

9. The method for preparing the dustproof and antibacterial thermoplastic polyurethane elastomer material according to claim 7, characterized in that, The molar ratio of AgNO3 to Zn(NO3)2 is 1:1-2.

10. The application of a dustproof and antibacterial thermoplastic polyurethane elastomer material obtained by the preparation method according to any one of claims 2-8 in medical catheters and / or guidewires.

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