Silicon-containing polyurethane material as well as preparation method and application thereof

Abstract

The invention provides a silicon-containing polyurethane material and a preparation method and application thereof.The silicon-containing polyurethane material comprises a hard segment and a soft segment, the hard segment is derived from reaction raw materials including diisocyanate and a chain extender, and the soft segment is derived from reaction raw materials including polysiloxane and macromolecular dihydric alcohol; in the process of preparing the silicon-containing polyurethane material by adopting the polysiloxane with the specific structure, rich fluorine atoms in the polysiloxane can be utilized to drive the polysiloxane to migrate to the surface of the material, so that a protective layer is formed on the surface of the material, and the biocompatibility and the biological stability of the material are enhanced. By adopting the mode, the silicon-containing polyurethane material with excellent biological stability, biocompatibility and mechanical property can be prepared on the premise of lower polysiloxane addition amount, and the problem that the biocompatibility and the mechanical property cannot be simultaneously considered when the polyurethane material is prepared by utilizing polysiloxane in the prior art is effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of polyurethane material preparation, and in particular to a silicon-containing polyurethane material and a preparation method and application thereof. Background Art

[0002] Silicone-containing polyurethane (PU) has long been used as a medical material, particularly biostable materials. This material has applications in a variety of medical device fields, such as pacemaker wires, artificial blood vessels, heart valves, spinal cord prostheses, breast prostheses, central venous catheters, and more. Currently, commercially available silicone-containing PUs include Aortech's Elast-Eon series and DSM's Carbosil series. Elast-Eon 2A has been used as the insulation layer for pacemaker wires in over 10 million cases and demonstrates excellent long-term performance. Carbosil supports multiple use scenarios, and several valve companies are currently using or planning to use this material to manufacture polymer valves. This shows that silicone-containing PU has gained unanimous recognition for long-term in vivo implantation.

[0003] The molecular structures of these silicon-containing PUs all utilize polydimethylsiloxane (PDMS) as the copolymer soft segment, with proportions ranging from 20-50%. Using PDMS in the synthesis of polyurethanes offers the following advantages: 1. Improved biostability of the PU; 2. Improved biocompatibility of the PU. This is primarily due to PDMS's low surface energy, which allows it to spontaneously migrate to the surface within the PU structure, forming a hydrophobic protective layer 5-100 nm thick. This layer protects the PU's sensitive functional groups, such as carbamate, ether, and carbonate bonds, from hydrolysis and oxidative degradation. Furthermore, this protective layer reduces the material's inflammatory response in the body, preventing immune cells such as macrophages from migrating, differentiating, and proliferating on the material, thereby enhancing the PU's biocompatibility. However, the introduction of PDMS into PU significantly reduces the material's mechanical properties. For example, Lubrizol's Pellethane, a polyether polyurethane with a hardness of approximately 80A, has a tensile strength of approximately 35MPa, while Aortech's Elast-Eon 2A (E2A), with a similar hardness, has a strength of only about 25MPa. Another example is Lubrizol's Carbothane, a polycarbonate polyurethane with a hardness of approximately 80A, with a tensile strength of approximately 50MPa, while DSM's Carbosil, with a hardness of approximately 80A, has a strength of only about 30MPa. Furthermore, PDMS only accounts for 20% of the PU mass fraction.

[0004] In the prior art, patent application number 201910354767.7, entitled "A Fluorine-Containing Silicone Polyurethane Material with High Biostability and Its Preparation Method," discloses a fluorosilicone polyurethane material with high biostability. The material is copolymerized with a polyether or polycarbonate diol as a first flexible segment, a polydimethylsiloxane diol as a second flexible segment, and a rigid segment consisting of a diisocyanate and a chain extender, wherein the chain extender is a blend of a small molecule diol or diamine and a diol with a fluoroalkyl side chain. By utilizing the low surface energy of the two elements, the two elements can synergistically migrate to the surface of the polyurethane during melt processing or solution processing to form a protective layer, which can prevent water and oxidizing media from penetrating into the interior of the material to improve the material's hydrolysis resistance and antioxidant properties. While improving biostability, it also gives the polyurethane material excellent surface properties and bulk properties. However, the above technical solution uses a fluorine-containing chain extender containing a secondary hydroxyl structure for the reaction, which has low reactivity, making it unfavorable for efficient synthesis. In addition, the resulting polyurethane is likely to have insufficient molecular weight, which may even affect its mechanical strength.

[0005] In view of this, it is necessary to design an improved silicon-containing polyurethane material and its preparation method and application to solve the above problems. Summary of the Invention

[0006] The purpose of the present invention is to provide a silicon-containing polyurethane material and a preparation method and application thereof.

[0007] To achieve the above-mentioned object of the invention, on the one hand, the present invention provides a silicon-containing polyurethane material, comprising:

[0008] A hard segment, which is derived from the reaction raw materials diisocyanate and chain extender; the mass of the hard segment is 20-80% of the total mass of the silicon-containing polyurethane material;

[0009] The soft segment is derived from the reaction raw materials polysiloxane and macromolecular diol;

[0010] The polysiloxane has a molecular formula of Formula I or Formula II:

[0011] Wherein, n is a natural number of 3-30, R is a C3-C8 straight-chain or branched alkyl group or a C3-C8 straight-chain or branched alkoxy group, R1 is a C3-C6 alkyl group, and R2 is a C1-C4 alkyl group; the molecular weight of the polysiloxane is 500-5000, and the mass fraction of the polysiloxane in the overall silicon-containing polyurethane material is 5-80%.

[0012] As an embodiment of the present invention, the molecular formula of the polysiloxane is:

[0013]

[0014] One of the following, where n is a natural number between 3 and 30.

[0015] On the other hand, the present invention also provides a method for preparing the above-mentioned silicon-containing polyurethane material, including a one-step method or a two-step method, wherein the two-step method comprises the following steps:

[0016] S1. Mixing dry polysiloxane, macromolecular diol and diisocyanate, and performing polymerization reaction at 40-120° C. to prepare a polyurethane prepolymer;

[0017] S2, mixing the polyurethane prepolymer obtained in step S1 with a chain extender, and performing a chain extension reaction at 40-120° C. to obtain the silicon-containing polyurethane material;

[0018] The one-step method comprises the following steps: uniformly mixing dry polysiloxane, macromolecular diol and chain extender, and reacting with diisocyanate at 50-70° C., and obtaining the silicon-containing polyurethane material after the reaction is completed.

[0019] As an embodiment of the present invention, the macromolecular diol is one or more of monomeric or copolymeric polycarbonate diol, polytetramethylene glycol, polyhexamethylene glycol, polyoctamethylene glycol, polydecamethylene glycol, polyisobutylene glycol, polybutadiene glycol, and polyisoprene glycol; the molecular weight of the macromolecular diol is 500-5000, and its mass fraction in the overall silicon-containing polyurethane material is 20-80%.

[0020] As an embodiment of the present invention, the diisocyanate includes one or more of diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate; the mass fraction of the diisocyanate in the entire silicon-containing polyurethane material is 10-50%.

[0021] As an embodiment of the present invention, the chain extender is one or more of 1,2-ethylenediamine, 1,3-propylenediamine, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol, and the mass fraction of the chain extender in the entire silicon-containing polyurethane material is 1-20%.

[0022] In particular, the silicon-containing polyurethane material prepared by the preparation method of the present invention can be used in the field of biomedical materials, including artificial valves or leaflet coatings of artificial valves.

[0023] As an embodiment of the present invention, an artificial valve includes a leaflet, and the leaflet includes the silicon-containing polyurethane material.

[0024] As an embodiment of the present invention, an artificial valve includes a leaflet, wherein the leaflet is provided with a coating, and the coating includes the silicon-containing polyurethane material.

[0025] The beneficial effects of the present invention are:

[0026] 1. The present invention provides a silicon-containing polyurethane material comprising a hard segment and a soft segment. The hard segment is derived from the reaction raw materials diisocyanate and chain extender, while the soft segment is derived from the reaction raw materials polysiloxane and macromolecular diol. The process of preparing the silicon-containing polyurethane material using polysiloxane having a specific structure utilizes the abundant fluorine atoms in the polysiloxane to drive the polysiloxane to migrate to the material surface, forming a protective layer on the surface and enhancing the biocompatibility and biostability of the material. Because this process primarily utilizes the fluorine-rich nature of polysiloxane, it can reduce the amount of polysiloxane added while producing a polyurethane material with excellent mechanical properties.

[0027] 2. The silicon-containing polyurethane material provided by the present invention, by selecting polysiloxane with a specific end group structure as a raw material, can not only ensure the chemical reactivity of the polysiloxane during the reaction process, which is conducive to efficient synthesis, but also can regulate the molecular weight of the synthesized silicon-containing polyurethane material, ensuring that the mechanical strength of the silicon-containing polyurethane material is at a high level, and giving the silicon-containing polyurethane material excellent performance as a biomedical material.

[0028] 3. The preparation method of the silicon-containing polyurethane material provided by the present invention can accurately control the degree of reaction by adjusting the addition amount of diisocyanate, chain extender, polysiloxane and macromolecular diol, reaction conditions and the end group of polysiloxane to ensure that the material with desired performance and structure is obtained. The process is easy to implement, has low requirements on preparation conditions, and is easy to realize large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic structural diagram of an integrated valve mold applied to Example 1 of the present invention;

[0030] Figure 2 for Figure 1 A diagram showing the state of the integrated valve mold and the metal stent being sheathed together;

[0031] The reference numerals are as follows:

[0032] 10. Support member; 20. Metal bracket. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] It should also be noted here that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions of the present invention are shown in the drawings, while other details that are not closely related to the present invention are omitted.

[0035] In addition, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0036] In one aspect, the present invention provides a method for preparing a silicon-containing polyurethane material. The silicon-containing polyurethane material comprises a hard segment and a soft segment. The hard segment is derived from the reaction raw materials diisocyanate and chain extender, and the soft segment is derived from the reaction raw materials polysiloxane and macromolecular diol. The mass of the hard segment accounts for 20-80% of the total mass of the silicon-containing polyurethane material. The specific preparation method comprises the following steps:

[0037] S1. Preparation of polyurethane prepolymer: polysiloxane and macromolecular diol are mixed uniformly, and then dehydrated; diisocyanate is added, and a polymerization reaction between the raw materials is used to prepare a polyurethane prepolymer;

[0038] S2. Preparation of silicon-containing polyurethane material: at 40-120° C., the polyurethane prepolymer prepared in step S1 is mixed with a chain extender to obtain a mixture, and a product is obtained by chain extension reaction between the raw materials; the product is then dried and solidified to obtain the silicon-containing polyurethane material.

[0039] As an embodiment of the present invention, in step S1, polysiloxane (PTFPMS) has a molecular formula of formula I, where formula I is In the molecular formula, n is a natural number of 3-30, and R is a C3-C8 straight chain or branched chain alkyl group or a C3-C8 straight chain or branched chain alkoxy group;

[0040] Or a molecular formula having formula II, formula II is Wherein, n is a natural number of 3-30, R1 is a C3-C6 alkyl group, and R2 is a C1-C4 alkyl group;

[0041] Furthermore, the molecular weight of PTFPMS is 500-5000, and the mass fraction of PTFPMS in the overall silicon-containing polyurethane material is 5-80%. Preferably, the molecular weight of PTFPMS is 600-2000, and the mass fraction of PTFPMS in the overall silicon-containing polyurethane material is 5-20%. More preferably, the mass fraction of PTFPMS in the overall silicon-containing polyurethane material is 8-15%.

[0042] Specifically, in some embodiments, the molecular formula of PTFPMS may be:

[0043]

[0044] Wherein, n in the above molecular formula is a natural number ranging from 3 to 30. In the above process, the reaction degree of the reaction process is regulated by selecting different end group structures and utilizing their different reactivity. In addition, different end group structures require different reaction temperatures and reaction times when participating in the reaction, thereby adjusting the reaction degree according to the actual reaction needs.

[0045] As one embodiment of the present invention, in step S1, the diisocyanate includes, but is not limited to, one or more of diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), isophorone diisocyanate (IPDI), and hexamethylene diisocyanate (HDI). Preferably, the diisocyanate is diphenylmethane diisocyanate, and its mass fraction in the total silicon-containing polyurethane material is 10-50%, and more preferably, the mass fraction of diphenylmethane diisocyanate is 27.5-42.5%.

[0046] As one embodiment of the present invention, in step S1, the macromolecular diol includes, but is not limited to, one or more of monomeric or copolymeric polycarbonate diol (PCDL), polytetramethylene glycol (PTMO), polyhexamethylene glycol (PHMO), polyoctamethylene glycol, polydecamethylene glycol, polyisobutylene glycol, polybutadiene glycol, and polyisoprene glycol. The macromolecular diol has a molecular weight of 500-5000 and accounts for 20-80% of the total weight of the silicone-containing polyurethane material; preferably, the molecular weight is 600-2000 and the weight fraction is 30-60%; more preferably, the weight fraction is 40-55%.

[0047] As an embodiment of the present invention, in step S1, the dehydration treatment is carried out in a vacuum environment, the dehydration treatment temperature is 70-120°C, preferably 85-105°C; the dehydration time is 0.5-24h, preferably 2-12h.

[0048] As an embodiment of the present invention, in step S1, the polymerization reaction temperature is 40-120° C., preferably 60-90° C.; and the polymerization time is 5-720 min, preferably 30-180 min.

[0049] As one embodiment of the present invention, in step S1, to improve the mixing efficiency of the polysiloxane and the macromolecular diol, mechanical stirring can be used. In other embodiments, other mixing methods can also be used as long as the purpose of uniform mixing of the raw materials can be achieved, and this is not limited here.

[0050] As an embodiment of the present invention, in step S1, in order to accelerate the reaction rate of the polymerization reaction, a catalyst may be added, the catalyst including but not limited to one or more of stannous octoate, dibutyltin dilaurate, and bismuth carboxylate, and the amount of the catalyst added is 0-1% of the mass of the polyurethane.

[0051] As one embodiment of the present invention, in step S2, the chain extender includes, but is not limited to, one or more of 1,2-ethylenediamine, 1,3-propylenediamine, 1,4-butanediol (BDO), 1,5-pentanediol (PDO), and 1,6-hexanediol (HDO). Preferably, the chain extender is 1,4-butanediol, with a mass fraction of 1-20%; more preferably, a mass fraction of 4-10%.

[0052] As an embodiment of the present invention, in step S2, the temperature of the chain extension reaction is 40-120° C., preferably 60-90° C.; the chain extension time is 5-600 s, preferably 30-300 s.

[0053] As an embodiment of the present invention, in step S2, the drying and curing temperature is 85-140°C, and the drying and curing time is 2-24 hours, preferably 4-12 hours.

[0054] As an embodiment of the present invention, in step S2, the polymerization reaction is carried out under high-speed stirring conditions at a rotation speed of 6000 r / min. Under this condition, the contact area between the reactants can be increased, which is conducive to the occurrence of the polymerization reaction, and can make the reaction more complete and avoid the formation of by-products.

[0055] On the other hand, the present invention also provides the application of the silicon-containing polyurethane material obtained by the above-mentioned preparation method in biomedical materials, specifically in the field of polymer valves. Before application, the product can be made into the required size and specification with the help of external auxiliary tools according to the needs of the specific application. As an embodiment of the present invention, in order to obtain a product of the required specification or size, the product can be spread on a smooth substrate before drying and curing, and a polymer valve is obtained after drying and curing. It should be noted that the substrate here is only used to assist in the molding of polymer valves, such as glassware, stainless steel plates, etc., as long as the corresponding purpose can be achieved, it is not limited to this here.

[0056] The silicon-containing polyurethane material, its preparation method and application proposed by the present invention are further described below with reference to specific embodiments:

[0057] Examples 1 to 3 all use hydroxyethoxypropyl-terminated PTFPMS (molecular weight 1000) as a raw material. The molecular formula of PTFPMS is as follows:

[0058] Example 1

[0059] In this embodiment, a silicon-containing polyurethane material is prepared using 10 parts of PTFPMS (molecular weight 1000), 33.4 parts of diphenylmethane diisocyanate, 50 parts of polycarbonate diol (molecular weight 1000), and 6.6 parts of 1,4-butanediol. No catalyst is used. The specific preparation method includes the following steps:

[0060] S1. After uniformly mixing polysiloxane and polycarbonate diol, dehydrate under vacuum at 105°C for 4 hours. After dehydration, lower the system temperature to 70°C, add molten diphenylmethane diisocyanate, and maintain the temperature at 80±2°C for 2 hours to obtain a polyurethane prepolymer.

[0061] S2. Lower the temperature of the polyurethane prepolymer to 60°C, add 1,4-butanediol, and stir at high speed for 1-2 minutes to obtain a mixture. The mixture is then poured into a Teflon-coated stainless steel plate and leveled. The mixture is then dried and cured at 100°C to produce a silicon-containing polyurethane material suitable for use as a polymer valve. It should be noted that the use of a stainless steel plate for drying and curing is merely to accelerate the drying rate and obtain a material with uniform thickness. This may be omitted in other embodiments, as long as the desired effect is selected. This is not intended to be limiting.

[0062] In order to explore the application of the silicon-containing polyurethane material prepared in this embodiment in the field of artificial heart valves, it was used to make a polymer valve. The specific preparation process is as follows: first, a silicon-containing polyurethane material / N,N-dimethylacetamide solution with a solid content of 16% was prepared, and then an integrated valve mold with a metal stent 20 was immersed in the above solution. After the mold was evenly covered with the solution, the mold was removed and dried at 65°C for 24 hours. After drying, the mold was demolded and trimmed to prepare a polymer valve. The corresponding test was carried out according to the standard items of YY / T1449.3-2016 transcatheter implantable artificial heart valve. The valve performance test results are shown in Table 1. The valve fatigue times of Example 1 exceeded 400 million times, and no failure occurred at the end of the test. The effective valve orifice area and regurgitation conditions of the valve met or significantly exceeded the minimum performance requirements of YY / T 1449.3-2016 transcatheter implantable artificial heart valve.

[0063] It should be noted that the one-piece valve mold used in the above process is as follows: Figure 1As shown, it includes a support member 10, which is used to support a metal bracket 20; specifically, the support member 10 includes a cylinder with a smooth outer wall, and the metal bracket 20 can be sleeved outside the cylinder. Figure 2 As shown, one end of the cylinder is provided with three recessed areas, the outer walls of which form a shape that matches the shape of the natural valve leaflets when open or closed. In other embodiments, the mold structure can also be adjusted as needed, as long as the corresponding selection and adjustment are made according to the shape of the valve and the requirements of the production process, and this is not limited here.

[0064] Table 1 Valve performance test results

[0065] project Example 1 Standard requirements Fatigue times / 100 million times 4.1 ≥2.0 <![CDATA[Effective valve area / cm 2 > 3.1 ≥1.70 Percentage of valve regurgitation (in forward flow) / % 7.5 ≤15 Total reflux percentage (in forward flow) / % 9.6 ≤20

[0066] Example 2

[0067] The only difference between Example 2 and Example 1 is that the polycarbonate diol in Example 1 is replaced by polytetramethylene glycol (molecular weight is 1000). Other steps and parameters are the same as those in Example 1 and are not repeated here.

[0068] Example 3

[0069] The only difference between Example 3 and Example 1 is that a one-step method is used for preparation, and dibutyltin dilaurate is selected as a catalyst in an amount of 0.2% of the total mass of the silicon-containing polyurethane material. The composition and content of the remaining raw materials are the same as those in Example 1 and are not repeated here. The specific preparation steps of Example 3 are as follows:

[0070] Pre-dry 10 parts of PTFPMS and 50 parts of polycarbonate diol in a vacuum oven at 85°C for 12 hours. Then, add PTFPMS and polycarbonate diol, 6.6 parts of 1,4-butanediol and dibutyltin dilaurate into an open PP beaker with mechanical stirring and stir evenly. Raise the temperature of the mixed liquid to 60°C, add molten diphenylmethane diisocyanate, and stir for about 3-5 minutes. After the viscosity increases significantly, pour it into a stainless steel plate with a Teflon coating and level it. Dry and cure it at 100°C to obtain a silicon-containing polyurethane film that can be used as a polymer valve.

[0071] Example 4

[0072] The only difference between Example 4 and Example 1 is that the molecular formula of the PTFPMS (molecular weight of 1000) used is as follows: In this embodiment, bismuth carboxylate is used as a catalyst, and its addition amount is 0.1% of the total mass of the silicon-containing polyurethane material. The composition and content of the remaining raw materials are the same as those in Example 1 and are not described here. The specific preparation method is as follows:

[0073] S1. After uniformly mixing polysiloxane and polycarbonate diol, dehydrate the mixture under vacuum at 105°C for 4 hours. After dehydration, lower the system temperature to 70°C, add molten diphenylmethane diisocyanate, and add bismuth carboxylate. Maintain the temperature at 80±2°C for 2 hours to obtain a polyurethane prepolymer.

[0074] S2. Lower the temperature of the polyurethane prepolymer to 60°C, add 1,4-butanediol, and stir at high speed for 1-2 minutes to obtain a mixture; then pour the mixture into a stainless steel plate with a Teflon coating and level it, and dry and cure it at 100°C to obtain a silicon-containing polyurethane material that can be used as a polymer valve.

[0075] Example 5

[0076] The only difference between Example 5 and Example 1 is that the PTFPMS used is different from that in Example 1. The molecular formula of PTFPMS (molecular weight 1000) in this example is as follows: The other steps and parameters are the same as those in Example 1 and will not be described again here.

[0077] Comparative Example 1

[0078] The only difference between Comparative Example 1 and Example 1 is that the PTFPMS in Example 1 is replaced with the same mass fraction of hydroxyethoxypropyl-terminated PDMS (polydimethylsiloxane). The other steps and parameters are the same as those in Example 1 and are not repeated here.

[0079] Comparative Example 2

[0080] The only difference between Comparative Example 2 and Example 1 is that the PTFPMS in Example 1 is replaced by hydroxyethoxypropyl-terminated PDMS, and the mass fraction of PDMS in Comparative Example 2 is 20 parts, and the mass fraction of polycarbonate diol is 40 parts. The other steps and parameters are the same as those in Example 1 and are not repeated here.

[0081] Comparative Example 3

[0082] The only difference between Comparative Example 3 and Example 1 is that the PTFPMS in Example 1 is replaced by PDMS terminated with hydroxyethoxypropyl, the macromolecular diol in Example 1 is replaced by polytetramethylene glycol (molecular weight of 1000), and the mass fraction of PDMS is 10 parts, and the mass fraction of polytetramethylene glycol is 50 parts. The other steps and parameters are the same as those in Example 1 and are not repeated here.

[0083] Comparative Example 4

[0084] The only difference between Comparative Example 4 and Example 1 is that the PTFPMS in Example 1 is replaced by hydroxyethoxypropyl-terminated PDMS, the macromolecular diol in Example 1 is replaced by polytetramethylene glycol (molecular weight of 1000), and the mass fraction of PDMS is 20 parts, and the mass fraction of polytetramethylene glycol is 40 parts. The other steps and parameters are the same as in Example 1 and are not repeated here.

[0085] Comparative Example 5

[0086] The only difference between Comparative Example 5 and Example 3 is that the PTFPMS in Example 3 is replaced with the same mass fraction of hydroxyethoxypropyl-terminated PDMS, and dibutyltin dilaurate is added as a catalyst during the preparation process, and the addition amount is 0.2% of the total mass of the silicon-containing polyurethane material. The amount of other raw materials, preparation method, and process parameters are the same as those in Example 3 and are not repeated here.

[0087] Comparative Example 6

[0088] The only difference between Comparative Example 6 and Example 3 is that the PTFPMS in Example 3 is replaced by hydroxyethoxypropyl-terminated PDMS, and the mass fraction of PDMS is 20 parts, the mass fraction of polycarbonate diol (molecular weight 1000) is 40 parts, and dibutyltin dilaurate is added as a catalyst during the preparation process, and the addition amount is 0.2% of the mass of the silicon-containing polyurethane. The amount of other raw materials, the preparation method, and the process parameters are the same as in Example 3 and are not repeated here.

[0089] The properties of the silicon-containing polyurethane materials prepared in Examples 1 to 5 and Comparative Examples 1 to 6 were tested. Before the test, the silicon-containing polyurethane materials were treated as follows: 5 g of the silicon-containing polyurethane material was cut into particles of uniform size and dissolved in 50 mL of N,N-dimethylacetamide; the solution obtained by fully dissolving the particles was poured into a watch glass dish and dried in a natural convection drying oven at 50°C for 48 h, and then dried in a vacuum drying oven at 50°C for 24 h to prepare a uniform film with a thickness of about 200 μm, which was used as a test sample.

[0090] The tensile properties of the samples were measured as follows: a polyurethane film was laser cut into dumbbell-shaped specimens. Test conditions: a tensile speed of 500 mm / min, 5-8 parallel specimens per group, and the test was conducted at room temperature.

[0091] The silicon content on the sample surface was determined as follows: a small piece of film sample was directly cut and tested by X-ray photoelectron spectroscopy (XPS). The ray source was an Al Kα single X-ray source with a take-off angle of 90°. The test depth of the corresponding sample was about 10 nm.

[0092] In vitro oxidative degradation tests were conducted as follows: polyurethane films were cut into 1 cm diameter discs and placed in a 20% hydrogen peroxide solution. 0.1 mol / L of cobalt chloride hexahydrate was added to the solution for accelerated degradation in vitro to determine the stability differences between polyurethanes of different composition. The oxidative degradation test lasted four weeks. The tensile strength of the samples was measured before and after degradation, and the percentage decrease in tensile strength was used to determine sample stability. This percentage decrease was calculated as follows: Percentage decrease = 100 × (tensile strength before degradation - tensile strength after degradation) / tensile strength before degradation.

[0093] The performance test results of the silicon-containing polyurethane materials prepared in Examples 1 to 5 and Comparative Examples 1 to 6 are shown in Table 2. By comparing Examples 1 to 5 with Comparative Examples 1, 3, and 5, and Examples 1 to 5 with Comparative Examples 2, 4, and 6 in the table, it can be found that when the same number of parts of polysiloxane are added, the tensile properties of the silicon-containing polyurethane materials prepared in the Examples and Comparative Examples are similar, but the surface silicon content of the Examples is much greater than that of the Comparative Examples, and the surface silicon content of the Examples is close to the surface silicon content when 2 times the mass parts of polysiloxane are added to the Comparative Examples (Comparative Examples 2, 4, and 6). The results show that the preparation method proposed by the present invention can effectively improve the tensile properties of the silicon-containing polyurethane materials. The surface silicon content of the polyurethane is increased, and the mechanical properties of the material are improved. This is because: when the PTFPMS in the present invention is used to prepare polyurethane, the fluorine atoms in the PTFPMS can be used to drive the siloxane segments to migrate to the surface during the formation of the polyurethane soft segment, and enrich the silicon protective layer on the material surface. The formation of the silicon protective layer can prevent the material from degrading in the body. Through the above principle, the amount of polysiloxane required for the preparation of polyurethane can be reduced without affecting the biocompatibility and biostability of the material, and a silicon-containing polyurethane material with better mechanical strength than the polyurethane prepared using PDMS in the traditional method can be produced.

[0094] Furthermore, in vitro accelerated degradation test results indicate that the Examples, due to the use of novel polysiloxanes, exhibit a high retention of mechanical strength after degradation, demonstrating a lower degree of degradation. Based on current research, increasing surface silicon content significantly enhances the biostability of materials. Therefore, the polyurethanes provided by this invention can be used to prepare medical devices requiring high biostability, particularly polymer artificial heart valves.

[0095] Table 2 Performance test results of silicon-containing polyurethane materials prepared in Examples 1 to 5 and Comparative Examples 1 to 6

[0096]

[0097] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A silicon-containing polyurethane material, characterized in that: include: A hard segment, which is derived from the reaction raw materials diisocyanate and chain extender; the mass of the hard segment is 20-80% of the total mass of the silicon-containing polyurethane material; The soft segment is derived from the reaction raw materials polysiloxane and macromolecular diol; The polysiloxane has a molecular formula of Formula I or Formula II: Wherein, n is a natural number of 3-30, R is a C3-C8 straight-chain or branched alkyl group or a C3-C8 straight-chain or branched alkoxy group, R1 is a C3-C6 alkyl group, and R2 is a C1-C4 alkyl group; the molecular weight of the polysiloxane is 500-5000, and the mass fraction of the polysiloxane in the entire silicon-containing polyurethane material is 5-80%.

2. The silicon-containing polyurethane material according to claim 1, characterized in that The molecular formula of the polysiloxane is: One of the following, where n is a natural number between 3 and 30.

3. The method for preparing the silicon-containing polyurethane material according to claim 1 or 2, characterized in that: It includes a one-step method or a two-step method, wherein the two-step method includes the following steps: S1. Mixing dry polysiloxane, macromolecular diol and diisocyanate, and performing polymerization reaction at 40-120° C. to prepare a polyurethane prepolymer; S2, mixing the polyurethane prepolymer obtained in step S1 with a chain extender, and performing a chain extension reaction at 40-120° C. to obtain the silicon-containing polyurethane material; The one-step method comprises the following steps: uniformly mixing dry polysiloxane, macromolecular diol and chain extender, and reacting with diisocyanate at 50-70° C., and obtaining the silicon-containing polyurethane material after the reaction is completed.

4. The method for preparing the silicon-containing polyurethane material according to claim 3, characterized in that: The macromolecular diol is one or more of monomeric or copolymeric polycarbonate diol, polytetramethylene glycol, polyhexamethylene glycol, polyoctamethylene glycol, polydecamethylene glycol, polyisobutylene glycol, polybutadiene glycol, and polyisoprene glycol; the molecular weight of the macromolecular diol is 500-5000, and its mass fraction in the entire silicon-containing polyurethane material is 20-80%.

5. The method for preparing the silicon-containing polyurethane material according to claim 3, characterized in that: The diisocyanate comprises one or more of diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate; the mass fraction of the diisocyanate in the entire silicon-containing polyurethane material is 10-50%.

6. The method for preparing the silicon-containing polyurethane material according to claim 3, characterized in that: The chain extender is one or more of 1,2-ethylenediamine, 1,3-propylenediamine, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol, and the mass fraction of the chain extender in the entire silicon-containing polyurethane material is 1-20%.

7. Use of the silicon-containing polyurethane material according to claim 1 or 2 in the field of biomedical materials.

8. The use according to claim 7, characterized in that The biomedical material includes an artificial valve or a leaflet coating of an artificial valve.

9. An artificial valve, characterized in that: It includes a leaflet, and the leaflet includes the silicon-containing polyurethane material described in right 1 or 2.

10. An artificial valve, characterized in that: It comprises a leaflet, wherein the leaflet is provided with a coating, and the coating comprises the silicon-containing polyurethane material described in right 1 or 2.

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