A polystyrene-based biomaterial for a mold release agent and improvement of biocompatibility and a preparation method thereof

Abstract

The present application provides a kind of release agent and the polystyrene biocompatible material of improving and its preparation method, release agent is the block copolymer by parent body material section and function section polymerization, parent body material section and at least one segment structure of body material are identical or similar, for physical entanglement with body material;Function section is different from the segment structure of body material, for after physical entanglement of parent body material section and body material, reduce the surface tension of body material and improve the biocompatibility of the body material.The beneficial effects of the present application are: 1. By block copolymerization, the function aid is firmly fixed on the material surface.2. Use the function aid in the form of release agent, avoid secondary processing.3. Use the function aid in the form of release agent, can ensure that the forming process of polystyrene block copolymer body material is not affected, so as to not affect the structure in the forming process of polystyrene block copolymer, ensure excellent mechanical properties.

Description

Technical Field

[0001] The present invention relates to a polystyrene biomaterial, in particular to a biomaterial whose biocompatibility is improved by applying a release agent and a preparation method thereof. Background Art

[0002] Among the many biomedical polymers, styrene-based thermoplastic elastomers (TPEs) represent a highly valuable new class of multifunctional biomedical materials. However, due to their low surface energy and strong hydrophobicity, these materials present a risk of plasma protein adhesion when in contact with blood. Therefore, improving the biocompatibility of these materials is crucial for expanding their application in biomedical materials. In particular, in the field of artificial heart valves, excellent biocompatibility effectively extends valve life.

[0003] The existing modification methods are divided into two categories:

[0004] The first type involves blending and modifying styrene block copolymers before forming them. This requires careful control of the material during the initial modification step, and also ensures a stable and efficient processing during subsequent forming. It's worth noting that the introduction of the blend may adversely affect the performance of the material after forming, thereby affecting its service life and effectiveness.

[0005] The second type involves physical or chemical modification of the surface of the styrene block copolymer after the material is formed. Representative applications of physical modification include annealing (including solvent annealing, thermal annealing, etc.) and patterning (such as solvent-induced patterning), which are often accompanied by partial changes in the physical or chemical properties of the material surface. Annealing only controls the thermal history of the material's formation and is relatively easy. Patterning, on the other hand, changes the surface morphology and destroys the specific beneficial phase structure formed during the formation of the styrene block copolymer. Chemical modification often uses physical methods (such as corona treatment and plasma treatment) or chemical reagents (such as dopamine) to impart specific functional groups to the surface, and then introduces functional groups to improve surface properties, which involves a relatively large number of steps.

[0006] In summary, in the existing technology, when modifying styrene-based biomaterials, the steps are usually complicated or easily damage the biomaterials themselves. Therefore, there is an urgent need to develop a new technology to simplify the modification process of styrene-based biomaterials. Summary of the Invention

[0007] In order to solve the problems existing in the above technologies, the present invention provides a biomaterial and a preparation method thereof, the biocompatibility of which is improved by applying a release agent.

[0008] The present invention provides a release agent for improving the biocompatibility of a bulk material. The bulk material is a block copolymer, and the release agent is a block copolymer formed by polymerizing a parent bulk material segment and a functional segment. The parent bulk material segment has the same or similar chain structure as or similar to at least one chain segment of the bulk material and is used for physically entangled with the bulk material; the functional segment has a different chain segment structure from that of the bulk material and is used for reducing the surface tension of the bulk material and improving the biocompatibility of the bulk material after the parent bulk material segment is physically entangled with the bulk material.

[0009] Preferably, the release agent is a diblock copolymer, a triblock copolymer or a copolymer of more blocks; the release agent is represented by the following formula: m [A n B p ] x A q , where A is the parent material segment, B is the functional segment, m ≥ 0, n ≥ 1, p ≥ 1, q ≥ 0, x ≥ 1;

[0010] Release Agent B m [A n B p ] x A q The number average molecular weight is 4000-10000Da;

[0011] Preferably, the parent body material segment is at least one of the following substances: polyolefin, polystyrene polymer; the polyolefin is polyethylene, polypropylene or liquid rubber, and the liquid rubber is liquid butadiene rubber;

[0012] The number average molecular weight of the parent material segment is in the range of 2000-5000Da;

[0013] The functional segment is a compound containing methylsiloxane or fluoride.

[0014] Preferably, the functional segment is one or more of polydimethylsiloxane, dimethylsiloxane, and poly 2,2,3,3,4,4,4-heptafluorobutyl acrylate;

[0015] The number average molecular weight of the material of the functional segment is in the range of 1000-5000 Da.

[0016] Preferably, the parent material segment and the functional segment are connected by chemical bonds generated by addition reaction or free radical reaction; wherein the chemical bond is at least one of the following: isocyanate bond, urea bond, CC covalent bond; the mass ratio of the parent material segment and the functional segment is 1:2 to 2:1.

[0017] The present invention provides a polystyrene biomaterial with improved biocompatibility, comprising:

[0018] Polystyrene-based bulk material, the bulk material is a block copolymer; the bulk material is represented by the following formula: C h D y C z , where h≥1, y≥1, z≥0;

[0019] A release agent, wherein the release agent is as described above and is physically entangled with the bulk material, wherein the functional segment reduces the surface tension of the bulk material and improves the biocompatibility of the bulk material after the bulk material segment is physically entangled with the bulk material;

[0020] The parent material segment of the release agent is identical or similar to at least one segment structure of the parent material, i.e., A in the release agent's molecular formula is identical or similar to C or D in the parent material's molecular formula. "Similar" can be understood as substances containing the same functional groups to satisfy the principle of similar miscibility, which is not elaborated here.

[0021] Preferably, the polystyrene-based bulk material is a block copolymer, and the polystyrene-based bulk material is a diblock copolymer, a triblock copolymer or a copolymer of more blocks.

[0022] Preferably, the polystyrene-based bulk material is at least one of the following substances: poly(styrene-b-butadiene-b-styrene) (SBS), poly(styrene-b-isoprene-b-styrene) (SIS), poly(styrene-b-(ethylene-co-butadiene)-b-styrene) (SEBS), poly(styrene-b-(ethylene-co-propylene)-b-styrene) (SEPS) and poly(styrene-b-isobutylene-b-styrene) (SIBS).

[0023] The present invention provides a method for preparing a polystyrene biomaterial with improved biocompatibility, which comprises the following steps:

[0024] Step 1: applying the release agent in the injection mold;

[0025] Step 2: Injecting polystyrene bulk material into the injection mold through an injection molding machine;

[0026] Step 3: Demolding completes the injection molding, and the release agent is attached and fixed to the polystyrene body material.

[0027] Preferably, the mold release agent is applied inside the injection mold by one of the following methods: spraying, dipping, or brushing;

[0028] The coating thickness is 5 μm or less, more preferably 1 μm or less, to avoid accumulation on the mold due to the flow of the melt during the molding process;

[0029] According to the direction of melt flow during injection molding, the thickness of the release agent is gradually reduced; that is, the closer to the injection port, the thicker the release agent is, so as to reduce the situation where the release agent is dragged by the melt flow, resulting in insufficient release agent on the surface in the final stage of injection molding;

[0030] During the injection molding process, when the bulk material contacts the release agent, the temperature must be at least 100°C higher than the glass transition temperature of the bulk material-friendly segment in the release agent. At this time, the bulk material and the release agent are in a molten state, and the bulk material-friendly segment of the release agent is physically entangled with the segments in the bulk material with the same or similar segment structure.

[0031] During the injection molding process, the mold temperature is within the range of 80-100°C and the holding time is within the range of 3-6 seconds, ensuring the material molding effect and the effective transfer of the release agent to the material surface. That is, the parent material segment of the release agent can be more fully physically entangled with the segment with the same or similar segment structure in the parent material, and the bonding force is higher. In addition, during this process, since the functional segment of the release agent is not identical or similar to any segment of the parent material, the functional segment will not be entangled with the parent material.

[0032] During the injection molding process, the melt flow rate is required to be 0.3cm 3 / s to 1cm 3 / s range, on the one hand, it avoids uneven release agent caused by melt flow when the flow speed is too low, and on the other hand, it ensures the molding effect and mechanical properties of the material.

[0033] Finally, the injection mold is cooled to 30°C-50°C at a cooling rate of 15°C / min-20°C / min, so that the bulk material and the release agent are cooled to below the glass transition temperature; the injection mold is opened, and the mold is demolded to complete the injection molding, and the release agent is attached and fixed on the polystyrene bulk material, that is, Figure 1 As shown, the parent material segment of the release agent is physically entangled with the parent material, and the functional segment of the release agent is combined with the parent material segment through chemical bonds and suspended on the surface of the parent material through the parent material segment, thereby providing the parent material with lower surface tension and higher biocompatibility.

[0034] The beneficial effects of the present invention are:

[0035] 1. The release agent is formed by block copolymerization of the parent material segment and the functional segment, so that the functional additive is firmly suspended on the surface of the parent material through the parent material segment.

[0036] 2. Using functional additives as release agents avoids secondary processing.

[0037] 3. Using the functional additive in the form of a release agent can ensure that the molding process of the styrene block copolymer bulk material is not affected, thereby not affecting the structure of the styrene block copolymer during the molding process and ensuring excellent mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the principle of combining the main material and the release agent of the present invention.

[0039] Figure 2 These are the cytotoxicity test results of styrene block copolymer-release agent composites.

[0040] Figure 3 Hemolysis test results of styrene block copolymer-release agent composites.

[0041] Figure 4 Calcification test results of styrene block copolymer-release agent composite materials after subcutaneous implantation in rats. DETAILED DESCRIPTION Comparative Example 1

[0042] a. Place the mold on an injection molding machine and inject the styrene block copolymer bulk material SIBS into the mold.

[0043] b. Demold to obtain the sample.

[0044] In this comparative example, no release agent was used to release or modify the styrene block copolymer bulk material SIBS. Comparative Example 2

[0045] a. Dilute KF-6000 (trade name Shin-Etsu KF-6000 modified silicone oil) with toluene to 1% solid content and use it as a release agent.

[0046] b. Dip the mold into the release agent solution and take it out. After it dries naturally, dry it at 110℃ for 5 minutes.

[0047] c. Place the mold on an injection molding machine and inject the styrene block copolymer bulk material SIBS into the mold.

[0048] d. Demolding to obtain the sample.

[0049] In this comparative example, a traditional release agent was used to dip-coat the mold, and the sample was finally demoulded. The release agent was simply coated on the surface of the styrene block copolymer body material SIBS, and there was no body material-friendly segment physically entangled with the body material, and no functional segment was suspended outside the body material.

[0050] Synthesis of release agent Example 1

[0051] 22.44 g (10 mmol, number-average molecular weight 2244 Da) of difunctional, hydroxyl-terminated liquid rubber POLYVEST HT (developed and produced by Evonik Degussa AG) was added to the reactor and dehydrated under vacuum at 80°C for 2 hours. Then, 5.00 g (20 mmol) of 4,4'-diphenylmethane diisocyanate (MDI, Wanhua) was added and allowed to react for 2 hours. Then, 9.35 g (20 mmol, number-average molecular weight 935 Da) of difunctional, hydroxyl-terminated polydimethylsiloxane KF-6000 (Shin-Etsu), which had been vacuum-treated at 80°C for 2 hours, was added. The reaction continued at 80°C for 4 hours. The disappearance of the isocyanate peak near 2276 on infrared monitoring indicated the completion of the reaction. Toluene was added as a solvent to yield triblock release agent A with a number-average molecular weight of 4352 Da. Example 2

[0052] To a 250 mL stoppered three-necked flask, 50 mL of cyclohexanone, 0.31 g of benzyl bromide, 0.21 g of triphenylphosphine, and 30 g of styrene were added in sequence and stirred thoroughly. After evacuation, nitrogen was bubbled through for 10 minutes to remove oxygen. During the nitrogen sparge, 0.709 g of FeCl₃.6H₂O was added, stirred for 5 minutes, and finally, 0.23 g of ascorbic acid was added. Solution polymerization was carried out in an oil bath at 110°C under nitrogen. The reaction was stopped when the number-average molecular weight reached approximately 2000 Da, as measured by GPC. The polymer solution was cooled to room temperature and then precipitated into a large amount of ice-cold methanol. The precipitate was repeatedly washed with methanol, and the crude product was then extracted three times with cyclohexane at room temperature, replacing the cyclohexane every 24 hours. The resulting product was washed with acetone, precipitated with methanol, and filtered, repeating this process three times. The product was then dried under vacuum at room temperature to a constant weight to obtain an intermediate with a number-average molecular weight of 2331 Da.

[0053] In a 50 mL stoppered three-necked flask, 10 mL of cyclohexanone, 2 g of the intermediate, and 4 g of 2,2,3,3,4,4,4-heptafluorobutyl acrylate were added in sequence and stirred to mix thoroughly. After evacuation, nitrogen was bubbled for 10 minutes to remove oxygen. During the nitrogen sparge, 0.012 g of copper bromide and 0.063 g of bipyridine were added. Solution polymerization was carried out in a 95°C oil bath. After 36 hours of reaction, the mixture was removed and cooled to room temperature. The polymer solution was poured into a large amount of ice methanol for precipitation and repeatedly washed with methanol. The crude product was then extracted three times with cyclohexane at room temperature, with the cyclohexane replaced every 24 hours. Finally, the resulting product was washed with acetone, precipitated with methanol, and filtered, repeating this process three times. The product was dried under vacuum at room temperature to constant weight to obtain diblock release agent B with a number average molecular weight of 6854 Da. Example 3

[0054] The preparation method is the same as that of Example 2, except that the number average molecular weight of the intermediate is 3347 Da, the number average molecular weight of the final release agent C is 9882 Da, and the release agent C is also a diblock polymer.

[0055] Specifically, 50 mL of cyclohexanone, 0.31 g of benzyl bromide, 0.21 g of triphenylphosphine, and 30 g of styrene were added to a 250 mL stoppered three-necked flask in sequence and stirred to mix thoroughly. After evacuation, nitrogen was bubbled through for 10 minutes to remove oxygen. During the nitrogen purging process, 0.709 g of FeCl₃.6H₂O was added, stirred for 7 minutes, and finally, 0.23 g of ascorbic acid was added. Solution polymerization was carried out in an oil bath at 110°C under nitrogen protection. The reaction was stopped when the number-average molecular weight reached approximately 3000 Da, as measured by GPC. The polymer solution was then cooled to room temperature and precipitated into a large amount of iced methanol. The precipitate was repeatedly washed with methanol, and the crude product was then extracted three times with cyclohexane at room temperature, with the cyclohexane replaced every 24 hours. The resulting product was washed with acetone, precipitated with methanol, filtered, and repeated three times. The product was then dried under vacuum at room temperature to a constant weight to obtain an intermediate with a number-average molecular weight of 3347 Da.

[0056] In a 50 mL stoppered three-necked flask, 10 mL of cyclohexanone, 2 g of the intermediate, and 4 g of 2,2,3,3,4,4,4-heptafluorobutyl acrylate were added in sequence and stirred to mix thoroughly. After evacuation, nitrogen was bubbled for 10 minutes to remove oxygen. During the nitrogen sparge, 0.012 g of copper bromide and 0.063 g of bipyridine were added. Solution polymerization was carried out in an oil bath at 100°C. After 48 hours of reaction, the mixture was removed and cooled to room temperature. The polymer solution was poured into a large amount of ice methanol for precipitation and repeatedly washed with methanol. The crude product was then extracted three times with cyclohexane at room temperature, with the cyclohexane replaced every 24 hours. Finally, the resulting product was washed with acetone, precipitated with methanol, and filtered three times. The mixture was dried under vacuum at room temperature to constant weight to obtain a diblock release agent C with a number average molecular weight of 9882 Da.

[0057] The examples of using the above release agent to form materials are as follows: Example 4

[0058] a. Dilute release agent A with toluene to 1% solid content (i.e., the mass fraction of release agent A is 1%).

[0059] b. Dip the mold into the release agent solution and take it out. After it dries naturally, dry it at 110℃ for 5 minutes.

[0060] c. Place the mold on an injection molding machine and inject the styrene block copolymer bulk material SIBS into the mold.

[0061] d. Demolding to obtain the sample. Example 5

[0062] a. Dilute release agent B with toluene to 0.3% solid content.

[0063] b. Use a brush to apply the release agent to the inner surface of the mold, wait for it to dry naturally, and then dry it at 110℃ for 5 minutes.

[0064] c. Place the mold on an injection molding machine and inject the styrene block copolymer bulk material SIBS into the mold.

[0065] d. Demolding to obtain the sample. Example 6

[0066] a. Dilute release agent B with toluene to 1% solid content.

[0067] b. Dip the mold into the release agent solution and take it out. After it dries naturally, dry it at 110℃ for 5 minutes.

[0068] c. Place the mold on an injection molding machine and inject the styrene block copolymer bulk material SIBS into the mold.

[0069] d. Demolding to obtain the sample. Example 7

[0070] a. Dilute release agent C with toluene to 1% solid content.

[0071] b. Dip the mold into the release agent solution and take it out. After it dries naturally, dry it at 110℃ for 5 minutes.

[0072] c. Place the mold on an injection molding machine and inject the styrene block copolymer bulk material SIBS into the mold.

[0073] d. Demolding to obtain the sample.

[0074] In the preferred embodiment, during the injection molding process, the temperature of the bulk material in contact with the release agent must be at least 100°C above the glass transition temperature of the "styrene-friendly block copolymer segment" in the release agent. If the "styrene-friendly block copolymer segment" is polybutadiene, the processing temperature should be approximately 20°C above the minimum, and considering the actual material processing performance, it should be approximately 190°C.

[0075] During the injection molding process, the mold temperature is within the range of 80-100°C and the holding time is within the range of 3-6s to ensure the molding effect of the material and the effective transfer of the release agent to the material surface.

[0076] During the injection molding process, the melt flow rate is required to be 0.3cm 3 / s to 1cm 3 / s range, on the one hand, it avoids uneven release agent caused by melt flow when the flow speed is too low, and on the other hand, it ensures the molding effect and mechanical properties of the material.

[0077] During the injection molding process, the specific injection molding process can be found in patent CN116509602A - Polymer Heart Valve and Preparation Method Thereof. During the injection molding process, the base material (styrene block copolymer) and the release agent are exposed to a temperature at least 100°C above the glass transition temperature of the base material-specific segments in the release agent. At this point, the base material and the release agent are molten, and the base material-specific segments of the release agent physically entangle with segments in the base material with the same or similar chain structure. The mold temperature is kept between 80°C and 100°C, and the holding time is between 3 and 6 seconds, ensuring both effective molding and efficient transfer of the release agent to the material surface. This allows the base material-specific segments of the release agent to more fully physically entangle with segments in the base material with the same or similar chain structure, resulting in a stronger bond. Furthermore, during this process, since the functional segments of the release agent are neither identical nor similar to any of the segments in the base material, they do not entangle with the base material. Finally, the injection mold is cooled to 30°C-50°C at a cooling rate of 15°C / min-20°C / min, so that the bulk material and the release agent are cooled to below the glass transition temperature; the injection mold is opened, and the mold is demolded to complete the injection molding, and the release agent is attached and fixed on the polystyrene bulk material, that is, Figure 1 As shown, the parent material segment of the release agent is physically entangled with the parent material, and the functional segment of the release agent is combined with the parent material segment through chemical bonds and suspended on the surface of the parent material through the parent material segment, thereby providing the parent material with lower surface tension and higher biocompatibility.

[0078] Test experiment:

[0079] The samples prepared according to the methods described in the above examples and comparative examples were subjected to in vitro cytotoxicity testing according to the method specified in GB / T 16886.5-2017. In vitro hemolytic performance testing was performed according to the method specified in GB / T 16886.4-2022. Anti-calcification performance testing was performed according to GB / T 16886. The test results are shown in Table 1.

[0080]

[0081] Note: There are numerical values in the following figures. It can be found from the above experimental data that the styrene block copolymer composite materials (Examples 4-7) obtained by processing the functional aid in the form of a release agent have better biocompatibility than the styrene block copolymer bulk materials (Comparative Examples 1 and 2) without using the release agent of the present application. Specifically, in Comparative Examples 1 and 2, the cytotoxicity values after 1 day are 1 and 2, respectively, while the cytotoxicity values in Examples 4 to 7 are all greater than 3, and the larger the number, the better the biocompatibility, so this shows that the improved release agent in Examples 4-7 of the present application has obtained a biocompatible biomaterial with better biocompatibility.

[0082] On the other hand, by means of block copolymerization, the release agent is firmly fixed on the surface of the material (Examples 4-7), which has more stable and long-term biocompatibility than the release agent simply coated on the styrene block copolymer bulk material (Comparative Example 2). Specifically, in Comparative Example 2, the compatibility decreased to "1" after 30 days, while the cytotoxicity values in Examples 4 to 7 remained unchanged, for example, all "3" in Example 4, indicating that the application of the release agent in Examples 4-7 of the present application has ensured the long-term biocompatibility.

[0083] In addition, the use of functional aids in the form of a release agent avoids secondary processing. The forming process of the styrene block copolymer bulk material can be ensured, so as not to affect the structure of the styrene block copolymer during the forming process, and excellent mechanical properties are ensured. For example, the mechanical performance indicators of Examples 4-7 compared to Comparative Examples: tensile strength, elongation at break, etc. have not decreased significantly.

[0084] On the other hand, referring to Figure 2 It can be seen that the use of the styrene block copolymer-release agent composite material provided by the present application has a biological response on L929 mammalian fibroblasts, so as to obtain the cytotoxicity test results as shown in Figure 2 Specifically, 12.5%, 25%, 50% and 100% concentrations of the extract were used, and blank control, negative control and positive control were also used. The blank control refers to a group without adding any extract, the negative control refers to adding an existing substance without cytotoxicity (for example, high-density polyethylene), and the positive control refers to adding an existing substance with cytotoxicity (for example, zinc diethyl dithiocarbamate). Among them, the lower the cell viability % (i.e., the number of living cells / total cell number), the greater the potential cytotoxicity, and the cell viability % of the 100% sample extract is the final detection result. The blank control is MEM culture medium containing 10% fetal bovine serum, the positive control is zinc diethyl dithiocarbamate, the negative control is high-density polyethylene, and the sample is the styrene block copolymer-release agent composite material of Example 6.

[0085] The acceptance criteria for the test data is that the survival rate drops to < 70% of the blank group, indicating potential cytotoxicity. The survival rate of 50% of the sample leachate should be the same or higher than that of 100% leachate, otherwise the test needs to be repeated. The series of gradient concentrations are set for the reliability of the data. The evaluation criteria are that if the cell viability of 100% concentration of the sample leachate is lower than 70% of the blank group, it indicates that the tested sample has potential cytotoxicity.

[0086] By Figure 2 As can be seen, the cell viability value of 100% leachate group of the styrene block copolymer-mold release agent composite provided by the embodiment of the present application is 80.1%, and has no potential toxic effect on L929 cells.

[0087] In another aspect, referring to Figure 3 As shown, the in vitro test is used to evaluate whether the styrene block copolymer-mold release agent composite provided by the embodiment of the present application has adverse effects on hemolysis. The sample is the styrene block copolymer-mold release agent composite of Example 6, the negative control is high-density polyethylene, the positive control is nitrile rubber, and the blank control sample is PBS (Phosphate-Buffered Saline). The evaluation criteria are that the average blank-corrected hemolysis index is 0-2, which is classified as no hemolysis. The average blank-corrected hemolysis index is 2-5, which is classified as mild hemolysis. The average blank-corrected hemolysis index is > 5, which is classified as hemolysis.

[0088] By Figure 3 As can be seen, the blank-corrected hemolysis index of the styrene block copolymer-mold release agent composite provided by the embodiment of the present application is 0.44 when directly contacted. Therefore, the styrene block copolymer-mold release agent composite provided by the embodiment of the present application has no effect on hemolysis.

[0089] In another aspect, referring to Figure 4 As shown, the rat subcutaneous implant model is established, and the implanted sample is taken out at 21 days and 60 days after the operation, respectively, and the in vitro test of calcium ion content is determined by inductively coupled plasma to evaluate the anti-calcification effect of the styrene block copolymer-mold release agent composite provided by the embodiment of the present application.

[0090] The sample is the styrene block copolymer-mold release agent composite of Example 6, and the control group is a styrene block copolymer. As can be seen from the results shown in the figure, the calcium deposition of the experimental group is significantly lower than that of the control group, indicating that the styrene block copolymer-mold release agent composite has better anti-calcification effect.

[0091] In addition, the method for modifying the styrene block copolymer provided by the embodiment of the present application improves the biocompatibility of the styrene block copolymer bulk material, and therefore, the styrene block copolymer bulk material can be used as a raw material for implantation / intervention medical devices. The implantation / intervention medical devices can include heart valves, biological implants, drug delivery devices and the like. The preparation method provided by the embodiment of the present application is also more simple and easy to control.

Claims

1. A release agent for improving the biocompatibility of a base material, wherein the base material is a block copolymer, characterized in that: The release agent is a block copolymer formed by polymerizing a parent material segment and a functional segment. The parent material segment has the same chain structure as at least one segment of the parent material and is used to physically entangle with the parent material. The functional segment has a different chain structure from that of the parent material and is used to reduce the surface tension of the parent material and improve the biocompatibility of the parent material after the parent material segment is physically entangled with the parent material. The release agent is a triblock copolymer; the release agent is represented by the following formula: B m [A n B p ] x A q , where A is the parent material segment, B is the functional segment, m ≥ 0, n ≥ 1, p ≥ 1, q ≥ 0, x ≥ 1; Release Agent B m [A n B p ] x A q The number average molecular weight is 4000-10000Da; The parent body material segment is at least one of the following substances: polystyrene polymer, polyethylene, polypropylene or liquid rubber; The number average molecular weight of the parent material segment is in the range of 2000-5000Da; The functional segment is one or both of polydimethylsiloxane and dimethylsiloxane; The number average molecular weight of the material of the functional segment is in the range of 1000-5000Da; The parent body material segment and the functional segment are connected by forming a chemical bond through an addition reaction, and the mass ratio of the parent body material segment to the functional segment is 1:2 to 2:

1.

2. The release agent for improving the biocompatibility of a base material according to claim 1, characterized in that: The chemical bond is a CC covalent bond.

3. A polystyrene biomaterial with improved biocompatibility, characterized in that: include: Polystyrene-based bulk material, the bulk material is a block copolymer; the bulk material is represented by the following formula: C h D y C z , where h≥1, y≥1, z≥0; The release agent adopts the release agent as claimed in any one of claims 1-2, wherein the parent body material segment is physically entangled with the parent material, and the functional segment reduces the surface tension of the parent material and improves the biocompatibility of the parent material after the parent body material segment is physically entangled with the parent material.

4. The polystyrene-based biomaterial with improved biocompatibility according to claim 3, characterized in that: The polystyrene-based bulk material is a diblock copolymer, a triblock copolymer or a copolymer of more blocks; The polystyrene-based bulk material is at least one of the following substances: poly(styrene-b-butadiene-b-styrene), poly(styrene-b-isoprene-b-styrene), poly(styrene-b-(ethylene-co-butadiene)-b-styrene), poly(styrene-b-(ethylene-co-propylene)-b-styrene) and poly(styrene-b-isobutylene-b-styrene).

5. Use of the polystyrene biomaterial with improved biocompatibility according to claim 3 or 4 as a raw material for implantable / interventional medical devices.

6. The method for preparing a polystyrene-based biomaterial with improved biocompatibility according to claim 3 or 4, characterized in that: The following steps are involved: Step 1: applying the release agent in the injection mold; Step 2: Injecting polystyrene bulk material into the injection mold through an injection molding machine; Step 3: Demolding completes the injection molding, and the release agent is attached and fixed to the polystyrene body material.

7. The method for preparing a polystyrene-based biomaterial with improved biocompatibility according to claim 6, wherein: Applying a release agent to the injection mold by one of the following methods: spraying, dipping, or brushing; The coating thickness is less than 5μm to avoid accumulation on the mold due to the flow of the melt during the molding process; According to the melt flow direction during injection molding, gradually reduce the thickness of the release agent; that is, the closer to the injection port, the thicker the release agent; During the injection molding process, when the bulk material contacts the release agent, the temperature must be at least 100°C higher than the glass transition temperature of the bulk material-friendly segment in the release agent. When the bulk material and the release agent are molten, the bulk material-friendly segment of the release agent and the segments with the same segment structure in the bulk material are physically entangled. During the injection molding process, the mold temperature is within the range of 80-100°C and the holding time is within the range of 3-6s; During the injection molding process, the melt flow rate is required to be 0.3cm 3 / s to 1cm 3 / s range.

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