Preparation method of polylactide caprolactone PLCL for medical field

Abstract

The invention belongs to the technical field of medical treatment, and particularly relates to a preparation method of polylactide caprolactone PLCL used in the medical field, which comprises the following steps: S1, polymerization reaction: taking lactide and caprolactone as raw materials, adding the raw materials into a polymerization kettle, adding a reaction solution into the polymerization kettle, vacuumizing the polymerization kettle, heating and stirring under the heating and stirring action of the polymerization kettle, and reacting for 2-4 hours to obtain a reaction solution; forming a mixed solution; s2, polymer separation: adding a precipitant into the mixed solution to precipitate PLCL, separating PLCL from the reaction solution, and removing the reaction solution on the upper layer to obtain PLCL; s3, polymer drying: heating the PLCL to remove an organic solvent in the PLCL to obtain dried PLCL; and S4, polymer refining: carrying out fine grinding on the dried PLCL by using a grinding machine, screening the ground PLCL by using a fine screen, returning the PLCL which cannot be leaked from meshes of the fine screen to the grinding machine for continuous grinding, and obtaining the PLCL which is high in purity and conforms to the medical implantation level by using the PLCL which is leaked from the meshes of the fine screen.

Description

Technical Field

[0001] This invention belongs to the field of medical technology, and in particular relates to a method for preparing polylactide caprolactone (PLCL) for use in the medical field. Background Technology

[0002] In the medical field, PLCLs can be used in the manufacture of absorbable medical sutures due to their excellent shape memory, biocompatibility, and biodegradability; they can be used in the manufacture of 3D printed bone repair scaffolds due to their high toughness, tensile strength, and adjustable elasticity; they can be made into microspheres for facial fillers and personal care products; and they can also be made into drug carriers for the treatment of tumor diseases. Traditional methods for preparing PLCLs are inefficient and produce PLCLs with low purity.

[0003] For example, patent application CN202110117283.8 describes a method for preparing polylactide-caprolactone (PLCL). Using lactide and caprolactone as raw materials, the reaction is carried out in stages using microwave heating at different powers. After the reaction is complete, the final product is obtained by dissolving ethanol in dichloromethane and separating the slurry. This invention uses microwave heating, which can rapidly raise the temperature of the reaction system and cause the initiator / capping agent to generate free radicals at a rate higher than that of conventional heating, shortening the reaction induction period and accelerating the reaction. However, the disadvantage of this technical solution is that the preparation efficiency of PLCL is low, and the purity of the obtained PLCL is low. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing polylactide caprolactone (PLCL) for use in the medical field, in order to solve the problems in the prior art. The specific technical solution is as follows:

[0005] A method for preparing polylactide caprolactone (PLCL) for medical use includes the following steps:

[0006] S1. Polymerization reaction: Using lactide and caprolactone as raw materials, the raw materials are added to the polymerization reactor, the reaction liquid is added to the polymerization reactor, and the polymerization reactor is evacuated. Under the heating and stirring action of the polymerization reactor, a mixture is formed.

[0007] S2. Polymer separation: Add a precipitant to the mixture to precipitate PLCL, separate it from the reaction solution, and remove the upper layer of reaction solution to obtain PLCL;

[0008] S3. Polymer drying: The organic solvent in PLCL is removed by heating to obtain dried PLCL;

[0009] S4. Polymer Refining: The dried PLCL is finely ground using a grinder.

[0010] Furthermore, in step S1, lactide is added to the polymerization reactor, and caprolactone is added after preheating.

[0011] Furthermore, in S1, the reaction solution is composed of a catalyst, an initiator, and an organic solvent;

[0012] The catalyst is stannous octoate;

[0013] The initiator is any one of ethylene glycol, glycerol, 1,4-butanediol, and benzyl alcohol;

[0014] The organic solvent is any one of benzene, toluene, trifluorotoluene, xylene, or trimethylbenzene.

[0015] Furthermore, in step S2, the mixture is placed in a collection tank, a precipitant is added, and the mixture is left to stand for 5-10 hours. The PLCL precipitates at the bottom of the collection tank, while the upper layer is the reaction liquid.

[0016] Furthermore, in step S3, a flexible tube is inserted into the collection tank to slowly remove the reaction liquid.

[0017] Furthermore, in step S3, the bottom of the collection tank is heated to heat the PLCL and evaporate the organic solvent in the PLCL.

[0018] Furthermore, the polymerization reactor includes a main body with four supports fixed on it. The upper end of the main body is provided with a material inlet and a pressure regulating port. A manhole and a temperature sensor are installed on the upper end of the main body. The main body is surrounded by a jacket. A threaded plate is provided between the jacket and the main body. A medium inlet is provided on the upper side of the jacket and a medium outlet is provided on the lower side of the jacket. A material outlet pipe is fixed at the lower end of the main body and is rotatably connected to a ball valve.

[0019] Furthermore, a support frame is fixed to the upper end of the main body, the support frame is rotatably connected to the first rotating wheel, the first rotating wheel is connected to the motor bearing, the support frame is fixedly connected to the motor, the first rotating wheel is connected to the mixing and stirring device through belt drive, and the mixing and stirring device is rotatably connected to the main body.

[0020] Furthermore, the mixing and stirring device includes a fixed ring frame, which is fixed to the upper end of the main body. The fixed ring frame is fixedly connected to one end of the connecting pipe, and the other end of the connecting pipe is fixedly connected to the outer shell. The upper end of the outer shell is provided with a conical surface. The belt is connected to the second rotating wheel for transmission. The second rotating wheel is fixedly connected to the first rotating shaft, and the upper end of the first rotating shaft is provided with a conical opening.

[0021] Furthermore, the lower end of the rotating shaft is rotatably connected to three conical wheel rods, the conical wheel rods are fixedly connected to the lower stirring blades, the first rotating shaft is rotatably connected to the fixed ring frame, the first rotating shaft is rotatably connected to the connecting pipe, the first rotating shaft is rotatably connected to the outer shell, the middle part of the first rotating shaft is fixedly connected to the first gear disk, the first gear disk meshes with two gears for transmission, the gears are rotatably connected to the gear brackets, both gear brackets are fixed inside the outer shell, both gears mesh with the second gear disk for transmission, the second gear disk is fixedly connected to the second rotating shaft, and the second rotating shaft is fixedly connected to the three upper stirring blades.

[0022] The advantages of this invention are:

[0023] 1. Under the dual action of heating and stirring, the raw materials can be rapidly polymerized into PLCL, which has high preparation efficiency, and high-purity PLCL can be obtained by precipitation method.

[0024] 2. The threaded plate between the jacket and the main body allows the medium to spiral downwards, resulting in high heat transfer efficiency and enabling the main body to heat up or cool down rapidly.

[0025] 3. The lower and upper stirring blades rotate in different directions, which can disrupt the flow of the mixture while stirring the raw materials. At the same time, the reaction liquid is added between the two sets of stirring blades to achieve rapid contact and reaction between the raw materials and the reaction liquid.

[0026] 4. Initially, the three lower stirring blades are in a vertical position, with a large contact area between the blade surface and the mixture, resulting in strong mixing ability during stirring. This is suitable for environments with medium viscosity. When the stirring angle of the three lower stirring blades exceeds 45 degrees, the contact area between the blade surface and the mixture decreases, resulting in a large axial flow rate during rotation. This is suitable for environments with reactants layered vertically, high heat balance requirements, and medium to low viscosity. Furthermore, the angle of the stirring blades can be adjusted according to the different viscosities of the raw material mixture to achieve the maximum raw material polymerization efficiency.

[0027] 5. The different angles of the lower and upper stirring blades result in different degrees of stirring of the mixture, causing the mixture to move randomly, accelerating the contact between the two raw materials and between the two raw materials and the reaction liquid, and speeding up the polymerization reaction. Attached Figure Description

[0028] Figure 1 This is a process flow diagram of the present invention;

[0029] Figure 2 This is a schematic diagram of the overall structure of the present invention. Figure 1 ;

[0030] Figure 3 This is a schematic diagram of the overall structure of the present invention. Figure 2 ;

[0031] Figure 4 This is a schematic diagram of the overall structure of the present invention. Figure 3;

[0032] Figure 5 This is a schematic diagram of the mixing and stirring device of the present invention. Figure 1 ;

[0033] Figure 6 This is a schematic diagram of the mixing and stirring device of the present invention. Figure 2 ;

[0034] Figure 7 This is a schematic diagram of the mixing and stirring device of the present invention. Figure 3 ;

[0035] Figure 8 This is a schematic diagram of the mixing and stirring device of the present invention. Figure 4 ;

[0036] Explanation of markings in the diagram:

[0037] 1. Main body; 2. Support frame; 3. Material inlet; 4. Air pressure regulating port; 5. Manhole; 6. Temperature gauge; 7. Jacket; 8. Threaded plate; 9. Medium inlet; 10. Medium outlet; 11. Ball valve; 12. Material outlet pipe; 13. Motor; 14. Rotary wheel one; 15. Belt; 16. Support frame; 17. Mixing and stirring device; 1701. Fixing ring frame; 1702. Connecting pipe; 1703. Outer shell; 1704. 1705. Rotating wheel 2; 1706. Rotating shaft 1; 1707. Conical wheel rod; 1708. Lower stirring blade; 1709. Gear disk 1; 1710. Gear support; 1711. Gear disk 2; 1712. Rotating shaft 2; 1713. Upper stirring blade; 1714. Feed chute; 1715. Lower outlet; 1716. Cover; 1717. Screw; 1718. Slide rod; 1719. Moving block; 1720. Rack. Detailed Implementation

[0038] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0040] Example 1

[0041] like Figure 1-8 As shown, a method for preparing polylactide caprolactone (PLCL) for medical use includes the following steps:

[0042] S1. Polymerization reaction: Using lactide and caprolactone as raw materials, the raw materials are added to the polymerization reactor, the reaction liquid is added to the polymerization reactor, and the polymerization reactor is evacuated. Under the heating and stirring action of the polymerization reactor, a mixture is formed.

[0043] S2. Polymer separation: Add a precipitant to the mixture to precipitate PLCL, separate it from the reaction solution, and remove the upper layer of reaction solution to obtain PLCL;

[0044] S3. Polymer drying: The organic solvent in PLCL is removed by heating to obtain dried PLCL.

[0045] The working principle of the above technical solution is as follows: lactide and caprolactone are added to the polymerization reactor in a ratio of 2:3. A reaction solution is added to the polymerization reactor, which can accelerate the polymerization of lactide and caprolactone. The stirring and heating devices in the polymerization reactor are started to stir the lactide, caprolactone and reaction solution, and accelerate the mixing reaction. After stirring for a certain period of time, a mixture of PLCL, unpolymerized lactide, unpolymerized caprolactone and reaction solution is obtained. A precipitant, which is methanol or ethanol, is added to the mixture. The precipitant can cause PLCL to precipitate. The upper layer of reaction solution is removed to obtain PLCL. The PLCL is heated to remove the water to obtain dry PLCL.

[0046] Under the combined action of heating and stirring, the raw materials can be rapidly polymerized into PLCL, resulting in high preparation efficiency. High-purity PLCL can be obtained using a precipitation method.

[0047] Example 2

[0048] like Figure 1-8 As shown, in S1, lactide is preheated beforehand, and caprolactone is added after preheating.

[0049] The working principle of the above technical solution is as follows: lactide is preheated, caprolactone is added after preheating, and then the reaction solution is added to the polymerization reactor for polymerization. This method is easier to polymerize than adding the raw materials directly into the polymerization reactor.

[0050] Example 3

[0051] like Figure 1-8 As shown, in S1, the reaction solution consists of a catalyst, an initiator, and an organic solvent;

[0052] The working principle of the above technical solution is as follows: the organic solvent serves as the carrier of the raw materials, which can move and polymerize in the organic solvent. The catalyst and initiator catalyze and accelerate the polymerization of lactide and caprolactone. The commonly used catalyst is stannous octoate, and the commonly used initiator is any one of ethylene glycol, glycerol, 1,4-butanediol, and benzyl alcohol. The commonly used organic solvent is any one of benzene, toluene, trifluorotoluene, xylene, and trimethylbenzene.

[0053] Example 4

[0054] like Figure 1-8 As shown, in step S2, the mixture is placed in a collection tank, a precipitant is added, and the mixture is left to stand for 5-10 hours. The PLCL precipitates at the bottom of the collection tank, and the upper layer is the reaction liquid. A flexible tube is inserted into the collection tank to slowly remove the reaction liquid.

[0055] The working principle of the above technical solution is as follows: Place the mixture into a collection tank, add a precipitant to the collection tank, and let it stand for 5-10 hours. PLCL will settle to the bottom of the collection tank. Insert a tubing into the reaction solution, ensuring that the tubing does not touch the PLCL at the bottom of the collection tank, and slowly remove the reaction solution to obtain PLCL.

[0056] Example 5

[0057] like Figure 1-8 As shown, the bottom of the heating collection tank is heated to heat the PLCL and evaporate the organic solvent in the PLCL.

[0058] The working principle of the above technical solution is as follows: the bottom of the collection tank is heated, which in turn heats the PLCL. The organic solvent mixed in the PLCL evaporates continuously, resulting in dry block PLCL.

[0059] Example 6

[0060] like Figure 1-8 As shown, in step S4, the ground PLCL is sieved through a fine sieve to obtain high-purity PLCL that meets the requirements for medical implantation.

[0061] The working principle of the above technical solution is as follows: After being continuously ground in the grinder, PLCL is sieved through a fine sieve to obtain high-purity PLCL that meets the medical implant grade. PLCL that cannot be sieved through the fine sieve is returned to the grinder for further grinding until it meets the medical implant grade.

[0062] Example 7

[0063] like Figure 1-8 As shown, the polymerization reactor includes a main body 1, four supports 2 are fixed on the main body 1, a material inlet 3 and a pressure regulating port 4 are provided at the upper end of the main body 1, a manhole 5 and a temperature sensor 6 are installed at the upper end of the main body 1, a jacket 7 is wrapped around the main body 1, a threaded plate 8 is provided between the jacket 7 and the main body 1, a medium inlet 9 is provided on the upper side of the jacket 7, a medium outlet 10 is provided on the lower side of the jacket 7, and a material outlet pipe 12 is fixed at the lower end of the main body 1. The material outlet pipe 12 is rotatably connected to a ball valve 11.

[0064] The working principle of the above technical solution is as follows: The main body 1 can be fixed by four supports 2. The raw material is added into the main body 1 through the material inlet 3. The air pressure regulating port 4 is connected to an external air pressure regulator, which can regulate the air pressure in the main body 1. The polymerization status of the raw material in the main body 1 can be observed through the manhole 5. The temperature measuring gauge 6 can display the temperature in the main body 1. The medium is added through the medium inlet 9. The medium will spiral down along the threaded plate 8 between the jacket 7 and the outer wall of the main body 1 and be discharged from the medium outlet 10. The temperature of the medium is adjusted according to the temperature of the main body 1 detected by the temperature measuring gauge 6, thereby ensuring a suitable polymerization temperature in the main body 1. When the polymerization in the main body 1 is completed, the ball valve 11 is turned, and the mixture in the main body 1 flows out from the material outlet pipe 12.

[0065] The threaded plate 8 between the jacket 7 and the main body 1 allows the medium to spiral downwards, resulting in high heat transfer efficiency and enabling the main body 1 to heat up or cool down rapidly.

[0066] Example 8

[0067] like Figure 1-8 As shown, a support frame 16 is fixed at the upper end of the main body 1. The support frame 16 is rotatably connected to the first rotating wheel 14. The first rotating wheel 14 is connected to the bearing of the motor 13. The support frame 16 is fixedly connected to the motor 13. The first rotating wheel 14 is connected to the mixing and stirring device 17 through the transmission of the belt 15. The mixing and stirring device 17 is rotatably connected to the main body 1.

[0068] The working principle of the above technical solution is as follows: the starting motor 13 drives the rotating wheel 14 to rotate, which in turn drives the belt 15 to rotate, which in turn drives the mixing and stirring device 17 to rotate, thereby stirring the raw materials and reaction liquid in the main body 1.

[0069] Example 9

[0070] like Figure 1-8As shown, the mixing and stirring device 17 includes a fixed ring frame 1701, which is fixed to the upper end of the main body 1. The fixed ring frame 1701 is fixedly connected to one end of the connecting pipe 1702, and the other end of the connecting pipe 1702 is fixedly connected to the outer shell 1703. The upper end of the outer shell 1703 is provided with a conical surface. The belt 15 is connected to the second rotating wheel 1704 for transmission. The second rotating wheel 1704 is fixedly connected to the first rotating shaft 1705. The upper end of the first rotating shaft 1705 is provided with a conical opening. The lower end of the rotating shaft 1705 is rotatably connected to three conical wheel rods 1706. The conical wheel rods 1706 are fixedly connected to the lower stirring blade 1707. The rotating shaft 1705 is rotatably connected to the fixed ring frame 1701, the connecting pipe 1702, and the outer casing 1703. The middle part of the rotating shaft 1705 is fixedly connected to the gear disk 1708. The gear disk 1708 meshes with two gears 1709 for transmission. Gear 1709 is rotatably connected to gear bracket 1710. Both gear brackets 1710 are fixed inside the outer casing 1703. Both gears 1709 mesh with gear disk 1711 for transmission. Gear disk 1711 is fixedly connected to shaft 1712. Shaft 1712 is fixedly connected to three upper stirring blades 1713. Shaft 1705 has a feed chute 1714 inside. The upper end of the feed chute 1714 is open, and the lower end of the feed chute 1714 passes through... The lower outlet 1715 is connected to the outside. The upper end of the rotating shaft 1705 is covered with a cover 1716. The center of the rotating shaft 1705 is threaded with a screw 1717. The screw 1717 is rotatably connected to the upper end of the slide rod 1718. The lower end of the slide rod 1718 is fixedly connected to the moving block 1719. The slide rod 1718 is slidably connected to the rotating shaft 1705. The moving block 1719 is fixedly connected to three racks 1720. The racks 1720 mesh with the conical wheel rod 1706 for gear transmission.

[0071] The working principle of the above technical solution is as follows: Raw materials are added into the main body 1 through the material inlet 3. The motor 13 is started to drive the first rotating wheel 14 to rotate, which drives the belt 15 to rotate, which drives the second rotating wheel 1704 to rotate, which drives the first rotating shaft 1705 to rotate clockwise, which drives the three conical wheel rods 1706 to rotate together with the first rotating shaft 1705, which drives the three lower stirring blades 1707 to rotate clockwise, thereby stirring the raw materials. The rotation of the first rotating shaft 1705 drives the first gear disk 1708 to rotate clockwise, which drives the two gears 1709 to rotate, which drives the second gear disk 1711 to rotate counterclockwise, which drives the second rotating shaft 1712 to rotate counterclockwise, which drives the three upper stirring blades 1713 to rotate counterclockwise. The lower stirring blades 1707 rotate in the opposite direction to the upper stirring blades 1713, which can disrupt the flow direction of the mixture while stirring the raw materials, so as to achieve rapid contact and reaction between the raw materials and the reaction liquid.

[0072] The reaction liquid is added from the upper end of the rotating shaft 1705 into the feed tank 1714. The reaction liquid enters the main body 1 from the three lower outlets 1715 and mixes with the raw materials. The reaction liquid is added between the lower stirring blade 1707 and the upper stirring blade 1713. The lower stirring blade 1707 and the upper stirring blade 1713 rotate in different directions and at the same time, the lower stirring blade 1707 and the upper stirring blade 1713 have different angles, resulting in different degrees of stirring of the mixture and further disrupting the flow of the mixture. The reaction liquid is added between the two sets of stirring blades to accelerate the contact between the raw materials and the reaction liquid.

[0073] Pull out the cover 1716 and use a screwdriver to turn the screw 1717. The screw 1717 rotates with the rotating shaft 1705, causing the screw 1717 to rise or fall, which in turn causes the slide bar 1718 to rise or fall, and the moving block 1719 and rack 1720 to rise or fall. This causes the three conical wheel rods 1706 to rotate with the rotating shaft 1705, which in turn causes the three lower stirring blades 1707 to rotate with the conical wheel rods 1706, thereby changing the stirring angle of the three lower stirring blades 1707. Initially, the three lower stirring blades 1707 are in a vertical position. With a large contact area between the surface and the mixture, it has strong mixing ability during stirring and is suitable for use in environments with medium viscosity. When the stirring angle of the three lower stirring blades 1707 exceeds 45 degrees, the contact area between the blade surface and the mixture decreases. During rotation, the axial flow rate is large, making it suitable for use in environments with high requirements for reactant stratification, high heat balance, and medium to low viscosity. Furthermore, the angle of the stirring blades can be adjusted according to the raw material mixture with different viscosities to achieve the maximum raw material polymerization efficiency. At the same time, different stirring angles of the lower stirring blades 1707 combined with the upper stirring blades 1713 also have different effects.

[0074] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A method for preparing polylactide-caprolactone (PLCL) for use in the medical field, characterized in that, Includes the following steps: S1. Polymerization reaction: Using lactide and caprolactone as raw materials, the raw materials are added to the polymerization reactor, the reaction liquid is added to the polymerization reactor, and the polymerization reactor is evacuated. Under the heating and stirring action of the polymerization reactor, a mixture is formed. S2. Polymer separation: Add a precipitant to the mixture to precipitate PLCL, separate it from the reaction solution, and remove the upper layer of reaction solution to obtain PLCL; S3. Polymer drying: The organic solvent in PLCL is removed by heating to obtain dried PLCL; S4. Polymer Refining: The dried PLCL is finely ground using a grinder.

2. The method for preparing polylactide-caprolactone (PLCL) for medical use according to claim 1, characterized in that, In step S1, lactide is added to the polymerization reactor, and caprolactone is added after preheating.

3. The method for preparing polylactide-caprolactone (PLCL) for medical use according to claim 1, characterized in that, In S1, the reaction solution consists of a catalyst, an initiator, and an organic solvent.

4. The method for preparing polylactide-caprolactone (PLCL) for medical use according to claim 1, characterized in that, In step S2, the mixture is placed in a collection tank, a precipitant is added, and the mixture is left to stand for 5-10 hours. The PLCL precipitates at the bottom of the collection tank, and the upper layer is the reaction liquid.

5. The method for preparing polylactide-caprolactone (PLCL) for medical use according to claim 4, characterized in that, In step S3, a flexible tube is inserted into the collection tank to slowly remove the reaction liquid.

6. The method for preparing polylactide-caprolactone (PLCL) for medical use according to claim 5, characterized in that, In step S3, the bottom of the collection tank is heated to heat the PLCL and evaporate the organic solvent in the PLCL.

7. The method for preparing polylactide-caprolactone (PLCL) for medical use according to claim 1, characterized in that, The polymerization reactor includes a main body (1), four supports (2) are fixed on the main body (1), a material inlet (3) and a pressure regulating port (4) are provided at the upper end of the main body (1), a manhole (5) and a temperature sensor (6) are installed at the upper end of the main body (1), a jacket (7) is wrapped around the main body (1), a threaded plate (8) is provided between the jacket (7) and the main body (1), a medium inlet (9) is provided on the upper side of the jacket (7), a medium outlet (10) is provided on the lower side of the jacket (7), and a material outlet pipe (12) is fixed at the lower end of the main body (1), and the material outlet pipe (12) is rotatably connected to a ball valve (11).

8. The method for preparing polylactide-caprolactone (PLCL) for medical use according to claim 7, characterized in that, The upper end of the main body (1) is fixed with a support frame (16), the support frame (16) is rotatably connected to the first rotating wheel (14), the first rotating wheel (14) is connected to the bearing of the motor (13), the support frame (16) is fixedly connected to the motor (13), the first rotating wheel (14) is connected to the mixing and stirring device (17) through the belt (15) transmission, and the mixing and stirring device (17) is rotatably connected to the main body (1).

9. The method for preparing polylactide-caprolactone (PLCL) for medical use according to claim 8, characterized in that, The mixing and stirring device (17) includes a fixed ring frame (1701), which is fixed on the upper end of the main body (1). The fixed ring frame (1701) is fixedly connected to one end of the connecting pipe (1702), and the other end of the connecting pipe (1702) is fixedly connected to the outer shell (1703). The upper end of the outer shell (1703) is provided with a conical surface. The belt (15) is connected to the rotating wheel (1704) for transmission. The rotating wheel (1704) is fixedly connected to the rotating shaft (1705), and the upper end of the rotating shaft (1705) is provided with a conical opening.

10. The method for preparing polylactide caprolactone (PLCL) for medical use according to claim 9, characterized in that, The lower end of the rotating shaft (1705) is rotatably connected to three conical wheel rods (1706), the conical wheel rods (1706) are fixedly connected to the lower stirring blade (1707), the rotating shaft (1705) is rotatably connected to the fixed ring frame (1701), the rotating shaft (1705) is rotatably connected to the connecting pipe (1702), the rotating shaft (1705) is rotatably connected to the outer shell (1703), and the middle part of the rotating shaft (1705) is fixedly connected to the gear disk (1708). The first gear (1708) meshes with two gears (1709) for transmission. The gear (1709) is rotatably connected to the gear bracket (1710). Both gear brackets (1710) are fixed inside the outer shell (1703). Both gears (1709) mesh with the second gear disk (1711) for transmission. The second gear disk (1711) is fixedly connected to the second rotating shaft (1712). The second rotating shaft (1712) is fixedly connected to the three upper stirring blades (1713).

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