Device for synthesizing high-purity L-lactide

Abstract

Aiming at the problem that L-lactide is low in purity and needs to be purified for multiple times after synthesis, the invention designs a device for synthesizing high-purity L-lactide, and the device mainly comprises a reaction kettle, a motor stirrer, a condenser pipe, a receiving tank, a buffer tank and a compressor. And after a series of operations such as temperature control and pressure reduction, a high-purity L-lactide product is obtained. The device has the characteristics of simple structure, low reaction temperature and the like, high-purity L-lactide can be obtained, and the subsequent purification process is simplified, so that the energy consumption is effectively reduced, and the economic cost of equipment is reduced.

Description

[Technical field]

[0001] The invention belongs to the technical field of polymer chemical synthesis, and in particular relates to a device for efficiently synthesizing high-purity L-lactide. [Background technology]

[0002] L-lactide is mainly used for homopolymerization to obtain L-polylactic acid, which is not only optically active, but also has a very regular three-dimensional structure, high crystallinity, a clear melting point, and excellent mechanical strength. In medicine, L-polylactic acid is often processed into orthopedic load-bearing bodies such as bone screws. In addition, L-lactide is also used to produce medical high polylactic acid, cyclic esterification agents, etc. These products are further used in surgical sutures, dentistry, ophthalmology, pharmaceutical controlled release systems, artificial skin, artificial blood vessels, bone and soft tissue defect fillers, bioresorbable scaffolds and other medical fields.

[0003] In recent years, the production and development of L-lactide have received more and more attention. In the process of synthesizing L-lactide, the design and operation of the entire device are particularly critical. It is necessary to ensure that the reaction is carried out under specific temperature and pressure conditions to fully mix the components and achieve the expected chemical reaction efficiency. Therefore, for the synthesis process of L-lactide, the structural design and operating parameters of the device must be carefully considered and strictly controlled to achieve the best production effect.

[0004] Patent CN219647487U "A crude lactide synthesis reactor" discloses a crude lactide synthesis reactor. The first motor is started to drive the long threaded rod at the output end to rotate, thereby controlling the lifting block to move in the support frame to achieve height adjustment of the barrel body. The support frame is used to provide an embracing support for the barrel body. The front of the two guide rails is fixedly installed on the surface of the lifting block, which enhances the stability of the movement of the lifting block and facilitates the separation of the barrel body and the sealing cover, thereby making it more convenient to clean the interior; a rubber layer sealing ring body is fixedly installed at the bottom of the sealing cover, and the groove at the bottom of the rubber layer sealing ring body is snap-fitted with the top of the barrel body. The rubber layer sealing ring body is located between the sealing cover and the barrel body, and the connection between the two is tighter, thereby improving the sealing performance. The second motor is started to drive the rotating rod at the output end to rotate, and the spiral stirring paddle is integrally processed on the surface of the rotating rod. The rotating rod drives the bottom stirring blade to fully stir the crude lactide synthesis in the barrel body. Patent CN115845747A "A lactide synthesis and purification device and method thereof" discloses a lactide synthesis and purification device and method thereof, the device comprising a first reactor, a second reactor, a main condenser, a secondary condenser, an evaporator, a crystallizer and a low-temperature vacuum dryer; the bottom of the first reactor is connected to the second reactor, the top of the second reactor is connected to the main condenser, the top of the main condenser is connected to the secondary condenser, the top of the secondary condenser is connected to a vacuum device, the bottom of the main condenser is connected to the evaporator through a first transmission screw, the top of the evaporator is connected to the crystallizer, and the bottom of the crystallizer is connected to the low-temperature vacuum dryer through a second transmission screw. By separating the two reactors, the influence of the early small molecule by-products on the separation of lactide is reduced; the insulated pipe is used to prevent the lactide vapor from condensing on the pipe wall when it is cold, and the secondary condenser is used to prevent the lactide in the main condenser from being vacuumed away and blocking the pipe. The existing L-lactide synthesis device has a complex structure, and it is necessary to further improve the device to improve the L-lactide synthesis efficiency and reduce the economic cost.

[0005] The present invention relates to a device for synthesizing high-purity L-lactide, which is mainly based on a reaction kettle with mechanical stirring, and realizes efficient production of L-lactide through a series of operations such as decompression and temperature control, and the optical purity reaches more than 99.9%. The device has a simple structure and reduces economic costs. [Summary of the invention]

[0006] [Technical issues to be solved]

[0007] The purpose of the present invention is to provide a novel device for efficiently synthesizing high-purity L-lactide.

[0008] Another object of the present invention is to solve the problem that L-lactide needs to be purified multiple times after synthesis, thereby reducing the number of purification times and saving resources.

[0009] [Technical solution]

[0010] The present invention aims at the problem that L-lactide needs to be purified multiple times after synthesis, designs a reactor with a stirring paddle, obtains a high-purity L-lactide product under certain temperature and pressure conditions, and reduces economic costs. This is achieved through the following technical solution.

[0011] A reactor device for synthesizing high-purity L-lactide, characterized in that the device mainly comprises the following parts: a reactor (R1), a motor stirrer (EM1), a condenser (CL1), a receiving tank (V1), a buffer tank (V2), and a compressor (C1). The specific implementation steps are as follows:

[0012] (1) The temperature of the reactor (R1) is set to 140°C-180°C, the insulation temperature of the condenser (CL1) is 75°C-100°C, and the device is evacuated with a compressor to maintain -0.1 MPa throughout the device.

[0013] (2) The stirring speed of the reactor (R1) is 90-120 rpm.

[0014] (3) The function of the buffer tank (V2) is to absorb the pressure fluctuations in the system when the pressure fluctuates, maintain the stability of the system, and prevent excessive L-lactide from being pumped away by the compressor (C1), thereby ensuring the normal operation of the system and extending the service life of the equipment.

[0015] [Beneficial Effects]

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) A reactor device with a stirring paddle can synthesize high-purity L-lactide under certain temperature and pressure conditions.

[0018] (2) The device is used to produce high-purity L-lactide, solving the problem of multiple purifications required after L-lactide synthesis.

[0019] (3) The device has the characteristics of simple structure and low economic cost.

Brief Description of the Drawings

[0020] Attached Figure 1 This is a diagram of an apparatus for producing high-purity L-lactide using a reactor with a stirring paddle according to the present invention.

[0021] In the figure, reactor-R1, motor stirring-EM1, condenser-CL1, receiving tank-V1, buffer tank-V2, compressor-C1. [Specific implementation method]

[0022] Embodiment 1:

[0023] (1) The temperature of the reactor (R1) is set to 140°C-170°C, the insulation temperature of the condenser (CL1) is 85°C-100°C, and the device is evacuated with a compressor to maintain -0.1 MPa throughout the device.

[0024] (2) The stirring speed of the reactor (R1) is 90-110 rpm.

[0025] (3) The function of the buffer tank (V2) is to absorb the pressure fluctuations in the system when the pressure fluctuates, maintain the stability of the system, and prevent excessive L-lactide from being pumped away by the compressor (C1), thereby ensuring the normal operation of the system and extending the service life of the equipment.

[0026] Embodiment 2:

[0027] (1) The temperature of the reactor (R1) is set to 145°C-170°C, the insulation temperature of the condenser (CL1) is 90°C-100°C, and the device is evacuated with a compressor to maintain -0.1 MPa throughout the device.

[0028] (2) The stirring speed of the reactor (R1) is 100-120 rpm.

[0029] (3) The function of the buffer tank (V2) is to absorb the pressure fluctuations in the system when the pressure fluctuates, maintain the stability of the system, and prevent excessive L-lactide from being pumped away by the compressor (C1), thereby ensuring the normal operation of the system and extending the service life of the equipment.

Claims

1. A device for synthesizing high-purity L-lactide, characterized in that: The device mainly includes the following parts: Reactor (R1), motor stirring (EM1), condenser (CL1), receiving tank (V1), buffer tank (V2), compressor (C1); The above-mentioned device is used to synthesize high-purity L-lactide, comprising the following steps: (1) The temperature of the reactor (R1) is set to 140°C-180°C, the insulation temperature of the condenser (CL1) is 75°C-100°C, and the device is evacuated with a compressor to maintain -0.1 MPa throughout the device. (2) Motor stirring (EM1) The speed of mechanical stirring is 90-120 rpm. (3) The function of the buffer tank (V2) is to absorb the pressure fluctuations in the system when the pressure fluctuates, maintain the stability of the system, and prevent excessive L-lactide from being pumped away by the compressor (C1), thereby ensuring the normal operation of the system and extending the service life of the equipment.

2. According to claim 1, the device is characterized in that the temperature of the reaction kettle (R1) is set to 150°C.

3. According to claim 1, the device is characterized in that the insulation temperature of the condenser (CL1) is 75°C-100°C.

4. According to claim 1, the device is characterized in that the speed of the stirring paddle of the reactor (R1) is 90-120 revolutions.

5. According to claim 1, the device is characterized in that the entire device is in a vacuum state to synthesize L-lactide, and the pressure is maintained at -0.1 MPa.

6. According to claim 1, another feature of the device is that the function of the buffer tank (V2) is to absorb the fluctuating pressure when the pressure in the system fluctuates, maintain the stability of the system, and prevent excessive L-lactide from being drawn away by the compressor (C1), thereby ensuring the normal operation of the system and extending the service life of the equipment.

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