A kind of experimental device for polymerization reaction of degradable polymer materials

Abstract

The present invention discloses a degradable polymer material polymerization reaction experimental device, which includes: a stirred tank reaction unit, an esterification reaction unit, a polycondensation reaction unit, and a control unit for respectively controlling the stirred tank reaction unit, the esterification reaction unit, and the control unit; the esterification reaction unit replaces the fractionation column with two sections, and controls the temperature of the upper section and the lower section separately; the polycondensation reaction unit includes a secondary condenser collection tank, and a double-path vacuum pipeline. The present invention solves the problem that the esterification reaction unit of the traditional method has only one temperature, which makes it difficult to take care of one thing while neglecting the other, and the vaporization and condensation effects are not ideal by replacing the fractionation column of the esterification reaction unit with two sections and controlling the temperature of the upper section and the lower section separately; the present invention organically combines the second-stage collection tank, the window of the first-stage collection tank, and the needle valve, and achieves the effect after the combination: the second-stage collection tank solves the problem of low by-product collection efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of polymerization reaction of polymer materials, and in particular relates to a polymerization reaction experimental device of degradable polymer materials. Background Art

[0002] In recent years, the increasing scarcity of oil resources has led to a surge in the price of plastic raw materials. The problem of coordinating the development of plastic materials and environmental protection has become increasingly prominent. The birth of degradable polymer plastic materials provides a new solution to the problem of environmental pollution. This new degradable polymer material with great development potential can effectively reduce the use of petroleum-based plastics, reduce carbon emissions, and help achieve carbon peak and carbon neutrality. Its new uses are very broad and it is expected to replace traditional polymers in many application fields, such as for the production of cosmetic containers, toothbrushes, cushioning materials, packaging materials, shopping bags, disposable gloves, etc.

[0003] However, due to high technical barriers, the United States and Japan have always been in the leading position in the production and development of degradable polymer plastic materials. Domestic research and development started late and was constrained by market size, and development has been stagnant for a long time. In recent years, with the advancement of the national plastic restriction policy, great support has been given to the development of degradable polymer plastic materials. For this reason, scientists can be more confident in the continued in-depth research and development of this new material (degradable polymer material).

[0004] The first difficulty in the polymerization reaction of biodegradable polymer materials is that the vaporization and condensation effects in the esterification reaction stage are not ideal. The vaporization refers to separating the by-products from the product by vaporization, and the condensation refers to condensing the vaporized products carried by the by-products and returning them to the reactor where the products are generated. Figure 2 As shown, the esterification reaction unit of the prior art is only a single distillation column 202. There are multiple by-products distilled from the distillation column 202, such as small molecules and macromolecules (although only one temperature is used, some impurities are inevitably entrained). The temperature required for vaporization of small molecules is lower, while the temperature required for vaporization of macromolecules is higher. If only one temperature is used, there is no way to re-condense the distilled macromolecules. Therefore, the condensation effect of the esterification reaction unit is not ideal. During the distillation in the distillation column 202, the macromolecules are not distilled as much as possible. Therefore, the temperature is not adjusted too high. If the temperature is too high, the macromolecules will be distilled. Due to the limitation that the temperature cannot be adjusted too high, some small molecules are not distilled. Therefore, the vaporization effect of the esterification reaction unit of the traditional method is not ideal.

[0005] The second difficulty in the polymerization reaction of degradable polymer materials is that the efficiency of collecting by-products in the polycondensation reaction stage is too low, which easily leads to air pollution (by-products are mostly chemical reagents) and damage to the vacuum pump. The reasons for the low collection efficiency are as follows: Figure 2 As shown, in the prior art, one condenser is equipped with one collecting tank 305, and one collecting tank often cannot collect all the materials. The reason why the air is easily polluted and the vacuum pump is damaged is that it is impossible to determine whether the polymer products are carried in the by-products in the collecting tank 305 per unit time. When there are more polymer products carried in the by-products in the collecting tank per unit time, since the collection efficiency of one collecting tank is relatively low, if the ball valve is opened at too large an angle, more by-products and polymers mixed in the by-products will be carried into the vacuum pump. When the vacuum pump discharges the small molecules of the by-products together with the polymers into the atmosphere through the exhaust port, the air will be polluted. At the same time, when there are more small molecules and polymers of the by-products in the vacuum pump, the vacuum pump will be damaged. Therefore, when it is impossible to determine whether there are more or less polymers in the collecting tank per unit time, it is impossible to avoid the by-products discharged during the polycondensation reaction stage from polluting the air and damaging the vacuum pump. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention proposes a biodegradable polymer material polymerization reaction experimental device, which aims to solve the problems of unsatisfactory vaporization and condensation effects in the esterification reaction stage and the low efficiency of collecting by-products in the polycondensation reaction stage, which easily pollutes the air and damages the vacuum pump.

[0007] The present invention proposes the following technical solutions to solve the technical problems:

[0008] A degradable polymer material polymerization reaction experimental device, the device comprising: a stirred tank reaction unit 100 for generating a polymer product, an esterification reaction unit 200 for removing byproducts of the polymer product in the first stage, a polycondensation reaction unit 300 for removing byproducts of the polymer product in the second stage, and a control unit 400 for respectively controlling the stirred tank reaction unit 100, the esterification reaction unit 200, and the polycondensation reaction unit 300;

[0009] The stirred tank reaction unit 100 is provided with a fractionation port 111, which is connected to the esterification reaction valve 201 of the esterification reaction unit 200 and the polycondensation reaction valve 301 of the polycondensation reaction unit 300 through the fractionation port 111; when the esterification reaction is in progress, the control unit 400 closes the polycondensation reaction valve 301 and opens the esterification reaction pipeline valve 201, and separates the by-product water and low molecular weight substances produced by the esterification reaction through the fractionation column 202 and the condenser reflux device 203 of the esterification reaction unit 200; when the polycondensation reaction is in progress, the control unit 400 controls the esterification reaction valve 201 to be closed and the polycondensation valve 301 to be opened, and the temperature is adjusted to the required temperature condition, and many identical or different small molecular substances interact with each other through the stirring system to generate high molecular substances, and at the same time, the precipitated small molecules, such as water, alcohol, ammonia, and halide, are separated and collected by vacuuming and condensing the receiving tank, and finally a relatively pure high molecular material is obtained in the reactor; it is characterized in that:

[0010] The esterification reaction unit 200 replaces the distillation column with two sections, and controls the temperature of the upper section and the lower section separately. On the one hand, the by-product water can be separated more accurately and the reactants can be protected from being evaporated to the greatest extent. On the other hand, part of the entrained and vaporized polymer products can be condensed and refluxed into the reactor.

[0011] The polycondensation reaction unit 300 includes a secondary condenser collection tank for improving the by-product collection efficiency, and a dual-path vacuum pipeline for reducing the extraction of high molecular gas products.

[0012] Furthermore, the esterification reaction unit 200 for removing by-products in the first-stage polymer product has a lower half section of a fractionation column 202 and an upper half section of a condenser reinjector 203; a fractionation column temperature sensor 204 and a condenser temperature sensor 205 are respectively provided on the fractionation column 202 and the condenser 203; through auxiliary heating of the fractionation column and monitoring of the fractionation column sensor 204, water and other small molecular products in the fractionation column 202 are vaporized; the small molecular products can be evaporated, and part of the entrained and vaporized polymer products can be condensed and refluxed into the reactor.

[0013] Furthermore, through the monitoring of the distillation column sensor 204, the small molecule products can be evaporated and part of the high molecular products that are entrained and vaporized can be condensed and refluxed into the reactor. Specifically, the water inlet of the condenser 203 is provided with a condensate regulating valve 207. The condensate regulating valve 207 adjusts the flow rate of condensate according to the different vaporization temperature requirements of the small molecule products and the temperature requirements required for the condensation of the high molecular products. By adjusting the flow rate of condensate, the temperature of the condenser reflux device 203 is changed, so as to achieve the requirements of both evaporating the small molecule products and condensing the part of the high molecular products that are entrained and vaporized into the reactor.

[0014] Furthermore, the by-product outlet of the condenser reflux device 203 is provided with a steam outlet regulating valve 206, and the steam outlet regulating valve 206 is a steam outlet for small molecules, which is used to adjust the steam flow rate to allow the by-products to be discharged slowly, and to carry as little high-molecular product as possible to achieve the best separation effect; at the same time, a jacketed collector 208 and a drain port 209 are provided at the tail end of the steam outlet regulating valve 206 for collecting the by-products. The jacketed collector 208 adopts a condensation collection method to turn the steam of small molecules into liquid, and the drain port 209 is used to discharge the liquid collected by the jacketed collector 208.

[0015] Furthermore, the polycondensation reaction unit 300 for removing by-products from the second-stage polymer product is provided with a first-stage interlayer collector 302 and a second-stage interlayer collector 305 between the vacuum pump 309 and the stirred tank reaction unit 100 in order to facilitate the control of the polycondensation process, improve the efficiency of collecting by-products in the second-stage, and ensure that small molecules are not drawn into the vacuum pump 309. The first-stage interlayer collector 302 and the second-stage interlayer collector 305 are respectively passed through a cooling liquid to condense the small molecules.

[0016] Furthermore, a viewing mirror is provided on the side of the first-stage interlayer collector 302, through which the extraction of part of the polymer product during polycondensation can be observed, and then the operation method of the dual-path vacuum pipeline can be adopted according to the extraction of the polymer product.

[0017] Furthermore, the dual-path vacuum pipeline is arranged in parallel between the vacuum pump 309 and the second-stage interlayer collector 305, and one of the dual-path vacuum pipelines arranged in parallel is provided with a small-diameter needle valve 307, and the other is provided with a large-diameter ball valve; the small-diameter needle valve 307 is used in the initial stage of gas discharge, in which the ball valve 308 is closed and the needle valve 307 is opened, and the extraction of the polymer product in the first-stage interlayer collector is observed through the sight glass arranged on the side of the first-stage interlayer collector 302. According to the situation, the needle valve 307 is adjusted to the best to allow the gas to be extracted slowly, thereby reducing the extraction of the polymer product. When the vacuum is drawn to a certain range, the diameter of the needle valve 307 is appropriately increased. Finally, when a high vacuum is reached, the needle valve 307 is closed and the ball valve 308 is opened to continue vacuuming until the polycondensation reaction is completed.

[0018] Furthermore, the stirred tank reaction unit 100 is provided with a jacketed tank barrel 101, a tank cover 102 on the top of the jacketed tank barrel 101, an agitator 103 extending through the tank cover into the tank, and the agitator 103 is connected to a stirring paddle 105; it is characterized in that: a discharge port 110 is provided at the bottom of the tank reaction unit 100, and since the viscosity of polymer materials is relatively large, the discharge port 110 is designed in the form of a pin, and the material can be discharged by unscrewing the nut and pulling out the pin, which has the advantages of anti-blocking, no dead angle, and no residue when discharging.

[0019] Advantages and effects of the present invention

[0020] 1. The present invention solves the problem that the esterification reaction unit of the traditional method has only one temperature, which makes the vaporization and condensation effects unsatisfactory by replacing the fractionation column of the esterification reaction unit with two sections and controlling the temperature of the upper section and the lower section separately: by controlling the temperature separately, the temperature of the fractionation column of the lower section can be adjusted as high as possible within the set range, which is convenient for distilling out by-products and achieving the best vaporization effect; by controlling the temperature separately, the condenser reflux device of the upper section can reduce the temperature as much as possible within the set range according to the different characteristics of the vaporization temperatures of small molecules and polymers, within the range allowed by the temperature difference, so that the polymer changes from gas to liquid again and refluxes into the stirred tank reaction unit. Thus, the vaporization and condensation effects are both achieved to the best effect.

[0021] 2. The present invention organically combines the second-stage collecting tank, the window of the first-stage collecting tank, and the needle valve to achieve the following effects: the second-stage collecting tank solves the problem of low by-product collection efficiency, and the combination of the window of the first-stage collecting tank and the needle valve controls the polymer products entrained from the reactor from the source, specifically by slowly discharging gas through the needle valve, so that the polymer entrained with the gas discharge is as small as possible, thereby blocking the loss at the source. In short, the combination of the second-stage collecting tank, the window of the first-stage collecting tank, and the needle valve solves the problem of polymers being drawn away from the vacuum pump and eventually polluting the air from two different stages, one from the stage before the polymers are entrained, and the other from the stage after the polymers are entrained. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the polymer polymerization reaction experimental device of the present invention;

[0023] Figure 2 It is a comparative diagram of the present invention - a schematic diagram of a polymer polymerization reaction experimental device in the prior art;

[0024] 100: stirred tank reactor; 101: jacketed tank drum; 102: tank cover; 103: stirrer; 140: stirring motor; 105: stirring paddle; 106: temperature sensor; 107: temperature sensor sleeve; 108: pressure sensor; 109: air inlet valve; 110: lower feed port; 111: fractionation port; 112: feed port; 113: feed tank; 114: stop valve; 115: liquid level gauge; 116 air inlet

[0025] 200: esterification reaction unit; 201: esterification reaction valve; 202: fractionation column; 203: condenser reflux device; 204: fractionation column temperature sensor; 205: condenser temperature sensor; 206: steam outlet regulating valve; 207: condensate regulating valve; 208: jacketed collector; 209: drain port;

[0026] 300: polycondensation reaction unit; 301: polycondensation reaction valve; 302: primary interlayer collector; 303: observation window; 304: drain valve; 305: secondary interlayer collector; 306: drain valve; 307: needle valve; 308: ball valve; 309: vacuum pump;

[0027] 400: Centralized controller. DETAILED DESCRIPTION

[0028] Design principle of the present invention

[0029] 1. Design principle of dual temperature controller esterification reaction unit: The upper and lower temperature sensors of the esterification reaction unit support and depend on each other: the temperature of the fractionation column 202 determines the temperature of the condenser reflux 203, and the temperature of the condenser reflux 203 is transmitted from the fractionation column 202, so they are interdependent. The temperature of the condenser reflux 203 is lower than that of the fractionation column 202, so the fractionation column 202 is one temperature, and the condenser reflux 203 is one temperature. The fractionation column 202 is a heating process, and the condenser reflux 203 is a cooling process. The condenser reflux 203 does not need as high a temperature as the fractionation column 202, so when the fractionation column 202 transmits a certain temperature to the condenser reflux 203, the condenser reflux 203 must adjust the amount of condensed water through the condensed water regulating valve 207, and then cooperate with the steam outlet regulating valve 206 to adjust to the required temperature. The reason why the fractionation column 202 and the condenser reflux 203 need two temperatures is Because the distilled product has multiple components, including small molecules and entrained polymers, the temperature of the distillation column 202 should be slightly higher than the vaporization temperature of the small molecules, and the condenser reflux device 203 should be slightly lower than the distillation column 202, that is, the vapor temperature of the small molecules must be the condensation temperature of the polymers. That is, when the temperature of the condenser reflux device 203 is lowered to a suitable temperature, the small molecules distilled out of the condenser reflux device 203 are still in the vapor state and run to the jacket collector 208 to be collected, and the polymers will change from gas to liquid again, and then return to the stirred tank reaction unit 100 after changing to liquid, thereby increasing the productivity of the polymer products in the stirred tank reaction unit.

[0030] 2. Design principle of secondary condenser collector and dual-path vacuum pipeline: The secondary condenser collector and dual-path vacuum pipeline support and depend on each other: 1) The relationship between the vacuum pump 309 and the stirred tank reaction unit 100. The vacuum pumping is to evacuate the stirred tank reaction unit 100. Since there are impurities in the stirred tank reaction unit 100 due to the presence of gas, the polymer continues to react under vacuum. The vacuum pumping is to remove the gas in the molten state. Finally, there is no gas in the stirred tank reaction unit 100, and only the viscous polymer is left, that is, the molten plastic state. Then, the valve opening angle is increased and the needle valve is changed to a ball valve. Although the valve is enlarged at this time, there is almost no gas, so there is no fear that the polymer will be entrained and drawn out. In summary, in order to solve the problem of too low efficiency in collecting by-products in the polycondensation reaction stage, which leads to air pollution and damage to the vacuum pump, the second-stage collection tank, the window of the first-stage collection tank, and the needle valve must be organically combined to produce the effect after the combination.

[0031] 2) When the stirred tank reaction unit 100 is evacuated, the valve 301 is opened, and the gas flows from the stirred tank reaction unit 100 through the pipeline into the first-stage and second-stage collecting tanks and the vacuum pump 309.

[0032] 3) The organic combination is an organic combination of the second-stage collecting tank, the window of the first-stage collecting tank, and the needle valve, which are interdependent: since the addition of the second-stage condenser collecting tank solves the problem of incomplete collection of by-products, the by-products extracted from the stirred tank reaction unit 100 are collected as much as possible without being sucked away by the vacuum pump to pollute the air. However, the addition of the second-stage condenser collecting tank cannot solve the problem of the opening angle of the valve, because the gas in the molten state in the reactor has just been extracted at the beginning of vacuuming, and there is a lot of gas at this time. Once the vacuuming valve opening angle is too large, the gas flow rate is fast, and the entrained polymer product is more when it is extracted. When the air valve opening angle is relatively small, the entrained polymer will be less when the gas in the molten state is extracted. Therefore, it is also necessary to solve the problem of the valve opening angle at the beginning of vacuuming. However, the valve opening angle depends on the observation of the amount of polymer white solid generated in the first-stage collection tank per unit time. When more polymer white solid is observed to be generated in the first-stage collection tank per unit time, it is determined that the part of the entrained polymer gas product to be extracted from the stirred tank reaction unit 100 must also be a lot. At this time, opening the needle valve very slowly will make the entrained polymer gas product when extracting gas from the stirred tank reaction unit 100 relatively less. When the vacuum is drawn to an absolute pressure of 100Pa, there is not much gas and by-products left in the polymer material. Then increase the valve opening angle and change from a needle valve to a ball valve. At this time, although the valve is enlarged, there is almost no gas, so there is no need to worry about the polymer being entrained and drawn out. In summary, in order to solve the problem of low efficiency in collecting by-products in the polycondensation reaction stage, which causes air pollution and damage to the vacuum pump, the second-stage collection tank, the window of the first-stage collection tank, and the needle valve must be organically combined to produce the combined effect.

[0033] Based on the above principles, the present invention designs a degradable polymer material polymerization reaction experimental device

[0034] A kind of experimental device for polymerization reaction of degradable polymer materials Figure 1 As shown, the device includes: a stirred tank reaction unit 100 for generating a polymer product, an esterification reaction unit 200 for removing by-products of the polymer product in the first stage, a polycondensation reaction unit 300 for removing by-products of the polymer product in the second stage, and a control unit 400 for respectively controlling the stirred tank reaction unit 100, the esterification reaction unit 200, and the polycondensation reaction unit 300;

[0035] The stirred tank reaction unit 100 is provided with a fractionation port 111, which is connected to the esterification reaction valve 201 of the esterification reaction unit 200 and the polycondensation reaction valve 301 of the polycondensation reaction unit 300 through the fractionation port 111; when the esterification reaction is in progress, the control unit 400 closes the polycondensation reaction valve 301 and opens the esterification reaction pipeline valve 201, and separates the by-product water and low molecular weight substances produced by the esterification reaction through the fractionation column 202 and the condenser reflux device 203 of the esterification reaction unit 200; when the polycondensation reaction is in progress, the control unit 400 controls the esterification reaction valve 201 to be closed and the polycondensation valve 301 to be opened, and the temperature is adjusted to the required temperature condition, and many identical or different small molecular substances interact with each other through the stirring system to generate high molecular substances, and at the same time, the precipitated small molecules, such as water, alcohol, ammonia, and halide, are separated and collected by vacuuming and condensing the receiving tank, and finally a relatively pure high molecular material is obtained in the reactor; it is characterized in that:

[0036] The esterification reaction unit 200 replaces the distillation column with two sections, and controls the temperature of the upper section and the lower section separately. On the one hand, the by-product water can be separated more accurately and the reactants can be protected from being evaporated to the greatest extent. On the other hand, part of the entrained and vaporized polymer products can be condensed and refluxed into the reactor.

[0037] The polycondensation reaction unit 300 includes a secondary condenser collection tank for improving the by-product collection efficiency, and a dual-path vacuum pipeline for reducing the extraction of high molecular gas products.

[0038] Furthermore, the esterification reaction unit 200 for removing by-products in the first-stage polymer product has a lower half section consisting of a fractionation column 202 and an upper half section consisting of a condenser reinjector 203; a fractionation column temperature sensor 204 and a condenser temperature sensor 205 are provided on the fractionation column 202 and the condenser 203, respectively; water and other small molecule products in the fractionation column 202 are vaporized by auxiliary heating of the fractionation column and monitoring of the fractionation column temperature sensor 204; the small molecule products can be evaporated and part of the entrained and vaporized polymer products can be condensed and refluxed into the reactor.

[0039] Furthermore, through the monitoring of the distillation column temperature sensor 204, the small molecule products can be evaporated and part of the high molecular products that are entrained and vaporized can be condensed and refluxed into the reactor. Specifically, the water inlet of the condenser 203 is provided with a condensate regulating valve 207. The condensate regulating valve 207 adjusts the flow rate of condensate according to the different vaporization temperature requirements of the small molecule products and the temperature requirements required for the condensation of the high molecular products. By adjusting the flow rate of condensate, the temperature of the condenser reflux device 203 is changed, so as to achieve the requirements of both evaporating the small molecule products and condensing the part of the high molecular products that are entrained and vaporized into the reactor.

[0040] Furthermore, the by-product outlet of the condenser reflux device 203 is provided with a steam outlet regulating valve 206, and the steam outlet regulating valve 206 is a steam outlet for small molecules, which is used to adjust the steam flow rate to allow the by-products to be discharged slowly, and to carry as little high-molecular product as possible to achieve the best separation effect; at the same time, a jacketed collector 208 and a drain port 209 are provided at the tail end of the steam outlet regulating valve 206 for collecting the by-products. The jacketed collector 208 adopts a condensation collection method to turn the steam of small molecules into liquid, and the drain port 209 is used to discharge the liquid collected by the jacketed collector 208.

[0041] Furthermore, the polycondensation reaction unit 300 for removing by-products from the second-stage polymer product is provided with a first-stage interlayer collector 302 and a second-stage interlayer collector 305 between the vacuum pump 309 and the stirred tank reaction unit 100 in order to facilitate the control of the polycondensation process, improve the efficiency of collecting by-products in the second-stage, and ensure that small molecules are not drawn into the vacuum pump 309. The first-stage interlayer collector 302 and the second-stage interlayer collector 305 are respectively passed through a cooling liquid to condense the small molecules.

[0042] Furthermore, a viewing mirror is provided on the side of the first-stage interlayer collector 302, through which the extraction of part of the polymer product during polycondensation can be observed, and then the operation method of the dual-path vacuum pipeline can be adopted according to the extraction of the polymer product.

[0043] Furthermore, the dual-path vacuum pipeline is arranged in parallel between the vacuum pump 309 and the second-stage interlayer collector 305, and one of the dual-path vacuum pipelines arranged in parallel is provided with a small-diameter needle valve 307, and the other is provided with a large-diameter ball valve; the small-diameter needle valve 307 is used in the initial stage of gas discharge, in which the ball valve 308 is closed and the needle valve 307 is opened, and the extraction of the polymer product in the first-stage interlayer collector is observed through the sight glass arranged on the side of the first-stage interlayer collector 302. According to the situation, the needle valve 307 is adjusted to the best to allow the gas to be extracted slowly, thereby reducing the extraction of the polymer product. When the vacuum is drawn to a certain range, the diameter of the needle valve 307 is appropriately increased. Finally, when a high vacuum is reached, the needle valve 307 is closed and the ball valve 308 is opened to continue vacuuming until the polycondensation reaction is completed.

[0044] Furthermore, the stirred tank reaction unit 100 is provided with a jacketed tank barrel 101, a tank cover 102 on the top of the jacketed tank barrel 101, an agitator 103 extending through the tank cover into the tank, and the agitator 103 is connected to a stirring paddle 105; it is characterized in that: a discharge port 110 is provided at the bottom of the tank reaction unit 100, and since the viscosity of polymer materials is relatively large, the discharge port 110 is designed in the form of a pin, and the material can be discharged by unscrewing the nut and pulling out the pin, which has the advantages of anti-blocking, no dead angle, and no residue when discharging.

[0045] Additional notes:

[0046] like Figure 1 As shown, the reaction unit is a stirred tank reactor 100. Since it is an experimental device for exploring reaction conditions, the volume does not need to be too large, 0.5L-5L is appropriate. If it is less, the product is not enough for the next step of testing, and if it is more, it is too wasteful.

[0047] The jacketed kettle barrel 101 uses external circulating heat transfer oil to provide heat for the reaction. The temperature can be adjusted arbitrarily from 50 to 330 degrees Celsius. A discharge port 110 is provided at the bottom of the kettle barrel. Because the viscosity of polymer materials is relatively large, the discharge port is designed in the form of a pin. When discharging, the nut is unscrewed and the pin is pulled out to discharge the material. The benefits are anti-blocking, no dead corners, and no residue when discharging.

[0048] A stirrer 103 is provided in the middle of the kettle cover 102, and the upper end of the stirrer is connected to a motor 104, which is connected to the 400 unit to control the stirring speed of 0-1000 rpm and monitor the torque of 0-10N.m. Different speeds can be adjusted according to different reaction stages, and the reaction process can be tracked according to the change of torque in each reaction stage.

[0049] The agitator 103 extends through the kettle cover into the kettle and is connected to the agitator paddle 105. The agitator paddle 105 is a combination of a scraping anchor type and a spiral ribbon type agitator paddle. Since the kettle wall temperature is relatively high and the viscosity of the polymer material is very high, the purpose of the scraping anchor type agitator paddle is to prevent the material from sticking to the wall for a long time and coking. The spiral ribbon type agitator paddle acts downward during stirring to prevent the material from climbing up along the agitator rod.

[0050] The kettle cover is also provided with an inlet valve 109 and an exhaust valve 110. The inlet valve is used to charge the kettle with reaction gas or protective gas nitrogen when necessary, and the exhaust valve is used for venting.

[0051] A temperature sensor 106 is also provided on the kettle cover, the upper end of which is connected to the 400 unit for monitoring and controlling the reaction temperature, and the lower end of which extends into the kettle and passes through the middle of the anchor propeller and the ribbon propeller.

[0052] The kettle cover is also provided with a pressure sensor 108 connected to the 400 unit for monitoring the pressure in the kettle.

[0053] The kettle cover is also provided with a rectification port 111, which is connected to the esterification reaction unit 200 and the polycondensation reaction unit 300 respectively;

[0054] The kettle cover is also provided with a feed port 112, which is connected to a feed tank 113. The feed tank 113 has two functions: one is to add a catalyst during the reaction, and the other is to add a cleaning agent after the reaction is completed and the material is discharged, so that the kettle can be washed without opening the kettle. When the feed tank is opened, it is used for feeding. A stop valve 114 is designed between the feed tank and the reactor, which is opened when feeding and closed when feeding is not required. A transparent bypass for observing the liquid level is provided on the side of the feed tank, so that the liquid level in the feed tank can be observed to facilitate the control of the flow rate. An air inlet valve 116 is provided on the upper cover of the feed tank, and nitrogen can be passed through to protect the catalyst when necessary.

[0055] It should be emphasized that the above specific embodiments are merely explanations of the present invention, and they are not limitations of the present invention. After reading this specification, those skilled in the art can make modifications to the above embodiments without any creative contribution as needed, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A degradable polymer material polymerization reaction experimental device, the device comprising: A stirred tank reactor (100) for producing a polymer product, an esterification reaction unit (200) for removing byproducts of the polymer product of the first stage, a polycondensation reaction unit (300) for removing byproducts of the polymer product of the second stage, and a control unit (400) for respectively controlling the stirred tank reactor (100), the esterification reaction unit (200), and the polycondensation reaction unit (300); The stirred tank reactor (100) is provided with a fractionation port (111), which is connected to the esterification reaction valve (201) of the esterification reaction unit (200) and the polycondensation reaction valve (301) of the polycondensation reaction unit (300) through the fractionation port (111); when the esterification reaction is in progress, the control unit (400) closes the polycondensation reaction valve (301) and opens the esterification reaction valve (201), and separates the byproduct water and low molecular weight substances produced by the esterification reaction through the fractionation column (202) and the condensation reflux device (203) of the esterification reaction unit (200); when the polycondensation reaction is in progress, the control unit (400) controls the esterification reaction valve (201) to be closed and the polycondensation reaction valve (301) to be opened, and the temperature is adjusted to the required temperature condition, and a plurality of identical or different small molecular substances interact with each other through the stirring system to generate a high molecular substance, and at the same time, the precipitated small molecules are separated and collected through vacuuming and a condensation receiving tank, and finally a relatively pure high molecular material is obtained in the reactor; the characteristics are: The esterification reaction unit (200) replaces the fractionation column with two sections, and controls the temperature of the upper section and the lower section separately, so as to more accurately separate the by-product water and protect the reactants from being evaporated to the greatest extent, and allow part of the entrained and vaporized high molecular weight products to be condensed and refluxed into the reactor; The polycondensation reaction unit (300) comprises a secondary condenser collection tank for improving the by-product collection efficiency, and a dual-path vacuum pipeline for reducing the extraction of high molecular gas products; The esterification reaction unit (200) for removing by-products from the first-stage polymer product has a lower half section being a fractionation column (202) and an upper half section being a condenser reflux device (203); a fractionation column temperature sensor (204) and a condenser temperature sensor (205) are provided on the fractionation column (202) and the condenser reflux device (203), respectively; water and other small molecular products in the fractionation column (202) are vaporized by auxiliary heating of the fractionation column and monitoring by the fractionation column temperature sensor (204); the small molecular products can be vaporized and part of the entrained and vaporized polymer products can be condensed and refluxed into the reactor; The polycondensation reaction unit (300) for removing by-products from the second-stage polymer product is provided with a first-stage interlayer collector (302) and a second-stage interlayer collector (305) between the vacuum pump (309) and the stirred tank reactor (100) in order to facilitate the control of the polycondensation process, improve the collection efficiency of the second-stage by-products, and ensure that small molecules are not drawn into the vacuum pump (309). The first-stage interlayer collector (302) and the second-stage interlayer collector (305) are respectively passed through a cooling liquid to condense the small molecules; The dual-path vacuum pipeline is arranged in parallel between the vacuum pump (309) and the second-stage interlayer collector (305). One of the dual-path vacuum pipelines arranged in parallel is provided with a small-diameter needle valve (307), and the other is provided with a large-diameter ball valve. The small-diameter needle valve (307) is used in the initial stage of gas discharge. In this initial stage, the ball valve (308) is closed and the needle valve (307) is opened. The situation of the polymer product in the first-stage interlayer collector (302) being extracted is observed through a sight glass arranged on the side of the first-stage interlayer collector (302). According to the situation, the needle valve (307) is adjusted to the best position to allow the gas to be extracted slowly, thereby reducing the extraction of polymer products. When the vacuum is drawn to a certain range, the diameter of the needle valve (307) is appropriately increased. Finally, when a high vacuum is drawn, the needle valve (307) is closed and the ball valve (308) is opened to continue vacuuming until the polycondensation reaction is completed.

2. The degradable polymer material polymerization reaction experimental device according to claim 1, characterized in that: The monitoring by the fractionation column temperature sensor (204) can not only evaporate the small molecule products, but also condense and reflux some of the entrained and vaporized high-molecular products into the reactor. Specifically, the water inlet of the condenser reflux device (203) is provided with a condensate regulating valve (207). The condensate regulating valve (207) regulates the flow rate of condensate according to different vaporization temperature requirements of the small molecule products and the temperature requirements for condensation of the high-molecular products. By regulating the flow rate of condensate, the temperature of the condenser reflux device (203) is changed, so that the small molecule products can be evaporated, and some of the entrained and vaporized high-molecular products can be condensed and refluxed into the reactor.

3. A degradable polymer material polymerization reaction experimental device according to claim 2, characterized in that: The by-product outlet of the condenser reflux device (203) is provided with a steam outlet regulating valve (206). The steam outlet regulating valve (206) is a steam outlet for small molecules and is used to regulate the steam flow rate so that the by-products are discharged slowly, and the entrainment of high-molecular products is minimized to achieve the best separation effect. At the same time, a jacketed collector (208) and a liquid discharge port (209) are provided at the tail end of the steam outlet regulating valve (206) for collecting the by-products. The jacketed collector (208) adopts a condensation collection method to convert the steam of small molecules into liquid, and the liquid discharge port (209) is used to discharge the liquid collected by the jacketed collector (208).

4. The degradable polymer material polymerization reaction experimental device according to claim 1, characterized in that: A viewing mirror is provided on the side of the first-stage interlayer collector (302), through which the extraction of part of the polymer product during polycondensation is observed, and then an operating method for the dual-path vacuum pipeline is adopted according to the extraction of the polymer product.

5. According to claim 1, a biodegradable polymer material polymerization reaction experimental device, the stirred tank reactor (100) is provided with a jacketed tank barrel (101), a tank cover (102) on the top of the jacketed tank barrel (101), an agitator (103) extending through the tank cover into the tank, and the agitator (103) is connected to a stirring paddle (105); the characteristics are: The bottom of the stirred tank reactor (100) is provided with a discharge port (110). Since the viscosity of polymer materials is relatively high, the discharge port (110) is designed to be in the form of a pin. When discharging the material, the nut is unscrewed and the pin is pulled out to discharge the material. The advantages are anti-blocking, no dead corners, and no residue when discharging the material.

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