A highly efficient small-scale polymerization method for isobutylene block copolymers

Abstract

The application discloses a high-efficiency small test polymerization method of isobutylene block copolymer, which comprises the following steps: purifying non-polar solvent to a water content of less than or equal to 10 ppm through a thin film evaporation unit, and purifying a vinyl aromatic monomer through a reduced pressure distillation unit; a first monomer mixture containing isobutylene is added into a reaction kettle at a certain temperature at a certain rate, a first-stage living polymerization is carried out according to a heat release-heat removal coupling model to control the reaction temperature fluctuation, the living chain is kept, a second monomer mixture is switched to be added at a certain rate to carry out a second-stage polymerization, and a block copolymer is formed; and the polymerization is terminated and post-treated. The single-batch yield is 50-1000 g, the total time is less than or equal to 24 h, and the product molecular weight distribution Mw / Mn is less than 1.3. The device comprises a material deep pretreatment module, a multi-monomer sequential feeding module, an ultralow-temperature polymerization reaction module and a central control module, the modules are sealingly connected and automatically coordinated to run by the central controller.

Description

Technical Field

[0001] This invention relates to the field of polymer synthesis technology, specifically to a pilot-scale polymerization process for isobutylene-based block copolymers. Background Technology

[0002] Isobutylene block copolymers are high-performance thermoplastic elastomers. Their soft segments are fully saturated polyisobutylene segments, while their hard segments are polystyrene or other vinyl aromatic segments. This unique molecular structure endows the material with excellent airtightness, shock absorption, heat aging resistance, biological stability, and tissue compatibility, making it a promising candidate for high-value-added applications in pharmaceutical packaging, medical devices, consumer electronics, and automotive parts.

[0003] Currently, laboratory-scale research on this type of material mainly relies on small glove box reactors (usually 250mL~2L glass reaction flasks). In existing technical solutions, a typical operating procedure is as follows: Styrene is distilled under reduced pressure (with calcium hydride to remove water) outside the glove box. Solvents such as hexane and cyclohexane are soaked in molecular sieves and heated under reflux to remove water (target water content <10ppm). Glassware is dried in an oven and then dried again inside the glove box using a vacuum drying gun. Subsequently, the reaction flask, solvent, monomer, initiator, etc., are transferred to the glove box. The low-temperature bath inside the glove box is turned on to cool to -85℃. Chloromethane and isobutylene are introduced into the glove box from a high-pressure cylinder, condensed in a low-temperature test tube, and then quantitatively collected. Solvent, a portion of isobutylene, initiator, and co-initiator are added sequentially to a 1L three-necked flask. The reaction is carried out at -85℃. After a period of time, the remaining isobutylene or another monomer is manually added dropwise through a dropping funnel. The temperature is controlled throughout the reaction by manually observing the thermometer and adjusting the low-temperature bath or the dropping rate. Methanol is added to terminate the reaction. Finally, the reaction solution is removed from the glove box, poured into a large amount of methanol to precipitate the polymer, washed, and then vacuum dried.

[0004] However, the aforementioned existing technologies have the following drawbacks: single-batch yield is only 20-40g, which is only sufficient for basic characterization needs such as gel permeation chromatography, and cannot meet the sample quantity requirements for mechanical property testing, processing performance evaluation, and downstream application development. Furthermore, a single experiment takes 1-2 weeks, resulting in extremely low R&D efficiency. The glove box's low-temperature bath has limited temperature control capabilities, leading to large temperature fluctuations (up to 30℃) during exothermic polymerization, which exacerbates side reactions such as chain transfer and results in a wide molecular weight distribution of the product. The product quality is unstable; there are many human-operated variables (feeding speed, dripping speed, temperature judgment, etc.), resulting in large batch-to-batch differences and making it difficult to establish a reliable correlation between process parameters and product performance; existing technologies are intermittent operations, which cannot simulate the real working conditions such as multi-stage feeding and constant temperature control in industrial continuous production, thus amplifying the risks. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention discloses a highly efficient small-scale polymerization method for isobutylene-based block copolymers, the technical solution of which is as follows:

[0006] A highly efficient pilot-scale polymerization method for isobutylene-based block copolymers, characterized by comprising the following steps:

[0007] (a) Material deep purification and platform pretreatment steps:

[0008] The online purification module, which is sealed and connected to the reactor, is activated by the central control system. This module includes a thin-film evaporation unit and a vacuum distillation unit.

[0009] A non-polar solvent is delivered to the thin-film evaporation unit and continuously evaporates under conditions of vacuum of 0.1 kPa to 1 kPa and temperature of 40°C to 80°C, so that the water content of the solvent at the outlet is ≤10 ppm.

[0010] The falling film evaporation is controlled according to the following water removal kinetic equation (1):

[0011]

[0012] In equation (1), Real-time water content of the solvent, in ppm; For processing time; The falling film mass transfer coefficient; The water content at the gas-liquid interface equilibrium; The effective area for falling film evaporation; The effective processing volume of the solvent in the thin-film evaporation unit is expressed in m³.

[0013] The vinyl aromatic monomer is fed to the vacuum distillation unit, where the polymerization inhibitor and trace water are removed at a temperature of 60℃~80℃ and a pressure of -0.095MPa~-0.1MPa. The residual amount of polymerization inhibitor in the purified vinyl aromatic monomer is ≤10ppm and the water content in the monomer is ≤50ppm.

[0014] The purified material is directly transported to the platform storage tank through a sealed pipeline, with nitrogen protection throughout the process;

[0015] (b) First stage of living polymerization:

[0016] The ultra-low temperature circulating refrigerator is turned on by the central controller, and the main reactor with an effective volume of ≥10L is cooled to -90℃~-60℃ and stabilized.

[0017] Verify the purity of the system based on the following impurity tolerance relationship (2):

[0018]

[0019] In equation (2), This represents the total molar concentration of trace water and proton impurities in the system. This represents the theoretical molar concentration of active centers that the initiator system can produce.

[0020] When the impurity tolerance relationship (2) is satisfied, the central controller instructs the high-precision feed pump to deliver the first monomer mixture containing isobutylene monomer, halogenated hydrocarbon solvent and initiator system from the premix tank to the main reactor at a constant rate of 50 mL / min to 100 mL / min.

[0021] During the polymerization reaction, the central controller dynamically adjusts the feed rate and chiller output according to the following coupling model of exothermic and heat transfer in the polymerization reaction, maintaining the reaction temperature fluctuation ≤ ±1℃, and performing the first stage of polymerization reaction. ;

[0022] During the steady-state phase of the reaction, the heat release and heat transfer coupling model satisfies the following relationship (3):

[0023]

[0024] In equation (3), The rate of exothermic reaction; This is the molar exothermic enthalpy of the polymerization reaction, which is a positive value. This refers to the volume of the reaction mixture inside the reactor. This refers to the instantaneous concentration of the monomer. This represents the instantaneous consumption rate of a single unit. The overall heat transfer coefficient of the reactor jacket; The heat transfer area of ​​the jacket; This is the logarithmic mean temperature difference between the reaction temperature inside the reactor and the temperature of the cooling medium in the jacket. This represents the actual heat transfer rate of the refrigeration unit;

[0025] The logarithmic mean temperature difference Calculate according to the following formula (4):

[0026] (4)

[0027] In equation (4), To determine the uniform temperature of the reaction mixture inside the reactor, the average value of multiple temperature sensor readings is taken. This is the temperature at which the cooling medium enters the jacket; The temperature at which the cooling medium leaves the jacket; , Let be the assumed inlet temperature and assumed outlet temperature of the reaction mixture circulating within the reactor, respectively. These can be approximated under conditions of thorough stirring and mixing. ;

[0028] During the reaction, the amount of feed is measured in real time using a weighing module. Once the preset value is reached, the feed valve is automatically closed to form polyisobutylene segments B containing active chain ends.

[0029] (c) Second sequential aggregation step:

[0030] Under the condition that polymerization is not terminated and the active chains are maintained, the first polymerization time After completion, the central controller automatically switches to the second feeding unit, closes the isobutylene feed valve, and opens the outlet valve of the vinyl aromatic monomer storage tank.

[0031] A second monomer mixture containing vinyl aromatic monomers is added to the same main reactor at a second set rate of 10 mL / min to 20 mL / min, and the second stage polymerization reaction is continued under a constant temperature condition of -90℃ to -60℃. ;

[0032] The vinyl aromatic monomer grows from the active polyisobutylene segment formed in step (b) to form an ABA-type triblock copolymer, wherein segment A is a vinyl aromatic polymer segment and segment B is a polyisobutylene segment.

[0033] (d) Termination and post-integration processing steps:

[0034] After the second polymerization reaction is completed, the central controller injects a terminator, and the reaction liquid is discharged to the post-processing unit through the valve at the bottom of the reactor. After washing and drying, the target product is obtained.

[0035] The single-batch product yield of the method is 50g to 1000g, and the total time from raw material purification in step (a) to obtaining crude product in step (d) does not exceed 24 hours.

[0036] Preferably, the number-average molecular weight of the obtained ABA-type block copolymer is: for to Molecular weight distribution The mass fraction of the A-segment is 20%-40%.

[0037] Preferably, in steps (b) and (c), the central controller has a pre-set "multi-segment aggregation program" that includes the following key parameter matrix for each aggregation segment: Where i is the polymerization segment index, i=1,2,…,n, ti is the polymerization reaction time of that segment, and Ti is the reaction temperature of that segment. Let Vi be the feed rate for that section, and Vi be the feed volume for that section. This refers to the mass or volume ratio of the monomer to the solvent in this segment;

[0038] During program execution, the central controller automatically switches the feeding units of different monomers in a preset matrix sequence and monitors the conversion rate of each segment in real time. When the instantaneous conversion rate of any monomer reaches 95% or more, it automatically triggers the feeding of the next monomer segment, thus achieving precise control of the segmented structure.

[0039] This invention also discloses a high-efficiency pilot-scale polymerization apparatus for realizing the above-described method of isobutylene block copolymers, the apparatus comprising:

[0040] Material deep pretreatment module: includes a thin-film evaporation unit and a vacuum distillation unit, used for online continuous purification of non-polar solvents and vinyl aromatic monomers;

[0041] Multi-unit sequential feeding module: Includes at least two independent high-precision feed pumps, a premixing tank, a weighing module, and a pipeline switching valve group controlled by a central controller, used to achieve segmented, quantitative, and timed automatic feeding of multiple monomers; the feeding error of the feed pumps is within ±1% of the set value, i.e. ;

[0042] The cryogenic polymerization reaction module includes a main reactor with an effective volume ≥10L and a full jacket, and a cryogenic circulating refrigerator connected to the central controller. The refrigerator can provide a cooling medium below -90℃, and in conjunction with the jacket, the temperature control accuracy of the reactor reaches ±1℃.

[0043] Central control module: a PLC or DCS control system, which is connected to the sensors, pumps, valves and refrigeration electromechanical components in the pretreatment module, feeding module and reaction module, and is configured to automatically execute the above methods.

[0044] Beneficial effects

[0045] (1) Significantly improve experimental efficiency and sample production capacity, breaking through the bottleneck of small-scale experimental verification.

[0046] This invention, through an integrated platform (10L main reactor, multi-feed pumps, and online pretreatment module) and automated program control, achieves a single-batch yield of 500g to 1000g, which is 25 to 50 times that of the traditional glove box process (20g to 40g). The total time from raw material purification to obtaining the crude product is no more than 24 hours, while the traditional process requires 1 to 2 weeks. Therefore, the obtained product is sufficient to meet the needs of mechanical property testing, processing performance evaluation, and downstream application development, completely solving the industry pain point of traditional small-scale trials being "capable of characterization but unable to verify applications," and revolutionizing R&D efficiency.

[0047] (2) Achieve precise temperature control at ultra-low temperatures, significantly improving product quality and process stability.

[0048] By utilizing an ultra-low temperature circulating refrigerator (which can provide cooling media below -90℃) and a fully jacketed reactor, combined with the exothermic-heat-transfer coupling model of the polymerization reaction and dynamic PID control of the heat transfer rate built into the central controller, the reaction temperature fluctuation is controlled within ±1℃, far superior to the ±10℃~30℃ of traditional processes. This effectively suppresses side reactions such as chain transfer and premature termination, ensuring that the molecular weight distribution width of the product can be stably below 1.3 (compared to ≥1.5 in traditional processes), and reducing the relative standard deviation (RSD) of the molecular weight distribution between batches by more than 50%, providing a high-quality, highly repeatable data foundation for process scale-up.

[0049] (3) To achieve automated and precise block control of multi-unit sequential feeding.

[0050] The central controller, with its preset multi-stage polymerization parameter matrix, can automatically switch between different monomer feeding units and precisely control the feeding rate, volume, ratio, and reaction time of each stage. The feeding error is ≤ ±1%, and the system automatically triggers the next feeding stage when the instantaneous monomer conversion rate exceeds 95%, ensuring the integrity of the block structure. The resulting ABA-type triblock copolymer exhibits a hard segment content precisely controlled between 20% and 40%, and a number-average molecular weight (Mn) of 5 × 10⁻⁶. 4 ~1.5×10 5 It is adjustable within a certain range, and its block efficiency is significantly higher than that of traditional processes that rely on manual dripping.

[0051] (4) Construct a fully enclosed, online purification material processing system to avoid secondary pollution.

[0052] The thin-film evaporation unit (used for continuous dehydration of non-polar solvents, based on falling film dehydration kinetics and dehydration efficiency equations) and the vacuum distillation unit (used for removing polymerization inhibitors from vinyl aromatic monomers) are directly connected to the polymerization reactor via sealed pipelines. The purified material has a water content ≤50ppm (preferably ≤10ppm), and the residual polymerization inhibitor is ≤10ppm, with nitrogen protection throughout the process and no exposure during transfer. In contrast, in traditional processes, the material is manually pretreated and then transferred to a glove box, making it highly susceptible to re-hygroscopicity or oxidation. The fully enclosed system of this invention increases the polymerization success rate from 60%–70% in traditional processes to over 95%, resulting in higher product purity.

[0053] (5) Simulate industrial production conditions to reduce the risk of amplification.

[0054] Traditional pilot-scale processes are intermittent and manually operated, unable to simulate key elements of industrial production such as continuous feeding and constant temperature control. This invention achieves multi-segment automated feeding, constant temperature reaction, and real-time parameter monitoring and recording, with control logic highly similar to industrial production equipment. Therefore, when scaling up the process parameters (temperature, feed rate, reaction time, etc.) obtained from this pilot-scale process, the success rate is far higher than that of traditional processes, effectively shortening the cycle from R&D to industrialization.

[0055] (6) Improve the stability of living polymerization and inhibit inactive initiation.

[0056] This invention introduces pyridine compounds as proton traps into the initiator system, and controls their addition to the premixing tank before titanium tetrachloride via a central controller. Based on the active center protection kinetics, trace proton impurities in the system are preferentially consumed, thereby maximizing the dominance of active cationic chain growth, further reducing the probability of side reactions, and improving the regularity of polymer chain structure and the controllability of molecular weight distribution. Attached Figure Description

[0057] Figure 1 A schematic diagram of the method flow of this invention. Detailed Implementation

[0058] Example 1

[0059] This embodiment provides an efficient pilot-scale polymerization method for isobutylene-based block copolymers. The method is implemented based on an integrated pilot-scale polymerization platform and aims to synthesize polystyrene-polyisobutylene-polystyrene (PS-PIB-PS) triblock copolymers.

[0060] (a) Deep purification of materials and platform pretreatment

[0061] To meet the extremely low impurity requirements (especially for water and proton impurities) of living cationic polymerization, this step is not a simple offline process. Instead, an online purification module, sealed to the reactor, is activated via a central control system (PLC). This module includes a thin-film evaporation unit and a vacuum distillation unit, achieving seamless integration from raw material purification to the reaction and avoiding secondary contamination caused by material transfer in traditional processes.

[0062] First, the nonpolar solvent methylcyclohexane is treated. It is then fed to a thin-film evaporation unit, the core of which is to use a scraper to form an extremely thin turbulent liquid film on the heated inner wall of the evaporation cylinder, significantly increasing the gas-liquid interface area. The process conditions are set at a vacuum of 0.1 kPa-1 kPa and a temperature of 40°C-80°C. This setting is because excessively high vacuum (<0.1 kPa) places extremely stringent requirements on equipment sealing, reducing economic efficiency; while excessively low vacuum (>1 kPa) results in insufficient water removal efficiency. Below 40°C, the evaporation rate of methylcyclohexane is too slow to effectively remove moisture; while above 80°C, thermal decomposition of the solvent or unnecessary side reactions may occur. Under these conditions, water molecules diffuse from the interior of the liquid film to the surface and evaporate into the gas phase, where they are removed by the vacuum system. To ensure controllable water removal, the central controller does not operate blindly but monitors the real-time water content of the solvent based on the following water removal kinetic equation. Perform closed-loop control: ; in, The solvent's real-time water content (ppm, mass fraction) is given by , and t is the processing time. is the falling film mass transfer coefficient (m / s). Let A be the equilibrium water content at the gas-liquid interface (ppm), and let A be the effective area of ​​falling film evaporation (m²). Characteristic volume of solvent treatment (m³); rate of change of solvent water content With mass transfer driving force The effective area A of falling film evaporation is directly proportional to the characteristic volume of solvent treatment. Inversely proportional. In practice, the controller changes the residence time of the solvent in the evaporator by adjusting the feed rate (i.e., changing...). Alternatively, the heating temperature can be adjusted to affect the mass transfer coefficient. and balance water content This allows for precise control of the outlet water content. Relying solely on experience, fluctuations in the feed rate can lead to drastic changes in the outlet water content, potentially causing polymerization initiation failure or even a broadening of the product's molecular weight distribution and performance degradation. After treatment in this unit, the water content of methylcyclohexane is stably controlled below 10 ppm.

[0063] Simultaneously, the vinyl aromatic monomer styrene is purified. Styrene typically contains polymerization inhibitors such as p-tert-butylcatechol, which quench the cationic active centers, preventing polymerization. Therefore, the styrene is fed to a vacuum distillation unit for distillation at temperatures of 60°C-80°C and pressures of -0.095 MPa to -0.1 MPa (i.e., absolute pressure 5 kPa to 50 kPa). Vacuum distillation is used because styrene's boiling point at atmospheric pressure is 145°C, and prolonged high-temperature heating would cause it to spontaneously polymerize. Under 60-80°C and negative pressure conditions, styrene can vaporize and condense at temperatures far below its atmospheric boiling point, effectively removing high-boiling-point polymerization inhibitors and trace amounts of water while avoiding the risk of monomer thermal polymerization. The purified styrene is directly transported to the platform storage tank through a sealed pipeline, continuously purged with high-purity nitrogen to ensure its purity is maintained until just before the reaction.

[0064] (b) First stage of living polymerization.

[0065] After purification, the synthesis of polyisobutylene (PIB) segments (i.e., B segments) began. The central controller first activated the cryogenic circulating refrigerator, cooling the 10L main reactor to the target temperature of -85°C and stabilizing it. -85°C was chosen because isobutylene exhibits extremely high cationic polymerization rates and low chain growth activation energies. At higher temperatures (such as above -60°C), chain transfer and other side reactions readily occur, leading to a wider molecular weight distribution. While the ultra-low temperature environment of -85°C presents greater challenges to the equipment, it significantly suppresses chain transfer, a crucial prerequisite for achieving a molecular weight distribution (Mw / Mn) <1.3.

[0066] After confirming that the reactor temperature is stable and the impurities in the system are below the tolerance limit, the central controller instructs the high-precision feed pump to deliver the first monomer mixture from the premixing tank to the main reactor at a constant rate of 80 mL / min. This mixture contains isobutylene monomer, chloromethane as a solvent (whose polarity helps stabilize the active center), and an initiator system (a ternary system of dicumyl chloride / titanium tetrachloride / pyridine compounds).

[0067] The initiator system in the first monomer mixture is a ternary system of dicumyl chloride / titanium tetrachloride / pyridine compounds; in step (b), the central controller controls the pyridine compounds to be added to the premixing tank before the titanium tetrachloride, and uses the following active center protection kinetic relationship to preferentially consume the initial total concentration of proton impurities in the system before the addition of the pyridine compounds. To inhibit inactive initiation:

[0068] in, The molar concentration (mol / L) of remaining proton impurities in the system at reaction time t (s). Let be the initial molar concentration of the pyridine compound. The proton capture reaction rate constant (L / (mol·s)) is given, and for the pyridine / TiCl4 system, the value ranges from 10. 3 -10 5 Ensure that the growth of active cationic chains is absolutely dominant;

[0069] This represents the initial molar concentration (mol / L) of the pyridine compound. Since pyridine is in excess by tens of times relative to impurities, it is approximately constant during the reaction.

[0070] This kinetic relationship ensures that the growth of active cation chains is absolutely dominant, suppressing inactive initiation.

[0071] The feed rate was chosen to be 80 mL / min within the range of 50-100 mL / min, based on considerations of heat balance: if the rate is too fast, the amount of polymerizable monomer added per unit time will be too large, increasing the exothermic reaction rate. The actual heat transfer rate of the refrigeration unit Too slow a reaction rate leads to uncontrolled reaction; too slow a rate prolongs the reaction time and increases the risk of deactivation of the active site.

[0072] Once polymerization begins, it is highly exothermic. If the heat is not removed in time, the temperature of the reaction system will rise rapidly, leading to chain transfer and premature termination. Therefore, the central controller incorporates a coupled model of exothermic and heat removal processes in the polymerization reaction.

[0073] ;

[0074] This model considers the exothermic rate of chemical reactions. Heat transfer rate with physics Real-time coupling was implemented. The controller estimates the monomer consumption rate using an online viscometer or calorimeter. Thus predicting Based on this, the output power of the chiller and the flow rate and temperature of the cooling medium in the jacket are dynamically adjusted to change the logarithmic mean temperature difference. ,make sure Always equal to This ensures that the reaction temperature fluctuation remains ≤ ±1°C. Without this dynamic adjustment capability, relying solely on a fixed cooling temperature will lead to an imbalance between the heat of reaction and heat transfer when there are slight fluctuations in the monomer feed or polymerization rate. Temperature fluctuations may exceed 5-10°C, and the molecular weight distribution of the product will broaden dramatically (e.g., Mw / Mn reaches 3.69 in Comparative Example 1). Simultaneously, the PID controller reads the average values ​​from multiple temperature sensors within the reactor in real time, based on the heat transfer rate equation... Fine-tuning was performed to ensure a constant reaction temperature. In this embodiment, the reaction time was 85 minutes, during which the temperature remained stable at -85±1°C. The weighing module measured the amount of material added in real time, and automatically closed the feed valve after reaching the preset value, forming polyisobutylene segments with active chain ends.

[0075] (c) Second sequential aggregation step.

[0076] After the first stage of polymerization, block polymerization of the styrene segment (A segment) is carried out while ensuring that the active chain ends do not terminate. The central controller automatically switches to the second feeding unit, closes the isobutylene feed valve, and opens the styrene storage tank outlet valve to prevent cross-contamination that could lead to uncontrolled polymer structure.

[0077] A mixture of styrene monomer and a portion of methylcyclohexane, representing a second monomer, is added to the same main reactor at a second set feed rate of 15 mL / min. The second feed rate (10-20 mL / min) is significantly lower than the first (50-100 mL / min) because the active chain growth rate of styrene is also very high; a slower feed rate allows for more effective control of the exothermic reaction and prevents localized overheating. Under isothermal conditions of -85°C, the styrene monomer undergoes chain growth starting from the active polyisobutylene segments formed in the first step, forming a polystyrene-polyisobutylene-polystyrene (PS-PIB-PS) triblock copolymer. The reaction lasts for 40 minutes.

[0078] In this process, the pre-set "multi-segment aggregation program" within the central controller plays a crucial role. This program includes a parameter matrix: In this embodiment, i=1,2; ti is the polymerization reaction time for this stage, and Ti is the reaction temperature for this stage. Let Vi be the feed rate for that section, and Vi be the feed volume for that section. This refers to the mass or volume ratio of the monomer to the solvent in this stage. The program monitors the instantaneous conversion rate of isobutylene and styrene in real time. The second stage of feeding is only triggered when the isobutylene conversion rate reaches 95% or higher. This "high conversion triggering" mechanism ensures that the monomer in the first stage is essentially consumed, avoiding the formation of random copolymers and guaranteeing the accuracy and integrity of the block structure. If the second monomer is added when the conversion rate is low (e.g., 80%), the remaining isobutylene will undergo random copolymerization with styrene, forming "gradual" blocks with unclear structures, severely impairing the thermoplastic elastomer properties of the material.

[0079] (d) Termination and integration post-processing steps.

[0080] After the second stage of polymerization, the central controller automatically injects pre-cooled methanol as a terminator. The hydroxyl hydrogen in the methanol reacts with the active cation chain ends, deactivating them. The reaction solution is discharged to the post-processing unit through a valve at the bottom of the reactor. The post-processing unit first removes catalyst residue and most of the solvent by washing and separating with water, followed by reprecipitation (dropping the polymer solution into a large amount of non-solvent) for further purification, and finally vacuum drying at 60°C to constant weight to obtain a white flocculent target product.

[0081] The yield of a single batch was measured to be 850 grams, and the total time from starting raw material purification to obtaining the crude product was only 20 hours, far shorter than the 1-2 weeks required by traditional processes. The number-average molecular weight (Mn) of the obtained product was 1.0 × 10⁻⁶. 5 The molecular weight distribution (Mw / Mn) was 1.25, and the mass fraction of the A segment (polystyrene) was 38%. Compared with the traditional glove box process (Comparative Example 1), this embodiment increased the yield by 25 times while significantly narrowing the molecular weight distribution width from 3.69 to 1.25, resulting in a qualitative leap in molecular weight controllability. This is directly attributed to the integrated platform, which enables online purification, precise temperature control (±1℃ vs. the drastic fluctuations in Comparative Example 1), automated sequential feeding, and model-based reaction heat management. Without any of these technical features, such as abandoning online moisture monitoring and relying solely on periodic calibration, or using simple PID temperature control without an exothermic-heat transfer coupling model, it would be difficult to consistently achieve excellent results with Mw / Mn < 1.3 at a 10L scale.

[0082] Example 2

[0083] This embodiment provides an integrated polymerization apparatus for implementing the efficient small-scale polymerization method of isobutylene block copolymers described in Example 1. The apparatus consists of four main functional units: a material deep pretreatment module, a multi-monomer sequential feeding module, an ultra-low temperature polymerization reaction module, and a central control module. These modules are physically connected and logically coupled through fully sealed stainless steel pipelines and controlled valves, forming a closed-loop automated system from raw material purification to product synthesis. The technical solution of this embodiment will be described in detail below, combining the specific structure of the apparatus and its application in the method of Example 1.

[0084] The material deep pretreatment module is directly connected to other modules of the device using a "ready-to-use" method, eliminating the risk of purified materials being exposed to the atmosphere and becoming damp again, as is common in traditional processes. This module includes a thin-film evaporation unit and a vacuum distillation unit, arranged in parallel, for continuous dehydration of non-polar solvents and removal of polymerization inhibitors from vinyl aromatic monomers, respectively. The main body of the thin-film evaporation unit is a vertical or horizontal evaporation cylinder with a scraper film-forming mechanism. Its effective evaporation area is designed to be 0.5-1.0 m² based on the solvent consumption rate of a 10L reactor (approximately 4-6L per batch). The outer wall of the evaporation cylinder is equipped with a heating jacket, providing a heating temperature of 40°C-80°C via heat transfer oil or an electric heating medium. The system is equipped with a vacuum pump group to maintain the absolute pressure inside the evaporation chamber at 0.1kPa-1kPa. After the solvent enters through the feed inlet at the top of the unit, it forms a uniform falling film under the centrifugal force of the rotating scraper, flowing downwards along the inner wall of the cylinder. During this process, water molecules, due to their saturated vapor pressure being much higher than that of the solvent (at the same temperature, the vapor pressure of water is typically 5-10 times that of the solvent), preferentially vaporize from the liquid film surface and are removed by the vacuum system. To achieve quantitative control of the dehydration effect, an online moisture meter (such as a Karl Fischer principle near-infrared analyzer or a capacitive moisture meter) is installed on the outlet pipe of the thin-film evaporation unit. This instrument sends the water content data of the purified solvent to the central control module in real time. When the detected value exceeds 50 ppm, the central control module, based on the falling film evaporation efficiency equation (which expresses the functional relationship between dehydration efficiency and mass transfer coefficient, evaporation area, and solvent flow rate), automatically reduces the speed of the solvent feed pump (reducing the flow rate to extend the residence time) or appropriately increases the temperature of the heating jacket (increasing the mass transfer driving force), forming a closed-loop feedback regulation. Only when the water content is continuously monitored for 30 seconds and is ≤10 ppm is the pneumatic diaphragm valve located at the unit outlet allowed to open, allowing the solvent to enter the sealed receiving tank and be ready for use. The vacuum distillation unit processes styrene monomers. Its core is a distillation vessel equipped with a heating jacket and a condenser. During operation, the pressure inside the vessel is controlled at -0.095 MPa to -0.1 MPa (absolute pressure 5-50 kPa) using a vacuum system, while the vessel is heated to 60°C-80°C. Under these conditions, styrene vaporizes at a temperature far below its atmospheric boiling point (145°C). High-boiling-point polymerization inhibitors (such as p-tert-butylcatechol, boiling point 285°C) remain at the bottom of the vessel. The styrene vapor is condensed and flows into a stainless steel receiving bottle protected by nitrogen. This receiving bottle is directly connected to the vinyl aromatic monomer storage tank in the multi-monomer sequential feed module via a sealed pipeline, with no exposed points in between.

[0085] The function of the multi-monomer sequential feeding module is to precisely deliver various materials purified by the pretreatment module to the cryogenic polymerization reaction module according to the timing, rate, and proportion specified in Example 1. This module contains at least two independent high-precision feed pumps (e.g., cryogenic, corrosion-resistant plunger pumps or diaphragm pumps), with the feeding error of each pump controlled within ≤±1% after factory calibration and periodic online calibration. The inlets of all feed pumps are connected to different material storage tanks via their respective pipeline valves: the first feed pump connects to the isobutylene storage tank, the halogenated hydrocarbon solvent (such as chloromethane) storage tank, and the premixing tank for the initiator system; the second feed pump connects to the vinyl aromatic monomer storage tank purified by vacuum distillation. The design of the premixing tank is crucial; its tank body is jacketed and can be connected to the refrigerant circulation pipeline of the cryogenic circulating refrigerator to precool the mixture to near the reaction temperature (-85°C). A set of switching valves controlled by a central control module is installed between the outlet of the premixing tank and the inlet of the reactor. This valve group can realize the logic of "selective conduction" or "sequential conduction" to ensure that materials from different stages are not mixed. The weighing module (usually a pressure or strain gauge weighing sensor installed at the bottom of the premixing tank or material storage tank) measures the cumulative mass or volume of each feed in real time and feeds the signal back to the central control module. When the deviation between the actual added amount and the preset value exceeds ±1%, the controller will automatically correct the operating frequency of the feed pump and issue an alarm if it cannot be corrected. This module directly corresponds to the multi-stage polymerization program described in Example 1: In the first stage of polymerization, the central controller reads the feed rate Rf,1 (50-100 mL / min) and feed volume V1 from the parameter matrix P1, and instructs the first feed pump to pump the mixture of isobutylene, chloromethane and initiator from the premixing tank into the reactor at this rate; after the weighing module reaches the mass corresponding to V1, the first feed valve is automatically closed. After entering the second polymerization stage, the controller switches the valve group and instructs the second feed pump to pump styrene and part of the solvent into the same reactor at Rf,2 (10-20 mL / min). The difference in feed rate stems from the difference in the exothermic polymerization rates of the two monomers—although the polymerization enthalpy of isobutylene (approximately -60 kJ / mol) is similar to that of styrene (approximately -70 kJ / mol), isobutylene has a higher polymerization rate constant at -85°C, thus requiring a faster feed rate to shorten the total reaction time, while not being too fast so that the exothermic reaction exceeds the cooling capacity; while styrene also has an extremely high chain growth rate, and using a slower feed rate (10-20 mL / min) helps the heat to be carried away by the jacket cooling medium immediately upon addition, avoiding local hot spots.

[0086] The cryogenic polymerization reaction module is the core hardware for implementing the "living polymerization" conditions in Example 1. This module includes a main reactor with an effective volume ≥10L and a matching cryogenic circulating refrigerator. The main reactor is made of austenitic stainless steel (e.g., 316L) and designed to withstand pressures from -0.1MPa to 0.5MPa to accommodate possible gas escape and vacuum operation. The reactor body is fully jacketed, with a coolant (typically low-viscosity silicone oil or fluorinated liquid) supplied and forcibly circulated by the cryogenic circulating refrigerator. The inner wall surface of the reactor is mechanically and electrochemically polished to a surface roughness Ra ≤0.4μm. This parameter is determined based on a deep understanding of the mechanism of living cationic polymerization: on wet-polished metal surfaces, numerous uncoordinated metal atoms and hydroxyl groups exist at microscopic protrusions. These sites have strong electrophilicity and readily undergo irreversible adsorption or electron transfer with carbocation active centers, leading to the "death" of the active chain. After polishing to Ra≤0.4μm, the effective surface area is reduced by approximately 70%, and a dense passivation film is formed on the surface, significantly reducing the consumption rate of active centers on the wall surface. A bottom-mounted agitator is installed at the bottom of the reactor. Its blade shape (e.g., an anchor-type paddle that perfectly conforms to the arc of the reactor bottom or a ribbon-type paddle with inclined blades) ensures axial circulating flow within a liquid level range of 10% to 100%. In the initial stage of the second-stage polymerization, due to the relatively small amount of styrene added, the reaction liquid level may only occupy 10%-15% of the reactor volume. If a traditional top-mounted inclined blade paddle is used at this time, the blades will be exposed above the liquid surface or can only agitate the upper layer of liquid, leading to the accumulation of styrene concentration in the lower layer, localized over-polymerization, and the generation of high-molecular-weight "tail peaks." However, the bottom-mounted agitator is always immersed in the liquid, and its downward-pushing flow pattern can push the material at the bottom of the reactor upwards along the center, forming a complete circulation and eliminating mixing dead zones. Experimental verification showed that when using a traditional stirrer, the GPC curve of the second-stage polymerization product exhibited a significant shoulder peak at the 200,000 molecular weight mark. In the comparative example without a bottom stirrer, this shoulder peak accounted for 15% of the total area, indicating severe mixing inhomogeneity. The cryogenic circulating refrigerator employs a cascade compression cycle, where the first-stage refrigerant (e.g., R404A) cools the second-stage refrigerant (e.g., R23 or ethane), allowing the refrigerant outlet temperature to reach below -95°C. The refrigerator's compressor uses a variable frequency drive, with its operating frequency controlled by a 4-20mA signal from the central control module. The refrigerator is also equipped with an electronic expansion valve and a hot gas bypass valve to achieve continuous and smooth adjustment within the range of -90°C to -60°C. This refrigerator, together with the reactor jacket, forms a temperature control system that, in conjunction with the exothermic-heat transfer coupling model and heat transfer rate equation described in Example 1, can control reaction temperature fluctuations within ±1°C.

[0087] The central control module is the decision-making and scheduling center of the entire device. Its hardware consists of an industrial-grade PLC (Programmable Logic Controller) or DCS (Distributed Control System), equipped with analog input / output modules, digital input / output modules, a communication module (supporting Modbus TCP, Profinet, and other protocols), and a human-machine interface (HMI). This controller is electrically connected via signal cables to components in the material deep pretreatment module, including a vacuum gauge, temperature sensor, online moisture meter, feed pump motor, and heater; in the multi-monomer sequential feeding module, to each feed pump, weighing module, and pneumatic diaphragm valve; and in the cryogenic polymerization reaction module, to multiple temperature sensors (at least three at different heights), pressure transmitter, agitator motor, temperature sensor of the refrigeration unit, and compressor frequency converter. The controller internally stores non-volatile firmware, pre-installed with the multi-segment polymerization parameter matrix P described in Example 1. i The system also includes algorithmic models such as impurity tolerance relationships, water removal kinetic equations, and exothermic-heat transfer coupling models. When running the method of Example 1, the controller automatically executes the following logic: First, it instructs the preprocessing module to start the purification process and continuously reads data from the online moisture analyzer. It uses the impurity tolerance relationship to determine whether the entry conditions of "solvent water content ≤ 50 ppm (preferably ≤ 10 ppm) and monomer polymerization inhibitor ≤ 10 ppm" are met. If not, it continues to intensify purification or issues an alarm. After the entry conditions are met, the controller instructs the chiller to start, cooling the reactor to the set temperature (e.g., -85°C) and stabilizing it for 30 minutes. During this period, the average value of the temperature sensor inside the reactor is compared with the set value, and the chiller output is adjusted using a PID algorithm. Once the temperature stabilizes, the controller enters the first polymerization stage: it opens the first feed pump and corresponding valves, pumping the first monomer mixture from the premix tank into the reactor at a rate Rf,1, while simultaneously reading the weighing module data in real time. The system shuts off when the preset V1 is reached. During polymerization, the controller continuously collects the temperature inside the reactor, dynamically estimates the current exothermic reaction rate using an exothermic-heat transfer coupling model, and adjusts the cooling capacity of the chiller and the flow rate of the jacketed refrigerant to offset the temperature rise caused by the heat of reaction. After the first stage of reaction time t1 is reached, the controller automatically switches to the second stage of polymerization: the first feed valve is closed, the second feed pump and corresponding valves are opened, the second monomer mixture is added at a rate Rf,2, and the above temperature control logic is repeated. When the entire reaction time is over, the controller instructs the terminator injection pump (optional) to inject the terminator and opens the reactor bottom valve to discharge the material to the post-processing unit. Throughout the process, all process parameters (temperature, pressure, flow rate, time, cumulative feed amount, etc.) are recorded in the controller's built-in memory card, which is traceable and exportable.

[0088] Interrelationship and Synergistic Effect of the Device Modules: The four modules mentioned above do not operate independently, but rather form an organic whole through the unified scheduling of the central control module and the transmission of materials, energy, and information. Specifically, the output of the material deep pretreatment module (purified solvent and monomer) is directly used as the input to the multi-monomer sequential feeding module, without any intermediate buffering or exposure. This is the premise of "full-process nitrogen protection to avoid secondary pollution" in the method of Example 1. The multi-monomer sequential feeding module delivers materials to the ultra-low temperature polymerization reaction module in a specific order and rate according to the parameter matrix of Example 1, and the precise temperature environment provided by the latter is a necessary condition for maintaining the living polymerization in Example 1. At the same time, the temperature and pressure signals in the ultra-low temperature polymerization reaction module and the mass signal from the weighing module are fed back to the central control module. The controller dynamically adjusts the purification intensity of the pretreatment module (such as the thin film evaporation temperature) and the feeding rate of the feeding module based on these real-time data, forming a multi-variable closed-loop control. For example, if the temperature sensor shows that the actual temperature is lower than the set value during the first stage of polymerization (indicating low reactivity, possibly due to trace impurities in the system not being completely captured), the controller can appropriately increase the subsequent feed rate within a preset safety range, using the exothermic reaction to naturally raise the temperature to the set point; conversely, if the temperature is higher than the set value, the feed rate is reduced and cooling is enhanced. This cross-module coordinated adjustment capability is something that traditional glovebox-type devices cannot achieve.

[0089] Basis for device parameter selection and effect verification: To prove the non-obviousness of the device parameter selection in this embodiment, a comparative example device was set up. This device is basically the same as the above device, but the following three features are removed: ① Online moisture closed-loop feedback of the thin film evaporation unit (replaced with timed manual sampling detection); ② Polishing of the inner wall of the reactor (retaining the original machined surface, Ra≈1.6μm); ③ Bottom-mounted agitator (replaced with ordinary top-mounted inclined blade paddle). The polymerization method of Example 1 was repeated three times using the comparative apparatus. The results showed that: in the first polymerization, due to the lag in manual moisture detection, the actual solvent water content entering the reactor reached 80 ppm, causing the pyridine compounds in the system to be unable to completely capture proton impurities, resulting in polymerization failure and an oily oligomer as the product; in the second polymerization, although a product was obtained, GPC testing showed Mw / Mn=1.9, and a significant tailing appeared at the high molecular weight end of the GPC curve (corresponding to the coupling product of polystyrene segments). The analysis showed that the rough reactor wall caused the active chain to be deactivated, and the deactivated chain ends underwent coupling reactions; in the third polymerization, when the second stage of feeding was underway, the top-mounted agitator generated eddies that entrained nitrogen gas at low liquid levels, causing dissolved oxygen in the system to destroy the active centers, resulting in a final product yield of only 55%. Even if only one of these characteristics of the comparative apparatus is retained (e.g., only a bottom agitator is added but manual moisture detection is still used), the failure rate is still as high as 40% or more. Conversely, after ten consecutive batches, the apparatus in this embodiment achieved an average yield of 845g, a mean Mw / Mn ratio of 1.26, and a batch-to-batch relative standard deviation (RSD) of 3.2%, significantly better than the comparative apparatus's 25% or more. These data clearly demonstrate that the apparatus features described in this embodiment—online purification closed-loop control, mirror polishing of the reactor inner wall, bottom-mounted stirrer—as well as the sealed connections and central coordination control between modules, form an interdependent and indispensable technical whole. The absence of any one of these features would cause the polymerization process to degrade from "active / controllable" to "inactive / uncontrollable," failing to achieve the yield, molecular weight distribution, and repeatability indicators required in Example 1.

[0090] The apparatus in this embodiment is the technical carrier that enables the successful implementation of the method in Example 1 on a 10L scale. The requirement for material purity (Cw≤10ppm) in Example 1 can only be stably achieved through the thin-film evaporation unit and its online moisture closed-loop feedback in this embodiment; the requirement for temperature fluctuation ≤±1°C in Example 1 can only be achieved through the ultra-low temperature circulating refrigerator, the fully jacketed reactor, and the exothermic-heat transfer coupling model built into the central controller in this embodiment; the precise control of multi-stage sequential feeding (feed error ≤±1%, automatic switching when conversion rate >95%) in Example 1 can only be accomplished through the high-precision feed pump, weighing module, switching valve group, and multi-stage polymerization parameter matrix in this embodiment. Conversely, without the polymerization formulation, reaction conditions, impurity tolerance judgment logic, and other process parameters provided in Example 1, the apparatus in this embodiment is merely a platform with hardware capabilities but cannot automatically generate specific operating instructions. Therefore, the method in Example 1 and the apparatus in Example 2 constitute a complete technical solution where "method-apparatus" mutually represent each other, jointly solving the technical problems of low yield, poor quality, and long cycle time in traditional small-scale processes.

[0091] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A highly efficient pilot-scale polymerization method for isobutylene-based block copolymers, characterized in that, Includes the following steps: (a) Material deep purification and platform pretreatment steps: The online purification module, which is sealed and connected to the reactor, is activated by the central control system. This module includes a thin-film evaporation unit and a vacuum distillation unit. A non-polar solvent is delivered to the thin-film evaporation unit and continuously evaporates under conditions of vacuum of 0.1 kPa to 1 kPa and temperature of 40°C to 80°C, so that the water content of the solvent at the outlet is ≤10 ppm. The falling film evaporation is controlled according to the following water removal kinetic equation (1): （1）； In equation (1), This represents the real-time water content of the solvent, in ppm. For processing time; The falling film mass transfer coefficient; The water content at the gas-liquid interface equilibrium; The effective area for falling film evaporation; The effective processing volume of the solvent in the thin-film evaporation unit is expressed in m³. The vinyl aromatic monomer is fed to the vacuum distillation unit, where the polymerization inhibitor and trace water are removed at a temperature of 60℃~80℃ and a pressure of -0.095MPa~-0.1MPa. The residual amount of polymerization inhibitor in the purified vinyl aromatic monomer is ≤10ppm and the water content in the monomer is ≤50ppm. The purified material is directly transported to the platform storage tank through a sealed pipeline, with nitrogen protection throughout the process; (b) First stage of living polymerization: The ultra-low temperature circulating refrigerator is turned on by the central controller, and the main reactor with an effective volume of ≥10L is cooled to -90℃~-60℃ and stabilized. Verify the purity of the system based on the following impurity tolerance relationship (2): （2）； In equation (2), This represents the total molar concentration of trace water and proton impurities in the system. This represents the theoretical molar concentration of active centers that the initiator system can produce. When the impurity tolerance relationship (2) is satisfied, the central controller instructs the high-precision feed pump to deliver the first monomer mixture containing isobutylene monomer, halogenated hydrocarbon solvent and initiator system from the premix tank to the main reactor at a constant rate of 50 mL / min to 100 mL / min. During the polymerization reaction, the central controller dynamically adjusts the feed rate and chiller output according to the following coupling model of exothermic and heat transfer in the polymerization reaction, maintaining the reaction temperature fluctuation ≤ ±1℃, and performing the first stage of polymerization reaction. ; During the steady-state phase of the reaction, the heat release and heat transfer coupling model satisfies the following relationship (3): （3）； In equation (3), The rate of exothermic reaction; This is the molar exothermic enthalpy of the polymerization reaction, which is a positive value. This refers to the volume of the reaction mixture inside the reactor. This refers to the instantaneous concentration of the monomer. This represents the instantaneous consumption rate of a single unit. The overall heat transfer coefficient of the reactor jacket; The heat transfer area of ​​the jacket; This is the logarithmic mean temperature difference between the reaction temperature inside the reactor and the temperature of the cooling medium in the jacket. This represents the actual heat transfer rate of the refrigeration unit; The logarithmic mean temperature difference Calculate according to the following formula (4): （4）； In equation (4), To determine the uniform temperature of the reaction mixture inside the reactor, the average value of multiple temperature sensor readings is taken. This is the temperature at which the cooling medium enters the jacket; The temperature at which the cooling medium leaves the jacket; , Let be the assumed inlet temperature and assumed outlet temperature of the reaction mixture circulating within the reactor, respectively. These can be approximated under conditions of thorough stirring and mixing. ; During the reaction, the amount of feed is measured in real time using a weighing module. Once the preset value is reached, the feed valve is automatically closed to form polyisobutylene segments B containing active chain ends. (c) Second sequential aggregation step: Under the condition that polymerization is not terminated and the active chains are maintained, the first polymerization time After completion, the central controller automatically switches to the second feeding unit, closes the isobutylene feed valve, and opens the outlet valve of the vinyl aromatic monomer storage tank. A second monomer mixture containing vinyl aromatic monomers is added to the same main reactor at a second set rate of 10 mL / min to 20 mL / min, and the second stage polymerization reaction is continued under a constant temperature condition of -90℃ to -60℃. ; The vinyl aromatic monomer grows from the active polyisobutylene segment formed in step (b) to form an ABA-type triblock copolymer, wherein segment A is a vinyl aromatic polymer segment and segment B is a polyisobutylene segment. (d) Termination and post-integration processing steps: After the second polymerization reaction is completed, the central controller injects a terminator, and the reaction liquid is discharged to the post-processing unit through the valve at the bottom of the reactor. After washing and drying, the target product is obtained. The single-batch product yield of the method is 50g to 1000g, and the total time from raw material purification in step (a) to obtaining crude product in step (d) does not exceed 24 hours.

2. The method according to claim 1, characterized in that, In steps (b) and (c), the central controller reads the average values ​​of multiple temperature sensors inside the reactor in real time. , and the set value In comparison, the PID algorithm is used to adjust the refrigerant flow rate and temperature of the cryogenic circulating refrigerator, and the thermal equilibrium of the reaction system is maintained according to the following heat transfer rate equation (5): （5）； In equation (5), The average density of the reaction mixture; This represents the volume of the reactants. The average isobaric specific heat capacity of the reaction mixture; For time; The overall heat transfer coefficient; The heat transfer area of ​​the jacket; This represents the average temperature of the cooling medium inside the jacket. The central controller controls the cryogenic refrigeration unit, enabling... The instantaneous fluctuation range remains within ±1℃.

3. The method according to claim 1, characterized in that, In step (a), an online moisture meter is installed at the outlet of the thin-film evaporation unit to monitor the water content of the purified solvent in real time. ; when When the solvent feed rate is ppm, the central controller automatically reduces the solvent feed rate or increases the film evaporation temperature, and adjusts the operating parameters according to the following film evaporation efficiency equation (6): （6）； In equation (6), For water removal efficiency; The falling film mass transfer coefficient; The effective area for falling film evaporation; This refers to the solvent feed volumetric flow rate; Continue adjusting the operating parameters until the solvent water content is reached. ppm is required for solvents to enter the receiving tank and be used in subsequent polymerization reactions.

4. The method according to claim 1, characterized in that, The number-average molecular weight of the obtained ABA-type block copolymer for to Molecular weight distribution The mass fraction of the A-segment is 20% to 40%.

5. The method according to claim 1, characterized in that, In steps (b) and (c), the central controller has a pre-set "multi-segment aggregation program", which includes the following parameter matrix for each aggregation segment. : ； in, For aggregate segment number index, ; For the first Phase polymerization reaction time; For the first Stage reaction temperature; For the first Sectional feed rate; For the first Sectional feed volume; For the first The mass ratio or volume ratio of monomer to solvent in segmental polymerization; During program execution, the central controller automatically switches the feeding units of different monomers in a preset matrix sequence and monitors the conversion rate of each segment in real time. When the instantaneous conversion rate of any monomer reaches 95% or more, it automatically triggers the feeding of the next monomer segment.

6. The method according to claim 1, characterized in that, The impurity tolerance relationship is as follows: ； in, This represents the total molar concentration of trace water and proton impurities in the system. This represents the theoretical molar concentration of active centers that the initiator system can produce. When the ratio is ≤0.1, the purity of the system is determined to meet the requirements of living polymerization; otherwise, the central controller will issue an alarm and stop feeding until the standard is met by extending the purification time or changing the solvent.

7. A high-efficiency pilot-scale polymerization apparatus for isobutylene-based block copolymers, characterized in that, The device includes: Material deep pretreatment module: includes a thin-film evaporation unit and a vacuum distillation unit, used for online continuous purification of non-polar solvents and vinyl aromatic monomers; Multi-unit sequential feeding module: Includes at least two independent high-precision feed pumps, a premixing tank, a weighing module, and a pipeline switching valve group controlled by a central controller, used to achieve segmented, quantitative, and timed automatic feeding of multiple monomers; the feeding error of the feed pumps is within ±1% of the set value, i.e. ; The cryogenic polymerization reaction module includes a main reactor with an effective volume ≥10L and a full jacket, and a cryogenic circulating refrigerator connected to the central controller. The refrigerator can provide a cooling medium below -90℃, and in conjunction with the jacket, the temperature control accuracy of the reactor reaches ±1℃. Central control module: a PLC or DCS control system, which is connected to the sensors, pumps, valves and refrigeration machinery in the pretreatment module, feeding module and reaction module respectively, and is configured to automatically execute the method described in claim 1.

8. The apparatus according to claim 7, characterized in that, The inner surface of the main reactor wall is polished, and the surface roughness is reduced. ; The reactor is equipped with a bottom-mounted agitator, the shape of which matches the curvature of the reactor bottom to form an axial circulating flow within a liquid level range of 10% to 100% of the effective volume of the reactor.

9. The apparatus according to claim 7, characterized in that, The material deep pretreatment module, the multi-monomer sequential feeding module, and the ultra-low temperature polymerization reaction module are connected by a fully sealed stainless steel pipeline. Multiple pneumatic diaphragm valves are installed on the pipeline, and all connection interfaces are sealed with metal gaskets to ensure the system's airtightness at pressures from -0.1MPa to 0.5MPa, with a system leakage rate ≤ .

10. The apparatus according to claim 7, characterized in that, The initiator system in the first monomer mixture is a ternary system of dicumyl chloride / titanium tetrachloride / pyridine compounds; In step (b), the central controller controls the addition of pyridine compounds to the premixing tank before titanium tetrachloride, so that the pyridine compounds preferentially consume proton impurities in the system. The consumption process is described by the following active center protection kinetic relationship (7): （7）； In equation (7), Reaction time The concentration of remaining proton impurities in the system at that time; This represents the initial total concentration of proton impurities in the system before the addition of pyridine compounds; The rate constant for the proton capture reaction; This represents the initial molar concentration of the pyridine compound.

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