Apparatus for preparing narrow distribution fluorosurfactant by VDF telomerization

Abstract

The utility model discloses a kind of VDF telomerization method preparation narrow distribution fluorine-containing surfactant's device, belong to fluorine fine chemical field.Device includes VDF vaporization delivery system, polymerization reaction system, raw material metering and delivery system, recovery system and PLC controller, realize VDF accurate vaporization by Inconel 600 vaporizer, microwave heating is combined with dynamic power regulation to maintain reaction temperature±0.5 ℃ stable, with triethylamine trihydrofluoric acid salt ionic liquid as green medium, cooperate high-precision metering pump and column pipe type condenser, realize product PDI≤1.2, solvent recovery rate≥95%.The device solves the problem that traditional process product distribution is wide, environmental protection is poor, applicable to high-end fine chemical field.

Description

Technical Field

[0001] This utility model belongs to the field of fluorine fine chemical technology, specifically relating to an apparatus for preparing narrow-distribution fluorinated surfactants using vinylidene fluoride (VDF) telomerization. Background Technology

[0002] Fluorinated surfactants are widely used in high-end fields such as coatings, electronics, and biomedicine due to their "three highs" (high surface activity, high heat stability, and high chemical inertness) and "two repulsives" (hydrophobic and oleophobic). Telomerization is the mainstream method for preparing fluorinated surfactant precursors (such as perfluoroalkyl iodides), but traditional processes have the following drawbacks: 1. Wide product distribution: Low precision in controlling reaction temperature and raw material ratio results in a polydispersity index (PDI) of products that is usually >1.7, which cannot meet the requirements of high-end products for performance uniformity; 2. Poor environmental performance: It uses toxic organic solvents (such as perfluorooctanoic acid PFOA) and has a low recovery rate of volatile substances (<80%), causing environmental pollution and waste of raw materials; 3. Outdated process control: Reliance on traditional heating methods (such as jacketed water baths) results in large temperature fluctuations (±2℃), unstable free radical generation rates, and further exacerbates the problem of wide product distribution.

[0003] While existing improved technologies (such as US20230345678A1) attempt to optimize the initiator system, the PDI remains >1.5, and the issues of solvent toxicity and recovery efficiency remain unresolved. Therefore, developing a VDF telomerization device that precisely controls product distribution and is both environmentally friendly and highly efficient is of great significance. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies, such as wide product distribution, high solvent toxicity, low recovery efficiency, and insufficient process control precision. It provides a device for preparing narrow-distribution fluorinated surfactants by VDF telomerization. By integrating precise temperature control, green media, and a high-efficiency recovery system, it achieves the technical goals of product PDI≤1.2, surface tension≤18mN / m, and solvent recovery rate≥95%.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: An apparatus for preparing narrow-distribution fluorinated surfactants by VDF telomerization includes a VDF vaporization and conveying system, a polymerization reaction system, a raw material metering and conveying system, a recovery system, and a PLC controller. These systems work together to achieve fully automated and precise control of the entire process. An apparatus for preparing narrow-distribution fluorinated surfactants by VDF telomerization includes: 1. VDF Vaporization and Conveying System: This system includes a VDF vaporizer equipped with a steam regulating valve, an outlet thermometer, a VDF compressor, a VDF regulating valve, and a VDF metering device for precise control of VDF vaporization, pressurization, and flow rate. This system ensures that the VDF feedstock enters the reaction system in a stable gaseous state and at a precise flow rate, which is the primary step in ensuring the reaction ratio and efficiency.

[0006] 2. Polymerization Reaction System: This system includes a polymerization reactor, a polymerization reactor stirrer, a microwave generator, a polymerization reactor temperature sensor, a polymerization reactor jacket circulating water regulating valve, and a power regulator. It is used for precise control of the reaction environment, maintaining a suitable free radical generation rate and a stable temperature in the reaction system. The combination of the microwave generator and the power regulator is one of the core technologies of this invention for precisely controlling the free radical generation rate and thus narrowing the molecular weight distribution.

[0007] 3. Raw material metering and conveying system: This includes a triethylamine trihydrofluoride ionic liquid storage tank and a triethylamine trihydrofluoride ionic liquid metering pump, an iodoethane liquid tank and an iodoethane liquid metering pump, used for the quantitative conveying of ionic liquid and iodoethane. This system ensures the accurate proportioning and stable feeding of the reaction monomers (VDF and iodoethane) and the green reaction medium (ionic liquid).

[0008] 4. Recovery System: This system includes a recovery condenser, cooling water regulating valve, condenser outlet temperature sensor, and recovery tank, used for the efficient recovery of volatile substances from the reaction. The PLC controller is connected to the key valves, meters, sensors, and regulators in the above systems to achieve automated integrated control and precise parameter adjustment of the entire process.

[0009] Furthermore, the VDF vaporizer has a volume of 10L and is preferably made of Inconel 600, a nickel-based alloy resistant to high temperatures and pressures. Its operating pressure range is 0.5-3MPa to ensure that the VDF vaporizes under safe and stable conditions. The steam regulating valve has a flow rate adjustment accuracy of ±0.1L / min, the outlet thermometer has a measurement accuracy of ±0.2℃, the VDF compressor has a maximum boosting capacity of 2MPa, the VDF regulating valve has a flow rate adjustment accuracy of ±0.05L / min, and the VDF metering device has a metering accuracy of ±0.02L / min. These high-precision components collectively ensure the accuracy of VDF feeding.

[0010] Furthermore, the polymerization reactor is made of Hastelloy C-276, a highly corrosion-resistant alloy, and has a volume of 5L. The reactor's agitator operates at speeds ranging from 0-1500 rpm, and the impeller is a double-layered inclined-blade turbine type, ensuring thorough mixing of materials. The microwave generator has an output power of 0-1000W and a frequency of 2.45GHz. The reactor temperature sensor has a measurement accuracy of ±0.1℃, the jacketed circulating water regulating valve has a flow rate regulation accuracy of ±0.2L / min, and the power regulator has a regulation accuracy of ±1W. The selection of the reactor's material and agitation method, as well as the high-precision control of microwave power and temperature, are key guarantees for achieving efficient, uniform reaction and a narrow product distribution.

[0011] Furthermore, the triethylamine trihydrofluoride ionic liquid storage tank is made of polytetrafluoroethylene lined with carbon steel to prevent corrosion from the ionic liquid; the flow rate accuracy of the triethylamine trihydrofluoride ionic liquid metering pump is ±0.03L / min; the iodoethane liquid tank is made of corrosion-resistant plastic, and the flow rate accuracy of the iodoethane liquid metering pump is ±0.04L / min; the recovery condenser adopts a shell-and-tube heat exchanger structure with a heat exchange area of ​​2m², and the cooling water regulating valve has a flow rate adjustment accuracy of ±0.1L / min to ensure efficient condensation and recovery of volatiles.

[0012] The method for preparing narrow-distribution fluorinated surfactants using the VDF telomerization method described above includes the following steps: 1. VDF Vaporization and Conveying: After purification, the VDF raw material is fed into the VDF vaporizer. The steam flow rate is stabilized by adjusting the steam regulating valve, and the VDF vaporization temperature is monitored using an outlet thermometer to ensure it is within 30°C. The vaporized VDF is then pressurized by the VDF compressor (e.g., to 1 MPa), and the flow rate is precisely controlled by the VDF regulating valve and VDF meter (e.g., 0.1 L / min, with an error not exceeding ±0.02 L / min) before entering the polymerization reactor.

[0013] 2. Raw Material Metering and Delivery: Triethylamine trihydrofluoride ionic liquid is pumped from the ionic liquid storage tank into the polymerization reactor at a metering pump at a rate of 30 wt% of the total monomer (VDF and iodoethane). The metering pump flow rate is controlled, for example, at 0.05 L / min, with an error of ±0.005 L / min. Iodoethane liquid is pumped from the iodoethane liquid tank into the polymerization reactor at a precise flow rate (e.g., 0.01 L / min, with an error of ±0.002 L / min) using an iodoethane liquid metering pump to ensure an accurate VDF:iodoethane ratio of 12:1 (mol).

[0014] 3. Microwave-assisted telomerization reaction: Inside the polymerization reactor, start the stirrer and set the speed (e.g., 800 rpm) to ensure thorough mixing of the materials. Turn on the microwave generator, initially setting the power to 200W. The power regulator adjusts the microwave power in real time based on feedback from the polymerization reactor temperature sensor. Combined with the regulating valve for the circulating water in the polymerization reactor jacket, the flow rate of the circulating water is controlled to precisely maintain a stable temperature of 80℃ inside the polymerization reactor, with an error range controlled within ±0.5℃. The reaction lasts for 4 hours. Through dynamic control of the microwave power, the generation rate of free radicals within the reaction system is precisely controlled, thereby achieving precise control over the chain length and distribution of the telomer.

[0015] 4. Volatile Product Recovery: Gaseous substances generated during the reaction escape from the top of the polymerization reactor and enter the recovery condenser. The cooling water flow rate is maintained at a constant level (e.g., 0.3 L / min) by adjusting the cooling water regulating valve, and monitored by a condenser outlet temperature sensor to ensure that the gaseous substances condense into liquid below 10°C and flow into the recovery tank. The recovered material can be analyzed, and reusable components can be pumped back into the polymerization reactor to participate in the reaction, improving raw material utilization.

[0016] After the reaction is complete, the reaction product in the polymerization reactor is transported to the finished product tank for subsequent separation and purification processes, and finally a narrow-distribution fluorinated surfactant is obtained.

[0017] The narrow-distribution fluorinated surfactant prepared using the apparatus of this invention has a number-average molecular weight of 1500-2500 Da and a polydispersity index (PDI) as low as 1.15. The PDI was determined by gel permeation chromatography (GPC) under the following conditions: mobile phase tetrahydrofuran, flow rate 1.0 mL / min, column temperature 30 °C, and polystyrene as the standard sample. The surface tension of the product can be stably reduced to 18 mN / m, exhibiting excellent surface activity. Simultaneously, through a highly efficient recovery system, the solvent recovery rate can reach 95%, significantly reducing material waste and environmental impact, meeting the requirements of green chemistry and sustainable development.

[0018] In summary, this utility model device includes a VDF vaporization and conveying system, a polymerization reaction system, a raw material metering and conveying system, a recovery system, and a PLC controller. Precise VDF flow control is achieved through an Inconel 600 vaporizer and high-precision metering components; the polymerization reactor employs microwave heating combined with dynamic power adjustment to maintain a stable reaction temperature within ±0.5℃; triethylamine trihydrofluoride ionic liquid is used as a green medium, along with a PTFE-lined storage tank and metering pump, ensuring accurate raw material proportioning; and a tubular condenser achieves a 95% solvent recovery rate. This device solves the problems of wide product distribution (PDI > 1.7) and poor environmental performance associated with traditional processes, achieving a product PDI ≤ 1.2 and a surface tension as low as 18 mN / m, making it suitable for high-end fine chemical applications. Attached Figure Description

[0019] Figure 1 This is a diagram of the apparatus for preparing narrow-distribution fluorinated surfactants using the VDF electropolymerization method of this utility model. In the diagram: 1-VDF vaporizer, 1.1-steam regulating valve, 1.2-VDF pipeline, 1.3-outlet thermometer, 1.4-VDF compressor, 1.5-VDF regulating valve, 1.6-VDF metering device, 2-polymerization reactor, 2.1-polymerization reactor stirrer, 2.2-microwave generator, 2.3-polymerization reactor temperature sensor, 2.4-polymerization reactor jacket circulating water regulating valve, 2.5-power regulator, 3-finished product tank, 4-triethylamine trihydrofluoride ionic liquid storage tank, 5-triethylamine trihydrofluoride ionic liquid metering pump, 6-iodoethane liquid tank, 7-iodoethane liquid metering pump, 8-recovery condenser, 8.1-cooling water regulating valve, 8.2-condenser outlet temperature sensor, 9-recovery tank, 10-PLC controller. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited to the following embodiments. Example

[0021] Reference Figure 1 The apparatus for preparing narrow-distribution fluorinated surfactants by VDF telomerization of this invention mainly consists of a VDF vaporization and conveying system, a polymerization reaction system, a raw material metering and conveying system, a recovery system, and a PLC controller. These systems work collaboratively to achieve automated and precise control of the entire process. The apparatus for preparing narrow-distribution fluorinated surfactants by VDF telomerization includes: 1. VDF Vaporization and Conveying System: This system includes a VDF vaporizer 1, which is equipped with a steam regulating valve 1.1, an outlet thermometer 1.3, a VDF compressor 1.4, a VDF regulating valve 1.5, and a VDF metering device 1.6, used for the vaporization, pressurization, and precise flow control of VDF. This system ensures that the VDF feedstock enters the reaction system in a stable gaseous state and at a precise flow rate, and is the primary step in ensuring the reaction ratio and efficiency.

[0022] 2. Polymerization Reaction System: This system includes a polymerization reactor 2, a polymerization reactor stirrer 2.1, a microwave generator 2.2, a polymerization reactor temperature sensor 2.3, a polymerization reactor jacket circulating water regulating valve 2.4, and a power regulator 2.5. It is used for precise control of the reaction environment, maintaining a suitable free radical generation rate and a stable temperature in the reaction system. The combination of the microwave generator and the power regulator is one of the core technologies of this invention for precisely controlling the free radical generation rate and thus narrowing the molecular weight distribution.

[0023] 3. Raw material metering and conveying system: This includes a triethylamine trihydrofluoride ionic liquid storage tank 4 and a triethylamine trihydrofluoride ionic liquid metering pump 5, an iodoethane liquid tank 6 and an iodoethane liquid metering pump 7, used for the quantitative conveying of ionic liquid and iodoethane. This system ensures the accurate proportioning and stable feeding of the reaction monomers (VDF and iodoethane) and the green reaction medium (ionic liquid).

[0024] 4. Recovery System: This system includes a recovery condenser 8, a cooling water regulating valve 8.1, a condenser outlet temperature sensor 8.2, and a recovery tank 9, used for the efficient recovery of volatile substances from the reaction. A PLC controller 10 is connected to the key valves, meters, sensors, and regulators in the above systems to achieve automated integrated control and precise parameter adjustment of the entire process.

[0025] The method for preparing narrow-distribution fluorinated surfactants using the VDF telomerization method described above includes the following steps: 1. Raw Material Preparation and Pretreatment: After purification treatment to remove trace amounts of moisture and inert gas impurities, the VDF raw material is introduced into the VDF vaporizer 1. The heating steam flow rate is stabilized at 0.5 L / min by adjusting the vaporizer steam regulating valve 1.1, and the VDF vaporization temperature is monitored using the vaporizer outlet thermometer 1.3 to ensure that it reaches 30℃. The VDF compressor 1.4 is turned on to pressurize the vaporized VDF to 1 MPa, and then controlled by the VDF regulating valve 1.5 and the VDF metering device 1.6 to stabilize the VDF flow rate entering the polymerization reactor 2 at 0.1 L / min, with the error strictly controlled within ±0.02 L / min.

[0026] The triethylamine trihydrofluoride ionic liquid is drawn from the triethylamine trihydrofluoride ionic liquid storage tank 4 by the triethylamine trihydrofluoride ionic liquid metering pump 5 at a rate of 30wt% of the total amount of VDF and iodoethane monomers, and then pumped into the polymerization reactor 2. The flow rate of the metering pump is controlled at 0.05L / min with an error of ±0.005L / min.

[0027] Iodoethane liquid is pumped from iodoethane liquid tank 6 into polymerization reactor 2 at a flow rate of 0.01 L / min (error ±0.002 L / min) via iodoethane liquid metering pump 7, thereby precisely controlling the molar ratio of VDF to iodoethane to be 12:1.

[0028] 2. Reaction Process Control: Inside the polymerization reactor 2, the agitator 2.1 is started and set to a speed of 800 rpm to ensure thorough mixing of the ionic liquid medium, VDF gas, and iodoethane liquid to form a homogeneous reaction system. Simultaneously, the microwave generator 2.2 is turned on, with an initial power setting of 200W. The power regulator 2.5 dynamically fine-tunes the microwave output power (adjustment accuracy ±1W) based on the real-time feedback of the reactor temperature from the reactor temperature sensor 2.3 (measurement accuracy ±0.1℃), and coordinates with the reactor jacket circulating water regulating valve 2.4 (flow rate adjustment accuracy ±0.2L / min) to regulate the jacket circulating water flow rate, precisely maintaining the reaction temperature inside the polymerization reactor at 80℃, with temperature fluctuations strictly controlled within ±0.5℃. The reaction duration is set to 4 hours, precisely timed by the built-in timer of the PLC controller 10, ensuring a reaction time error of less than ±0.1 seconds.

[0029] 3. Volatile Product Recovery and Collection: Unreacted VDF monomers and a small amount of low-boiling-point byproduct gaseous substances generated during the reaction process enter the recovery condenser 8 through the top pipe of the polymerization reactor. The cooling water regulating valve 8.1 is adjusted to maintain the cooling water flow rate at 0.3 L / min, and the condenser outlet temperature is monitored by the condenser outlet temperature sensor 8.2 to ensure that the condenser outlet temperature is controlled below 10℃, allowing the gaseous volatiles to fully condense into liquid and flow into the recovery tank 9. The material in the recovery tank 9 is periodically sampled and analyzed for its composition. Reusable VDF and iodoethane are reintroduced into the polymerization reactor 2 through appropriate transfer pumps and metering devices to participate in the reaction, effectively improving the raw material utilization rate.

[0030] After the reaction is completed, microwave generator 2.2 and all raw material delivery pumps are turned off. The reaction product (a mixture of crude fluorinated surfactant and ionic liquid) in polymerization reactor 2 is transported to finished product tank 3 through the bottom discharge valve for storage, pending subsequent separation, purification and refining.

[0031] Product performance testing: GPC analysis of the fluorinated surfactant prepared in this embodiment showed that its number-average molecular weight (Mn) was 2000 Da (within the range of 1500-2500 Da), and its polydispersity index (PDI) was 1.15. The surface tension of its 0.1% aqueous solution was determined using the ring method, and the result was 18 mN / m. Through the measurement and analysis of the condensate in recovery tank 9, the total recovery rate of the solvent (mainly ionic liquid vapor and unreacted monomers) was calculated to be 95%.

[0032] The above results show that the fluorinated surfactant prepared by this invention has a narrow molecular weight distribution, excellent surface activity, and achieves a high solvent recovery rate.

Claims

1. An apparatus for preparing narrow-distribution fluorinated surfactants by VDF telomerization, characterized in that, include: VDF vaporization and delivery system: including VDF vaporizer (1), the VDF vaporizer (1) is equipped with steam regulating valve (1.1), outlet thermometer (1.3), VDF compressor (1.4), VDF regulating valve (1.5) and VDF meter (1.6) for precise control of VDF vaporization, pressurization and flow rate; Polymerization reaction system: including polymerization reactor (2), polymerization reactor stirrer (2.1), microwave generator (2.2), polymerization reactor temperature sensor (2.3), polymerization reactor jacket circulating water regulating valve (2.4) and power regulator (2.5), used for precise control of reaction environment, maintaining suitable free radical generation rate and stable temperature of reaction system; Raw material metering and conveying system: including triethylamine trihydrofluoride ionic liquid storage tank (4) and triethylamine trihydrofluoride ionic liquid metering pump (5), iodoethane liquid tank (6) and iodoethane liquid metering pump (7), for quantitative conveying of ionic liquid and iodoethane; Recovery system: including recovery condenser (8), cooling water regulating valve (8.1), condenser outlet temperature sensor (8.2) and recovery tank (9), for efficient recovery of reactive volatiles.

2. The apparatus according to claim 1, characterized in that: The VDF vaporizer (1) has a volume of 10L and is made of high-temperature and high-pressure resistant alloy; the steam regulating valve (1.1) has a flow regulation accuracy of ±0.1L / min, the outlet thermometer (1.3) has a measurement accuracy of ±0.2℃, the VDF compressor (1.4) has a maximum boosting capacity of 2MPa, the VDF regulating valve (1.5) has a flow regulation accuracy of ±0.05L / min, and the VDF meter (1.6) has a metering accuracy of ±0.02L / min.

3. The apparatus according to claim 2, characterized in that: The high-temperature and high-pressure resistant material of the VDF vaporizer (1) is nickel-based alloy Inconel 600, and the working pressure range is 0.5-3MPa.

4. The apparatus according to claim 1, characterized in that: The polymerization reactor (2) is made of Hastelloy C-276 and has a volume of 5L; the polymerization reactor agitator (2.1) has a speed range of 0-1500rpm and the agitator blade is a double-layer inclined blade turbine; the microwave generator (2.2) has an output power of 0-1000W and a frequency of 2.45GHz; the polymerization reactor temperature sensor (2.3) has a measurement accuracy of ±0.1℃; the jacket circulating water regulating valve (2.4) has a flow regulation accuracy of ±0.2L / min; and the power regulator (2.5) has a regulation accuracy of ±1W.

5. The apparatus according to claim 1, characterized in that: The triethylamine trihydrofluoride ionic liquid storage tank (4) is made of polytetrafluoroethylene lined with carbon steel, and the flow accuracy of the triethylamine trihydrofluoride ionic liquid metering pump (5) is ±0.03L / min; the iodoethane liquid tank (6) is made of corrosion-resistant plastic, and the flow accuracy of the iodoethane liquid tank (6) and the iodoethane liquid metering pump (7) is ±0.04L / min.

6. The apparatus according to claim 1, characterized in that: The recovery condenser (8) adopts a shell-and-tube heat exchanger structure with a heat exchange area of ​​2m² and a cooling water regulating valve (8.1) with a flow rate regulation accuracy of ±0.1L / o.

7. The apparatus according to claim 1, characterized in that: The steam regulating valve (1.1), VDF meter (1.6), microwave generator (2.2), polymerization reactor temperature sensor (2.3), polymerization reactor jacket circulating water regulating valve (2.4), power regulator (2.5), cooling water regulating valve (8.1), and condenser outlet temperature sensor (8.2) are connected to the PLC controller (10) via signal.

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