Continuous production process of CO2-based multipolymer

Abstract

The invention discloses a continuous production process of a CO2-based multipolymer, and belongs to the technical field of polycarbonate synthesis. The technological process comprises the following steps: firstly, preparing an auxiliary agent, a solid-state monomer, a liquid-state reaction monomer and any solvent into a mixed solution in a premixer (1); continuously feeding carbon dioxide and the mixed solution into a multi-stage continuous reactor for mixing and heating to initiate a reaction, wherein the total reaction residence time of the materials in the multi-stage continuous reactor is controlled to be 10 minutes to 5 hours; and after the reaction is completed, carrying out post-treatment to complete the continuous production of the CO2-based multipolymer. The process particularly optimizes the effective continuous polymerization of high-molecular and high-viscosity materials of the CO2-based multipolymer. Through accurate control of the multi-stage tubular reactor, appropriate reaction viscosity is realized, further reaction uniformity of materials in the screw extrusion reactor is ensured, and reaction efficiency is improved.

Description

Technical Field

[0001] A CO 2 The invention discloses a continuous production process of a polycarbonate copolymer, belonging to the technical field of polycarbonate synthesis. Background Art

[0002] In CO 2 In the field of synthesis of polymers, tank reactors are widely used due to their low cost and simple operation. However, with the advancement of synthesis technology, the intermittent operation mode of tank reactors has gradually exposed the problem of long process time, which limits the large-scale production of polymer products.

[0003] To solve this problem, tubular reactors, as a continuous reaction equipment, are believed to improve the efficiency and controllability of polymerization reactions due to their advantages such as rapid material mixing, easy temperature control, and precise material residence time control, thereby reducing the occurrence of side reactions. In addition, tubular reactors can adapt to different reaction conditions and realize a variety of polymerization processes. However, it has limitations when dealing with slow-reacting and high-viscosity materials.

[0004] Screw extruders, especially twin-screw extruders, are increasingly used in polymer synthesis, devolatilization and modification. Reactive extrusion technology combines chemical reactions with polymer processing, allowing steps such as feeding, mixing, reaction and devolatilization to be carried out continuously. However, the extrusion process, especially the twin-screw extrusion process, faces challenges in experimental research and theoretical analysis due to its complex closed flow channel. In polymer melt reactions, the microscopic phase separation problem of multiple components causes mixing and reaction to occur simultaneously, making it difficult to separate the products and complicating the description of reaction kinetics. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a CO 2 Continuous production process of polyolefin-based copolymers.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a CO 2 The continuous production process of multi-component copolymers is characterized in that the process flow is as follows:

[0007] Firstly, in a pre-mixer, an auxiliary agent, a solid monomer, a liquid reaction monomer and any solvent are prepared into a mixed liquid;

[0008] Then the carbon dioxide and the mixed liquid are continuously fed into a multi-stage continuous reactor for mixing and heating to initiate the reaction. The total residence time of the materials in the multi-stage continuous reactor is controlled to be 10min~5h. After the reaction is completed, the CO 2 Continuous production of multi-polymers.

[0009] The present invention realizes CO by a multi-stage gas-liquid mixing method. 2 The continuous feeding, continuous reaction and continuous discharge of the continuous tubular reaction of multi-polymers solves the problem of CO 2 The problems of the base multi-polymer are poor mixing effect, slow reaction, low viscosity in the early stage, high viscosity in the later stage, and batch quality differences.

[0010] CO 2 The reactivity of the comonomers in the multi-component copolymers is not high, and the reaction efficiency is low. 2 The continuous production process of the multi-component copolymer achieves efficient production through a multi-stage reaction system. First, in a multi-stage tubular reactor, the non-gaseous reaction monomers are mixed with a catalyst and copolymerized with carbon dioxide under controlled pressure and temperature until the material reaches the required viscosity (about 17000mPa·s~25000mPa·s). The continuous reactor design at this stage helps to accurately control the reaction conditions and adapt to the characteristics of slow-reacting and high-viscosity materials.

[0011] Preferably, the CO 2 In the continuous production process of the multi-polymer, the liquid reaction monomer includes an epoxy compound, and the epoxide includes one or more of ethylene oxide, propylene oxide, cyclohexene oxide, and epichlorohydrin; the solid monomer includes any amount of anhydride monomers, and the anhydride monomers include one or more of phthalic anhydride, 1,8-naphthalene anhydride, 2,3-naphthalene anhydride, glutaric anhydride, succinic anhydride, and adipic anhydride.

[0012] Specifically, the auxiliary agent includes a catalyst, an initiator, and optionally a chain transfer agent, a chain extender, and a cross-linking agent.

[0013] Preferably, the CO 2 In the continuous production process of the multi-polymer, the heating temperature is 40°C to 80°C.

[0014] Specifically, the multi-stage continuous reactor comprises a static distributor and a dynamic tubular reactor connected in series; the discharge port of the static distributor is connected to the feed port of the dynamic tubular reactor through a transfer pipeline; the premixer is arranged on the static distributor, and a stirring device is provided in the built-in reaction tube of the dynamic tubular reactor.

[0015] Preferably, the static distributor (2) comprises a static mixer and a microchannel distributor.

[0016] Preferably, the above CO 2 In the continuous production process of the multi-component copolymer, the materials are mixed in the static distributor for 1 second to 30 minutes and then transferred to the dynamic tubular reactor.

[0017] The main function of the static distributor is to fully mix the reaction monomers with carbon dioxide to ensure the uniformity of the reactants. Both static mixers and microchannel distributors can meet this requirement. When using a static mixer, the materials can be mixed quickly, and the residence time is extremely short, only one to several seconds; secondly, it is responsible for copolymerizing the materials at the beginning of the reaction, which needs to be carried out in a microchannel distributor. At this time, the overall viscosity of the materials is relatively small, and sufficient material contact can be achieved in the microchannel distributor to achieve efficient copolymerization. After the copolymerization reaches a certain degree, the materials enter the dynamic tubular reactor to continue copolymerization, and continue to react under controlled pressure and temperature until the required reaction degree and viscosity are reached.

[0018] The multi-stage continuous reactor realizes the continuity and efficiency of the reaction and can precisely control the reaction conditions and the introduction of additives, thus achieving CO 2 The slow reaction of multi-component copolymerization and the effective polymerization of high-viscosity materials provide an ideal reaction environment.

[0019] Preferably, the aspect ratio of the built-in reaction tube of the dynamic tubular reactor is 50-400:1.

[0020] Preferably, a back pressure valve is provided before the discharge port of the dynamic tubular reactor; the pressure in the multi-stage continuous reactor is controlled at 1MPa~2MPa by the back pressure valve and carbon dioxide. Optimized to 1.1~1.5MPa. By providing a back pressure valve on the discharge port of the dynamic tubular reactor, the pressure reaction of the multi-stage continuous reactor is achieved.

[0021] In this process, a continuous multi-stage reactor is used instead of a traditional kettle reactor, which can produce efficiently at a lower reaction pressure. The reactor has a continuous flow characteristic, which allows the reactants and products to pass through the reactor continuously, maintaining the continuity and uniformity of the reaction. The large surface area to volume ratio of the tubular reactor is used to improve the heat and mass transfer efficiency, ensuring that the reactants can effectively contact and react at a lower pressure. In addition, this reaction method can more effectively utilize the catalyst, optimize the distribution and concentration of the catalyst, and achieve a highly efficient polymerization reaction.

[0022] The post-treatment mainly refers to the washing and degassing of the materials after the polymerization reaction is completed, so as to remove impurities and unreacted monomers, and finally obtain high-quality CO through granulation and drying processes. 2 The whole process realizes continuous operation from reaction to post-processing, which improves production efficiency.

[0023] For some products with smaller molecular weight, which are often liquid products, they only need to be heated in a devolatilizer to remove impurities and unreacted monomers.

[0024] Furthermore, for some products with a large molecular weight, when the material reaches a high viscosity (up to 25000mPa·s) in the continuous multi-stage reactor, further reaction is still required. At this time, the material needs to be transferred to the screw extrusion reactor for further reaction. The screw extrusion reactor can be a twin-screw extruder, which ensures that the material further reacts continuously and evenly at high temperature, ensuring high reaction efficiency and product quality.

[0025] The screw extruder reactor can not only further the polymerization reaction, but also improve the mixing and dispersion of materials through the mechanical action of the screw, and further adjust the viscosity and fluidity of the materials. By controlling the viscosity of the materials, the fluidity and reaction efficiency of the materials in the screw extruder reactor can be ensured, and the processing difficulties and equipment wear caused by too high viscosity can be avoided, while preventing the physical properties of the products from being affected by too low viscosity. Preferably, the above CO 2 In the continuous production process of the multi-polymer, the material is transferred to the screw extrusion reactor when the reaction viscosity reaches 20000mPa.s. The reaction viscosity of the material in the multi-stage continuous reactor is precisely controlled to have rheological properties that are more suitable for further processing.

[0026] Preferably, the washing and drying machine contains washing liquid, and the washing liquid is selected from one or a combination of water, alcohol substances, and ether substances.

[0027] The washing and degassing machine is a device that washes and degasses the adhesive solution in one machine. The washing liquid is contained in the machine, and the washing and degassing are performed at a set temperature and vacuum degree. The washed and degassing materials are pelletized by stranding or underwater pelletizing, and dried to prepare the finished product. The twin-screw degassing machine disclosed in patent CN221697501U is preferably used.

[0028] Specifically, the alcohol substance is selected from one or a combination of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol, n-hexanol, methyl propanol, cyclopentanol, and cyclohexanol.

[0029] Specifically, the ether substance is selected from one or a combination of diethyl ether, n-butyl ether, isobutyl ether, n-propyl ether and isopropyl ether.

[0030] Preferably, the weight ratio of the glue solution to the washing liquid in the washing and drying machine is 1:0.5~10, and more preferably 1:2~5.

[0031] Preferably, the elution temperature in the integrated washing and drying machine is 20°C to 100°C, more preferably 35°C to 80°C, and even more preferably 40°C to 60°C.

[0032] The CO of the present invention 2The continuous production process of multi-component copolymers can realize continuous CO 2 Preparation of multi-polymers.

[0033] Compared with the prior art, a CO 2 The continuous production process of multi-component copolymers has the following beneficial effects: the process particularly optimizes the CO 2 The effective continuous polymerization of high molecular weight and high viscosity materials based on multi-component copolymers. Through the precise control of the multi-stage tubular reactor, the appropriate reaction viscosity is achieved, ensuring the further reaction uniformity of the material in the screw extrusion reactor and improving the reaction efficiency. The continuous operation of the entire process not only improves production efficiency, but also reduces energy consumption, while ensuring the consistency and excellent performance of the product, achieving efficient polymerization of slow-reacting and high-viscosity materials, and demonstrating significant economic benefits and environmental friendliness. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A CO of the present invention 2 Flow chart of the continuous production process of multi-polymers.

[0035] In the figure: 1, premixer 2, static distributor 3, dynamic tubular reactor 301, transfer pipeline 302, output pipeline 4, gas phase pipeline 5, return pipeline 6, screw extrusion reactor 601, emptying pipeline 7, washing and degassing machine 701, primary vacuum pipeline 702, secondary vacuum pipeline 703, tertiary vacuum pipeline 704, underwater pelletizer 8, recovery condenser 9, distillation tower 10, devolatilization condenser 11, dryer. DETAILED DESCRIPTION

[0036] The following is combined with Figure 1 The continuous production process of the present invention is further described.

[0037] See attached Figure 1 :A CO of the present invention 2 Schematic diagram of the process of continuous production of multi-component copolymers. Solid and liquid reaction monomers, additives and solvents are first mixed in a pre-mixer 1. The mixed materials and CO 2The materials are pressurized and sent to the tubular microchannel reactor as the static distributor 2, mixed and heated for pre-copolymerization to obtain a uniform copolymer material, and reacted until the viscosity of the material reaches 10000mPa.s~15000mPa.s, then transferred to the dynamic tubular reactor 3; they enter the dynamic tubular reactor 3 through the transfer pipeline 301 and are heated to continue the reaction. The length-to-diameter ratio of the built-in reaction tube of the dynamic tubular reactor 3 is 50~400:1, and a back pressure valve is provided in front of the discharge port of the dynamic tubular reactor 3 to maintain the pressure in the reactor; until the reaction viscosity reaches 170 When the pressure is between 00mPa.s and 25000mPa.s, the material is transferred into the screw extrusion reactor 6 through the output pipeline 302, and the screw extrusion reactor 6 is kept heated for further reaction. The end of the screw extrusion reactor 6 is connected to the devolatilization condenser 10 through the emptying pipeline 601. The rubber liquid that has reacted in the screw extrusion reactor 6 enters the washing and degassing integrated machine 7 for washing and degassing. The end of the washing and degassing integrated machine 7 is provided with an underwater pelletizer 704. The washed and degassing material is directly pelletized underwater in the underwater pelletizer 704, and then dried and refined into a product by the dryer 11. The front, middle and rear parts of the washing and drying machine 7 are respectively connected to the exhaust pipeline 601 through the primary vacuum pipeline 701, the secondary vacuum pipeline 702 and the tertiary vacuum pipeline 703. The condensate obtained by the devolatilization condenser 10 enters the distillation tower 9 for distillation and solvent recovery. The gas phase solvent at the top of the distillation tower 9 enters the recovery condenser 8 for condensation through the gas phase pipeline 4, and the condensed solvent returns to the premixer 1 through the return pipeline 5 for recycling.

[0038] The present invention is described in detail below by taking the preparation of PPCP as an example through specific embodiments. 2 The material operation of the multi-component copolymer is the same as that of the embodiment, and is not listed here one by one. If there is no other explanation, the raw materials used are all commercially available.

[0039] Example 1

[0040] The initiator tetra-n-butylammonium bromide and the catalyst triethylboron are added into the tubular microchannel reactor as the static distributor 2 through the premixer 1. The length-diameter ratio of the built-in reaction tube of the static distributor 2 is 700:1, and the inner diameter is preferably 5 mm. Propylene oxide and phthalic anhydride are mixed in the premixer 1 and then enter the static distributor 2 for pre-copolymerization. At the same time, CO is added. 2The pressure is controlled at 1.2MPa, and the temperature is heated to 45°C; after 20 minutes of residence, the viscosity of the reaction material reaches 12000mPa.s. The material enters the dynamic tubular reactor 3 through the transfer pipeline 301. The length-diameter ratio of the built-in reaction tube of the dynamic tubular reactor 3 is 100:1, and the inner diameter is preferably 10cm; the temperature in the dynamic tubular reactor 3 is heated to 55°C; after 4 hours of residence, the reaction viscosity reaches 21000mPa.s, and the material is transferred to the screw extrusion reactor 6 for further reaction. The reacted glue enters the washing and degassing machine 7. The glue is filled with ethanol in the washing and degassing machine. The weight ratio of the glue and ethanol is 1:2.5, and the elution temperature is 60°C~80°C (the temperature in the washing and degassing machine 7 gradually increases from front to back). The washing and degassing machine 7 is used for washing, granulation, drying and refining to form the product.

[0041] Example 2

[0042] The initiator tetra-n-butylammonium bromide and the catalyst triethylboron are added into the plate-type microchannel reactor as the static distributor 2 through the premixer 1. The length-to-diameter ratio of the built-in reaction tube of the static distributor 2 is 700:1, and the inner diameter is preferably 5 mm. Propylene oxide and phthalic anhydride are mixed in the premixer 1 and then enter the static distributor 2 for premixing. At the same time, CO is added. 2 The pressure is controlled at 1.1MPa, and the temperature is heated to 50℃; after 25min of residence, the viscosity of the reaction material reaches 13000mPa.s. The material enters the dynamic tubular reactor 3 through the transfer pipeline 301. The length-diameter ratio of the built-in reaction tube of the dynamic tubular reactor 3 is 100:1, and the inner diameter is preferably 10cm; the temperature in the dynamic tubular reactor 3 is heated to 60℃; after 3.5 minutes of residence, the reaction viscosity reaches 20000mPa.s, and the material is transferred to the screw extrusion reactor 6 for further reaction. The reacted glue enters the washing and degassing machine 7, and the glue is filled with methanol in the washing and degassing machine. The weight ratio of the glue and methanol is 1:2, and the elution temperature is 40℃~67℃ (the temperature in the washing and degassing machine 7 gradually increases from front to back). The washing and degassing machine 7 is used for washing, granulation, drying and refining to form the product.

[0043] Example 3

[0044] The initiator tetra-n-butylammonium bromide and the catalyst triethylboron are added into the tubular microchannel reactor as the static distributor 2 through the premixer 1. The length-diameter ratio of the built-in reaction tube of the static distributor 2 is 700:1, and the inner diameter is preferably 5 mm. Propylene oxide and phthalic anhydride are mixed in the premixer 1 and then enter the static distributor 2 for premixing. At the same time, CO is added. 2The pressure is controlled at 1.5MPa, and the temperature is heated to 60°C; after 17 minutes of residence, when the viscosity of the reaction material reaches 11000mPa.s, the material enters the dynamic tubular reactor 3 through the transfer pipeline 301. The length-diameter ratio of the built-in reaction tube of the dynamic tubular reactor 3 is 100:1, and the inner diameter is preferably 10cm; the temperature in the dynamic tubular reactor 3 is heated to 60°C; after 4.2 hours of residence, when the reaction viscosity reaches 22000mPa.s, the material is transferred to the screw extrusion reactor 6 for further reaction, and the reacted glue enters the washing and degassing machine 7, which is filled with n-propyl ether. The weight ratio of the glue and n-propyl ether is 1:5, and the elution temperature is 60°C~93°C (the temperature in the washing and degassing machine 7 gradually increases from front to back). The washing and degassing machine 7 is used for washing, granulation, drying and refining to form the product.

[0045] Example 4

[0046] The initiator tetra-n-butylammonium bromide and the catalyst triethylboron are added to the static mixer 2 through the pre-mixer 1. The propylene oxide and phthalic anhydride are mixed in the pre-mixer 1 and then enter the static distributor 2 for pre-mixing. At the same time, CO is added. 2 The pressure is controlled at 1 MPa and heated to 40°C; the reaction materials are mixed for only 1 second and then enter the dynamic tubular reactor 3 through the transfer pipeline 301. The length-to-diameter ratio of the built-in reaction tube of the dynamic tubular reactor 3 is 400:1, and the inner diameter is preferably 2 cm; the temperature in the dynamic tubular reactor 3 is heated to 50°C; after staying for 10 minutes, the materials are transferred to the steam-stripping kettle to remove impurities and unreacted monomers, and canned.

[0047] Example 5

[0048] The initiator tetra-n-butylammonium bromide and the catalyst triethylboron are added into the tubular microchannel reactor as the static distributor 2 through the premixer 1. The length-diameter ratio of the built-in reaction tube of the static distributor 2 is 500:1, and the inner diameter is preferably 20 mm. Propylene oxide and phthalic anhydride are mixed in the premixer 1 and then enter the static distributor 2 for premixing. At the same time, CO is added. 2The pressure is controlled at 2MPa, and the temperature is heated to 80°C; after 30 minutes of residence, when the viscosity of the reaction material reaches 15000mPa.s, the material enters the dynamic tubular reactor 3 through the transfer pipeline 301. The length-to-diameter ratio of the built-in reaction tube of the dynamic tubular reactor 3 is 50:1, and the inner diameter is preferably 30cm; the temperature in the dynamic tubular reactor 3 is heated to 80°C; after 5 hours of residence, when the reaction viscosity reaches 25000mPa.s, the material is transferred to the screw extrusion reactor 6 for further reaction, and the reacted glue enters the washing and degassing machine 7, which is filled with ether, and the weight ratio of the glue to ether is 1:0.5, and the elution temperature is 35°C~45°C (the temperature in the washing and degassing machine 7 gradually increases from front to back). The washing and degassing machine 7 is used for washing, granulation, drying and refining to form the product.

[0049] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A continuous production process of CO2-based multi-polymer, characterized in that: The process is: First, in a pre-mixer (1), an auxiliary agent, a solid monomer, a liquid reaction monomer and any solvent are prepared into a mixed liquid; Then the carbon dioxide and the mixed liquid are continuously fed into a multi-stage continuous reactor for mixing and heating to initiate the reaction. The total residence time of the materials in the multi-stage continuous reactor is controlled within 10 minutes to 5 hours. After the reaction is completed, the continuous production of the CO2-based multi-polymer is completed through post-treatment.

2. A CO2-based multi-polymer continuous production process according to claim 1, characterized in that: The liquid reaction monomer includes epoxy compounds, and the epoxide includes one or more of ethylene oxide, propylene oxide, cyclohexene oxide, and epichlorohydrin; the solid monomer includes any amount of anhydride monomers, and the anhydride monomers include one or more of phthalic anhydride, 1,8-naphthalene anhydride, 2,3-naphthalene anhydride, glutaric anhydride, succinic anhydride, and adipic anhydride.

3. A continuous production process of CO2-based multi-polymer according to claim 1, characterized in that: The auxiliary agents include catalysts, initiators, and optional chain transfer agents, chain extenders, and crosslinking agents.

4. A continuous production process of CO2-based multi-polymer according to claim 1, characterized in that: The heating temperature is 40°C to 80°C.

5. A CO2-based multi-polymer continuous production process according to claim 1, characterized in that: The multi-stage continuous reactor comprises a static distributor (2) and a dynamic tubular reactor (3) connected in series; the discharge port of the static distributor (2) is connected to the feed port of the dynamic tubular reactor (3) via a transfer pipeline; the premixer (1) is arranged on the static distributor (2), and a stirring device is arranged in the built-in reaction tube of the dynamic tubular reactor (3).

6. A CO2-based multi-polymer continuous production process according to claim 5, characterized in that: The static distributor (2) comprises a static mixer and a microchannel distributor.

7. A CO2-based multi-polymer continuous production process according to claim 5, characterized in that: The materials are mixed in the static distributor (2) for 1 second to 30 minutes and then transferred into the dynamic tubular reactor (3).

8. A CO2-based multi-polymer continuous production process according to claim 5, characterized in that: The length-to-diameter ratio of the built-in reaction tube of the dynamic tubular reactor (3) is 50-400:

1.

9. A CO2-based multi-polymer continuous production process according to claim 5, characterized in that: A back pressure valve is provided in front of the discharge port of the dynamic tubular reactor (3); the pressure in the multi-stage continuous reactor is controlled at 1 MPa to 2 MPa by the back pressure valve and carbon dioxide.

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