Sebacic acid polycarbonate polyether polyol and production process thereof

Abstract

The invention provides sebacic acid polycarbonate polyether polyol and a production process thereof, and relates to the technical field of chemical engineering. The production process is carried out in a tubular reaction device, and raw materials are premixed and then fed into a reaction pipeline for polymerization reaction at one time. In the polymerization reaction process, the residual sebacic acid can be effectively reduced by performing refined temperature control, replenishing the catalyst in the middle and rear sections of the reaction and increasing the circulating flow rate, the acid value of the obtained product is lower than 0.3 mgKOH / g, the molecular weight difference index is smaller than 3%, and the application scene of the polyhydric alcohol is greatly expanded. The production process is carried out in a tubular reaction device, so that reaction conditions and parameters are easy to control, and the production process can be suitable for large-scale industrial production.

Description

Technical Field

[0001] This invention relates to the field of chemical engineering technology, and particularly to a sebacic acid polycarbonate polyether polyol and its production process. Background Technology

[0002] Polycarbonate polyether polyols are a class of polyols containing carbonate groups within their molecules and hydroxyl groups at the ends of their molecular chains. They can be obtained through copolymerization reactions of carbon dioxide and epoxides. Carbon dioxide, as one of the raw materials, is inexpensive, readily available, non-toxic, and non-flammable, possessing a clear chemical fixation effect. Furthermore, the reaction requires relatively low temperatures and low energy consumption, making the carbon dioxide-epoxide copolymerization method promising and industrially valuable. Polycarbonate polyether polyols simultaneously possess the high modulus, high hydrogen bond density, high weather resistance, and abrasion resistance inherent in carbonate bonds, as well as the flowability and flexibility provided by ether bonds, making them widely applicable in polyurethane fields. Polyurethane coatings, adhesives, foams, and other products prepared using these polyols exhibit superior performance. The market prospects for these polyols are broad, and their synthesis and industrial production have been extensively and deeply studied globally.

[0003] Sebacic acid polycarbonate polyether polyol is a polyol synthesized by the polymerization of carbon dioxide and propylene oxide using sebacic acid as a small molecule initiator and catalyzed by a DMC catalyst. However, using sebacic acid as an initiator can easily lead to an excessively high acid value (the mass of KOH consumed per gram of sample from the acidic component). In existing technologies, the acid value of sebacic acid products is generally around 1.5 mg KOH / g. A high acid value often limits the use of polyols in the synthesis of polyurethanes, causing synthesis difficulties and affecting downstream applications. During the preparation process, it is necessary to control the acid value of the sebacic acid product to below 0.3 mg KOH / g to facilitate its widespread downstream applications. Therefore, controlling the residual amount of sebacic acid and synthesizing a sebacic acid product with a low acid value has become a current technical challenge.

[0004] Furthermore, because sebacic acid is a plate-like crystal, readily soluble in propylene oxide, and reacts slowly, it requires a higher reaction temperature compared to other initiators. For example, bisphenol A type polycarbonate polyether polyols react at 80°C, while sebacic acid type polycarbonate polyether polyols require 90°C. This reaction is exothermic, releasing a large amount of heat and causing a rapid temperature rise. The increased reaction temperature increases the risk of uncontrollable polymerization, leading to a high molecular weight variation index, poor batch stability, and a tendency for scale-up effects. The scale-up effect refers to the significant difference between the results obtained from small-scale chemical process experiments (e.g., laboratory-scale) under the same operating conditions and those obtained from large-scale production facilities (e.g., industrial-scale). The impact of these differences is called the scale-up effect. Summary of the Invention

[0005] The purpose of this invention is to provide a production process for sebacic acid polycarbonate polyether polyols. This process utilizes a specialized tubular reactor to improve heat exchange and temperature control, ensuring efficient gas-liquid mass transfer and solid-liquid-gas mixing of the reactants. Sufficient heating and heat dissipation effectively prevent explosive polymerization. This production process has no scale-up effect, making it suitable for large-scale industrial production of sebacic acid polycarbonate polyether polyols. It solves the problem of excessively high acid values ​​in the product, effectively improving the overall conversion rate and safety, reducing production costs, and enhancing its direct applicability in various polyurethane applications.

[0006] This invention provides a production process for sebacic acid polycarbonate polyether polyol, carried out in a tubular reactor, which includes a premixing vessel, a reaction pipeline, and a circulating pump. The production process includes: adding an epoxy compound, sebacic acid, and a catalyst to the premixing vessel and mixing them with CO2 to obtain a premix; introducing the premix into the reaction pipeline in a single pass and introducing CO2 at 2-6 MPa; heating the material in the reaction pipeline to a preset reaction temperature of 80-95°C and circulating the material within the reaction pipeline at a first circulation flow rate for polymerization; during the polymerization reaction, monitoring the material temperature and density within the reaction pipeline and performing the following steps: when the CO2 pressure drop in the reaction pipeline exceeds 0.1 MPa and the material temperature rises above the preset reaction temperature by more than 2°C, reducing the temperature of the heat exchange medium in the reaction pipeline to 70-80°C until the material temperature in the reaction pipeline drops to the preset reaction temperature, then raising the temperature of the heat exchange medium back to 80-95°C; when the material density reaches 1 g / cm³... 3During the reaction, catalyst is added to the reaction pipeline, and the material is adjusted to a second circulation flow rate, wherein the second circulation flow rate is greater than the first circulation flow rate, and the amount of catalyst added is 5-10% of the mass of the catalyst in the premixing vessel; the sebacic acid polycarbonate polyether polyol obtained after the reaction meets the following requirements: acid value less than 0.3 mg KOH / g, molecular weight difference index ΔM less than 3%, and batch stability coefficient Q less than 5.

[0007] Specifically, the acid value of the product was determined according to the method in GB / T 12008.5-2010 "Plastic Polyether Polyols Part 5: Determination of Acid Value".

[0008] The molecular weight difference index ΔM is used to characterize the difference between the theoretical molecular weight of the product calculated according to the feed ratio and the actual molecular weight of the product obtained after the reaction. The smaller the molecular weight difference index, the smaller the difference between the actual molecular weight and the theoretical molecular weight, indicating better controllability of the production equipment and process, higher yield of the target product, and higher product quality. The molecular weight difference index ΔM can be calculated using the following formula (1): ΔM=|g 实际 -g 理论 | / g 理论 ×100% (1); In equation (1), g 实际 The number-average molecular weight of the product, in g. 理论 The theoretical molecular weight is calculated using the following formula (2): g 理论 =A×B+D Equation (2); In equation (2), A is the average molecular weight of the repeating unit, calculated as shown in equation (3); B is the number of repeating units, calculated as shown in equation (4); and D is the molecular weight of the initiator.

[0009] A = X × 10² + Y × 58 (3); In formula (3), X represents the proportion of ester units in the product, and Y represents the proportion of ether units in the product.

[0010] B = K × C × (1 - Z) (4); In equation (4), K is the molar ratio of initiator feed, C is the conversion rate, and Z is the mass percentage of polypropylene carbonate.

[0011] Specifically, in this embodiment of the invention, the formula for calculating the batch stability coefficient Q is as shown in equation (5): Q = E × H (5); In equation (5), E is the fluctuation coefficient, which is calculated as shown in equation (6); H is the average difference, which is calculated as shown in equation (7). E=(g 最大 -g 最小 ) / g 理论中值 (6); In equation (6), g 最大 The maximum actual molecular weight across all batches, in g. 最小 The minimum actual molecular weight among all batches, g 理论中值 This refers to the theoretical molecular weight (g) in all tested batches. 理论1 g 理论2 ...g 理论n The median of ), where n is the number of batches; H = √(1 / n(g1-g)) 理论1 ) 2 +(g2-g 理论2 ) 2 +(g3-g 理论3 ) 2 +...(g) n -g 理论n ) 2 )) (7) In equation (7), g1, g2, g3...gn represent the actual molecular weight of each batch; g 理论1 g 理论2 g 理论3 ...g 理论n This represents the theoretical molecular weight for each batch.

[0012] In an exemplary embodiment of the present invention, the rate of the second circulating flow rate is 1.2 to 2 times that of the first circulating flow rate.

[0013] In an exemplary embodiment of the present invention, the catalyst in the premixing vessel is a DMC catalyst; the molar ratio of the epoxide compound to the sebacic acid is 15:1 to 70:1, and the mass of the catalyst is 0.04% to 0.09% of the mass of the epoxide compound. More preferably, the mass of the catalyst is 0.054% to 0.07% of the mass of the epoxide compound.

[0014] In an exemplary embodiment of the present invention, in the premixing step, CO2 is introduced by slowly bubbling CO2 from the bottom at a rate of 40-60 bubbles / min; the pressure inside the premixing vessel is 0.1-2 MPa; the premixing temperature is 0-40°C; and the premixing time is 1-2 h; preferably, the pressure inside the premixing vessel is 0.1-0.5 MPa, the premixing temperature is 40°C, and the premixing time is 1 h.

[0015] In an exemplary embodiment of the present invention, the reaction pipeline is connected to a circulation pump, through which the material is circulated.

[0016] In an exemplary embodiment of the present invention, the tubular reaction device is provided with multiple reaction pipes arranged in parallel, and each reaction pipe forms the same material circulation path as the connecting pipe and the circulating pump.

[0017] In an exemplary embodiment of the present invention, the reaction pipeline includes a dispersion plate, a gas-liquid mixing heat conduction zone, and a solid-liquid mixing zone arranged sequentially. The dispersion plate is used to disperse and control the material in the gas-liquid mixing heat conduction zone to disperse into liquid droplets for mass and heat transfer without contacting the pipeline wall. The solid-liquid mixing zone is used to realize the real-time mixing and polymerization reaction of the catalyst and the epoxy compound. After being dispersed by the dispersion plate, the material in the reaction pipeline flows from the gas-liquid mixing heat conduction zone to the solid-liquid mixing zone, and then flows back to the gas-liquid mixing heat conduction zone through the dispersion plate.

[0018] In an exemplary embodiment of the present invention, the reaction pipeline has an inlet end and an outlet end. A cycle is defined as the reaction mixture flowing through the outlet end of the reaction pipeline is circulated to the inlet end of the reaction pipeline by a circulation pump, and passes through the dispersion plate, the gas-liquid mixing heat conduction zone and the solid-liquid mixing zone of the reaction pipeline to reach the outlet end. The first circulation flow rate is controlled so that the circulation pump completes one cycle in 10 to 15 minutes; or, the circulation pump is controlled to complete one cycle in 10 minutes.

[0019] In an exemplary embodiment of the present invention, the multiple reaction pipelines are independent of each other and each is equipped with a valve that can be controlled independently.

[0020] In an exemplary embodiment of the present invention, when the premixture is introduced into the reaction pipeline in one go, the reaction pipeline is controlled to meet the following conditions: temperature is 35~45°C, and CO2 pressure is 0.1~2MPa.

[0021] In an exemplary embodiment of the present invention, a temperature sensor and a densitometer are provided inside the reaction pipeline. The temperature sensor determines the temperature of the material inside the reaction pipeline, and the densitometer determines the density of the material.

[0022] In an exemplary embodiment of the present invention, the density of the reaction product reaches 1.1~1.3 g / cm³. 3 And the change was less than 0.01 g / cm within 5 minutes. 3 The reaction is terminated at that time.

[0023] In an exemplary embodiment of the present invention, the catalyst contains only two metal elements besides impurities: zinc and cobalt. The catalyst is obtained by reacting water-soluble metal salts of zinc and cobalt in a water-soluble solvent, wherein the water-soluble metal salt of cobalt is a cyanide salt of cobalt. The catalyst is modified by a mixed acid during synthesis, wherein the mixed acid contains at least one organic acid and at least one water-soluble inorganic acid, wherein: the water-soluble inorganic acid is selected from dilute sulfuric acid and dilute hydrochloric acid, and the pH value is between 0 and 5; the organic acid is selected from any one or more of succinic acid, glutaric acid, phthalic acid, iminodiacetic acid, pyromellitic acid, and butanetetracarboxylic acid, and the molar ratio of the water-soluble inorganic acid to the organic acid is 1:10 to 10:1.

[0024] According to a second aspect of the invention, a sebacic acid polycarbonate polyether polyol prepared according to the production process described in any one of the above claims is provided, the sebacic acid polycarbonate polyether polyol having the structural formula represented by Formula I: Formula I; In Formula I, R1 and R2 are selected from Formula II or OH; Formula II; In Equation II, m / (m+n)+n / (m+n)=1, 0.1<n / (m+n)<0.9, and * indicates the connection position; The sebacic acid polycarbonate polyether polyol has a number-average molecular weight of 1500~4000 g / mol, a molecular weight polydispersity index (PDI) ≤ 1.5, a hydroxyl value of 30~60 mgKOH / g, and a carbonate repeating ratio F. CO2 ≥45%.

[0025] Specifically, the polydispersity index (PDI) is determined by gel permeation chromatography (GPC). A lower PDI value indicates a narrower molecular weight distribution and more uniform product quality.

[0026] Specifically, the carbonate repeating unit ratio F CO2 F is used to characterize the ester content of the product. CO2 The higher the value, the better the carbon dioxide fixation effect. CO2 With the help of 1 The determination was performed using ¹H-NMR, based on the product... 1 Calculate the integral area of ​​the H-NMR spectrum and its associated proton peaks, and calculate the proportion (molar ratio) of carbonate repeating units F in the copolymerization reaction. CO2 The specific calculation method is as follows: F CO2 =(A 5.0 +A 4.2 -2×A 4.6 ) / [(A 5.0 +A 4.2 -2×A4.6 )+A 3.5 ]×100%; where, A 5.0 A represents the integral area of ​​the peak at 5.0 ppm. 4.2 Indicates the integrated area of ​​the peak at 4.2 ppm; A 4.6 A represents the integral area of ​​the peak at 4.6 ppm. 3.5 The peak at 3.5 ppm represents the proton peak; 5.0 ppm and 4.2 ppm represent the proton peaks on the methylene and methyl groups of the polycarbonate chain; 4.9 ppm, 4.6 ppm, 4.5 ppm and 4.1 ppm represent the proton peaks on the methylene and methyl groups of the five-membered ring carbonate; and 3.5-3.8 ppm represent the proton peaks on the ether chain.

[0027] The beneficial effects of the production process of sebacic acid polycarbonate polyether polyol in this embodiment of the invention are as follows: (1) Compared with traditional processes, the production process provided by this invention replenishes the catalyst in the middle and later stages of the reaction. By controlling and adjusting the reaction process, the product obtained has a low residual acid value, not exceeding 0.3 mg KOH / g, and no additional post-processing steps are required, simplifying the production process. The obtained sebacic acid product can be used in the synthesis of downstream products such as polyurethane, and has broad application prospects.

[0028] (2) During the reaction, the reaction temperature is precisely controlled according to the heating and CO2 consumption, which can effectively avoid the occurrence of explosive polymerization and the product quality decline caused by temperature runaway. The molecular weight difference index of the obtained product is less than 3%.

[0029] (3) This invention utilizes a special tubular reaction device to conduct the reaction, allowing the materials to react in multiple reaction pipes and continuously mix them through a circulating pump. This allows for precise control of the heating and cooling of each reaction pipe while preventing significant differences in the products from each pipe, resulting in a milder reaction, reducing the risk of explosive polymerization, and ensuring that the ester content remains within a suitable range through appropriate reaction time. Furthermore, the special structure of the reaction pipes allows for sufficient gas-liquid heat conduction and gas-liquid-solid mixing, effectively improving product quality.

[0030] (4) The product obtained by the present invention has a narrow molecular weight distribution and no scale-up effect. The molecular weight of the product is highly controllable, production is stable between batches, and the product quality is high. At the same time, the production process is safe, does not produce explosive polymerization, and has no scale-up effect, making it suitable for large-scale industrial production. Attached Figure Description

[0031] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0032] Figure 1 This is a schematic diagram of the tubular reaction apparatus for producing sebacic acid polycarbonate polyether polyols provided in an embodiment of the present invention.

[0033] Icons: M - Stirrer; 101 - Premixing vessel; 102 - Carbon dioxide replenishment port; 103 - Catalyst replenishment tank; 104 - Feed mixer; 105 - Upper dispersant; 106 - Jacket; 107 - Static mixer; 108 - Lower dispersant; 109 - Reaction pipeline; 110 - Circulation pump; 111 - Separation unit; 112 - Purification unit; 113 - Distillation unit. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0035] The following provides a detailed description of the sebacic acid polycarbonate polyether polyol and its production process according to embodiments of the present invention. Specifically, the sebacic acid polycarbonate polyether polyol is synthesized using sebacic acid as a small molecule initiator, along with an epoxide compound and CO2, under the action of a DMC catalyst.

[0036] The structural formula of sebacic acid polycarbonate polyether polyol in this invention is represented by Formula I: Formula I; In Formula I, R1 and R2 are selected from Formula II or OH; Formula II; In Equation II, m / (m+n)+n / (m+n)=1, 0.1<n / (m+n)<0.9, and * indicates the connection position; The actual number-average molecular weight of this sebacic acid polycarbonate polyether polyol is 2000~3000 g / mol, the molecular weight polydispersity index (PDI) does not exceed 1.5, and the carbonate repeating ratio F CO2The content of the product is greater than 55%, the acid value is less than 0.3 mg KOH / g, the molecular weight difference index ΔM is less than 3%, and the batch stability coefficient Q is less than 5.

[0037] This production process is carried out in a tubular reactor. By using a dedicated tubular reactor and precise control of the temperature and CO2 pressure during the reaction process, the heat exchange and temperature control capabilities are improved, the solid-liquid-gas mixing efficiency is increased, and problems such as explosive polymerization are avoided. This one-step synthesis of sebacic acid polycarbonate polyether polyol has no scale-up effect and is suitable for large-scale industrial production. It solves the problem of excessively high acid value of the product, effectively improves the total conversion rate and safety, and reduces production costs.

[0038] It should be noted that the one-step synthesis of sebacic acid polycarbonate polyether polyol refers to adding all the reactants, the epoxy compound and sebacic acid, into the reaction apparatus in a single step, without adding any more epoxy compound or sebacic acid during the subsequent reaction. The epoxy compound is selected from one or more of ethylene oxide, propylene oxide, 2-epoxybutane, 1,4-epoxybutane, and epichlorohydrin. Preferably, in this embodiment, propylene oxide is selected as the epoxy compound.

[0039] Furthermore, the DMC catalyst used in this embodiment is a mixed acid-modified zinc-cobalt bimetallic cyanide catalyst. The catalyst, excluding impurities, contains only zinc and cobalt. The catalyst is obtained by reacting water-soluble metal salts of zinc and cobalt in a water-soluble solvent. The water-soluble metal salt of cobalt is a cyanide salt of cobalt. The catalyst is synthesized by modification with a mixed acid, which contains at least one organic acid and at least one water-soluble inorganic acid. The water-soluble inorganic acid is selected from dilute sulfuric acid and dilute hydrochloric acid, and has a pH value between 0 and 5. The organic acid is selected from any one or more of succinic acid, glutaric acid, phthalic acid, iminodiacetic acid, pyromellitic acid, and butanetetracarboxylic acid. The molar ratio of the water-soluble inorganic acid to the organic acid is 1:10 to 10:1.

[0040] Specifically, please refer to Figure 1In a preferred embodiment, the tubular reaction apparatus includes a premixing vessel 101, reaction pipes 109, a circulating pump 110, and a carbon dioxide injection port 102. The premixing vessel 101 is equipped with a stirrer M. Multiple reaction pipes 109 are connected in parallel. Each reaction pipe 109 has a jacket 106 on its outer side. Steam, water, heat transfer oil, or other media are introduced into the jacket 106 to regulate the temperature of the reaction pipe 109. The space between the multiple reaction pipes 109 is filled with a heat transfer medium, and an insulation layer is provided outside the heat transfer medium. The carbon dioxide injection port 102 is connected to the reaction pipes 109 and is used to replenish carbon dioxide into the reaction pipes 109. The lower outlets of the multiple reaction pipes 109 converge through connecting pipes, pass through the circulating pump 110 to the top liquid distributor, and then disperse back into the individual reaction pipes to complete the circulation.

[0041] Preferably, each reaction pipe 109 forms the same material circulation path as the connecting pipe and the circulating pump 110. The number of reaction pipes 109 is 2 to 8, for example, 4 or 6. The multiple reaction pipes 109 are independent of each other and each is equipped with an independently controllable valve. By independently controlling each reaction pipe 109, if the temperature of a particular reaction pipe 109 becomes too high or other adverse conditions occur, timely individual control can be implemented to avoid affecting the entire reaction process.

[0042] Further preferably, the reaction pipe 109 can be divided into an upper gas-liquid mixing heat conduction zone and a lower solid-liquid mixing zone through a circulation system. The reaction pipe 109 is equipped with an upper dispersing plate 105 and a lower dispersing plate 108. The upper dispersing plate 105 is used to disperse and control the material in the gas-liquid mixing heat conduction zone, dispersing it into droplets for mass and heat transfer. The solid-liquid mixing zone is used to achieve real-time mixing and polymerization of the catalyst and epoxide compound. After being dispersed by the upper dispersing plate 105, the material in the reaction pipe 109 flows from the gas-liquid mixing heat conduction zone to the solid-liquid mixing zone, and then flows back to the gas-liquid mixing heat conduction zone via the lower dispersing plate 108 and the upper dispersing plate 105. The loop between the upper dispersing plate 105, the upper CO2 space of the reaction pipe 109, and the circulation pump 110 together constitutes a gas-liquid mixing heat conduction path, allowing the mixture with low CO2 content in the reaction pipe 109 to redissolve CO2, while simultaneously exchanging heat in the gas-liquid mixing heat conduction zone. A static mixer 107 is installed in the solid-liquid mixing zone. The loop between the static mixer 107, the reaction pipe 109, and the circulating pump 110 together constitutes the solid-liquid mixing path. The lower dispersion plate 108 is used to fix the static mixer 107 and further disperse and mix the flowing-down product. The solid-liquid mixing path ensures that the solid catalyst is uniformly dispersed in the epoxy compound, while also dispersing the generated heat of reaction, reducing the temperature difference between the center and the wall of the reaction pipe 109, and preventing the formation of explosive polymerization points.

[0043] More preferably, the upper dispersing plate 105 is positioned 10-50 mm from the top of the reaction pipe 109, and the lower dispersing plate 108 is positioned 10-50 mm from the bottom of the reaction pipe 109. Both the upper and lower dispersing plates 105 and 108 have multiple dispersing holes. More preferably, the multiple dispersing holes are arranged in an array, such as a rectangular or ring array. By setting the upper and lower dispersing plates 105 and 108, the reactants can be uniformly dispersed and flow down in droplets at the end, increasing the mass and heat transfer area. Combined with the static mixer 107 and circulating pump 110 built into the reaction pipe 109, the entire circulating dispersion system can replace the traditional stirring process, allowing the reactants to be continuously mixed during circulation, and effectively enabling better gas-liquid mass transfer and releasing excess heat in the gas region.

[0044] In a further preferred embodiment, a temperature sensor is installed inside the reaction pipe 109, and a densitometer is installed at the outlet. The temperature sensor measures the temperature of the material inside the reaction pipe 109, and the densitometer measures the density of the material. The temperature of the jacket 106 is adjusted according to the material density and the internal temperature of the reactor to control the reaction rate.

[0045] The production process of sebacic acid polycarbonate polyether polyol provided in this embodiment of the invention includes the following steps: (1) At a temperature of 0~40℃, an epoxy compound, sebacic acid, and a catalyst are added to a premixing vessel 101 in one step, and CO2 is introduced for mixing to obtain a premix. Specifically, in the premixing vessel 101, carbon dioxide is provided by a carbon dioxide storage tank or carbon dioxide recovered and purified by a carbon dioxide purification device, and is introduced into the premixing vessel 101 through a carbon dioxide gas inlet 102. The propylene oxide raw material is introduced into the carbon dioxide atmosphere premixing vessel 101 through a metering pump. A fixed amount of sebacic acid and catalyst are added to the premixing vessel 101 using a weighing hopper. After the raw materials are mixed in the premixing vessel 101, a premix is ​​obtained. Preferably, the temperature of the premixing vessel 101 is 0~40℃, the pressure is 0.1~2MPa, and the premixing time is 1~2h. More preferably, the temperature of the premixing vessel 101 is 30~40℃, the pressure is 0.1~0.5MPa, and the premixing time is 1h.

[0046] (2) The premixture is fed into the reaction pipe 109 in one go. When the raw material enters the reaction pipe 109, the reaction pipe 109 is controlled to meet the following conditions: the temperature of the reaction pipe 109 is 35~45℃ and the CO2 pressure is 0.1~2MPa. More preferably, the temperature is lower during the feeding process to avoid the initiator decomposing into small molecules.

[0047] (3) Once the raw materials have completely entered the reaction pipeline 109, the feeding is complete. Carbon dioxide is supplied through the carbon dioxide supply port 102 until the pressure inside the reaction pipeline 109 is 2~6 MPa, more preferably 3 MPa. When the pressure is too low, a solenoid valve is used to automatically supply carbon dioxide through the carbon dioxide supply port 102 to replenish the pressure.

[0048] (4) Turn on the circulating pump 110 and adjust the temperature of the medium in the jacket 106 to raise the temperature of the reaction pipe 109 to the preset reaction temperature of 80~95℃ for reaction. For example, if the preset reaction temperature is 90℃, raise the temperature to 90℃ for reaction. During the reaction, the circulating pump 110 maintains the first circulation flow rate, which is preferably such that the material completes one cycle in 1~20 minutes. Throughout the reaction process, the reaction temperature and material density in the reaction pipe 109 are monitored by a temperature sensor and a density meter.

[0049] When the pressure drop of CO2 in reaction pipe 109 exceeds 0.1 MPa and the temperature rise of the material in reaction pipe 109 exceeds 2°C, the temperature of the medium in jacket 106 is reduced to 70-80°C, for example, to 80°C, until the temperature of the material in reaction pipe 109 drops to 80-95°C, for example, to 80°C. Then, the temperature of the medium in jacket 106 is increased to 80-95°C, for example, the temperature of the heating medium is increased to 80°C. Because the sebacic acid product itself requires a relatively high reaction temperature, the CO2 consumption value and the rise in reaction temperature are used to determine if the reaction rate is too fast, and the temperature is adjusted in time to avoid the risk of explosive polymerization.

[0050] When the material density is monitored to reach 1 g / cm³ 3 At this time, catalyst is added from catalyst replenishment tank 103 to reaction pipeline 109 through feed mixer 104, and the speed of circulation pump 110 is increased from the first circulation flow rate to the second circulation flow rate, which is greater than the first circulation flow rate. More preferably, the second circulation flow rate is 1.2 to 2 times the first circulation flow rate. The amount of catalyst added is 5 to 10% of the mass of the catalyst in step (1). The material density reaches 1 g / cm³. 3 When the reaction proceeds to the middle or later stages, adding a certain amount of catalyst and increasing the circulation flow rate can accelerate the efficient conversion of sebacic acid and reduce the acid value of the product.

[0051] The reaction was terminated when the material density reached the reaction endpoint. The reaction endpoint was defined as a material density of 1.1–1.3 g / cm³. 3 And / or, the fluctuation value of the material density within 5 minutes is not greater than 0.01 g / cm³. 3 .

[0052] More preferably, in the above reaction process, the reaction mixture at the outlet end of the reaction pipe 109 is collected by a connecting pipe at one end to the circulating pump 110, and then converges with the connecting pipe at the other end of the circulating pump 110 to the liquid distributor at the top of the reaction pipe 109. It then passes through the upper dispersion plate 105, the gas-liquid mixing heat conduction zone, the solid-liquid mixing zone, and the lower dispersion plate 108 of the reaction pipe 109 to reach the outlet end, completing one cycle. The first circulation flow rate is controlled so that the circulating pump 110 completes one cycle within 1 to 20 minutes. More preferably, the first circulation flow rate is controlled so that the circulating pump 110 completes one cycle within 10 to 15 minutes. By adjusting the circulation flow rate of the circulating pump 110, the heat conduction, gas-liquid mass transfer, and solid-liquid mixing processes are fully carried out in the reaction process, ensuring the stable progress of the reaction process and improving the quality of the product and production efficiency.

[0053] (5) After the reaction is complete, the reaction product is a mixture containing polycarbonate polyether polyol, cyclic carbonate, and unreacted propylene oxide, which flows out from the outlet. The discharge from the outlet at one time shall not exceed 80% of the volume of the reaction pipe 109. Then the reaction product is fed into the separation unit 111 in the post-processing zone. The separation unit 111 separates the propylene oxide and dissolved CO2 in the mixture to obtain a crude product, and adjusts the viscosity of the crude product at the same time. The crude product is fed into the purification unit 112, where a refining agent is added for adsorption treatment. After filtration, a crude product with a catalyst metal content of less than 5 ppm is obtained. The purified crude product is fed into the distillation unit 113 to separate the main product, polycarbonate polyether polyol, and the by-product, cyclic carbonate, to obtain the polycarbonate polyether polyol product.

[0054] It should be noted that the aforementioned premixing vessel 101, separation unit 111, purification unit 112, distillation unit 113, etc., can all refer to the existing structure, and will not be described in detail here.

[0055] It should be noted that the control strategy in the later stages of the polymerization reaction in the above embodiments has a new technical weakness. This control strategy is an open-loop trigger control mode based on a static threshold. It presupposes that the optimal time to add catalyst and increase the circulation flow rate is when the material density reaches a fixed point of 1 g / cm³, and the amount added is also limited to a fixed range of 5% to 10% of the initial catalyst mass. This control logic essentially ignores the highly dynamic nature of the polymerization reaction process and the inevitable subtle differences between different production batches, especially failing to fully consider and utilize the complex nonlinear relationship between the instantaneous changes in reaction rate and the catalyst addition efficiency.

[0056] Specifically, this control strategy fails to quantify the real-time progress of the reaction. While both approaches achieve a density of 1 g / cm³, the underlying reaction processes can be drastically different. The reaction might have undergone a gradual decline in activity, or it might have been achieved after a period of intense exothermic reaction. These two states require vastly different amounts and types of catalyst. Using a fixed replenishment ratio is a one-size-fits-all approach lacking adaptive adjustment capabilities. It cannot accurately calculate the most economical and efficient catalyst replenishment amount based on the real-time reaction status, easily leading to catalyst waste or insufficient catalytic efficiency. Furthermore, the adjustment of the circulation flow rate is decoupled from the catalyst replenishment amount and the foreseeable rate of heat release after replenishment, failing to form a dynamic closed-loop coupled feedback. The ideal flow rate should be precisely matched to the expected heat and mass transfer requirements to maintain the optimal reaction microenvironment.

[0057] To address the aforementioned technical deficiencies, in another preferred embodiment of the present invention, a smart catalytic and fluid coupling control method based on model prediction and adaptive adjustment is introduced. This method no longer employs a fixed catalyst replenishment ratio and a fixed second circulation flow rate, but instead uses closed-loop feedback control based on real-time dynamic data of the reaction process. Specifically, it may include the following steps: acquiring time-series data of material density, carbon dioxide pressure, and material temperature; determining the apparent reaction rate and catalyst activity decay factor based on the time-series data of material density, carbon dioxide pressure, and material temperature; making a dynamic catalyst replenishment decision based on the apparent reaction rate, catalyst activity decay factor, current material density, and initial catalyst mass to obtain the catalyst replenishment amount; and adaptively adjusting the circulation flow rate based on the catalyst replenishment amount, the first circulation flow rate, and the current material temperature to obtain the second circulation flow rate.

[0058] Specifically, firstly, the reaction state is characterized and quantified in real time. To overcome the limitation that a single material density threshold cannot fully reflect the complex reaction kinetics, this preferred embodiment continuously collects time-series data on material density, carbon dioxide pressure, and material temperature within the reaction pipeline at high frequency. This data is then input into a built-in kinetic model to calculate the apparent reaction rate in real time. With activity decay factor These two core state parameters provide a dynamic basis for subsequent accurate decision-making.

[0059] Among them, apparent reaction rate It can be preferably estimated by the rate of change of material density, and the calculation formula is as follows:

[0060] In this formula, Represents the apparent reaction rate at time t; Let be the material density at time t; It is an empirical coefficient used to correlate the density change rate with the actual rate of polymerization. Its value can be calibrated based on historical production data, for example, its range can be 0.8 to 1.2.

[0061] Activity decay factor The formula for quantifying and assessing the current health status of a catalyst can preferably be:

[0062] In this formula, The catalyst activity decay factor at time t; This represents the current apparent reaction rate; It is the maximum reaction rate in the historical data or theoretical model of this process; The current material temperature; This is the optimal reaction temperature preset in the process. For example, according to the process conditions of Embodiment 1 of the present invention, It can be specifically set to 90℃. It can be obtained based on historical batch data, for example, by setting it to 0.05 g / (cm³·min).

[0063] It should be noted that when the actual reaction rate Significantly lower than its peak rate or actual reaction temperature Deviation from optimal process temperature hour, The value will decrease, which clearly indicates that the overall catalytic efficiency of the catalyst is declining, thus providing direct numerical basis for whether to add catalyst and how much to add.

[0064] Secondly, adaptive decision-making is performed on the dynamic catalyst replenishment amount. When the material density is detected to enter a preset decision range (e.g., 0.95 g / cm³ to 1.05 g / cm³), the control system will activate the decision module, and dynamically calculate the optimal catalyst replenishment amount based on the real-time calculated apparent reaction rate and catalyst activity decay factor. t).

[0065] In this way, catalyst replenishment is transformed from a static process command into a dynamic optimization process that responds to real-time operating conditions. While ensuring the reaction rate, the minimum effective dosage of catalyst is added, avoiding both tailing and excessively high acid values ​​caused by insufficient addition, and preventing localized explosive polymerization or the formation of byproducts due to excessive addition. This ensures product quality while improving economic efficiency.

[0066] The calculation formula is as follows:

[0067] in, The amount of catalyst to be added is calculated dynamically. The initial mass of catalyst added to the premixing vessel; It is the target reaction rate that the process is expected to achieve; It is the current real-time apparent reaction rate; This represents the current catalyst activity attenuation factor. In a specific embodiment, The value can be set to 0.04 g / (cm³·min) to ensure a stable reaction.

[0068] It should be noted that this formula introduces the concept of proportional control based on control theory. This ensures that the amount of replenishment is proportional to the deviation between the current rate and the target rate. More importantly, this is achieved through a sigmoid function. Nonlinear compensation is performed on the catalyst activity decay state, where The sensitivity coefficient is used to adjust the steepness of the compensation curve. When the catalyst activity declines significantly ( When the value is low, the function output value increases significantly, thereby increasing the catalyst replenishment amount; conversely, when the value is high, the replenishment amount decreases. In embodiments of the present invention, A value of 10 represents a balanced choice that considers both response speed and stability, making it suitable for large-scale industrial production. Finally, η serves as a constraint coefficient that integrates economic efficiency and process safety boundaries, ensuring that the calculation results remain within a reasonable and safe range. Specifically, η can be set to 1.0, representing calculations performed within standard safety boundaries.

[0069] Secondly, adaptive coupling adjustment of the circulation flow rate and reaction load is implemented. While calculating the catalyst replenishment amount, the control system does not switch to a fixed second circulation flow rate. Instead, based on the replenishment amount, it estimates the upcoming additional reaction heat load and, combined with the current system temperature, calculates an optimal second circulation flow rate. The calculation formula is as follows:

[0070] In this formula, The newly calculated second circulation velocity; This is the current first circulation flow rate; This refers to the catalyst replenishment amount calculated in the second step; It is the total mass of catalyst in the reaction system after the addition of catalyst (i.e., + ); The current material temperature; This is the preset optimal reaction temperature. It is a coupling coefficient that correlates the combined effects of the relative increase in catalyst and the system temperature deviation on the desired heat transfer efficiency. In the tubular reactor of this invention, it inherently possesses good heat transfer performance, thus... The setting of 1.5 reflects the principle of ensuring efficient response while leaving sufficient safety margin for industrial production.

[0071] It should be noted that in this step, the increment of the circulation flow rate is proportional to the relative increase in catalyst concentration and the degree of deviation of the current temperature from the ideal temperature. This means that the more heat the system is expected to generate, the stronger the mixing and heat exchange capacity provided by the circulation pump.

[0072] Through the implementation of the above preferred embodiment, the overall production process has achieved a fundamental shift from open-loop control relying on human experience and static thresholds to predictive closed-loop intelligent control based on real-time data and mechanistic models. This preferred embodiment significantly improves the level of refined control in the production process of sebacic acid polycarbonate polyether polyols by precisely quantifying the reaction state, dynamically evaluating catalyst efficiency, adaptively deciding on the amount of catalyst added, and coupling the adjustment of the circulation flow rate. This directly leads to optimized product quality, including lower residual acid values, a narrower molecular weight distribution index (PDI), and a higher batch stability coefficient (smaller Q value). Simultaneously, by precisely adding catalyst as needed, catalyst utilization efficiency is maximized, reducing the production cost per unit product. More importantly, this preferred embodiment fundamentally enhances the inherent safety of the process by dynamically matching the heat generation and removal rates, effectively avoiding the risk of explosive polymerization caused by reaction runaway, and providing a solid technical guarantee for the long-term, stable, and large-scale industrial production of this process.

[0073] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0074] Example 1 This embodiment provides a sebacic acid polycarbonate polyether polyol, using the tubular reaction apparatus mentioned above, and the reaction process is as follows: 8L of propylene oxide, 4g of DMC catalyst, and 660g of sebacic acid were added to a premixing reactor 101. After introducing carbon dioxide at 0.4MPa, the mixture was stirred at 40℃ for 1 hour. The mixture was then forced into an 8L×2 tubular reactor, where each reaction pipe 109 has a diameter of 100mm and a length of 1000mm. Once the entire pipe was inserted into the reactor 109, carbon dioxide was introduced to 3MPa and maintained at this pressure. A circulation pump 110 was started, with the flow rate controlled to complete one cycle in 10 minutes (the first cycle flow rate, approximately 600g / min for the circulation pump 110). The temperature of the heat exchange medium in the jacket 106 of the reaction pipe 109 was controlled to raise the temperature of the reaction pipe 109 to the preset reaction temperature of 90℃, initiating the polymerization reaction.

[0075] During the reaction, the material temperature and density are monitored, and the following steps are performed: (1) When the material temperature in the reaction pipeline 109 is monitored to be higher than 92°C (more than 2°C higher) and the CO2 consumption is greater than 0.1MPa, the temperature of the heat exchange medium is reduced to 80°C to lower the material temperature. When the material temperature drops to 90°C, the temperature in the jacket 106 is adjusted to 85°C.

[0076] (2) When the material density is monitored to reach 1.0 g / cm³ 3 At the middle and late stages of the reaction, 0.2 g of DMC catalyst was added. The flow rate of the circulation pump 110 was adjusted to approximately 6.7 (10 / 1.5 ≈ 6.7) min to complete one cycle (the second cycle flow rate, the circulation pump flow rate is approximately 900 g / min). After reacting at 90℃ for 3 hours, the density uniformly increased to 1.12 g / cm³. 3 Maintain the temperature for 5 minutes, at which point the reaction ends, and the product is removed by lowering the temperature. After removing the catalyst using a catalyst filtration device, the main and by-products are separated using a scraped evaporator.

[0077] The aforementioned DMC catalyst is a zinc-cobalt bimetallic cyanide complex catalyst prepared by reacting water-soluble metal salts of zinc and cobalt in an aqueous solvent. The specific preparation method is as follows: Potassium hexacyanocobalaminate and zinc bromide are weighed in a molar ratio of 1:4, dissolved in an aqueous solvent containing water and tert-butanol, and stirred continuously. The total mass ratio of the metal salts (i.e., cobalt and zinc salts) to the aqueous solvent is 1:5. An inorganic acid and an organic acid are added. The inorganic acid is dilute hydrochloric acid with a pH of 2, and the organic acid is glutaric acid. The molar ratio of the inorganic acid to the organic acid is 5:1, and the ratio of the total molar amount of the metal salt to the molar amount of the acid is 4:1. The mixture is stirred at 10-100℃ for several hours, resulting in continuous precipitation. The precipitate is then filtered and dried to obtain a filter cake. The filter cake was re-slurryed and washed with an aqueous solvent at a temperature of 10-100℃. Specifically, the washing temperature was 100℃, the washing time was 3 minutes, and after stirring for several hours, the filter cake was dried by vacuum filtration. The above slurrying, washing, and drying steps were repeated multiple times at a temperature of 10-100℃ until the pH of the liquid system was 6-7. Specifically, the temperature was 60℃, and the drying time was 6 minutes each time. The solid product was further dried under vacuum at 80-100℃ to obtain the final catalyst. Before use, the catalyst was processed into powder particles by mechanical grinding under anhydrous drying conditions.

[0078] The purified products were sampled and analyzed. Specifically, the polymerization products (polycarbonate-polyether polyol, cyclic propylene carbonate, and unreacted propylene oxide) were collected in a container. The polymerization product samples were characterized by 1H NMR spectroscopy to calculate the ratio of polymer to cyclic small molecules in the crude product. The polymer was purified and then subjected to 1H NMR spectroscopy to calculate the ratio of polycarbonate segments to polyether segments on the polymer backbone. The polymer backbone has only two structures, polycarbonate segments and polyether segments, and the sum of their percentages is 100%.

[0079] With the help of 1 The amount of carbon dioxide introduced into the polycarbonate polyether polyol (carbonate repeatr content) and the ratio of propylene carbonate (cyclic carbonate) to polycarbonate polyether polyol were determined by ¹H-NMR (Bruker, DPX400, 400 MHz; pulse program zg30, waiting time d1:10 s, 64 scans). In all cases, the sample was dissolved in deuterated chloroform. 1 The relevant resonance proton peaks in H-NMR (based on TMS=0ppm) are as follows: Among them, 5.0 ppm and 4.2 ppm belong to the proton peaks on the methylene and methine groups of polycarbonate chains, 4.9 ppm, 4.5 ppm and 4.1 ppm belong to the proton peaks on the methylene and methine groups of five-membered ring carbonates, and 3.5-3.8 ppm belong to the proton peaks of ether chains. The integrated area of ​​a peak at a certain ppm on the 1H NMR spectrum is represented by the capital letter A followed by a numerical subscript, for example, A... 5.0This represents the integrated area of ​​the peak at 5.0 ppm. Based on the crude copolymer product... 1 Calculate the integral area of ​​the H-NMR spectrum and its associated proton peaks, and calculate the proportion (molar ratio) of carbonate repeating units F in the copolymerization reaction. CO2 and cyclic carbonate content (mass fraction W) PC Carbon dioxide insertion amount M CO2 The specific calculation method is as follows: F CO2 =(A 5.0 +A 4.2 -2×A 4.6 ) / [(A 5.0 +A 4.2 -2×A 4.6 )+A 3.5 ×100%; W PC =102×A 1.5 / [102×(A 5.0 +A 4.2 -2×A 4.6 +A 1.5 )+58×A 3.5 ×100%; M CO2 =44×F CO2 / [102×F CO2 +58×(1-F CO2 )]×100%.

[0080] Coefficient 44 represents the molar mass of carbon dioxide, coefficient 58 represents the molar mass of PO (propylene oxide), and coefficient 102 represents the sum of the molar masses of carbon dioxide (44 g / mol) and PO (58 g / mol).

[0081] The formula for calculating the product conversion rate n is n = m × (1 - M) CO2 ) / (Mm×M CO2 ); where m is the mass of the product after removing propylene oxide, and M is the total sample mass containing propylene oxide.

[0082] The number-average molecular weight (Mn) and the polydispersity index (PDI) of the polymer were determined by gel permeation chromatography (GPC).

[0083] The molecular weight difference index ΔM is used to characterize the difference between the theoretical molecular weight of the product calculated according to the feed ratio and the actual molecular weight of the product obtained after the reaction. A smaller molecular weight difference index indicates a smaller difference between the actual and theoretical molecular weights, signifying better controllability of the production equipment and process, higher yield of the target product, and higher product quality. The molecular weight difference index ΔM can be calculated using the following formula: ΔM = |g实际 -g 理论 | / g 理论 ×100%, where g 实际 The number-average molecular weight of the product, in g. 理论 Represents the theoretical molecular weight.

[0084] The acid value was determined according to the method in GB / T 12008.5-2010 "Plastics Polyether Polyols Part 5: Determination of Acid Value".

[0085] The hydroxyl value (OHV) is determined by GB / T 12008.3-2009 Plastics Polyether Polyols Part 3: Determination of Hydroxyl Value.

[0086] Examples 2-6 The preparation and testing methods of Example 1 are used as described in Table 1. The material parameters and process parameters are shown in Table 1, and the performance test results are shown in Table 2.

[0087] Example 7 This embodiment aims to verify the performance improvement effect of the intelligent catalysis and fluid coupling control method based on model prediction and adaptive adjustment described in the preferred embodiment on product performance.

[0088] This embodiment uses basically the same equipment, raw materials and initial feed amount as in Example 1, specifically: 8L propylene oxide, 4g DMC catalyst, 660g sebacic acid, and the premixing and initial reaction conditions are consistent with those in Example 1.

[0089] The difference lies in the control strategy for the later stages of the reaction. This embodiment employs the intelligent control method described in the preferred embodiment, replacing the fixed threshold control in Embodiment 1. The model parameters within the control system are set to: the optimal reaction temperature preset by the process. The target reaction rate is 90℃. The maximum reaction rate is 0.04 g / (cm³·min). The value is 0.05 g / (cm³·min), and the adjustment coefficients are as follows: =1.0, =10, =1.0, =1.5.

[0090] During the reaction, when the material density reached 1.01 g / cm³, the system monitored a catalyst activity decay factor. It decreased to 0.75, and the apparent reaction rate The rate was 0.032 g / (cm³·min), lower than the target rate. Model calculations determined the dynamic catalyst replenishment amount to be 0.22 g (5.5% of the initial catalyst mass). Based on this replenishment amount and the material temperature of 90.5℃, the second circulation flow rate was calculated to be adjusted to complete one cycle in approximately 7.1 (10 / 1.41≈7.1) min.

[0091] After the reaction was completed, the product was purified and its performance was tested. The specific performance parameters are shown in Table 2.

[0092] Table 1

[0093]

[0094] The test results of Examples 1-6 are shown in Table 2 below: Table 2

[0095] As can be seen from Tables 1 and 2, the method of adding an additional catalyst in the latter half of the reaction, combined with temperature control and reaction cycle rate control, can stably synthesize the product. The acid value of the product is stable below 0.3 mg KOH / g, and it can meet the requirements for the synthesis of polyurethane without further treatment.

[0096] Examples 3-6 involved scale-up reactions, achieved by adding parallel reaction pipes 109. For instance, reaction pipe 109 was replaced from 8L×2 to 8L×8, and the flow rate of the circulation pump 110 was increased accordingly without further adjustments. Tables 1 and 2 show that during scale-up, after adding catalyst, the polymer's molecular weight, molecular weight distribution, and conversion rate did not fluctuate significantly. The molecular weight difference index was small, and the molecular weight distribution was narrow. This indicates that the production process provided in this embodiment has no scale-up effect and is suitable for industrial production.

[0097] Meanwhile, comparing Example 7 with Example 1 shows that the adaptive intelligent control method can more accurately replenish the catalyst as needed based on the actual "health status" of the reaction (the optimal replenishment amount was dynamically calculated to be 5.5%), and dynamically match the optimal circulation flow rate. As a result, even though the catalyst replenishment amount is basically at the same level as in Example 1 (5%), a higher conversion rate (98.5% vs 97%) was still achieved due to the more intelligent and precise adjustment of the replenishment timing and flow rate. This resulted in a product with a narrower molecular weight distribution (PDI 1.25 vs 1.30), a molecular weight closer to the theoretical value (ΔM 0.85% vs 1.19%), and especially a lower residual acid value (0.18 vs 0.27 mgKOH / g). This fully demonstrates the significant superiority of this preferred embodiment in improving product quality and enhancing the level of process refinement.

[0098] Example 8 Batch stability test: The experiment was repeated under the same preparation method and reaction apparatus as in Example 1. The products obtained were denoted as 8-1, 8-2, 8-3, and 8-4. The performance parameters are shown in Table 3.

[0099] The formula for calculating the batch stability coefficient Q is as follows: Q = E × H Where E is the volatility coefficient, which is calculated as follows: E=(g 最大 -g 最小 ) / g 理论中值 Where g 理论中值 This refers to the theoretical molecular weight (g) in all tested batches. 理论1、 g 理论2 ...g 理论n The median of the difference, H, is the average difference, which is calculated as follows: H = √(1 / n(g1-g)) 理论1 ) 2 +(g2-g 理论2 ) 2 +(g3-g 理论3 ) 2 +...(g) n -g 理论n ) 2 ), where g 最大 The maximum actual molecular weight across all batches, in g. 最小 The minimum actual molecular weight for all batches, g1, g2, g3...g n The actual molecular weight for each batch is in g. 理论1 g 理论2 g 理论3 ...g 理论nThis represents the theoretical molecular weight for each batch.

[0100] Table 3

[0101] Steps for calculating Q value: 1. Determine the theoretical median: Theoretical values ​​are sorted as follows: 2155, 2158, 2165, 2166. The theoretical median = (2158 + 2165) / 2 = 2161.5 2. Calculate the volatility coefficient (E): E = (2168 - 2153) / 2161.5 = 15 / 2161.5 ≈ 0.00694 3. Calculate the average difference (H): H = √[((2156 - 2165)] 2 + (2161 - 2155) 2 + (2153 -2158) 2 + (2168 - 2166) 2 =√[(81 + 36 + 25 + 4) / 4] = √(146 / 4) = √36.5 ≈ 6.0415 4. Calculate the batch stability coefficient (Q): Q = E × H = 0.00694 × 6.0415 ≈ 0.042 As shown in Table 3, the batch stability coefficient Q of Example 8 is calculated to be 0.042, which means that when synthesizing the same product in different batches, the product obtained by the device and process provided in this embodiment of the invention has small differences between batches, good stability, high conversion rate, and narrow molecular weight distribution, which reduces the quality instability and application difficulty caused by batch differences in downstream applications.

[0102] Comparative Example 1 This comparative example provides a sebacic acid polycarbonate polyether polyol, using the same tubular reaction apparatus as Example 1. The difference between this example and Example 1 is that no additional catalyst was added in the later stages of the reaction, and the circulating pump 110 was maintained at the first circulation flow rate throughout the reaction process. Three batches of products were obtained, denoted as CK1-1, CK1-2, and CK1-3, and their performance parameters are shown in Table 4.

[0103] Comparative Example 2 This comparative example provides a sebacic acid polycarbonate polyether polyol, using the same tubular reaction apparatus as Example 1. The difference between this example and Example 1 is that the circulation flow rate of the circulation pump 110 remains constant after the catalyst is added. Three batches of products were obtained, denoted as CK2-1, CK2-2, and CK2-3, and their performance parameters are shown in Table 4.

[0104] Comparative Example 3 This comparative example provides a sebacic acid polycarbonate polyether polyol, using the same tubular reaction apparatus as Example 1. The difference in the reaction process compared to Example 1 is that the amount of catalyst added is 0.6 g (15%). Three batches of products were obtained, denoted as CK3-1, CK3-2, and CK3-3, and their performance parameters are shown in Table 4.

[0105] Comparative Example 4 This comparative example provides a sebacic acid polycarbonate polyether polyol, using the same tubular reaction apparatus as Example 1. The difference between this example and Example 1 is that the medium temperature inside jacket 106 is maintained at 90°C without temperature control, and the reaction temperature during the reaction process is 90~100°C. Three batches of products were obtained, denoted as CK4-1, CK4-2, and CK4-3, and their performance parameters are shown in Table 4.

[0106] Table 4

[0107] Example of batch calculation for CK1: 1. Determine the theoretical median: Theoretical median = 2014 2. Calculate the volatility coefficient (E): E = (1926 - 1908) / 2014 ≈ 0.0089 3. Calculate the average difference (H): H = √[((1917 - 2034)] 2 + (1926 - 2014) 2 + (1908 - 1988) 2 ) / 3] = √(27833 / 3) ≈ 96.32 4. Calculate the batch stability coefficient (Q): Q = E × H = 0.0089 × 96.32 ≈ 0.86 Compared to Example 1, Comparative Example 1 only differed in that no catalyst was added in the middle and later stages of the reaction, resulting in insufficient reaction, excessive sebacic acid residue, and a higher acid value of the product.

[0108] Compared to Example 1, Comparative Example 2 did not adjust the circulation flow rate after adding the catalyst. Adding the catalyst would change the reaction rate in the reaction system. Without adjusting the flow rate, the internal reaction would be uneven, and the reaction rate in some areas would be too fast, resulting in a decrease in ester content. Furthermore, due to the uneven reaction, the acid value was not reduced to below the target value.

[0109] Compared to Example 1, Comparative Example 3 only differs in that the amount of catalyst added exceeds 15%. Excessive addition of catalyst causes the reaction rate to be too fast and uncontrollable, resulting in a further decrease in ester content and a risk of explosive polymerization.

[0110] Compared to Example 1, Comparative Example 4 did not perform temperature control, but instead maintained the temperature of the jacket 106 as the reaction temperature. Maintaining only the temperature of the jacket 106 as the reaction temperature would cause the temperature inside the reaction pipe 109 to be unable to be transferred in a timely and effective manner. This would result in the material not being able to maintain the reaction temperature when a large amount of heat is released during the rapid reaction, which would cause explosive polymerization, producing a large amount of polyether, and the molecular weight distribution would be very high.

[0111] As can be seen from the above embodiments and comparative examples, the tubular reaction apparatus provided in this invention uniformly mixes the raw materials in one go through the premixing vessel 101. Combined with the gas-liquid mixing heat conduction zone and solid-liquid mixing zone in the reaction pipeline 109, it can achieve thorough mixing of materials and provide better reaction conditions. During the reaction process, the degree of reaction is synergistically improved by precise temperature control and batch addition of catalyst, resulting in low sebacic acid residue, low acid value and narrow molecular weight distribution of the prepared sebacic acid-type polycarbonate polyether polyol, small difference between the actual product molecular weight and the target theoretical value, stable molecular weight of different batches of products, safe production process, no explosive polymerization, no scale-up effect, and suitable for large-scale industrial production.

[0112] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A production process for sebacic acid polycarbonate polyether polyol, characterized in that, The process is carried out in a tubular reactor, which includes a premixing vessel, reaction pipelines, and a circulating pump; the production process includes: An epoxy compound, sebacic acid, and a catalyst are added to a premixing reactor, and CO2 is introduced to mix them, resulting in a premix. The premixture is introduced into the reaction pipeline in one go, and CO2 at 2~6MPa is introduced; the material in the reaction pipeline is heated to a preset reaction temperature of 80~95℃, and the material is circulated in the reaction pipeline at a first circulation flow rate to carry out the polymerization reaction; During the polymerization reaction, the material temperature and density within the reaction pipeline are monitored, and the following steps are performed: When the pressure drop of CO2 in the reaction pipeline exceeds 0.1 MPa and the material temperature rises more than 2°C above the preset reaction temperature, the temperature of the heat exchange medium in the reaction pipeline is reduced to 70-80°C until the material in the reaction pipeline is reduced to the preset reaction temperature, at which point the temperature of the heat exchange medium is raised back to 80-95°C. When the density of the material was monitored to reach 1 g / cm³ 3 At that time, catalyst is added to the reaction pipeline, and the material is adjusted to a second circulation flow rate, wherein the second circulation flow rate is greater than the first circulation flow rate, and the amount of catalyst added is 5-10% of the mass of the catalyst in the premixing vessel; The sebacic acid polycarbonate polyether polyol obtained after the reaction meets the following requirements: acid value less than 0.3 mg KOH / g, molecular weight difference index ΔM less than 3%, and batch stability coefficient Q less than 5.

2. The production process of sebacic acid polycarbonate polyether polyol according to claim 1, characterized in that, The first circulation flow rate is 1 to 20 minutes to complete one cycle, and the second circulation flow rate is 1.2 to 2 times the first circulation flow rate.

3. The production process of sebacic acid polycarbonate polyether polyol according to claim 2, characterized in that, The first circulation flow rate is such that one cycle is completed in 10 to 15 minutes.

4. The production process of sebacic acid polycarbonate polyether polyol according to claim 1, characterized in that, In the premixing vessel, the molar ratio of the epoxy compound to the sebacic acid is 15:1 to 70:

1.

5. The production process of sebacic acid polycarbonate polyether polyol according to claim 1, characterized in that, In the premixing vessel, the mass of the catalyst is 0.04% to 0.09% of the mass of the epoxy compound.

6. The production process of sebacic acid polycarbonate polyether polyol according to claim 1, characterized in that, In the premixing vessel, CO2 is introduced by slowly bubbling it from the bottom at a rate of 40-60 bubbles / min; the pressure inside the premixing vessel is 0.1-2 MPa; the premixing temperature is 0-40℃; and the premixing time is 1-2 h.

7. The production process of sebacic acid polycarbonate polyether polyol according to claim 1, characterized in that, The reaction pipeline is connected to the circulation pump, which circulates the material. The reaction pipeline has an inlet end and an outlet end. A cycle is completed when the reaction mixture flowing through the outlet end of the reaction pipeline is circulated back to the inlet end of the reaction pipeline by the circulation pump, and then passes through the dispersion plate, the gas-liquid mixing heat conduction zone, and the solid-liquid mixing zone of the reaction pipeline to reach the outlet end.

8. The production process of sebacic acid polycarbonate polyether polyol according to claim 1, characterized in that, When the premixture is introduced into the reaction pipeline in one go, the reaction pipeline is controlled to meet the following conditions: temperature 35~45℃, CO2 pressure 0.1~2MPa; the reaction pipeline is equipped with a temperature sensor and a density meter, the temperature of the material in the reaction pipeline is determined by the temperature sensor, and the density of the material is determined by the density meter; the density of the reaction product reaches 1.1~1.3g / cm³. 3 And the change was less than 0.01 g / cm within 5 minutes. 3 The reaction is terminated at that time.

9. The production process of sebacic acid polycarbonate polyether polyol according to claim 2, characterized in that, The catalyst, excluding impurities, contains only zinc and cobalt. It is obtained by reacting water-soluble metal salts of zinc and cobalt in a water-soluble solvent, wherein the water-soluble metal salt of cobalt is a cobalt cyanide salt. The catalyst is modified with a mixed acid during synthesis. This mixed acid comprises at least one organic acid and at least one water-soluble inorganic acid. Specifically, the water-soluble inorganic acid is selected from dilute sulfuric acid and dilute hydrochloric acid, with a pH value between 0 and 5. The organic acid is selected from any one or more of succinic acid, glutaric acid, phthalic acid, iminodiacetic acid, pyromellitic acid, and butanetetracarboxylic acid. The molar ratio of the water-soluble inorganic acid to the organic acid is 1:10 to 10:

1.

10. A sebacic acid polycarbonate polyether polyol prepared by the production process according to any one of claims 1 to 9, characterized in that, The structural formula of the sebacic acid polycarbonate polyether polyol is shown below: Formula I; In formula I, R1 and R2 are selected from formula (2) or OH; Formula II; In Equation II, m / (m+n)+n / (m+n)=1, 0.1<n / (m+n)<0.9, and * indicates the connection position; The sebacic acid polycarbonate polyether polyol has a number-average molecular weight of 1500~4000 g / mol, a molecular weight polydispersity index (PDI) ≤ 1.5, a hydroxyl value of 30~60 mgKOH / g, and a carbonate repeating ratio F. CO2 ≥45%.

Images