Amino-modified polymers, methods of making and use

Abstract

The application belongs to the field of petrochemical industry, and particularly relates to an amino-modified polymer, a preparation method and application, more particularly to an amino-modified polymer as a surfactant for use as a crude oil demulsifier in crude oil dehydration. The amino-modified polymer with a snowman-like molecular structure is prepared by seed emulsion polymerization and post-modification, and is composed of a hydrophilic silicon-containing inorganic "head" and an oil-wet amino-modified organic group "body". The average particle size of the amino-modified polymer is 1-2 microns. When the amino-modified polymer is used as a crude oil demulsifier, the dehydration rate of crude oil can reach 80-97% within 90 minutes at 60 DEG C.

Description

Technical Field

[0001] This invention belongs to the field of petrochemicals, specifically relating to an amino-modified polymer, its preparation method and application, and more specifically, to an amino-modified polymer as a surfactant used as a crude oil demulsifier in crude oil dehydration. Background Technology

[0002] In today's energy sector, with the continuous expansion of crude oil extraction and the widespread application of oil extraction technologies, the properties of crude oil emulsions have undergone significant changes. Currently, the stability of crude oil emulsions is showing a continuously increasing trend, leading to a year-on-year rise in the water content of crude oil extracted from oil fields, placing a heavy burden on crude oil processing procedures. Specifically, the workload in the demulsification and dehydration stage of emulsified crude oil has increased dramatically. The original processing procedures and equipment are proving inadequate for handling crude oil with high water content. This not only increases the pressure on storage facilities but also requires more frequent maintenance and monitoring during transportation to ensure safe transport, while also accelerating wear and tear on transportation equipment. More importantly, during the refining process, the load on equipment increases sharply, severely impacting production efficiency. Furthermore, due to the high water content of crude oil, fuel consumption also increases significantly during heating to achieve the appropriate processing state, undoubtedly increasing production costs.

[0003] Among existing demulsification technologies, traditional demulsifiers have many drawbacks. On the one hand, these traditional demulsifiers often have special requirements for demulsification equipment, requiring specific equipment environments to ensure the smooth progress of the demulsification process. This means that companies need to invest additional funds in purchasing and maintaining these special equipment, greatly increasing the complexity and cost of operation. On the other hand, in order to achieve the ideal demulsification effect, the amount of traditional demulsifier used often needs to be increased, which further increases the cost of crude oil processing.

[0004] CN118562525A discloses a high-temperature resistant crude oil demulsifier and its preparation method. This demulsifier exhibits certain advantages by utilizing the synergistic effect between silicone oil-modified polyether and PDA@MXene / UiO-66 nanocomposite material. Specifically, it can promote the rapid migration of the demulsifier to the oil-water interface and interact with the natural surfactants of the oil-water interface film, thereby significantly reducing the oil-water interfacial tension and effectively promoting the demulsification process. In its formulation, the silicone oil-modified polyether introduces a triazine structure, a hyperbranched structure, and silicone oil. These components work together to improve the high-temperature resistance and demulsification ability of the matrix. The nanocomposite material uses MXene nanosheets as a substrate, with PDA coated on its surface and UiO-66 generated in situ. This structural design also synergistically improves the high-temperature resistance and demulsification ability of the matrix. However, in-depth analysis revealed several technical issues requiring improvement in this demulsifier: First, regarding cost, some of its raw materials are expensive, and the preparation process is complex, involving multiple steps and special process conditions, which may lead to high production costs. Therefore, it is necessary to explore more economical raw material alternatives or methods to simplify the preparation process. Second, in terms of production efficiency and product quality stability, the complexity of the preparation process makes it susceptible to interference from various factors, making it difficult to further improve production efficiency and resulting in poor product quality stability. Performance differences may exist between batches, posing a significant challenge for large-scale industrial applications. Furthermore, regarding crude oil adaptability, the applicability of this demulsifier to different types of crude oil needs further expansion. Crude oil properties vary significantly across different oil fields and at different stages of extraction. To meet broader market demands, it is necessary to improve the compatibility of the demulsifier with various crude oils.

[0005] Wang et al. developed a low-temperature, high-efficiency organosilicon-modified polyether demulsifier for Karamay crude oil emulsions (J. Petrochem Univ 2015; 28(3) 28-31). During the research, the researchers determined suitable synthesis conditions and accurately verified the structure of the target product using infrared spectroscopy. Simultaneously, the demulsification and dehydration performance of this demulsifier on various crude oils, including Karamay tertiary oil recovery, aged oil from Liaohe Oilfield, Liaohe Shuguang crude oil, and Daqing crude oil, was investigated. The results showed that the demulsifier had the best dehydration effect on Karamay tertiary oil recovery, with a dehydration rate of up to 87.5%, indicating its adaptability and wide applicability to various crude oils. However, this demulsifier also has some issues that cannot be ignored: First, regarding stability and broad-spectrum applicability, although it has a good demulsification effect on some crude oils, its stability and demulsification ability on other types of crude oils need to be improved when faced with more complex changes in crude oil composition or extreme environmental conditions, to ensure that it can function stably in a wider range of application scenarios; Second, from an environmental friendliness perspective, with the increasing awareness of environmental protection and increasingly stringent environmental regulations, this demulsifier may pose potential environmental risks, such as adverse effects on soil, water bodies, and other environmental elements after use, or the generation of more pollutants during the production process, which limits its long-term application; Finally, in terms of cost and economics, its raw material costs, preparation costs, and comprehensive costs during use all need to be further optimized to improve its competitiveness in the market and meet the needs of enterprises for cost reduction.

[0006] In conclusion, in the field of crude oil demulsifiers, developing a crude oil demulsifier with a wide range of applications, high dehydration efficiency, simple and easy preparation method, and stable product quality has become a key technical challenge that urgently needs to be overcome. This is of vital importance for improving crude oil processing efficiency, reducing costs, and protecting the environment. Summary of the Invention

[0007] Snowman-shaped crude oil demulsifiers represent a novel demulsifier morphology concept currently under research and exploration. These uniquely structured snowman-like components typically consist of a "head" and a "body," containing hydrophilic and lipophilic groups respectively, to enhance adsorption capacity and demulsification efficiency at the oil-water interface. Synthesis methods include chemical polymerization and grafting reactions. By precisely controlling its structure and composition, its performance can be optimized, and its synthesis efficiency and yield can be improved, thereby reducing costs.

[0008] Yeti-shaped demulsifiers, due to their unique structure, form a tight adsorption layer at the interface, enabling them to more effectively disrupt the emulsion film at the oil-water interface and accelerate the oil-water separation process. Therefore, they typically exhibit better interfacial activity. Because of their highly efficient demulsification capabilities, yeti-shaped demulsifiers can often achieve the same or even better results than traditional demulsifiers at lower concentrations, thereby reducing the amount of chemicals used and costs. Furthermore, the oil-water separation process using yeti-shaped demulsifiers may be simpler, reducing operational complexity and special equipment requirements.

[0009] To address the problems of existing demulsifiers, this invention aims to provide a snowman-shaped crude oil demulsifier, its preparation method, and its application. By grafting polymers to alter the hydrophilicity and hydrophobicity of particles, the oil-water interfacial tension is reduced, allowing water to better leave the oil phase. This facilitates the aggregation and coalescence of oil droplets in the emulsion, thereby accelerating the demulsification process. The snowman-shaped crude oil demulsifier of this invention can be applied to process stages such as wellheads, metering rooms, transfer stations, three-phase separators in combined stations, and crude oil settling tanks. It achieves efficient demulsification and dehydration of crude oil emulsions in oilfield gathering and transportation systems, resulting in highly efficient demulsification of produced fluids. This invention is implemented through the following technical solutions: An amino-modified polymer, characterized in that the amino-modified polymer is a nonionic polymer with an irregular structure, its molecular structure is smooth and snowman-like, consisting of a hydrophilic silicon-containing inorganic "head" and an oleophilic amino-modified organic group "body", with an average particle size of 1-2 μm. The amino-modified polymer, in its infrared spectrum at 3500 cm⁻¹, exhibits... -1 A distinct amino characteristic peak is observed at 1090 cm⁻¹. -1 The strong and broad absorption peak at the point is due to the Si-O-Si antisymmetric stretching vibration; EDX testing shows the presence of silicon, indicating that the snowman-shaped silicon-containing inorganic "head" structure has been successfully prepared.

[0010] Furthermore, the silicon-containing inorganic "head" is composed of any one of SiO2, silicic acid, vinyl silanol, and triethyl silanol; the amino-modified organic group "body" is composed of any one of amino-modified polystyrene, amino-modified polymethyl methacrylate, amino-modified polyvinyl chloride, amino-modified polypropylene, and amino-modified polybutene-1.

[0011] Furthermore, the amino-modified polymer is prepared by seed emulsion polymerization and post-modification, the method comprising the following steps: Step 1: Preparation of polymer particles Polymer monomers, dispersants, initiators, and solvents are placed in a container and stirred under inert gas overpressure to produce polymer particles. Step 2: Prepare snowman-shaped seed granules The polymer particles described in step 1 are dispersed in deionized water, heated to swell, a hydrophilic source is introduced, and the reaction is continued to obtain snowman-shaped particle protrusions. The snowman-shaped particle protrusions are washed with anhydrous ethanol and deionized water, centrifuged, and freeze-dried to obtain snowman-shaped seed particles. Step 3: Preparation of amino-modified polymer The snowman-shaped seed particles described in step 2 were added to deionized water, ultrasonically dispersed, then transferred to an oil bath for heating and stirring. A modifier was introduced, and the reaction continued to obtain the modified polymer.

[0012] Further, in step 1, the polymer monomer is any one of styrene, methyl methacrylate, vinyl chloride, polypropylene, and 1-butene; the dispersant is any one of polyvinylpyrrolidone, polyethylene glycol, and low-substituted hydroxypropyl cellulose; the initiator is any one of azobisisobutyronitrile and azobisisoheptanenitrile; the solvent is any one of methanol, deionized water, and anhydrous ethanol; the inert gas is any one of N2 and Ar; and the organic solvent is any one of methanol and anhydrous ethanol.

[0013] Further, in step 2, the hydrophilic source is any one of 3-(isobutenoyloxy)propyltrimethoxysilane, propyl orthosilicate, vinyltriethoxysilane, and vinyltrimethoxysilane.

[0014] Further, in step 3, the modifier is either 3-aminopropyltriethoxysilane or 3-aminopropyltrimethoxysilane.

[0015] More specifically, taking the preparation of an amino-modified polymer with a hydrophilic silica "head" and an oleophilic polystyrene "body" as an example, the process includes the following steps: Step 1: Preparation of polystyrene particles The monomer styrene, polyvinylpyrrolidone, initiator, and solvent were placed in a round-bottom flask. Inert gas was purged for 2-5 minutes, and the mixture was stirred at room temperature for 30-60 minutes. Then, the flask was heated to 60-80°C under inert gas overpressure and stirred for 18-24 hours at a pressure of 0.12-5 MPa and a stirring rate of 200-300 r / min. After the reaction was completed, the polystyrene particle dispersion was centrifuged, then centrifuged 2-3 times in an organic solvent, washed 3-5 times with deionized water, and freeze-dried for 18-24 hours at a temperature of -50°C to -40°C to obtain polystyrene particles. Step 2: Prepare snowman-shaped seed granules The polystyrene particles described in step 1 are dispersed in deionized water and continuously swollen in an oil bath at 70°C for 10-20 min to obtain a polystyrene dispersion. A monomer emulsion of 3-(isobutenoyloxy)propyltrimethoxysilane is added dropwise to the polystyrene dispersion to carry out a polymerization reaction at a dropping rate of 30-60 drops / min, which is completed within 10-20 min. After the addition is completed, the reaction is stirred for 18-24 h at a stirring rate of 200-300 r / min and a temperature of 60-80°C. After the polymerization reaction is completed, a single silica ball protrudes on the polystyrene microspheres to obtain snowman-shaped particle protrusions. The snowman-shaped particle protrusions are washed with anhydrous ethanol and deionized water, centrifuged 3-4 times at a centrifugation speed of 9000-10000 r / min, and freeze-dried for 18-24 h at a temperature of -50°C to -40°C to obtain snowman-shaped seed particles. Step 3: Surface modification of snowman-shaped particles Add the snowman-shaped seed particles described in step 2 to deionized water, ultrasonically disperse for 20-30 min, then transfer to an oil bath and stir at 50-60℃ for 10-20 min. Slowly add 3-aminopropyltriethoxysilane at a dropping rate of 40-50 drops / min. After the addition is complete, stir the reaction for 30-60 min at a stirring rate of 250-350 r / min to obtain an amino-modified snowman-shaped seed dispersion. Dissolve polyethyleneimine in deionized water and add... Glutaraldehyde was stirred until a uniform solution was obtained. This solution was then added dropwise to the amino-modified snowman-shaped seed dispersion at a rate of 40-50 drops / min. After the addition was complete, the mixture was heated and stirred for 6-8 hours at a temperature of 60-80°C and a stirring rate of 250-350 r / min. After the reaction was complete, the mixture was centrifuged and washed with water 6-8 times at a speed of 9000-10000 r / min. The mixture was then vacuum dried at 80-120°C for 24-36 hours to obtain the snowman-shaped crude oil demulsifier.

[0016] Further, in step 1, the initiator is any one of azobisisobutyronitrile and azobisisoheptanenitrile, the solvent is any one of methanol, deionized water, and anhydrous ethanol, the inert gas is any one of N2 and Ar, and the organic solvent is any one of methanol and anhydrous ethanol.

[0017] Further, in step 2, the monomer emulsion of 3-(isobutenoyloxy)propyltrimethoxysilane is prepared by adding 3-(isobutenoyloxy)propyltrimethoxysilane, a 1wt% potassium persulfate aqueous solution, and sodium dodecyl sulfate to deionized water and mixing them evenly to prepare the monomer emulsion of 3-(isobutenoyloxy)propyltrimethoxysilane.

[0018] Further, in step 2, the mass ratio of 3-(isobutyryloxy)propyltrimethoxysilane to polystyrene particles is 3-6:5.

[0019] Further, in step 2, the mass ratio of 3-(isobutyryloxy)propyltrimethoxysilane, 1wt% potassium persulfate aqueous solution, and sodium dodecyl sulfate is (18-36):(18-36):1.

[0020] Further, in step 3, the mass ratio of 3-aminopropyltriethoxysilane, polyethyleneimine, and glutaraldehyde is (3-6):(1-3):1.

[0021] The present invention also provides a surfactant, wherein the surfactant uses the aforementioned amino-modified polymer.

[0022] The present invention also provides a crude oil demulsifier, wherein the crude oil demulsifier uses the aforementioned surfactant.

[0023] The present invention also provides a crude oil demulsification method, wherein the crude oil demulsification method uses the aforementioned crude oil demulsifier.

[0024] Furthermore, the crude oil demulsification method includes the following steps: take crude oil, add the crude oil demulsifier, shake to disperse the demulsifier evenly, place it in an oven at 60-90℃, and observe the demulsification and dehydration. The crude oil demulsifier achieves a dehydration rate of 80-97% for crude oil within 90 minutes.

[0025] The beneficial effects of this invention are as follows: (1) This invention provides an amino-modified polymer as a surfactant for use as a crude oil demulsifier in crude oil dehydration. The crude oil demulsifier is prepared by seed emulsion polymerization and post-modification. It is a non-ionic demulsifier with an irregular structure. Its molecular structure is a smooth snowman-like structure. Its "head" is a hydrophilic silicon-containing inorganic substance, and its "body" is a lipophilic amino-modified organic group. This structure unexpectedly enhances the adsorption capacity of the demulsifier at the oil-water interface, which can more effectively destroy the emulsion film on the oil-water interface and improve the demulsification efficiency. (2) The crude oil demulsifier of the present invention can unexpectedly achieve a dehydration rate of 80-97% of crude oil at 60°C within 90 minutes. Compared with the prior art, the crude oil demulsifier of the present invention does not require excessive energy consumption to heat crude oil, which not only reduces energy costs, but is also easier to operate and control in actual industrial production scenarios, and helps to improve the overall efficiency of crude oil processing. (3) This invention achieves the preparation of a high-efficiency demulsifier through a special process using low-cost raw materials, thereby improving the demulsification efficiency of crude oil while reducing costs; (4) The crude oil demulsifier of the present invention has a simple, cost-controllable and easy-to-implement operation method for crude oil dehydration. It can reduce production costs to the maximum extent and improve the market competitiveness of the product while ensuring product quality. Attached Figure Description

[0026] Figure 1 Here is a scanning electron microscope (SEM) image of the crude oil demulsifier in Example 1; Figure 2 The image shows an elemental analysis (EDX) image of the crude oil demulsifier in Example 1; Figure 3 The infrared spectrum of the crude oil demulsifier in Example 1; Depend on Figure 1 It can be seen that the molecular structure of this crude oil demulsifier is a smooth, snowman-like structure. Depend on Figure 2 It can be seen that the snowman-shaped particles contain silicon, and the snowman-shaped particles with silicon dioxide heads were successfully prepared. Depend on Figure 3 It can be seen that the crude oil demulsifier synthesized in this embodiment has a viscosity of 3500 cm⁻¹. -1 A distinct amino characteristic peak was observed at 1090 cm⁻¹. -1 The strong and broad absorption peak at the point is due to the Si-O-Si antisymmetric stretching vibration, indicating that the protruding silica "head" of the snowman-like particles has been successfully modified with amino groups. Detailed Implementation

[0027] The technical solution of the present invention will be described in detail below with reference to specific embodiments of the present invention. The described embodiments are only a part of the present invention, and the present invention is not limited to the embodiments described below.

[0028] Example 1 Step 1: Preparation of polystyrene particles 25g of styrene, 1.5g of polyvinylpyrrolidone, 0.25g of azobisisobutyronitrile, and 70g of methanol were placed in a 250mL round-bottom flask. N2 was introduced to purge the mixture for 5min, and the mixture was stirred at room temperature for 30min. Then, the flask was heated to 70℃ under slight N2 overpressure and stirred for 24h at a pressure of 3MPa and a stirring rate of 200r / min. After the reaction was completed, the resulting polystyrene particle dispersion was centrifuged and repeatedly centrifuged and washed three times in methanol, then washed three times with deionized water. The mixture was then freeze-dried for 24h at -40℃ to obtain polystyrene particles. Step 2: Prepare snowman-shaped seed granules Disperse 0.6g of the polystyrene particles described in step 1 in 20g of deionized water and allow them to swell continuously in a 70°C oil bath for 10 minutes. Add 0.36g of 3-(isobutenoyloxy)propyltrimethoxysilane, 0.36g of a 1wt% potassium persulfate aqueous solution, and 0.02g of sodium dodecyl sulfate to 10g of deionized water and mix thoroughly to prepare a monomer emulsion of 3-(isobutenoyloxy)propyltrimethoxysilane. Then, slowly add this monomer emulsion dropwise to the polystyrene. In the dispersion, the reaction was completed within 20 minutes. After the addition was complete, the mixture was stirred for 24 hours at a stirring rate of 300 r / min and a temperature of 70 °C to ensure the complete polymerization of 3-(isobutenoyloxy)propyltrimethoxysilane. After the polymerization reaction was completed, complete silica protrusions were obtained on the polystyrene, resulting in snowman-shaped particles. The snowman-shaped particles were washed with anhydrous ethanol and deionized water, centrifuged 4 times at a centrifugation speed of 10000 r / min, and freeze-dried for 24 hours at a temperature of -40 °C to obtain snowman-shaped seed particles. Step 3: Surface modification of snowman-shaped particles Add 0.1g of the snowman-shaped seeds described in step 2 to 25mL of deionized water, sonicate for 30min, then transfer to an oil bath and heat to 50℃, stir for 10min, slowly add 1.5mL of 3-aminopropyltriethoxysilane at a dropping rate of 40 drops / min, and stir for 30min after the addition is complete to obtain an amino-modified snowman-shaped seed dispersion; dissolve 0.5mL of polyethyleneimine in 10mL of deionized water, add 0.5mL of glutaraldehyde, stir to obtain a mixed solution, add this mixed solution to the amino-modified snowman-shaped seed dispersion at a dropping rate of 40 drops / min, heat and stir for 6h at 60℃ and a stirring rate of 250r / min, centrifuge and wash 6 times with water at 10000r / min, and vacuum dry at 80℃ for 24h to obtain the snowman-shaped crude oil demulsifier.

[0029] Example 2 Step 1: Preparation of polystyrene particles 25g of styrene, 1.5g of polyvinylpyrrolidone, 0.25g of azobisisobutyronitrile, and 70g of methanol were placed in a 250mL round-bottom flask. N2 was introduced to purge the mixture for 5min, and the mixture was stirred at room temperature for 30min. Then, the flask was heated to 70℃ under slight N2 overpressure and stirred for 24 hours at a pressure of 3MPa and a stirring rate of 200r / min. After the reaction was completed, the resulting polystyrene particle dispersion was centrifuged and repeatedly centrifuged and washed three times in methanol, then washed three times with deionized water. The mixture was then freeze-dried for 24h at -40℃ to obtain polystyrene particles. Step 2: Prepare snowman-shaped seed granules Disperse 0.6g of the polystyrene particles described in step 1 in 20g of deionized water and allow them to swell continuously in a 70°C oil bath for 10 minutes. Add 0.48g of 3-(isobutenoyloxy)propyltrimethoxysilane, 0.48g of a 1wt% potassium persulfate aqueous solution, and 0.02g of sodium dodecyl sulfate to 10g of deionized water and mix thoroughly to prepare a monomer emulsion of 3-(isobutenoyloxy)propyltrimethoxysilane. Then, slowly add the monomer emulsion dropwise to the polystyrene. In the dispersion, the reaction was completed within 20 minutes. After the addition was complete, the mixture was stirred for 24 hours at a stirring rate of 300 r / min and a temperature of 70 °C to ensure the complete polymerization of 3-(isobutenoyloxy)propyltrimethoxysilane. After the polymerization reaction was completed, complete silica protrusions were obtained on the polystyrene, resulting in snowman-shaped particles. The snowman-shaped particles were washed with anhydrous ethanol and deionized water, centrifuged 4 times at a centrifugation speed of 10000 r / min, and freeze-dried for 24 hours at a temperature of -40 °C to obtain snowman-shaped seed particles. Step 3: Surface modification of snowman-shaped particles Add 0.1g of the snowman-shaped seeds described in step 2 to 25mL of deionized water, sonicate for 30min, then transfer to an oil bath and heat to 50℃, stir for 10min, slowly add 1.5mL of 3-aminopropyltriethoxysilane at a dropping rate of 40 drops / min, and stir for 30min after the addition is complete to obtain an amino-modified snowman-shaped seed dispersion; dissolve 0.5mL of polyethyleneimine in 10mL of deionized water, add 0.5mL of glutaraldehyde, stir to obtain a mixed solution, add this mixed solution to the amino-modified snowman-shaped seed dispersion at a dropping rate of 40 drops / min, heat and stir for 6h at 60℃ and a stirring rate of 250r / min, centrifuge and wash 6 times with water at 10000r / min, and vacuum dry at 80℃ for 24h to obtain the snowman-shaped crude oil demulsifier.

[0030] Example 3 Step 1: Preparation of polystyrene particles 25g of styrene, 1.5g of polyvinylpyrrolidone, 0.25g of azobisisobutyronitrile, and 70g of methanol were placed in a 250mL round-bottom flask. N2 was introduced to purge the mixture for 5min, and the mixture was stirred at room temperature for 30min. Then, the flask was heated to 70℃ under slight N2 overpressure and stirred for 24h at a pressure of 3MPa and a stirring rate of 200r / min. After the reaction was completed, the resulting polystyrene particle dispersion was centrifuged and repeatedly centrifuged and washed three times in methanol, then washed three times with deionized water. The mixture was then freeze-dried for 24h at -40℃ to obtain polystyrene particles. Step 2: Prepare snowman-shaped seed granules Disperse 0.6g of the polystyrene particles described in step 1 in 20g of deionized water and allow them to swell continuously in a 70°C oil bath for 10 minutes. Add 0.6g of 3-(isobutenoyloxy)propyltrimethoxysilane, 0.6g of a 1wt% potassium persulfate aqueous solution, and 0.02g of sodium dodecyl sulfate to 10g of deionized water and mix thoroughly to prepare a monomer emulsion of 3-(isobutenoyloxy)propyltrimethoxysilane. Then, slowly add the monomer emulsion dropwise to the polystyrene mixture. In the dispersion, the reaction was completed within 20 minutes. After the addition was complete, the mixture was stirred for 24 hours at a stirring rate of 300 r / min and a temperature of 70 °C to allow 3-(isobutenoyloxy)propyltrimethoxysilane to fully polymerize. After the polymerization reaction was completed, complete silica protrusions were obtained on the polystyrene, resulting in snowman-shaped particles. The snowman-shaped particles were washed with anhydrous ethanol and deionized water, centrifuged 4 times at a centrifugation speed of 10000 r / min, and freeze-dried for 24 hours at a temperature of -40 °C to obtain snowman-shaped seed particles. Step 3: Surface modification of snowman-shaped particles Add 0.1g of the snowman-shaped seeds described in step 2 to 25mL of deionized water, sonicate for 30min, then transfer to an oil bath and heat to 50℃, stir for 10min, slowly add 1.5mL of 3-aminopropyltriethoxysilane at a dropping rate of 40 drops / min, and stir for 30min after the addition is complete to obtain an amino-modified snowman-shaped seed dispersion; dissolve 0.5mL of polyethyleneimine in 10mL of deionized water, add 0.5mL of glutaraldehyde, stir to obtain a mixed solution, add this mixed solution to the amino-modified snowman-shaped seed dispersion at a dropping rate of 40 drops / min, heat and stir for 6h at 60℃ and a stirring rate of 250r / min, centrifuge and wash 6 times with water at 10000r / min, and vacuum dry at 80℃ for 24h to obtain the snowman-shaped crude oil demulsifier.

[0031] Example 4 Step 1: Preparation of polystyrene particles 25g of styrene, 1.5g of polyvinylpyrrolidone, 0.25g of azobisisobutyronitrile, and 70g of methanol were placed in a 250mL round-bottom flask. N2 was introduced to purge the mixture for 5min, and the mixture was stirred at room temperature for 30min. Then, the flask was heated to 70℃ under slight N2 overpressure and stirred for 24h at a pressure of 3MPa and a stirring rate of 200r / min. After the reaction was completed, the resulting polystyrene particle dispersion was centrifuged and repeatedly centrifuged and washed three times in methanol, then washed three times with deionized water. The mixture was then freeze-dried for 24h at -40℃ to obtain polystyrene particles. Step 2: Prepare snowman-shaped seed granules Disperse 0.6g of the polystyrene particles described in step 1 in 20g of deionized water and allow them to swell continuously in a 70°C oil bath for 10 minutes. Add 0.72g of 3-(isobutenoyloxy)propyltrimethoxysilane, 0.72g of a 1wt% potassium persulfate aqueous solution, and 0.02g of sodium dodecyl sulfate to 10g of deionized water and mix thoroughly to prepare a monomer emulsion of 3-(isobutenoyloxy)propyltrimethoxysilane. Then, slowly add the monomer emulsion dropwise to the polystyrene. In the dispersion, the reaction was completed within 20 minutes. After the addition was complete, the mixture was stirred for 24 hours at a stirring rate of 300 r / min and a temperature of 70 °C to ensure the complete polymerization of 3-(isobutenoyloxy)propyltrimethoxysilane. After the polymerization reaction was completed, complete silica protrusions were obtained on the polystyrene, resulting in snowman-shaped particles. The snowman-shaped particles were washed with anhydrous ethanol and deionized water, centrifuged 4 times at a centrifugation speed of 10000 r / min, and freeze-dried for 24 hours at a temperature of -40 °C to obtain snowman-shaped seed particles. Step 3: Surface modification of snowman-shaped particles Add 0.1g of the snowman-shaped seeds described in step 2 to 25mL of deionized water, sonicate for 30min, then transfer to an oil bath and heat to 50℃, stir for 10min, slowly add 1.5mL of 3-aminopropyltriethoxysilane at a dropping rate of 40 drops / min, and stir for 30min after the addition is complete to obtain an amino-modified snowman-shaped seed dispersion; dissolve 0.5mL of polyethyleneimine in 10mL of deionized water, add 0.5mL of glutaraldehyde, stir to obtain a mixed solution, add this mixed solution to the amino-modified snowman-shaped seed dispersion at a dropping rate of 40 drops / min, heat and stir for 6h at 60℃ and a stirring rate of 10000r / min after the addition is complete, centrifuge and wash 6 times with water at 10000r / min, and vacuum dry at 80℃ for 24h to obtain the snowman-shaped crude oil demulsifier.

[0032] Comparative Example Dehydrated polyether demulsifiers BP01 and TA01 were crosslinked with water-based polyether demulsifier QPE01 to prepare crosslinked polyether demulsifiers D-BP and D-TA. The specific synthesis steps are as follows: Preparation of BP01: 0.2 g of 1,3-propanediol and 0.2 g of potassium hydroxide crystals were added to a high-pressure reactor. The air inside the reactor was replaced twice with N2, each replacement lasting 15 min. 10 g of propylene oxide (PO) and 30 g of ethylene oxide (EO) were then introduced into the reactor sequentially. During the introduction process, the stirring device was turned on at a stirring speed of 500 r / min and the reaction pressure was 0.25 MPa. The reaction temperature was first raised to 125 °C and reacted for 5 h, and then the temperature was raised to 135 °C and the reaction was continued for 5 h. After the reaction was completed, the reactor was cooled to room temperature, and glacial acetic acid was slowly added dropwise while stirring continuously to neutralize the potassium hydroxide and bring the pH of the reaction system to 7. The product was removed from the reactor and filtered to obtain BPO1. Preparation of TA01: 0.2 g of tetraethylenepentamine and 0.2 g of potassium hydroxide crystals were added to a high-pressure reactor. The air inside the reactor was replaced twice with N2, each replacement lasting 15 min. 10 g of propylene oxide (PO) and 30 g of ethylene oxide (EO) were then introduced into the reactor sequentially. During the introduction process, the stirring device was turned on at a stirring speed of 500 r / min and the reaction pressure was 0.25 MPa. The reaction temperature was first raised to 125 °C and reacted for 5 h, and then the temperature was raised to 135 °C and the reaction was continued for 5 h. After the reaction was completed, the reactor was cooled to room temperature, and glacial acetic acid was slowly added dropwise while stirring continuously to neutralize the potassium hydroxide and bring the pH of the reaction system to 7. The product was removed from the reactor and filtered to obtain TA01. Comparative Example 1: Preparation of Crosslinked Polyether Demulsifier D-BP A four-necked flask was placed in a constant-temperature water bath at 60°C. 50 mL of tetrahydrofuran, 4 g of polystyrene-maleic anhydride copolymer (SMA; molecular weight approximately 10,000, maleic anhydride content 20%; Zhengzhou Huiju Chemical Co., Ltd.), and 4 g of p-toluenesulfonic acid were added. The mixture was stirred for 1 hour at 250 rpm to obtain an SMA solution. Two clean beakers were taken, and 20 mL of tetrahydrofuran was added to each. In one beaker, 2 g of the aforementioned BP01 was added, and the mixture was stirred with a glass rod until fully dissolved to obtain a tetrahydrofuran solution of BP01, which was then poured into a dropping funnel. In the other beaker, 2 g of a water-based polyether demulsifier QPE01 (whose main structure contains...) was added. A triblock polyether with a polyamine polymer as an initiator (Tianjin Hairun Jinke Technology Co., Ltd.) was stirred to dissolve the QPE01 tetrahydrofuran solution and poured into a dropping funnel. The tetrahydrofuran solutions of BP01 and QPE01 were simultaneously added dropwise to the four-necked flask, with the addition time controlled at 40 min. After the addition was completed, the temperature of the constant temperature water bath was raised to 80 °C, and the reaction was continued to be stirred for 6 h. After the reaction was completed, the temperature was lowered to room temperature, and 1 wt% sodium hydroxide solution was added dropwise to neutralize the reaction system to pH=7. The lower organic phase was then extracted with chloroform, and the organic phase was washed three times with distilled water and the solvent was evaporated to obtain the crosslinked polyether demulsifier D-BP. Comparative Example 2: Preparation of Crosslinked Polyether Demulsifier D-TA A four-necked flask was placed in a constant-temperature water bath at 60°C. 50 mL of tetrahydrofuran, 4 g of SMA, and 4 g of p-toluenesulfonic acid were added, and the mixture was stirred for 1 hour at 250 rpm to obtain an SMA solution. Two clean beakers were taken, and 20 mL of tetrahydrofuran was added to each. In one beaker, 2 g of the aforementioned TA01 was added, and the mixture was stirred with a glass rod until fully dissolved to obtain a tetrahydrofuran solution of TA01, which was then poured into a dropping funnel. In the other beaker, 2 g of the water-based polyether demulsifier QPE01 was added and stirred until dissolved to obtain Q... A tetrahydrofuran solution of PE01 was poured into a dropping funnel; the tetrahydrofuran solutions of TA01 and QPE01 were simultaneously added dropwise to the four-necked flask over a period of 40 minutes. After the addition was complete, the temperature of the constant temperature water bath was raised to 80°C, and the reaction was stirred for 6 hours. After the reaction was complete, the temperature was lowered to room temperature, and 1 wt% sodium hydroxide solution was added dropwise to neutralize the reaction system to pH 7. The lower organic phase was then extracted with chloroform, and the organic phase was washed three times with distilled water and the solvent was evaporated to obtain the crosslinked polyether demulsifier D-TA. Performance evaluation of crude oil demulsifiers Take 25 mL of crude oil from 6 samples (crude oil from Yanchang Oilfield, with a water content of 0.8%), add 10 mg each of the snowman-shaped crude oil demulsifier from Examples 1-4 and the cross-linked polyether demulsifiers D-BP and D-TA from the comparative examples, shake until the demulsifier is evenly dispersed, and place in a 60℃ oven to observe the demulsification and dehydration. The results are shown in Table 1.

[0033] Table 1. Results of Demulsifying Performance Test

[0034] As shown in Table 1, compared to the comparative examples, the crude oil demulsifier of the present invention exhibits a better demulsification effect than Comparative Examples 1 and 2 (D-BP and D-TA). In Example 3, the demulsifier with the best performance was obtained when the mass ratio of 3-(isobutenoyloxy)propyltrimethoxysilane to polystyrene particles was 1:1, achieving a 95% dehydration rate of the crude oil within 90 minutes. This indicates that the crude oil demulsifier with its irregular structure unexpectedly enhances the adsorption capacity of the demulsifier at the oil-water interface, enabling more effective disruption of the emulsion film at the oil-water interface and improving demulsification efficiency.

[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any modifications or equivalent changes made based on the technical essence of the present invention shall still fall within the scope of protection claimed by the present invention.

Claims

1. An amino-modified polymer, characterized in that, The amino-modified polymer is a nonionic polymer with an irregular structure. Its molecular structure is smooth and snowman-like, consisting of a hydrophilic silicon-containing inorganic "head" and an oleophilic amino-modified organic "body", with an average particle size of 1-2 μm. The amino-modified polymer, in its infrared spectrum at 3500 cm⁻¹, exhibits... -1 A distinct amino characteristic peak is observed at 1090 cm⁻¹. -1 The strong and broad absorption peak at the point is due to the Si-O-Si antisymmetric stretching vibration; EDX testing shows the presence of silicon, indicating that the snowman-shaped silicon-containing inorganic "head" structure has been successfully prepared.

2. The amino-modified polymer according to claim 1, characterized in that, The silicon-containing inorganic "head" is composed of any one of SiO2, silicic acid, vinyl silanol, and triethyl silanol; the amino-modified organic group "body" is composed of any one of amino-modified polystyrene, amino-modified polymethyl methacrylate, amino-modified polyvinyl chloride, amino-modified polypropylene, and amino-modified polybutene-1.

3. A method for preparing the amino-modified polymer according to claim 1, characterized in that, The amino-modified polymer is prepared by seed emulsion polymerization and post-modification, and the method includes the following steps: Step 1: Preparation of polymer particles Polymer monomers, dispersants, initiators, and solvents are placed in a container and stirred under inert gas overpressure to produce polymer particles. Step 2: Prepare snowman-shaped seed granules The polymer particles described in step 1 are dispersed in deionized water, heated to swell, a hydrophilic source is introduced, and the reaction is continued to obtain snowman-shaped particle protrusions. The snowman-shaped particle protrusions are washed with anhydrous ethanol and deionized water, centrifuged, and freeze-dried to obtain snowman-shaped seed particles. Step 3: Preparation of amino-modified polymer The snowman-shaped seed particles described in step 2 were added to deionized water, ultrasonically dispersed, and then transferred to an oil bath for heating and stirring. A modifier was introduced, and the reaction continued to obtain the amino-modified polymer.

4. The method for preparing the amino-modified polymer according to claim 3, characterized in that, In step 1, the polymer monomer is any one of styrene, methyl methacrylate, vinyl chloride, polypropylene, and 1-butene; the dispersant is any one of polyvinylpyrrolidone, polyethylene glycol, and low-substituted hydroxypropyl cellulose; the initiator is any one of azobisisobutyronitrile and azobisisoheptanenitrile; the solvent is any one of methanol, deionized water, and anhydrous ethanol; the inert gas is any one of N2 and Ar; and the organic solvent is any one of methanol and anhydrous ethanol.

5. The method for preparing the amino-modified polymer according to claim 3, characterized in that, In step 2, the hydrophilic source is any one of 3-(isobutenoyloxy)propyltrimethoxysilane, propyl orthosilicate, vinyltriethoxysilane, and vinyltrimethoxysilane.

6. The method for preparing the amino-modified polymer according to claim 3, characterized in that, In step 3, the modifier is either 3-aminopropyltriethoxysilane or 3-aminopropyltrimethoxysilane.

7. A surfactant, characterized in that, The amino-modified polymer according to claim 1 is used.

8. A crude oil demulsifier, characterized in that, Use the surfactant as described in claim 7.

9. A method for demulsifying crude oil, characterized in that, Use the crude oil demulsifier as described in claim 8.

10. The crude oil demulsification method according to claim 9, characterized in that, The method includes: taking crude oil, adding the crude oil demulsifier, shaking to disperse the demulsifier evenly, placing it in an oven at 60-90℃, and observing the demulsification and dehydration. The crude oil demulsifier achieves a dehydration rate of 80-97% for crude oil within 90 minutes.

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