A method for preparing a scale inhibitor based on olefin-functional polymers

Abstract

The application provides a method for preparing a scale inhibitor based on an olefin functional polymer, and the method comprises the following steps: passing low-carbon olefins into a reactor, then increasing the temperature and pressure, and then adding a functional monomer, an initiator and a solvent into the reactor to generate a polymerization reaction; after the polymerization reaction, first performing gas-solid-liquid separation to recover the low-carbon olefins, and then performing solid-liquid separation on the remaining material to obtain an olefin functional polymer; performing an esterification reaction on the olefin functional polymer and an alcohol, and then performing a reaction on the obtained esterified olefin functional polymer and a quaternary ammonium salt, a base or an acid to obtain a cationic or anionic polymer scale inhibitor. Through the pressurized reaction of low-carbon gaseous olefins and a functional monomer, the application realizes the same-chain alternating copolymerization of the two, adopts a heterogeneous polymerization mode, improves the monomer concentration and the reaction efficiency, and then prepares different kinds of polymer scale inhibitors through esterification and anionization or cationization, so that the polymer scale inhibitors have good thermal stability and excellent water treatment performance; the application has the advantages of simple operation, mild conditions, easy separation and purification and green environmental protection.

Description

Technical Field

[0001] This invention belongs to the field of organic polymerization technology and relates to a method for preparing scale inhibitors based on olefin functional polymers. Background Technology

[0002] With the continuous development of society, the adverse effects of human activities on water bodies are becoming increasingly severe. Domestic sewage, industrial wastewater, and agricultural runoff all contribute to the continuous deterioration of water quality. Phosphorus compounds pollute water bodies and cause eutrophication, which is one of the important reasons for water quality deterioration. Chemical treatment methods are often used to treat polluted water bodies, purifying the water by adding wastewater treatment agents.

[0003] Scale inhibitors are a commonly used class of wastewater treatment agents, including natural polymer scale inhibitors and synthetic polymer scale inhibitors. The latter can be further divided into carboxylic acid polymers, sulfonic acid polymers, phosphorus-containing polymers, and environmentally friendly scale inhibitors. Traditional scale inhibitors are usually phosphorus-containing, but with increasingly stringent environmental protection requirements, the development of low-phosphorus and phosphorus-free scale inhibitors has become a research hotspot. Polycarboxylic acid scale inhibitors are an existing class of phosphorus-free scale inhibitors, including polyacrylic acid, polymethyl acrylate, and polymaleic acid inhibitors.

[0004] Olefin functional polymers, as functional polymer materials, have attracted great attention due to their wide range of applications in engineering plastic chain extension, high-performance composite materials, nylon wetting, ink dispersion, microencapsulation, and filtration membrane formation. Among them, olefin-maleic anhydride polymers can serve as a novel scale inhibitor. The carboxyl groups in their molecular structure can form chelates with ions such as calcium, magnesium, and barium, exhibiting good lattice distortion and dispersion effects, low environmental pollution, and the advantages of being green and efficient.

[0005] The raw materials for synthesizing olefin functional polymers are mainly olefins and functional monomers. Depending on the type of olefin or functional monomer in the raw materials, corresponding synthesis processes are required. However, currently, when using maleic anhydride as a functional monomer to polymerize with olefins, the olefins used are usually C4 or higher olefins, and are typically liquid olefins such as dienes, cycloolefins, and isomeric olefins. The polymerization reaction of gaseous olefins below C4 has not been involved.

[0006] CN 1560323A discloses a method for preparing a scale inhibitor of maleic anhydride and vinyl acetate copolymer. The method uses maleic anhydride and vinyl acetate as raw materials, water as solvent, and a redox system as initiator for free radical polymerization. By improving the initiator system, the bromine value of the product is reduced and the scale inhibition performance is improved. However, this method does not involve the steps of further esterification and anionization of olefin functional polymers to prepare scale inhibitors. The synthesis of olefin functional polymers also uses liquid olefins, and vinyl acetate can also be regarded as a functional monomer. It does not involve the synthesis process of gaseous olefins and functional monomers.

[0007] CN 104262546A discloses an alkenyl polyoxyethylene ether / maleic anhydride / acrylic acid copolymer, its preparation method, and its application. The copolymer is polymerized using maleic anhydride, acrylic acid, and alkenyl polyoxyethylene ether as monomers, and carboxylic acid groups and oxyethylene repeating units are introduced, so that it contains highly hydrophilic polyether groups and carboxylate ions that can chelate calcium and magnesium ions. It is a novel water treatment agent. In this method, no esterification reaction is carried out after the copolymer is synthesized, and the polymer does not involve the polymerization process of low carbon olefins and functional monomers.

[0008] CN 111253516A discloses a method for preparing a novel polyether scale inhibitor integrating carboxylic acid groups, ester groups, and ether groups, and its application. The polymer uses maleic anhydride, fatty alcohol polyoxyethylene ether, and sodium hydroxide as raw materials, and potassium persulfate as an initiator, undergoing a copolymerization reaction in an aqueous solution. The resulting polymer is green and environmentally friendly. This method also avoids further esterification after copolymerization, and the polymer does not involve the polymerization process of low-carbon olefins and functional monomers.

[0009] In summary, for the synthesis of olefin functional polymers and their application in preparing scale inhibitors, especially the polymerization of low-carbon olefins below C4 with functional monomers, it is necessary to select appropriate synthesis processes based on the characteristics of the raw materials to improve production efficiency, and to further react the functional groups of olefin functional polymers to prepare scale inhibitors and improve scale inhibition performance. Summary of the Invention

[0010] To address the problems existing in the prior art, the present invention aims to provide a method for preparing scale inhibitors based on olefin functional polymers. This method achieves alternating copolymerization of low-carbon gaseous olefins and functional monomers through a pressurized reaction. By employing heterogeneous polymerization, the monomer concentration and production efficiency are increased, resulting in the synthesis of solid olefin functional polymers. These polymers are then used to prepare different types of polymer scale inhibitors through esterification and anionization / cationization reactions, exhibiting excellent water treatment performance. The method features mild reaction conditions, simple operation, easy separation and purification, energy savings, and cost reduction.

[0011] To achieve this objective, the present invention adopts the following technical solution:

[0012] This invention provides a method for preparing scale inhibitors based on olefin functional polymers, the method comprising the following steps:

[0013] (1) After the low carbon olefin is introduced into the reactor, the temperature and pressure are increased. After reaching the reaction temperature and reaction pressure, the raw material liquid prepared by the functional monomer, initiator and solvent is added into the reactor to carry out the polymerization reaction.

[0014] (2) The material after the polymerization reaction in step (1) is first subjected to gas-solid-liquid separation to recover low-carbon olefins. The remaining material is then subjected to solid-liquid separation to obtain solid-phase olefin functional polymer and liquid-phase material.

[0015] (3) The olefin functional polymer obtained in step (2) is subjected to an esterification reaction with alcohols to obtain an esterified olefin functional polymer;

[0016] (4) React the olefin functional polymer obtained in step (2) or the esterified olefin functional polymer obtained in step (3) with a quaternary ammonium salt, a base or an acid to obtain a cationic polymer scale inhibitor or an anionic polymer scale inhibitor.

[0017] In this invention, the selection of olefins and functional monomers has a significant impact on the performance of olefin functional polymers. This invention selects low-carbon gaseous olefins to react with liquid functional monomers. The difference in their phase states makes the reaction relatively difficult when both the olefin and functional monomers are liquid. Moreover, low-carbon gaseous olefins usually do not contain side chains, making the reaction more difficult compared to liquid olefins. This invention improves the monomer concentration and reaction rate by using pressurized reaction and heterogeneous polymerization, thereby increasing the raw material conversion rate and product yield. This enables the alternating copolymerization of gaseous olefin monomers and functional monomers with the same chain to obtain olefin functional polymers.

[0018] Different types of cationic or anionic polymer scale inhibitors are prepared by esterification and cationic / anionic reactions of olefin functional polymers. These inhibitors have good thermal stability, high scale inhibition rate, and excellent water treatment performance. The method is simple to operate, has mild reaction conditions, is easy to separate and purify, the raw materials can be recycled, save energy, have low cost, and are environmentally friendly.

[0019] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The technical objectives and beneficial effects of the present invention can be better achieved and realized through the following technical solutions.

[0020] As a preferred technical solution of the present invention, the low carbon olefin in step (1) includes any one or a combination of at least two of ethylene, propylene, butene or butadiene. Typical but non-limiting examples of such combinations include: a combination of ethylene and propylene, a combination of propylene and butene, a combination of ethylene, propylene and butene, etc.

[0021] Preferably, before introducing the low-carbon olefin in step (1), the reactor is first evacuated and then replaced with a protective gas, which can be nitrogen or an inert gas.

[0022] Preferably, the reactor in step (1) includes any one of a batch reactor, tubular reactor, microchannel reactor, tower reactor, fluidized bed reactor or boiling bed reactor.

[0023] As a preferred technical solution of the present invention, the functional monomer in step (1) includes any one or at least two of maleic anhydride, maleimide or maleic acid. Typical but non-limiting examples of such combinations include: a combination of maleic anhydride and maleimide, a combination of maleimide and maleic acid, a combination of maleic anhydride, maleimide and maleic acid, etc.

[0024] Preferably, the initiator in step (1) includes azo compounds and / or peroxide compounds.

[0025] Preferably, the azo compound includes any one or a combination of at least two of azobisisobutyronitrile, azobisisovalerate, azobisisoheptanenitrile, azobiscyclohexylformitrile, or dimethyl azobisisobutyrate. Typical but non-limiting examples of such combinations include: a combination of azobisisobutyronitrile and azobisisovalerate, a combination of azobisisobutyronitrile and azobisisoheptanenitrile, a combination of azobisisobutyronitrile, azobiscyclohexylformitrile, and dimethyl azobisisobutyrate, and a combination of azobisisovalerate, azobisisoheptanenitrile, and dimethyl azobisisobutyrate, etc.

[0026] Preferably, the peroxide compounds include benzoyl peroxide, dicumyl peroxide, diisobutyryl peroxide, di(2,4-dichlorobenzoyl peroxide), dodecyl peroxide, tert-butyl peroxyheptanate, tert-butyl peroxyneodecanate, disec-butyl peroxydicarbonate, di(hexadecyl)dicarbonate, tert-pentyl peroxyneodecanate, tert-butyl peroxyneodecanate, di-(4-tert-butylcyclohexyl peroxydicarbonate), dicyclohexyl peroxydicarbonate, diisopropyl peroxydicarbonate, dibutyl peroxydicarbonate, di(2-ethylhexyl peroxydicarbonate), tert-butyl peroxydiethylhexanoate, ditetradecyl peroxydicarbonate, tert-butyl peroxyacetate, isopropylbenzene peroxyneodecanate, ditert-butyl peroxide, cyclohexylsulfonyl acetate, and 1, 1, 3, decanoic acid peroxide. The combination of any one or at least two of 3-tetramethylbutyl ester, di-3-methoxybutyl peroxydicarbonate, or 1,1,3,3-tetramethylbutyl peroxydicarbonate, with typical but non-limiting examples including: a combination of benzoyl peroxide and dodecyl peroxide, a combination of benzoyl peroxide and dicumyl peroxide, a combination of dodecyl peroxide, dicumyl peroxide, and diisopropyl peroxydicarbonate, etc.

[0027] Preferably, the solvent in step (1) includes any one or a combination of at least two of organic alkanoates, alkanes, or aromatics. Typical but non-limiting examples of such combinations include: combinations of organic alkanoates and alkanes, combinations of alkanes and aromatics, and combinations of organic alkanoates, alkanes, and aromatics.

[0028] Preferably, the general structural formula of the organic alkanoate compound is as follows: R1 is any one of H, C1-C20 alkane group or C6-C10 aromatic group, and R2 is any one of C1-C20 alkane group or C6-C10 aromatic group.

[0029] Preferably, the organic alkyl ester compound includes any one or a combination of at least two of the following: ethyl formate, propyl formate, isobutyl formate, amyl formate, ethyl acetate, butyl acetate, isobutyl acetate, amyl acetate, isoamyl acetate, benzyl acetate, phenyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, isobutyl butyrate, isoamyl butyrate, ethyl isobutyrate, ethyl isovalerate, isoamyl isovalerate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, isoamyl benzoate, methyl phenylacetate, ethyl phenylacetate, propyl phenylacetate, butyl phenylacetate, or isoamyl phenylacetate. Typical but non-limiting examples of such combinations include combinations of ethyl acetate and butyl acetate, combinations of butyl acetate and isobutyl acetate, and combinations of butyl acetate and isoamyl acetate.

[0030] Preferably, the alkane compound includes any one or a combination of at least two of n-hexane, cyclohexane, n-heptane, n-pentane, n-octane, or n-decane. Typical but non-limiting examples of such combinations include: combinations of n-hexane and cyclohexane, n-hexane and n-pentane, combinations of cyclohexane and n-heptane, combinations of n-hexane, cyclohexane, and n-octane, etc.

[0031] Preferably, the aromatic compound includes any one or a combination of at least two of benzene, toluene, ethylbenzene, or xylene. Typical but non-limiting examples of such combinations include: combinations of benzene and ethylbenzene, benzene and toluene, ethylbenzene and toluene, ethylbenzene and xylene, and combinations of benzene, ethylbenzene, and xylene.

[0032] As a preferred technical solution of the present invention, the molar ratio of the initiator to the functional monomer in step (1) is (0.001~0.2):1, for example 0.001:1, 0.005:1, 0.01:1, 0.05:1, 0.1:1, 0.15:1 or 0.2:1, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0033] Preferably, the mass ratio of the solvent to the functional monomer in step (1) is (2~50):1, for example 2:1, 5:1, 10:1, 20:1, 25:1, 30:1, 35:1, 40:1 or 50:1, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0034] Preferably, the raw material liquid in step (1) is removed from impurities and preheated before being added to the reactor.

[0035] Preferably, the raw material liquid in step (1) is pressurized and pumped into the reactor by a transfer pump.

[0036] In this invention, since low-carbon olefins are first introduced into the reactor and pressurized, the raw material liquid also needs to be pressurized in advance before it can be introduced.

[0037] As a preferred technical solution of the present invention, the temperature of the polymerization reaction in step (1) is 50~150℃, such as 50℃, 60℃, 80℃, 100℃, 120℃, 140℃ or 150℃, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0038] Preferably, the pressure of the polymerization reaction in step (1) is 0.1~10MPa, such as 0.1MPa, 0.5MPa, 1MPa, 3MPa, 5MPa, 6MPa, 8MPa or 10MPa, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0039] Preferably, the residence time of the raw material liquid in step (1) is 10s to 10h, such as 10s, 0.01h, 0.1h, 0.5h, 1h, 3h, 5h, 6h, 8h or 10h, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0040] Preferably, during the polymerization reaction in step (1), low-carbon olefins are continuously introduced to maintain the pressure.

[0041] As a preferred technical solution of the present invention, the low-carbon olefins discharged during the gas-solid-liquid separation process in step (2) are recycled.

[0042] Preferably, the remaining material after recovering low-carbon olefins in step (2) is discharged in a solid-liquid manner.

[0043] Preferably, the discharged low-carbon olefins are returned to step (1) for reuse after being pressurized.

[0044] As a preferred technical solution of the present invention, the solid-liquid separation method in step (2) includes any one or a combination of at least two of decantation, filtration or centrifugation. Typical but non-limiting examples of such combinations include: a combination of decantation and filtration, a combination of filtration and centrifugation, a combination of decantation, filtration and centrifugation, etc., preferably pressure filtration.

[0045] Preferably, the remaining material is filtered by pressure using a protective gas, and the resulting filter cake is washed, dried, and then crushed.

[0046] Preferably, the washing is performed using the solvent in step (1), or an ether compound may be used, such as a C1-C10 saturated ether compound, preferably diethyl ether and / or propyl ether.

[0047] Preferably, the olefin functional polymer in step (2) is a microsphere with a particle size of 10~50μm, such as 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm or 50μm, but not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0048] Preferably, the liquid phase material in step (2) is separated, and the separation method includes any one or a combination of at least two of distillation, membrane separation, washing or extraction. Typical but non-limiting examples of such combinations include: a combination of distillation and membrane separation, a combination of distillation and extraction, a combination of distillation, membrane separation and washing, etc., preferably distillation, and more preferably rectification.

[0049] Preferably, the recovered solvent obtained after separation is returned to step (1) and / or step (2) for reuse in preparing the feed solution and / or washing the filter cake.

[0050] As a preferred technical solution of the present invention, the alcohols in step (3) include any one or at least two combinations of methanol, ethanol, butanol, ethylene glycol or propylene glycol. Typical but non-limiting examples of such combinations include: combinations of methanol and ethanol, combinations of ethanol and ethylene glycol, combinations of methanol, ethanol and butanol, combinations of ethanol, ethylene glycol and propylene glycol, etc.

[0051] Preferably, the molar ratio of acid anhydride to alcohol in the olefin functional polymer in step (3) is 1:(1~10), such as 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:8 or 1:10, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0052] Preferably, the temperature of the esterification reaction in step (3) is 50~80℃, such as 50℃, 55℃, 60℃, 65℃, 70℃, 75℃ or 80℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0053] Preferably, the pressure of the esterification reaction in step (3) is 0~0.5MPa, such as 0MPa, 0.1MPa, 0.2MPa, 0.3MPa, 0.4MPa or 0.5MPa, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0054] Preferably, the esterification reaction time in step (3) is 0.5 to 24 hours, such as 0.5 hours, 1 hour, 3 hours, 5 hours, 7 hours, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours or 24 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0055] Preferably, after the esterification reaction, the product is subjected to condensation, phase separation, filtration, and drying to obtain the esterified olefin functional polymer.

[0056] Preferably, the esterified olefin functional polymer includes a monoesterified olefin functional polymer.

[0057] As a preferred technical solution of the present invention, the quaternary ammonium salt in step (4) includes any one or a combination of at least two of glycidyltrimethylammonium chloride, octadecyldimethylammonium chloride, octadecylamine polyoxyethylene ether bisquaternary ammonium salt or bisdodecylamine polyoxyethylene ether monoquaternary ammonium salt. Typical but non-limiting examples of such combinations include: a combination of glycidyltrimethylammonium chloride and octadecyldimethylammonium chloride, a combination of octadecyldimethylammonium chloride and octadecylamine polyoxyethylene ether bisquaternary ammonium salt, a combination of glycidyltrimethylammonium chloride, octadecyldimethylammonium chloride and bisdodecylamine polyoxyethylene ether monoquaternary ammonium salt, etc.

[0058] Preferably, the alkali in step (4) includes a caustic alkali, which is added in the form of an alkaline solution.

[0059] Preferably, the acid in step (4) includes any one or a combination of at least two of sulfuric acid, persulfate, or phosphorus pentoxide. Typical but non-limiting examples of such combinations include: a combination of sulfuric acid and persulfate, a combination of persulfate and phosphorus pentoxide, a combination of sulfuric acid, persulfate, and phosphorus pentoxide, etc.

[0060] Preferably, when using the quaternary ammonium salt in step (4), an alkaline solution is added simultaneously.

[0061] Preferably, the molar ratio of the anhydride in the olefin functional polymer or the carboxyl group in the esterified olefin functional polymer to the quaternary ammonium salt in step (4) is 1:(1~10), such as 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:5, 1:8 or 1:10, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0062] Preferably, the molar ratio of acid anhydride to base in the olefin functional polymer of step (4) is 1:(1~10), such as 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:5, 1:8 or 1:10, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0063] Preferably, the esterified olefin functional polymer reacting with acid in step (4) is obtained by reacting an olefin functional polymer with a diol.

[0064] Preferably, the molar ratio of hydroxyl groups to acids in the esterified olefin functional polymer of step (4) is 1:(1~10), such as 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:5, 1:8 or 1:10, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0065] As a preferred technical solution of the present invention, the reaction temperature in step (4) is 30~120℃, such as 30℃, 40℃, 50℃, 60℃, 80℃, 100℃ or 120℃, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable. The time is 0.5~24h, such as 0.5h, 3h, 6h, 8h, 10h, 12h, 15h, 18h, 20h or 24h, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0066] Preferably, the raw materials for the reaction in step (4) also include an organic solvent.

[0067] Preferably, the organic solvent includes any one or a combination of at least two of dichloromethane, acetone, and acetonitrile. Typical but non-limiting examples of such combinations include: a combination of dichloromethane and acetone, a combination of acetone and acetonitrile, a combination of dichloromethane, acetone, and acetonitrile, etc.

[0068] Preferably, after the reaction in step (4), the residue is crystallized and dried to obtain a cationic polymer scale inhibitor, or after the reaction, the residue is dried and dried to obtain an anionic polymer scale inhibitor.

[0069] In this invention, when the scale inhibitor is used as a water treatment agent, the amount of scale inhibitor added is 10~100mg / L, such as 10mg / L, 20mg / L, 30mg / L, 50mg / L, 60mg / L, 80mg / L or 100mg / L, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0070] As a preferred technical solution of the present invention, the method includes the following steps:

[0071] (1) After introducing low-carbon olefins into the reactor, the temperature and pressure are increased. The low-carbon olefins include any one or a combination of at least two of ethylene, propylene, butene, or butadiene. The reactor includes any one of a batch reactor, tubular reactor, microchannel reactor, tower reactor, fluidized bed reactor, or boiling bed reactor. After reaching the reaction temperature and pressure, a feed liquid prepared from functional monomers, initiators, and solvents is added to the reactor. The functional monomers include any one or a combination of at least two of maleic anhydride, maleimide, or maleic acid. The initiator includes azo compounds and / or peroxides. The polymer is a polymer compound, wherein the solvent includes any one or a combination of at least two of organic alkanoates, alkanes, or aromatics; the molar ratio of the initiator to the functional monomer is (0.001~0.2):1; the mass ratio of the solvent to the functional monomer is (2~50):1; the feed liquid is pressurized by a delivery pump and pumped into the reactor at a uniform speed to undergo a polymerization reaction; the polymerization reaction temperature is 50~150℃, the pressure is 0.1~10MPa, and the residence time is 10s~10h; and low-carbon olefins are continuously introduced to maintain the pressure during the polymerization reaction.

[0072] (2) The material after the polymerization reaction in step (1) is first subjected to gas-solid-liquid separation to recover low-carbon olefins. The discharged low-carbon olefins are returned to step (1) for reuse after being pressurized. The remaining material is discharged in a solid-liquid manner and then subjected to solid-liquid separation. The material is filtered by pressure using a protective gas. The resulting filter cake is dried to obtain solid-phase olefin functional polymer and liquid-phase material. The olefin functional polymer is microsphere particles with a particle size of 10~50μm. The liquid-phase material is separated. The separation method includes any one or at least two of distillation, membrane separation, washing or extraction. The recovered solvent after separation is returned to step (1) and / or step (2) for reuse to prepare raw material liquid and / or wash filter cake.

[0073] (3) The olefin functional polymer obtained in step (2) is subjected to an esterification reaction with an alcohol, wherein the alcohol includes any one or a combination of at least two of methanol, ethanol, butanol, ethylene glycol or propylene glycol, the molar ratio of the acid anhydride in the olefin functional polymer to the alcohol is 1:(1~10), the temperature of the esterification reaction is 50~80℃, the pressure is 0~0.5MPa, and the time is 0.5~24h. After condensation, phase separation, filtration and drying, a monoesterified olefin functional polymer is obtained.

[0074] (4) The olefin functional polymer obtained in step (2) or the esterified olefin functional polymer obtained in step (3) is reacted with a quaternary ammonium salt, a base or an acid. The quaternary ammonium salt includes any one or a combination of at least two of glycidyltrimethylammonium chloride, octadecyldimethylammonium chloride, octadecylamine polyoxyethylene ether bisquaternary ammonium salt or bisdodecylamine polyoxyethylene ether monoquaternary ammonium salt. The base includes caustic alkali, which is added in the form of an alkaline solution. The acid includes any one or a combination of at least two of sulfuric acid, persulfate or phosphorus pentoxide. When the quaternary ammonium salt is used, an alkaline solution is added at the same time. The raw materials for the reaction also include an organic solvent, which includes any one or a combination of at least two of dichloromethane, acetone or acetonitrile. The reaction temperature is 30~120℃ and the time is 0.5~24h. After the reaction, the residue is crystallized and dried to obtain a cationic polymer scale inhibitor, or after the reaction, the residue is dried by vacuum distillation to obtain an anionic polymer scale inhibitor.

[0075] Compared with the prior art, the present invention has the following beneficial effects:

[0076] (1) The method described in this invention achieves alternating copolymerization of the same chain of low-carbon gaseous olefins and functional monomers through pressurized reaction, adopts heterogeneous polymerization, improves monomer concentration and raw material utilization, synthesizes solid olefin functional polymers, and has high production efficiency.

[0077] (2) The method described in this invention prepares different kinds of polymer scale inhibitors through esterification reaction of olefin functional polymers and alcohols, followed by anionization and cationization reactions. These polymer scale inhibitors have good thermal stability, high scale inhibition rate, and excellent water treatment performance.

[0078] (3) The method described in this invention has a simple operation process, mild reaction conditions, easy separation and purification, and the raw materials can be recycled, saving energy consumption, with low cost and high economic benefits. Detailed Implementation

[0079] To better illustrate the present invention and facilitate understanding of its technical solutions, the present invention is further described in detail below. However, the following embodiments are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0080] The specific embodiments of this invention provide a method for preparing scale inhibitors based on olefin functional polymers, the method comprising the following steps:

[0081] (1) After the low carbon olefin is introduced into the reactor, the temperature and pressure are increased. After reaching the reaction temperature and reaction pressure, the raw material liquid prepared by the functional monomer, initiator and solvent is added into the reactor to carry out the polymerization reaction.

[0082] (2) The material after the polymerization reaction in step (1) is first subjected to gas-solid-liquid separation to recover low-carbon olefins. The remaining material is then subjected to solid-liquid separation to obtain solid-phase olefin functional polymer and liquid-phase material.

[0083] (3) The olefin functional polymer obtained in step (2) is subjected to an esterification reaction with alcohols to obtain an esterified olefin functional polymer;

[0084] (4) React the olefin functional polymer obtained in step (2) or the esterified olefin functional polymer obtained in step (3) with a quaternary ammonium salt, a base or an acid to obtain a cationic polymer scale inhibitor or an anionic polymer scale inhibitor.

[0085] The following are typical but non-limiting embodiments of the present invention:

[0086] Example 1:

[0087] This embodiment provides a method for synthesizing olefin functional polymers and a method for preparing scale inhibitors, the method comprising the following steps:

[0088] (1) After the low carbon olefin is introduced into the tubular reactor, the temperature and pressure are increased. The low carbon olefin is ethylene. Before the low carbon olefin is introduced, nitrogen gas is introduced to replace it. After the reaction temperature and reaction pressure are reached, the raw material liquid prepared by the functional monomer, initiator and solvent is pumped into the tubular reactor. The functional monomer is maleic anhydride, the initiator is azobisisobutyronitrile, the solvent is isoamyl acetate, the molar ratio of the initiator to the functional monomer is 0.1:1, and the mass ratio of the solvent to the functional monomer is 30:1. The polymerization reaction occurs. The temperature of the polymerization reaction is 70°C, the pressure is 7MPa, and the residence time is 9h. The low carbon olefin is continuously introduced to maintain the pressure during the polymerization reaction.

[0089] (2) The material after the polymerization reaction in step (1) is first separated by gas-solid-liquid separation to recover low-carbon olefins. The discharged low-carbon olefins are pressurized and returned to step (1) for reuse. The remaining material is discharged in a solid-liquid manner and then filtered by nitrogen. The resulting filter cake is washed and dried. The washing solvent is n-hexane to obtain solid-phase olefin functional polymer and liquid-phase material. The olefin functional polymer is microsphere particles. The liquid-phase material is distilled. The distillate from the top of the column after distillation is the recovered solvent of each component, which is returned to step (1) and step (2) for reuse to prepare raw material liquid and wash filter cake.

[0090] (3) The olefin functional polymer obtained in step (2) is subjected to esterification reaction with methanol. The molar ratio of the acid anhydride in the olefin functional polymer to methanol is 1:5. The esterification reaction is carried out at a temperature of 65°C, a pressure of 0.13 MPa, and a time of 4 h. After condensation and phase separation, the ester-containing fraction is filtered and dried to obtain monoesterified polyethylene maleic anhydride.

[0091] (4) The monoesterified polyethylene maleic anhydride obtained in step (3) is mixed with glycidyltrimethylammonium chloride and dichloromethane solvent and reacted. At the same time, an alkaline solution of sodium hydroxide is added. The molar ratio of the carboxyl group in the monoesterified polyethylene maleic anhydride to glycidyltrimethylammonium chloride is 1:1.5. The reaction temperature is 80℃ and the time is 4h. After the reaction, the solvent is removed by vacuum distillation. The residue is recrystallized with a 1:1 volume ratio of acetone / ethanol mixed solvent and then vacuum dried to obtain an amine salt type cationic polymer scale inhibitor.

[0092] Example 2:

[0093] This embodiment provides a method for synthesizing olefin functional polymers and a method for preparing scale inhibitors, the method comprising the following steps:

[0094] (1) After the low carbon olefin is introduced into the microchannel reactor, the temperature and pressure are increased. The low carbon olefin is ethylene. Before the low carbon olefin is introduced, nitrogen gas is introduced to replace it. After the reaction temperature and reaction pressure are reached, the raw material liquid prepared by the functional monomer, initiator and solvent is pumped into the reactor. The functional monomer is maleic anhydride, the initiator is azobiscyclohexylformonitrile, the solvent is xylene, the molar ratio of the initiator to the functional monomer is 0.15:1, and the mass ratio of the solvent to the functional monomer is 40:1. The polymerization reaction occurs. The polymerization reaction temperature is 50°C, the pressure is 8 MPa, and the residence time is 0.02 h. The low carbon olefin is continuously introduced to maintain the pressure during the polymerization reaction.

[0095] (2) The material after the polymerization reaction in step (1) is first separated by gas-solid-liquid separation to recover low-carbon olefins. The discharged low-carbon olefins are pressurized and returned to step (1) for reuse. The remaining material is discharged in a solid-liquid manner and then filtered by nitrogen. The resulting filter cake is washed and dried. The washing solvent is xylene to obtain solid-phase olefin functional polymer and liquid-phase material. The olefin functional polymer is microsphere particles. The liquid-phase material is distilled. The distillate from the top of the column is used to recover the solvent and is returned to steps (1) and (2) for reuse in preparing raw material liquid and washing filter cake.

[0096] (3) The olefin functional polymer obtained in step (2) is subjected to esterification reaction with ethanol. The molar ratio of acid anhydride in the olefin functional polymer to ethanol is 1:3. The esterification reaction is carried out at a temperature of 70°C, a pressure of 0 MPa, and a time of 3.5 h. After condensation and phase separation, the ester-containing fraction is filtered and dried to obtain monoesterified polyethylene maleic anhydride.

[0097] (4) The monoesterified polyethylene maleic anhydride obtained in step (3) is mixed with glycidyltrimethylammonium chloride and water to react, and sodium hydroxide alkaline solution is added at the same time. The molar ratio of the carboxyl group in the monoesterified polyethylene maleic anhydride to glycidyltrimethylammonium chloride is 1:2.5. The reaction temperature is 70℃ and the time is 6h. After the reaction, the solvent is removed by vacuum distillation. The residue is recrystallized with a 1:1 volume ratio of acetone / ethanol mixed solvent and then vacuum dried to obtain an amine salt type cationic polymer scale inhibitor.

[0098] Example 3:

[0099] This embodiment provides a method for synthesizing olefin functional polymers and a method for preparing scale inhibitors, the method comprising the following steps:

[0100] (1) After the low carbon olefin is introduced into the reactor, the temperature and pressure are increased. The low carbon olefin is propylene. Before the low carbon olefin is introduced, nitrogen gas is introduced to replace it. After the reaction temperature and reaction pressure are reached, the raw material liquid prepared by the functional monomer, initiator and solvent is pumped into the reactor. The functional monomer is maleic anhydride, the initiator is benzoyl peroxide, the solvent is isoamyl acetate and toluene in a volume ratio of 1:1, the molar ratio of the initiator to the functional monomer is 0.01:1, and the mass ratio of the solvent to the functional monomer is 10:1. The polymerization reaction occurs. The temperature of the polymerization reaction is 100°C, the pressure is 2 MPa, and the residence time is 3 h. The low carbon olefin is continuously introduced to maintain the pressure during the polymerization reaction.

[0101] (2) The material after the polymerization reaction in step (1) is first separated by gas-solid-liquid separation to recover low-carbon olefins. The discharged low-carbon olefins are pressurized and returned to step (1) for reuse. The remaining material is discharged in a solid-liquid manner and then filtered by nitrogen. The filter cake is washed and dried to obtain solid-phase olefin functional polymer and liquid-phase material. The olefin functional polymer is microsphere particles. The liquid-phase material is distilled. The distillate from the top of the column is used to recover the solvent and is returned to step (1) for reuse in preparing the raw material liquid.

[0102] (3) The olefin functional polymer obtained in step (2) is subjected to esterification reaction with butanol. The molar ratio of acid anhydride in the olefin functional polymer to butanol is 1:6. The esterification reaction is carried out at a temperature of 80°C, a pressure of 0.2 MPa, and a time of 3 h. After condensation and phase separation, the ester-containing fraction is filtered and dried to obtain monoesterified polypropylene maleic anhydride.

[0103] (4) The monoesterified polypropylene maleic anhydride obtained in step (3) is mixed with octadecylamine polyoxyethylene ether bisquaternary ammonium salt and solvent dichloromethane and reacted. At the same time, sodium hydroxide alkaline solution is added. The molar ratio of the carboxyl group in the monoesterified polypropylene maleic anhydride to the octadecylamine polyoxyethylene ether bisquaternary ammonium salt is 1:1. The reaction temperature is 35℃ and the time is 12h. After the reaction, the solvent is removed by vacuum distillation. The residue is recrystallized with a 2:1 volume ratio of acetone / ethanol mixed solvent and then vacuum dried to obtain an amine salt type cationic polymer scale inhibitor.

[0104] Example 4:

[0105] This embodiment provides a method for synthesizing olefin functional polymers and a method for preparing scale inhibitors, the method comprising the following steps:

[0106] (1) After the low carbon olefin is introduced into the reactor, the temperature and pressure are increased. The low carbon olefin is propylene. Before the low carbon olefin is introduced, nitrogen gas is introduced to replace it. After the reaction temperature and reaction pressure are reached, the raw material liquid prepared by the functional monomer, initiator and solvent is pumped into the reactor. The functional monomer is maleic anhydride, the initiator is benzoyl peroxide, the solvent is isoamyl acetate and n-heptane in a volume ratio of 1:1, the molar ratio of the initiator to the functional monomer is 0.02:1, and the mass ratio of the solvent to the functional monomer is 15:1. The polymerization reaction occurs. The polymerization reaction temperature is 90°C, the pressure is 5 MPa, and the residence time is 6 h. The low carbon olefin is continuously introduced to maintain the pressure during the polymerization reaction.

[0107] (2) The material after the polymerization reaction in step (1) is first separated by gas-solid-liquid separation to recover low-carbon olefins. The discharged low-carbon olefins are pressurized and returned to step (1) for reuse. The remaining material is discharged in a solid-liquid manner and then filtered by nitrogen. The resulting filter cake is washed and dried. The washing solvent is diethyl ether to obtain solid-phase olefin functional polymer and liquid-phase material. The olefin functional polymer is microsphere particles. The liquid-phase material is distilled. The distillate from the top of the column after distillation is the recovered solvent of each component, which is returned to step (1) and step (2) for reuse to prepare raw material liquid and wash filter cake.

[0108] (3) The olefin functional polymer obtained in step (2) is subjected to esterification reaction with propylene glycol. The molar ratio of acid anhydride in the olefin functional polymer to propylene glycol is 1:3.5. The esterification reaction is carried out at a temperature of 70°C, a pressure of 0.3 MPa, and a time of 4 h. After condensation and phase separation, the ester-containing fraction is filtered and dried to obtain monoesterified polypropylene maleic anhydride.

[0109] (4) Dissolve the monoesterified polypropylene maleic anhydride obtained in step (3) in dichloromethane, and then gradually add phosphorus pentoxide to react. The molar ratio of the hydroxyl group in the monoesterified polypropylene maleic anhydride to phosphorus pentoxide is 1:2. The reaction temperature is 65°C and the time is 3h. After the reaction, remove the dichloromethane by rotary evaporation and dry the residue to obtain a phosphate-type anionic polymer scale inhibitor.

[0110] Example 5:

[0111] This embodiment provides a method for synthesizing olefin functional polymers and a method for preparing scale inhibitors, the method comprising the following steps:

[0112] (1) After the low carbon olefin is introduced into the fluidized bed reactor, the temperature and pressure are increased. The low carbon olefin is propylene. Before the low carbon olefin is introduced, nitrogen is introduced to replace it. After the reaction temperature and reaction pressure are reached, the raw material liquid prepared by the functional monomer, initiator and solvent is pumped into the fluidized bed reactor. The functional monomer is maleic anhydride. The initiator is dimethyl azobisisobutyrate and benzoyl peroxide in a molar ratio of 1:1. The solvent is ethylbenzene. The molar ratio of the initiator to the functional monomer is 0.002:1. The mass ratio of the solvent to the functional monomer is 5:1. The polymerization reaction occurs. The temperature of the polymerization reaction is 150°C, the pressure is 0.2 MPa, and the residence time is 2 h. The low carbon olefin is continuously introduced to maintain the pressure during the polymerization reaction.

[0113] The operation of steps (2) to (4) is the same as in Example 1.

[0114] Based on the content detection of raw material monomers and olefin functional polymers before and after the reaction in the above embodiments, the conversion rate of functional monomers, the yield of olefin functional polymers and the acid anhydride value were calculated; the scale inhibitors prepared in the above embodiments were subjected to flocculation performance testing, and the results are shown in Table 1.

[0115] The flocculation performance determination requires the preparation of a standard turbidity solution, the preparation steps of which include: transferring 25.0 mL of 10 g / L hydrazine sulfate solution and 25.0 mL of 100 g / L hexamethylenetetramine solution into a 500 mL volumetric flask and shaking well; allowing it to stand at (25±3)℃ for 24 h, then diluting it to the mark with distilled water and shaking well; measuring 75.0 mL of the above stock solution into a 1000 mL volumetric flask, diluting it to the mark, and shaking well; the turbidity of this suspension is 30 mg / L;

[0116] Preparation of scale inhibitor sample: Take 1.25g of scale inhibitor sample, add it to a 250mL volumetric flask, add deionized water to make up to volume, and obtain the scale inhibitor sample.

[0117] Flocculation test: Add 1000 mL of standard turbidity solution to a beaker and place it below the agitator paddle, so that the paddle is off-center from the beaker and about 6 mm away from the beaker wall; start the agitator and stir rapidly at 120 r / min for 10 min, then add 2 mL of scale inhibitor sample and continue stirring rapidly for 1 min; reduce the speed to 50 r / min and stir slowly for 20 min, then stop stirring and let it stand for 20 min. Take the supernatant for turbidity analysis; the method for determining water turbidity (mg / L) refers to standard GB / T12151-1989.

[0118] Table 1. Results of polymerization reaction and flocculation tests in Examples 1-7

[0119]

[0120] As shown in Table 1, in the above embodiments, using low-carbon olefins and functional monomers as raw materials, the olefin functional polymers were synthesized by the method described above. The conversion rate of the functional monomers could reach over 97.6%, and the polymer yield could also reach over 94.5%. The anhydride value of the polymer was over 68.2%. Different types of polymer scale inhibitors were prepared by esterification and anionization reactions with alcohols. The turbidity values ​​measured in Examples 1-5 were all below 5 mg / L, which was significantly lower than the turbidity value of 19 mg / L after using the traditional polymaleic acid scale inhibitor under the same measurement conditions. The lower the turbidity value, the better the flocculation performance.

[0121] Among them, amine salt cationic polymer scale inhibitors have strong stability, are stable in both acidic and alkaline solutions, and have excellent surface activity and bactericidal effects; carboxylate anionic polymer scale inhibitors are inexpensive and have moderate performance; sulfate ester anionic polymer scale inhibitors are inexpensive, highly water-soluble, and have excellent performance; phosphate anionic polymer scale inhibitors have excellent water treatment performance, high water solubility, and high molecular weight.

[0122] As can be seen from the above embodiments, this invention achieves alternating copolymerization of low-carbon gaseous olefins and functional monomers through a pressurized reaction, employing a heterogeneous polymerization method to improve monomer concentration and raw material utilization, synthesizing solid olefin functional polymers with high reaction efficiency. Furthermore, through esterification and anion / cationization reactions, different types of polymer scale inhibitors are prepared, exhibiting good thermal stability, high scale inhibition rate, and excellent water treatment performance. This invention features a simple operation process, mild reaction conditions, easy separation and purification, recyclable raw materials, energy savings, low cost, and high economic benefits.

[0123] The present invention has been illustrated with the above embodiments to explain the detailed method of the present invention. However, the present invention is not limited to the detailed method described above, that is, it does not mean that the present invention must rely on the detailed method described above to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the method of the present invention, additions of auxiliary steps, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing scale inhibitors based on olefin functional polymers, characterized in that, The method includes the following steps: (1) After the low carbon olefin is introduced into the reactor, the temperature and pressure are increased. After reaching the reaction temperature and reaction pressure, the raw material liquid prepared by the functional monomer, initiator and solvent is added into the reactor to carry out the polymerization reaction. The functional monomer includes maleic anhydride. (2) The material after the polymerization reaction in step (1) is first subjected to gas-solid-liquid separation to recover low-carbon olefins. The remaining material is then subjected to solid-liquid separation to obtain solid-phase olefin functional polymer and liquid-phase material. (3) The olefin functional polymer obtained in step (2) is subjected to an esterification reaction with alcohols to obtain an esterified olefin functional polymer; (4) React the olefin functional polymer obtained in step (2) or the esterified olefin functional polymer obtained in step (3) with a quaternary ammonium salt, a base or an acid to obtain a cationic polymer scale inhibitor or an anionic polymer scale inhibitor.

2. The method according to claim 1, characterized in that, The low-carbon olefins in step (1) include any one or a combination of at least two of ethylene, propylene, butene or butadiene.

3. The method according to claim 1, characterized in that, Before introducing the low-carbon olefins in step (1), the reactor is first evacuated and then replaced with a protective gas.

4. The method according to claim 1, characterized in that, The reactor in step (1) includes any one of the following: a batch reactor, a tubular reactor, a microchannel reactor, a tower reactor, a fluidized bed reactor, or a boiling bed reactor.

5. The method according to claim 1, characterized in that, The initiator in step (1) includes azo compounds and / or peroxide compounds.

6. The method according to claim 5, characterized in that, The azo compounds include any one or a combination of at least two of azobisisobutyronitrile, azobisisovalerate, azobisisoheptanenitrile, azobiscyclohexylformitrile, or dimethyl azobisisobutyrate.

7. The method according to claim 5, characterized in that, The peroxide compounds include any one or a combination of at least two of benzoyl peroxide, dodecyl peroxide, dicumyl peroxide, or diisopropyl peroxide dicarbonate.

8. The method according to claim 1, characterized in that, The solvent in step (1) includes any one or a combination of at least two of the following: organic alkanoates, alkanes, or aromatics.

9. The method according to claim 8, characterized in that, The general structural formula of the organic alkanoate compound is as follows: R1 is any one of H, C1-C20 alkane group or C6-C10 aromatic group, and R2 is any one of C1-C20 alkane group or C6-C10 aromatic group.

10. The method according to claim 8, characterized in that, The alkane compounds include any one or a combination of at least two of the following: n-hexane, cyclohexane, n-pentane, n-heptane, n-octane, or n-decane.

11. The method according to claim 8, characterized in that, The aromatic compounds include any one or a combination of at least two of benzene, toluene, ethylbenzene, or xylene.

12. The method according to claim 1, characterized in that, The molar ratio of the initiator to the functional monomer in step (1) is (0.001~0.2):

1.

13. The method according to claim 1, characterized in that, The mass ratio of the solvent to the functional monomer in step (1) is (2~50):

1.

14. The method according to claim 1, characterized in that, Before adding the raw material liquid in step (1) to the reactor, it is first removed for impurities and preheated.

15. The method according to claim 1, characterized in that, In step (1), the raw material liquid is pressurized by a transfer pump and then pumped into the reactor at a constant speed.

16. The method according to claim 1, characterized in that, The polymerization reaction in step (1) is carried out at a temperature of 50~150℃.

17. The method according to claim 1, characterized in that, The pressure of the polymerization reaction in step (1) is 0.1~10 MPa.

18. The method according to claim 1, characterized in that, The residence time of the raw material liquid in step (1) is 10s~10h.

19. The method according to claim 1, characterized in that, In step (1), during the polymerization reaction, low-carbon olefins are continuously introduced to maintain the pressure.

20. The method according to claim 1, characterized in that, In step (2), the low-carbon olefins discharged during the gas-solid-liquid separation process are recovered.

21. The method according to claim 1, characterized in that, Step (2) The remaining material after recovering low-carbon olefins is discharged in a solid-liquid manner.

22. The method according to claim 20, characterized in that, The recovered low-carbon olefins are returned to step (1) for reuse after being pressurized.

23. The method according to claim 1, characterized in that, The solid-liquid separation method in step (2) includes any one or a combination of at least two of decantation, filtration, or centrifugation.

24. The method according to claim 23, characterized in that, The solid-liquid separation method is pressure filtration.

25. The method according to claim 1, characterized in that, The remaining material is filtered by pressure using a protective gas, and the resulting filter cake is washed, dried, and then crushed.

26. The method according to claim 1, characterized in that, The olefin functional polymer in step (2) is a microsphere with a particle size of 10~50μm.

27. The method according to claim 1, characterized in that, In step (2), the liquid phase material is separated by a method including any one or a combination of at least two of distillation, membrane separation, washing or extraction.

28. The method according to claim 27, characterized in that, The separation method is distillation.

29. The method according to claim 27, characterized in that, The recovered solvent obtained after separation is returned to step (1) and / or step (2) for reuse in preparing the feed solution and / or washing the filter cake.

30. The method according to claim 1, characterized in that, The alcohols mentioned in step (3) include any one or a combination of at least two of methanol, ethanol, butanol, ethylene glycol or propylene glycol.

31. The method according to claim 1, characterized in that, In step (3), the molar ratio of acid anhydride to alcohol in the olefin functional polymer is 1:(1~10).

32. The method according to claim 1, characterized in that, The temperature of the esterification reaction in step (3) is 50~80℃.

33. The method according to claim 1, characterized in that, The pressure of the esterification reaction in step (3) is 0~0.5MPa.

34. The method according to claim 1, characterized in that, The esterification reaction in step (3) takes 0.5 to 24 hours.

35. The method according to claim 1, characterized in that, After the esterification reaction, the product is condensed, phase separated, filtered, and dried to obtain the esterified olefin functional polymer.

36. The method according to claim 1, characterized in that, The esterified olefin functional polymers include monoesterified olefin functional polymers.

37. The method according to claim 1, characterized in that, The quaternary ammonium salt in step (4) includes any one or a combination of at least two of the following: glycidyltrimethylammonium chloride, octadecyldimethylammonium chloride, octadecylamine polyoxyethylene ether bisquaternary ammonium salt or bisdodecylamine polyoxyethylene ether monoquaternary ammonium salt.

38. The method according to claim 1, characterized in that, The alkali in step (4) includes caustic alkali, which is added in the form of an alkaline solution.

39. The method according to claim 1, characterized in that, The acid in step (4) includes any one or a combination of at least two of sulfuric acid, persulfate, or phosphorus pentoxide.

40. The method according to claim 1, characterized in that, When using the quaternary ammonium salt described in step (4), an alkaline solution is added simultaneously.

41. The method according to claim 1, characterized in that, In step (4), the molar ratio of the anhydride in the olefin functional polymer or the carboxyl group in the esterified olefin functional polymer to the quaternary ammonium salt is 1:(1~10).

42. The method according to claim 1, characterized in that, In step (4), the molar ratio of acid anhydride to base in the olefin functional polymer is 1:(1~10).

43. The method according to claim 1, characterized in that, The esterified olefin functional polymer that reacts with acid in step (4) is obtained by reacting an olefin functional polymer with a diol.

44. The method according to claim 1, characterized in that, In step (4), the molar ratio of hydroxyl groups to acids in the esterified olefin functional polymer is 1:(1~10).

45. The method according to claim 1, characterized in that, The reaction in step (4) is carried out at a temperature of 30~120℃ for 0.5~24h.

46. ​​The method according to claim 1, characterized in that, The raw materials for the reaction in step (4) also include organic solvents.

47. The method according to claim 46, characterized in that, The organic solvent includes any one or a combination of at least two of dichloromethane, acetone, or acetonitrile.

48. The method according to claim 1, characterized in that, After the reaction in step (4), the residue is crystallized and dried to obtain a cationic polymer scale inhibitor, or after the reaction, the residue is dried and dried to obtain an anionic polymer scale inhibitor.

49. The method according to claim 1, characterized in that, The method includes the following steps: (1) After introducing low-carbon olefins into the reactor, the temperature and pressure are increased. The low-carbon olefins include any one or a combination of at least two of ethylene, propylene, butene, or butadiene. The reactor includes any one of a batch reactor, tubular reactor, microchannel reactor, tower reactor, fluidized bed reactor, or boiling bed reactor. After reaching the reaction temperature and pressure, a feed liquid prepared from functional monomers, initiators, and solvents is added to the reactor. The functional monomers include maleic anhydride, the initiators include azo compounds and / or peroxide compounds, and the solvents... The reaction mixture includes any one or a combination of at least two of the following: organic alkanoates, alkanes, or aromatics. The molar ratio of the initiator to the functional monomer is (0.001~0.2):1, and the mass ratio of the solvent to the functional monomer is (2~50):

1. The feed liquid is pressurized by a delivery pump and then pumped into the reactor at a uniform speed to carry out a polymerization reaction. The polymerization reaction temperature is 50~150℃, the pressure is 0.1~10MPa, and the residence time is 10s~10h. Low-carbon olefins are continuously introduced to maintain the pressure during the polymerization reaction. (2) The material after the polymerization reaction in step (1) is first subjected to gas-solid-liquid separation to recover low-carbon olefins. The discharged low-carbon olefins are returned to step (1) for reuse after being pressurized. The remaining material is discharged in a solid-liquid manner and then subjected to solid-liquid separation. The material is filtered by pressure using a protective gas. The resulting filter cake is dried to obtain solid-phase olefin functional polymer and liquid-phase material. The olefin functional polymer is microsphere particles with a particle size of 10~50μm. The liquid-phase material is separated. The separation method includes any one or at least two of distillation, membrane separation, washing or extraction. The recovered solvent after separation is returned to step (1) and / or step (2) for reuse to prepare raw material liquid and / or wash filter cake. (3) The olefin functional polymer obtained in step (2) is subjected to an esterification reaction with an alcohol, wherein the alcohol includes any one or a combination of at least two of methanol, ethanol, butanol, ethylene glycol or propylene glycol, the molar ratio of the acid anhydride in the olefin functional polymer to the alcohol is 1:(1~10), the temperature of the esterification reaction is 50~80℃, the pressure is 0~0.5MPa, and the time is 0.5~24h. After condensation, phase separation, filtration and drying, a monoesterified olefin functional polymer is obtained. (4) The olefin functional polymer obtained in step (2) or the esterified olefin functional polymer obtained in step (3) is reacted with a quaternary ammonium salt, a base or an acid. The quaternary ammonium salt includes any one or a combination of at least two of glycidyltrimethylammonium chloride, octadecyldimethylammonium chloride, octadecylamine polyoxyethylene ether bisquaternary ammonium salt or bisdodecylamine polyoxyethylene ether monoquaternary ammonium salt. The base includes caustic alkali, which is added in the form of an alkaline solution. The acid includes any one or a combination of at least two of sulfuric acid, persulfate or phosphorus pentoxide. When the quaternary ammonium salt is used, an alkaline solution is added at the same time. The raw materials for the reaction also include an organic solvent, which includes any one or a combination of at least two of dichloromethane, acetone or acetonitrile. The reaction temperature is 30~120℃ and the time is 0.5~24h. After the reaction, the residue is crystallized and dried to obtain a cationic polymer scale inhibitor, or after the reaction, the residue is dried by vacuum distillation to obtain an anionic polymer scale inhibitor.

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