Cationic polymer scale inhibitor as well as preparation method and application thereof

Abstract

The invention discloses a cationic polymer scale inhibitor as well as a preparation method and application thereof, and relates to the field of scale inhibitors in geothermal pipelines, the scale inhibitor limits easy-to-scale metal from adhering and scaling on a coating through cationic groups on polymer molecule side chains, meanwhile, the surface contact angle of the coating is increased through functional components with low surface energy, and the scale inhibitor can be used for inhibiting scale formation of the coating. The cationic polymer-based scale inhibitor has the advantages that the cationic polymer-based scale inhibitor is added into the geothermal fluid, so that some granular solid components of the geothermal fluid are difficult to accumulate on the coating to form a crystallized nucleation center, the problems of scaling and accumulation are fundamentally solved, in addition, the cationic polymer-based scale inhibitor has excellent adhesive force with the geothermal pipeline, and guarantee is provided for the corrosion resistance and the long-term effect of the coating.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of scale inhibition and scale prevention in geothermal pipelines, and in particular to a cationic polymer scale inhibitor, a preparation method and applications thereof. BACKGROUND

[0002] Geothermal resources are an important part of renewable energy and have abundant resource potential. However, during the exploitation and utilization of geothermal energy, the problem of scaling has become one of the key difficulties affecting the normal operation of geothermal systems. When geothermal fluid is transported from the heat reservoir to the ground through fluid transport pipelines, or transported in the pipeline and conducted in the heat exchanger, due to changes in temperature and pressure, some components in the fluid reach the saturation state, and solid substances are precipitated and deposited on the inner wall of the pipeline or the surface of the heat exchanger, forming a scale layer. This phenomenon not only increases the resistance of fluid flow and reduces the heat transfer efficiency, but also the incomplete scale layer is prone to induce under-deposit corrosion, further damaging geothermal utilization equipment, pipelines and fittings, and seriously hindering the efficient and economic utilization of geothermal energy.

[0003] The chemical composition of geothermal fluid is extremely complex, containing Ca 2+ , Mg + and Ba 2+ and other easily scaling ions, which exacerbate the severity of the scaling problem. In order to address this problem, polymer scale inhibitors have been widely used in geothermal systems due to their good corrosion resistance, thermal stability, and low dosage. This type of scale inhibitor mainly increases the solubility of scale-forming ions in the solution through the dispersion of polyacrylic acid, polyacrylamide, and polysulfonic acid compounds, thereby preventing the formation and deposition of scale. However, traditional polymer scale inhibitors mostly belong to anionic systems, which inhibit the continued growth of scale-forming microcrystals by physical and chemical adsorption with CaCO3 microcrystal particles, and make the surface of the microcrystal particles have a double-layer structure, reducing the chance of collision to form large crystal precipitates. Although this method is effective to some extent, its scale inhibition effect is easily affected by concentration, and it cannot eradicate scale microcrystals, making it difficult to ensure sustainability.

[0004] In contrast, cationic polymer structures exhibit unique advantages in scale inhibition. They can weaken the adsorption coordination between metal ions and polymer coatings, ensuring that Ca 2+ , Mg + and Ba 2+ ions cannot adhere to the coating, while increasing the number of these easily scaling ions in geothermal fluid, fundamentally inhibiting the formation of scale.

[0005] In the prior art, although there are some patent disclosures about scale inhibitors, they still have limitations in solving the scaling problem of geothermal systems. For example, Chinese Patent CN118955781A discloses a quaternary copolymer scale inhibitor. Although the scale inhibitor has the ability to chelate and disperse substances by using carboxyl, sulfonic acid and hydroxyl groups, it can interfere with the crystallization process of calcium scale, but its effective group is still anionic, which can only partially reduce the formation of scale, and the long-term effectiveness needs to be improved. Chinese Patent CN117965095A discloses a scale-inhibiting coating, which reduces the adhesion of scale by reducing the surface energy to achieve physical scale inhibition, but this method cannot achieve high-efficiency scale inhibition.

[0006] In summary, it is particularly important to design a cationic polymer scale inhibitor with excellent comprehensive performance that can efficiently solve the scaling problem of geothermal systems. Such a scale inhibitor not only needs to have excellent scale inhibition performance, but also needs to have good adhesion and hydrophobicity to ensure long-term stable operation in the complex environment of geothermal systems. SUMMARY

[0007] The purpose of the present application is to provide a cationic polymer scale inhibitor, a preparation method and its application. The scale inhibitor restricts the adhesion of scale-forming metals on the coating through the cationic groups on the side chains of the polymer molecules, and improves the contact angle of the coating surface through the low surface energy functional components, thereby making it difficult for some particulate solid components of the geothermal fluid to accumulate on the coating to form nucleation centers for crystallization, fundamentally solving the scaling and accumulation problems. In addition, the cationic polymer-based scale inhibitor has excellent adhesion to geothermal pipelines, providing protection for the corrosion resistance and long-term effectiveness of the coating.

[0008] To achieve the above-mentioned purposes, the present application provides the following technical solutions:

[0009] The cationic polymer scale inhibitor is obtained by polymerization of the following components in mass fraction: acryloxy iodide ammonium 5-25 parts; acrylate monomer 6-16 parts; fluorine-containing acrylate monomer 5-15 parts; functional monomer containing silane group and methacrylate group 1-5 parts.

[0010] Further, the cationic polymer scale inhibitor is obtained by polymerization of the following components in mass fraction: acryloxy iodide ammonium 18-25 parts; acrylate monomer 12-16 parts; fluorine-containing acrylate monomer 8-15 parts; functional monomer containing silane group and methacrylate group 3-5 parts.

[0011] Further, the cationic polymer scale inhibitor is obtained by polymerization of the following components in mass fraction: acryloxy iodide ammonium 21 parts; acrylate monomer 16 parts; fluorine-containing acrylate monomer 9 parts; functional monomer containing silane group and methacrylate group 3.6 parts.

[0012] Further, the acryloxy iodide ammonium is one or a mixture of several of methyl methacryloxyethyl trimethyl ammonium iodide, acryloxyethyl trimethyl ammonium iodide, methyl methacryloxypropyl trimethyl ammonium iodide, acryloxypropyl trimethyl ammonium iodide.

[0013] Further, the acryloxy iodide ammonium is one or a mixture of several of methyl methacryloxyethyl trimethyl ammonium iodide, acryloxyethyl trimethyl ammonium iodide, methyl methacryloxypropyl trimethyl ammonium iodide, acryloxypropyl trimethyl ammonium iodide.

[0014] Further, the fluorine-containing acrylate monomer is one or a mixture of several of hexafluorobutyl methacrylate, octafluoropentyl methacrylate, tridecafluoro octyl methacrylate, dodecafluoroheptyl methacrylate, 2-perfluorododecyl ethyl methacrylate.

[0015] Further, the functional monomer is one or a mixture of several of methyl methacryloxypropyl trimethoxysilane, methyl methacryloxypropyl triethoxysilane, methyl methacryloxypropyl methyl dimethoxysilane, methyl methacryloxypropyl methyl diethoxysilane.

[0016] The preparation method of the cationic polymer scale inhibitor comprises the following steps:

[0017] According to the composition and mass fraction, 70-80% by weight of the acryloxy iodide ammonium and 70-80% by weight of the acrylate monomer are stirred, deionized water is gradually added to the monomer for stirring, an initiator is added, and stirring is continued to obtain an emulsion, which is stored for standby use;

[0018] The remaining acryloxy iodide ammonium, acrylate monomer, fluorine-containing acrylate monomer, and functional monomer are stirred, an initiator is added, and stirring is performed to obtain a premix, which is stored for standby use;

[0019] According to the volume ratio, 20-30% of the emulsion in the emulsion is heated to 60-80°C, and stirring is performed for reaction, the remaining emulsion is gradually added to the reaction kettle for dropwise addition, after the dropwise addition is completed, reaction is performed, then the premix is gradually added for dropwise addition, after the dropwise addition is completed, reaction is performed, then the temperature is increased to 80-85°C for reaction, after the reaction is completed, the temperature is decreased to below 45°C, and filtration is performed to obtain the cationic polymer scale inhibitor.

[0020] Preferably, the acryloyloxy ammonium iodide and the acrylate monomer are stirred at a speed greater than 800 rpm / min for 10 minutes, deionized water is gradually added to the monomer and stirred, stirring is stopped after 30 minutes, the initiator is added, and after stirring for 15 minutes, the emulsion is stored for later use, wherein the amount of acryloyloxy ammonium iodide, acrylate monomer and initiator added is 80% of the total reaction amount;

[0021] The remaining raw materials, acryloyloxy ammonium iodide, acrylate monomer, fluorinated acrylate monomer, and functional monomer were stirred at a speed of more than 800 rpm / min for 10 minutes, the remaining initiator was added, stirred for 15 minutes, and then stored for later use;

[0022] According to the volume ratio, 25% of the emulsion in the emulsion was heated to 75°C and reacted for 30 minutes under stirring. The remaining 75% of the emulsion was gradually added dropwise to the reactor for 120 minutes. After the addition was completed, the reaction was continued for 120 minutes. The premixed liquid was gradually added dropwise to the reactor for 120 minutes. After the addition was completed, the reaction was continued for 90 minutes. The temperature was raised to 85°C and the reaction was continued for 120 minutes. When there was no obvious odor, the temperature was lowered to below 45°C and the material was filtered to obtain the cationic polymer.

[0023] Furthermore, the initiator is one or a mixture of azobisisobutyronitrile, peroxyazobisisoheptanonitrile, ammonium persulfate, and potassium persulfate, and the amount added is 0.2-2 parts by mass.

[0024] Preferably, the amount of initiator added is 0.5-1.8 parts by mass,

[0025] Preferably, the amount of the initiator added is 0.34 parts by mass.

[0026] The present invention also protects the use of the cationic polymer scale inhibitor in geothermal pipelines.

[0027] The present invention also provides a cationic polymer scale inhibitor, which is cationic, has a solid content of 40-55% by mass, a viscosity of 500-5000 mPa.s at 25°C, a pH of 6-7, a solid glass transition temperature of 50-110°C, and a particle size of 10-100 nm. The polymer scale inhibitor is mainly obtained by chemical polymerization of the following monomer components in the following mass percentages:

[0028] Acryloyloxy ammonium iodide: 5%-25%;

[0029] Acrylate monomer: 6%-16%;

[0030] Fluorinated acrylate monomer: 5%-15%;

[0031] Functional monomer: 1-5%;

[0032] Initiator: 0.2%-2%;

[0033] Deionized water: 45%-60%.

[0034] Among the monomer components of the above cationic polymer scale inhibitor:

[0035] The acryloxy iodide ammonium in the present application is one or a mixture of several of methyl acryloxy ethyl trimethyl iodide, acryloxy ethyl trimethyl iodide, methyl acryloxy propyl trimethyl iodide, acryloxy propyl trimethyl iodide; its dosage is preferably 18%-25%.

[0036] The acrylate monomer in the present application is one or a mixture of several of methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, isooctyl methacrylate, dodecyl methacrylate, hexadecyl methacrylate, octadecyl methacrylate, norbornyl methacrylate, ethyl acrylate, butyl acrylate, isooctyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, N-hydroxymethyl acrylamide, N,N-dimethyl acrylamide, styrene; its dosage is preferably 12%-16%.

[0037] The fluorine-containing acrylate monomer in the present application is one or a mixture of several of hexafluorobutyl methacrylate, octafluoropentyl methacrylate, tridecafluorooctyl methacrylate, dodecafluoroheptyl methacrylate, 2-perfluorododecylethyl methacrylate; its dosage is preferably 8%-15%.

[0038] The functional monomer in the present application is one or a mixture of several of methyl acryloxy propyl trimethoxysilane, methyl acryloxy propyl triethoxysilane, methyl acryloxy propyl methyl dimethoxysilane, methyl acryloxy propyl methyl diethoxysilane; its dosage is preferably 3%-5%.

[0039] The initiator in the present application is one or a mixture of several of azobisisobutyronitrile, perazobisisoheptyl nitrile, ammonium persulfate, potassium persulfate; its dosage is preferably 0.5%-1.8%.

[0040] The second object of the present application is to provide a preparation method of a cationic polymer scale inhibitor, comprising the following steps:

[0041] Pre-emulsion 1: 80% of acryloxy iodide ammonium, acrylate monomer is stirred at a dispersing disc rotation speed of more than 800 rpm / min for 10 min, a proportional amount of deionized water is gradually added to the monomer for stirring, stirring is stopped after 30 min, a proportional amount of initiator is added, and stirring is carried out for 15 min, and then the emulsion is stored for standby.

[0042] Premix solution 2: the remaining 20% of acryloxy ammonium iodide, acrylate monomer, fluorine-containing acrylate monomer, functional monomer were mixed in the proportion, stirred for 10 min at a dispersing disc rotation speed greater than 800 rpm / min, and then the initiator was added in the proportion. After stirring for 15 min, it was stored for standby use.

[0043] The pre-emulsion solution in the proportion of 25% was added to the reaction kettle, and the temperature was raised to 75 DEG C. After stirring for 30 min, the remaining 75% of the pre-emulsion was gradually added dropwise to the reaction kettle, and the dropping time was 120-150 min. After the dropping was completed, the reaction was carried out for 120 min. The premix solution was gradually added dropwise to the reaction kettle, and the dropping time was 90-120 min. After the dropping was completed, the reaction was carried out for 90 min. The temperature was raised to 85 DEG C, and the reaction was carried out for 120 min. After the odor disappeared, the temperature was lowered to below 45 DEG C, and the filtrate was obtained, thereby obtaining the cationic polymer.

[0044] The third object of the present application is to provide an application of the cationic polymer scale inhibitor in the geothermal pipeline.

[0045] Compared with the prior art, the technical advantages of the present application are that:

[0046] The polymer scale inhibitor provided by the present application is cationic, which can limit the flow of anions and inhibit the adsorption of scale-prone cationic metal ions on the coating surface by dynamic coordination with the anions in the geothermal pipeline fluid, so that the deposition of scale-prone cationic metal ions on the coating surface to form scale can be greatly reduced. In addition, the ammonium iodide group in the polymer has excellent antibacterial property, which can prevent the parasitic attachment of microorganisms.

[0047] The polymer scale inhibitor provided by the present application is modified by a fluorine-containing system to have low coating surface energy, which can achieve a large contact angle and prevent the formation and attachment of scale, so that the coating surface can be kept clean for a long time during the transportation of geothermal fluid.

[0048] Through the copolymerization of the functional monomer, the surface of the core-shell structure polymer formed has silane components, which can form cross-linking through dehydration condensation after the coating is applied, so as to further improve the service life of the coating. Meanwhile, the silicon hydroxyl groups generated by the hydrolysis of silane can condense with the hydroxyl groups on the pipeline, so as to improve the long-term attachment of the polymer scale inhibitor on the surface. DETAILED DESCRIPTION

[0049] The present application will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present application and are not used to limit the scope of the present application. In addition, it should be understood that after reading the content of the present application, those skilled in the art can make various modifications or changes to the present application, and these equivalent forms also fall within the scope defined by the appended claims.

[0050] Example 1

[0051] Pre-emulsion 1: 105 g of methacryloyloxyethyl trimethyl ammonium iodide, 60 g of methyl methacrylate, 10 g of isooctyl acrylate, 10 g of hydroxyethyl methacrylate mixed liquid 1 was stirred for 10 min at a dispersing disc rotation speed of more than 800 rpm / min, and then was reserved. 80% of the mixed liquid was taken, and 200 g of deionized water was gradually added to the monomers for stirring. After 30 min, stirring was stopped, 1.2 g of ammonium persulfate was added, and the emulsion was stored for later use after stirring for 15 min.

[0052] Pre-mixed liquid 2: the remaining 20% of the mixed liquid 1, i.e. 37 g, 45 g of hexafluorobutyl methacrylate, 18 g of methacryloyloxypropyl methyl dimethoxy silane, was stirred for 10 min at a dispersing disc rotation speed of more than 800 rpm / min, 0.5 g of azobisisobutyronitrile was added, and the pre-mixed liquid was stored for later use after stirring for 15 min.

[0053] 87.3 g of pre-emulsion 1 (25% of the amount of pre-emulsion) was taken and added to the reaction kettle, 50 g of deionized water was added, and the temperature was raised to 75°C. After stirring for 30 min, the remaining 261.9 g of pre-emulsion 1 was gradually added dropwise to the reaction kettle, and the dropwise addition time was 120 min. After the dropwise addition was completed, the reaction was carried out at 75°C for 120 min. 100.5 g of pre-mixed liquid 2 was gradually added dropwise to the reaction kettle, and the dropwise addition time was 90 min. After the dropwise addition was completed, the reaction was carried out at 75°C for 90 min, and then the temperature was raised to 85°C for 120 min. After the odor disappeared, the temperature was lowered to below 45°C, and the product was filtered out, thereby obtaining the cationic polymer.

[0054] Example 2

[0055] Pre-emulsion 1: 97 g of methacryloyloxypropyl trimethyl ammonium iodide, 50 g of methyl methacrylate, 20 g of n-butyl methacrylate mixed liquid 1 was stirred for 10 min at a dispersing disc rotation speed of more than 800 rpm / min, and then was reserved. 80% of the mixed liquid was taken, and 225 g of deionized water was gradually added to the monomers for stirring. After 30 min, stirring was stopped, 2.0 g of potassium persulfate was added, and the emulsion was stored for later use after stirring for 15 min.

[0056] Pre-mixed liquid 2: the remaining 20% of the mixed liquid 1, i.e. 33.4 g, 35 g of dodecafluoroheptyl methacrylate, 20 g of methacryloyloxypropyl methyl trimethoxy silane, was stirred for 10 min at a dispersing disc rotation speed of more than 800 rpm / min, 1.0 g of azobisisobutyronitrile was added, and the pre-mixed liquid was stored for later use after stirring for 15 min.

[0057] Take 89.65g of pre-emulsion 1 (25% of the amount of pre-emulsion) into the reaction kettle, add 50g of deionized water, heat to 75°C, react for 30min under stirring, add the remaining 268.95g of pre-emulsion 1 to the reaction kettle gradually, the dropping time is 120min, after the dropping is completed, react for 120min at 75°C, add 89.4g of premix 2 to the reaction kettle gradually, the dropping time is 90min, after the dropping is completed, react for 90min at 75°C, heat to 85°C and react for 120min, wait until there is no obvious odor, cool to below 45°C, filter the product, and the cationic polymer is obtained.

[0058] Example 3

[0059] Pre-emulsion 1: 65g of methacryloyloxyethyl trimethyl ammonium iodide and 50g of acryloyloxypropyl trimethyl ammonium iodide, 60g of mixed solution 1 of methyl norbornyl methacrylate are stirred at a dispersing disc speed greater than 800rpm / min for 10min, then stored for standby, take 80% of the mixed solution, gradually add 170g of deionized water to the monomers for stirring, stop stirring after 30min, add 6g of ammonium persulfate, stir for 15min, then store the emulsion for standby.

[0060] Premix 2: according to the proportion, take the remaining 20% of the mixed solution 1, i.e. 35g, 60g of octafluoropentyl methacrylate, 12g of tridecafluoro octyl methacrylate, 25g of methacryloyloxypropyl methyl trimethoxysilane are stirred at a dispersing disc speed greater than 800rpm / min for 10min, add 0.5g of azobisisobutyronitrile, stir for 15min, then store the premix for standby.

[0061] Take 89.65g of pre-emulsion 1 (25% of the amount of pre-emulsion) into the reaction kettle, add 50g of deionized water, heat to 75°C, react for 30min under stirring, add the remaining 268.95g of pre-emulsion 1 to the reaction kettle gradually, the dropping time is 120min, after the dropping is completed, react for 120min at 75°C, add 89.4g of premix 2 to the reaction kettle gradually, the dropping time is 90min, after the dropping is completed, react for 90min at 75°C, heat to 85°C and react for 120min, wait until there is no obvious odor, cool to below 45°C, filter the product, and the cationic polymer is obtained.

[0062] Comparative Example 1

[0063] Pre-emulsion: 130g of methyl methacrylate, 30g of styrene, 60g of isooctyl acrylate, 40g of dimethylaminoethyl methacrylate, 15g of glacial acetic acid, 1.5g of OP-10 were mixed and stirred for 15 min, 200g of deionized water was emulsified at 800 rpm / min for 30 min, 5g of ammonium persulfate was added, stirred for 15 min, and stored for standby.

[0064] Preparation of water-based polymer scale inhibitor: 50g of deionized water was added to the reaction kettle, 0.5g of OP-10 was added, stirred for 15 min until the emulsifier was completely dissolved, 119g of pre-emulsion was added, stirred evenly, then heated to 75℃, reacted for 30 min, the remaining pre-emulsion was added to the reaction kettle at a constant speed, the dropwise time was 150 min, after the dropwise addition was completed, it was reacted at 75℃ for 120 min, then heated to 85℃ for 90 min, when there was no obvious odor, cooled to below 45℃, filtered out the material, and the cationic acrylate polymer was obtained.

[0065] Comparative Example 2

[0066] Pre-emulsion: 130g of methyl methacrylate, 30g of styrene, 60g of isooctyl acrylate, 55 methyl methacryloyloxyethyl trimethylammonium chloride, 1.5g of OP-10 were mixed and stirred for 15 min, 200g of deionized water was emulsified at 800 rpm / min for 30 min, 5g of ammonium persulfate was added, stirred for 15 min, and stored for standby.

[0067] Preparation of water-based polymer scale inhibitor: 50g of deionized water was added to the reaction kettle, 0.5g of OP-10 was added, stirred for 15 min until the emulsifier was completely dissolved, 119g of pre-emulsion was added, stirred evenly, then heated to 75℃, reacted for 30 min, the remaining pre-emulsion was added to the reaction kettle at a constant speed, the dropwise time was 150 min, after the dropwise addition was completed, it was reacted at 75℃ for 120 min, then heated to 85℃ for 90 min, when there was no obvious odor, cooled to below 45℃, filtered out the material, and the cationic acrylate polymer was obtained.

[0068] The waterborne polyurethane dispersions prepared according to the methods of Examples 1-3 and Comparative Examples 1-2 were tested for the following indicators or properties according to international standards or industry standard methods. Emulsion solid content test: according to the provisions of GB / T 1725-2007, 5.00 g of emulsion was placed in an aluminum foil container with a diameter of about 5 cm, and placed in an oven with forced ventilation at 105°C for several hours until the weight variation of the previous two times was less than 0.01 g, and the solid content of the emulsion was calculated; the emulsion viscosity was tested according to the provisions of GB / T 21059-2007; the pH was tested according to GB / T 8325-1987; the emulsion particle size was tested according to the provisions of GB / T 29022-2021 “Particle Size Analysis Dynamic Light Scattering Method”; and the glass transition temperature was tested according to the provisions of GB / T 19466 “Plastics Differential Scanning Calorimetry (DSC)”.

[0069] Preparation of cationic polymer scale inhibitor: The cationic polymers prepared according to the methods of Examples 1-3 and Comparative Examples 1-2 were applied in the field of geothermal pipeline scale inhibition, and the cationic polymer scale inhibitor was prepared as follows: 100 g of cationic polymer was added to hydrophobic nano-silicon dioxide (SiO2) under high-speed stirring, 0.2 g of TEGO TWIN 4100 wetting agent, 0.2 g of BYK 1789 defoamer, 0.2 g of BYK 333, a proportion of ethylene glycol butyl ether, and an appropriate amount of deionized water were added to obtain the cationic polymer scale inhibitor polymer.

[0070] Coating performance test: water contact angle test was performed according to GB / T 30693-2014 “Measurement of Water Contact Angle of Plastic Film”; adhesion test was performed according to GB / T 9286-2021 “Standard for Gravure Test of Color Paint and Varnish”, and the test substrate was Q235 steel.

[0071] Scale inhibition performance test: static scale inhibition experiment was performed according to GB / T 16632-2019 “Determination of Scale Inhibition Performance of Water Treatment Agent — Calcium Carbonate Deposition Method”, and the scale inhibition rate of the cationic polymer prepared in (1) at a concentration of 10 mg / L was determined at a temperature of 80°C. The static scale inhibition rate of the cationic polymer scale inhibitor on CaCO3 was measured. The specific chemical components of geothermal water are shown in Table 1. According to the components in Table 1, the scale inhibition rate of the copolymer scale inhibitor was determined by simulating geothermal water or directly taking geothermal water, and the static scale inhibition experiment was performed according to GB / T 16632-2019 “Determination of Scale Inhibition Performance of Water Treatment Agent — Calcium Carbonate Deposition Method”.

[0072] Table 1 Chemical components of geothermal water

[0073]

[0074] Table 2 Components and properties of cationic polymer scale inhibitor

[0075]

[0076] As can be seen from Table 1 and Table 2, the cationic polymer scale inhibitor prepared by using the formulation and process of the present application has excellent scale inhibition rate, and at the same time has excellent adhesion and hydrophobicity. In addition, the scale inhibitor prepared by using the cationic polymer scale inhibitor in Comparative Examples 1 and 2 has a scale inhibition rate on the geothermal water in the pipeline which is not as good as that of the cationic polymer prepared by using the present application.

[0077] The components listed in the present application, as well as the upper and lower limits, interval values of the components of the present application can all achieve the present application, and examples are not listed one by one. The above lists a part of the specific examples to illustrate the present application, and it is necessary to point out that the specific examples are only used to further illustrate the present application, and do not represent the limitation of the protection scope of the present application. At the same time, the cationic polymer scale inhibitor prepared by the present application is mixed with other conventional components to form a scale inhibitor or the cationic polymer of the present application in other fields.

Claims

1. A cationic polymer scale inhibitor, characterized in that: The cationic polymer scale inhibitor is obtained by polymerizing the following components in parts by mass: 5-25 parts of acryloyloxy ammonium iodide; 6-16 parts of acrylate monomers; 5-15 parts of fluorine-containing acrylate monomers; and 1-5 parts of functional monomers containing silane groups and methacrylate groups.

2. The cationic polymer scale inhibitor according to claim 1, characterized in that The cationic polymer scale inhibitor is obtained by polymerizing the following components in parts by mass: 18-25 parts of acryloyloxy ammonium iodide; 12-16 parts of acrylate monomers; 8-15 parts of fluorine-containing acrylate monomers; and 3-5 parts of functional monomers containing silane groups and methacrylate groups.

3. The cationic polymer scale inhibitor according to claim 1, characterized in that The cationic polymer scale inhibitor is obtained by polymerizing the following components in parts by mass: 21 parts of acryloyloxy ammonium iodide; 16 parts of acrylate monomers; 9 parts of fluorine-containing acrylate monomers; and 3.6 parts of functional monomers containing silane groups and methacrylate groups.

4. The cationic polymer scale inhibitor according to claim 1, characterized in that The acryloyloxy ammonium iodide is one of methacryloyloxyethyl trimethyl ammonium iodide, acryloyloxyethyl trimethyl ammonium iodide, methacryloyloxypropyl trimethyl ammonium iodide, and acryloyloxypropyl trimethyl ammonium iodide, or a mixture thereof.

5. The cationic polymer scale inhibitor according to claim 1, characterized in that The acrylic acid ester monomer is one or a mixture of methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, isooctyl methacrylate, dodecyl methacrylate, hexadecyl methacrylate, octadecyl methacrylate, norbornyl methacrylate, ethyl acrylate, butyl acrylate, isooctyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, N-hydroxymethyl acrylamide, N,N-dimethyl acrylamide, and styrene.

6. The cationic polymer scale inhibitor according to claim 1, characterized in that The fluorine-containing acrylate monomer is one or a mixture of hexafluorobutyl methacrylate, octafluoropentyl methacrylate, tridecafluorooctyl methacrylate, dodecafluoroheptyl methacrylate, and 2-perfluorododecylethyl methacrylate.

7. The cationic polymer scale inhibitor according to claim 1, characterized in that The functional monomer is one or a mixture of methacryloxypropyltrimethoxysilane, methacryloxypropyltriethoxysilane, methacryloxypropylmethyldimethoxysilane and methacryloxypropylmethyldiethoxysilane.

8. A method for preparing the cationic polymer scale inhibitor according to any one of claims 1 to 7, comprising the following steps: According to the above composition and mass fractions, 70-80% by weight of acryloyloxy ammonium iodide and 70-80% by weight of acrylic ester monomer are stirred, deionized water is gradually added to the monomer and stirred, and then an initiator is added and stirred continuously to obtain an emulsion, which is stored for later use; Stir the remaining acryloyloxy ammonium iodide, acrylate monomer, fluorine-containing acrylate monomer, and functional monomer, add the initiator, and stir to obtain a premixed solution, which is stored for later use; According to the volume ratio, 20-30% of the emulsion in the emulsion is heated to 60-80°C and reacted while stirring. The remaining emulsion is gradually added dropwise to the reactor, and reacted after the addition is completed. Then, the premixed liquid is gradually added dropwise, and reacted after the addition is completed. Then, the temperature is raised to 80-85°C for reaction. After the reaction is completed, the temperature is lowered to below 45°C and filtered to obtain a cationic polymer scale inhibitor.

9. The preparation method according to claim 8, characterized in that The initiator is one or a mixture of azobisisobutyronitrile, peroxyazobisisoheptanonitrile, ammonium persulfate, and potassium persulfate, and the amount added is 0.2-2 parts by mass. Preferably, the amount of the initiator added is 0.5-1.8 parts by mass.

10. Use of the cationic polymer scale inhibitor according to any one of claims 1 to 7 in geothermal pipelines.

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