High-efficiency phosphorus-free scale-inhibiting dispersant for grey water and preparation method thereof

Abstract

The application relates to the technical field of grey water dispersants, and discloses a high-efficiency phosphorus-free grey water scale and dispersant and a preparation method thereof. A green amino acid monomer is used to seal the carboxyl groups of a prepared carboxyl group and sulfonic acid group-containing polyether long-chain monomer, so as to improve the biodegradability of the macromolecular polyether monomer, and copolymerization with an acrylic monomer is carried out to enhance the steric hindrance and hydrophilicity of the dispersant. The carboxyl groups and sulfonic acid groups of the aspartic acid-terminated polyether type alkenyl monomer can chelate iron ions, and hydrophilic groups such as amino groups and ether groups can make the chelate dissolve or suspend in a solution, and the dispersing performance is good. The active carboxyl groups and sulfonic acid groups in the molecular chain of the dispersant can chelate Ca 2+ , Ba 2+ , and the polyethylene glycol alkyl long chain makes certain mutual repulsion exist between anions and cations. The scale and dispersant has the functions of scale inhibition and dispersion, does not have phosphorus in the molecular structure, is easy to degrade after being discharged, and belongs to an environment-friendly multifunctional scale and dispersant.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of grey water dispersant, in particular to a high-efficiency phosphorus-free grey water scale inhibition dispersant and a preparation method thereof. BACKGROUND

[0002] Coal gasification grey water is a kind of water quality prone to scale formation in the water circulation process of coal chemical industry, which has the characteristics of high hardness, high alkalinity and wide pH range. In the operation process of coal gasification water circulation, it is often accompanied by the problems of pipeline scaling and blocking. Therefore, the treatment of coal gasification grey water is an important environmental protection and production link. Through effective treatment process, not only can the discharge of waste water be reduced and the pollution to the environment be reduced, but also the recycling of water resources can be realized and the production cost can be reduced. At present, the popular formula at home and abroad is phosphorus-based, which is widely used in most coal gasification water circulation systems in China. However, a large amount of phosphorus-containing waste water discharge is easy to cause water eutrophication. With the continuous deterioration of water quality and the increasing of water hardness, the requirements for phosphorus-containing waste water discharge are becoming more and more strict at home and abroad. Therefore, it has become a research hotspot to prepare a new type of grey water scale inhibition dispersant which is more efficient and more environmentally friendly.

[0003] The main function of coal gasification grey water scale inhibition dispersant is to disperse the suspended solids and microcrystalline particles in the grey water through physical or chemical action, so as to prevent their aggregation and deposition. At the same time, it can also form stable complexes with calcium, magnesium and other hard water ions in the grey water, so as to reduce their concentration and inhibit the formation of hard scale. Polyaspartic acid is a kind of water-soluble biological macromolecular material inspired by the metabolism of marine animals. The carboxyl group in its structure can change the crystal structure of calcium salt. Compared with traditional scale inhibition dispersants, it can be completely biodegraded. Although polyaspartic acid has chelating properties, its scale inhibition and dispersion ability is not as good as that of the widely used acrylic acid and maleic acid polymers. Especially when polyaspartic acid is applied to high hardness water quality, the scale inhibition and dispersion effect is not satisfactory.

[0004] The invention patent CN108439618B discloses a coal gasification grey water scale inhibitor and a preparation method thereof. The macromolecular polymer is modified by oxidation degradation, sulfonation, selective amination and graft copolymerization, and mixed with the amination modified product obtained by amination of the sulfonated modified product and the copolymerization product to be used as a coal gasification grey water scale inhibitor. The final obtained coal gasification grey water scale inhibitor has high scale inhibition rate. However, the reaction site of natural polymer is more, the reaction is uncontrollable and the preparation process is complex, so the application range is limited. The present application aims to realize the coordination of multiple functional groups such as carboxyl, sulfonic acid group, ester group and polyethyleneoxy group through molecular design, so as to prepare a multifunctional green scale inhibition dispersant and broaden its application in coal gasification grey water dispersion. SUMMARY

[0005] The present application aims at solving the problems in the prior art, and provides a high-efficiency phosphorus-free lime water scale and corrosion inhibitor and a preparation method thereof, which has good scale and corrosion inhibition and solves the problems of phosphorus pollution, single function, poor use stability and small application range of the current scale and corrosion inhibitor.

[0006] The present application is realized by the following technical scheme:

[0007] The preparation method of the high-efficiency phosphorus-free lime water scale and corrosion inhibitor comprises the following steps:

[0008] In step (1), under a nitrogen atmosphere, an enyl aspartic acid potassium sulfonate monomer with a structural formula of and N-methyl pyrrolidone are added to a reaction flask equipped with a thermometer, and then polyethylene glycol monomethyl ether 1000 is added after uniform stirring, and then stirring reaction is performed, and then the aspartic acid-terminated polyether type enyl monomer is obtained after distillation under reduced pressure.

[0009]

[0010] In step (2), under a nitrogen atmosphere, deionized water, ammonium persulfate, sodium dodecyl benzene sulfonate and OP-10 are added to a reaction flask equipped with a dropping funnel, and then stirring and dissolution are performed; a mixed solution of uniformly mixed methyl methacrylate, butyl acrylate, acrylic acid and the aspartic acid-terminated polyether type enyl monomer is added to the dropping funnel, 1 / 3 of the mixed solution is added dropwise first, and then reaction is performed at 75-90 DEG C for 2-5 h, and then the remaining mixed solution is added dropwise, and then reaction is continuously performed for 2-4 h, and then ammonia water is added to adjust the pH to 7-8, and finally emulsified silicone oil is added, and then the high-efficiency phosphorus-free lime water scale and corrosion inhibitor is obtained.

[0011] Preferably, in step (1), the molar ratio of the enyl aspartic acid potassium sulfonate monomer to polyethylene glycol monomethyl ether 1000 is 1:1.2-1.5.

[0012] Preferably, in step (1), the reaction temperature is 90-110 DEG C, and the reaction time is 3-8 h.

[0013] Preferably, in step (2), the mass ratio of deionized water, ammonium persulfate, sodium dodecyl benzene sulfonate, OP-10, methyl methacrylate, butyl acrylate, acrylic acid, the aspartic acid-terminated polyether type enyl monomer and emulsified silicone oil is 20-35:2-4:3-6:5-8:100:30-40:5-10:3-15:0.5-2.

[0014] Preferably, the preparation method of the enyl aspartic acid potassium sulfonate monomer in step (1) comprises the following steps:

[0015] ​Step S1, under nitrogen atmosphere, L-aspartic acid and methanol were added into a reaction flask, after stirring, 3-(acryloyloxy) propane-1-sulfonic acid potassium was added, after stirring reaction, after reaction, under reduced pressure, column chromatography separation (dichloromethane:methanol:ammonia water=90:9:1), aspartic acid sulfonic acid potassium monomer was obtained. Preparation reaction formula as follows:

[0016]

[0017] Step S2, under nitrogen atmosphere, aspartic acid sulfonic acid potassium monomer and N,N-dimethylformamide were added into a reaction flask, after stirring, acryloyl chloride and triethylamine were added, after stirring reaction, after reaction, deionized water was added for extraction, organic phase was concentrated, column chromatography separation (dichloromethane:methanol=85:15), alkenyl aspartic acid sulfonic acid potassium monomer was obtained. Preparation reaction formula as follows:

[0018]

[0019] Preferably, the molar ratio of L-aspartic acid and 3-(acryloyloxy) propane-1-sulfonic acid potassium in step S1 is 1:1.05-1.1.

[0020] Preferably, the reaction temperature in step S1 is 65-80℃, and the reaction time is 12-24h.

[0021] Preferably, the ratio of aspartic acid sulfonic acid potassium monomer, acryloyl chloride and triethylamine in step S2 is 1:1.2-1.35:1.5-1.8.

[0022] Preferably, the reaction temperature in step S2 is 80-100℃, and the reaction time is 8-16h.

[0023] Compared with the prior art, the beneficial effects of the present application are as follows:

[0024] The present application first utilizes the amino group of L-aspartic acid and the alkenyl group of 3-(acryloyloxy) propane-1-sulfonic acid potassium to occur Michael addition reaction, to obtain aspartic acid sulfonic acid potassium monomer, then reacts with acryloyl chloride under the action of triethylamine, to obtain alkenyl aspartic acid sulfonic acid potassium monomer, then esterification reaction with polyethylene glycol monomethyl ether 1000, to obtain aspartic acid terminated polyether type alkenyl monomer, finally polymerization with acrylic monomer, to obtain high-efficiency non-phosphorus ash water scale inhibition dispersant.

[0025] The application adopts green amino acid monomers to cap the carboxyl and sulfonic acid group of the prepared polyether long-chain monomer, so as to improve the biodegradability of the macromolecular polyether monomer, and through copolymerization with acrylic monomers, the space steric hindrance and hydrophilicity of the dispersant are enhanced, and the dispersant has good scale inhibition and dispersion performance; the carboxyl and sulfonic acid group of the aspartic acid capped polyether type alkenyl monomer can chelate iron ions, and the hydrophilic groups such as amino and ether groups can make the chelate dissolved or suspended in the solution, so as to prevent the deposition of iron oxide and achieve the effect of dispersing iron oxide; the polyethylene glycol alkyl long-chain compound in the dispersant acts as a solvation chain, can form effective space steric hindrance to prevent the flocculation and deposition between particles, so as to realize the stable dispersion of iron ions in the medium.

[0026] The active carboxyl and sulfonic acid groups in the molecular chain of the grey water scale inhibition and dispersion agent can chelate Ca 2+ , Ba 2+ , inhibit the nucleation of crystals, and can effectively disperse particles on the pipe or container wall, so as to ensure the long-term effect of chelating scale inhibition and dispersion, and the particles are not easy to form a precipitate in the environment with high Ca 2+ , Ba 2+ concentration; the polyethylene glycol alkyl long chain makes there be a certain mutual repulsion between anions and cations, and at the same time, the molecular chain is stretched, so as to reduce the collision probability of BaSO4 and CaCO3 crystal particles, and avoid the aggregation and precipitation of the crystals. The scale inhibition and dispersion agent prepared by the application has both scale inhibition and dispersion functions, is suitable for coal gasification circulating water and other water with easy scaling, and has no phosphorus in the molecular structure, is easy to degrade after discharge, and belongs to an environmentally friendly multifunctional scale inhibition and dispersion agent. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the application will be clearly and completely described below in combination with the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0028] Unless otherwise specified, the raw materials and reagents used in the application are commercially available or can be prepared by known methods.

[0029] L-aspartic acid, CAS number 56-84-8.

[0030] 3-(acryloyloxy)propane-1-sulfonic acid potassium salt, CAS number 31098-20-1.

[0031] Polyethylene glycol monomethyl ether 1000, CAS number 9004-74-4.

[0032] Example 1

[0033] (1) Under nitrogen atmosphere, 42 mmol of L-aspartic acid and 315 mL of methanol were added to a reaction flask, stirred uniformly, 44.8 mmol of 3-(acryloyloxy)propane-1-sulfonic acid potassium salt was added, reacted at 75℃ for 16 h, concentrated under reduced pressure, and column chromatography separation (dichloromethane:methanol:ammonia water = 90:9:1) was performed to obtain aspartic acid sulfonic acid potassium salt monomer.

[0034] (2) Under nitrogen atmosphere, 35 mmol of aspartic acid sulfonic acid potassium salt monomer and 630 mL of N,N-dimethylformamide were added to a reaction flask, stirred uniformly, 45.5 mmol of acryloyl chloride and 58.8 mmol of triethylamine were added, reacted at 90℃ for 12 h, deionized water was added for extraction, the organic phase was concentrated, and column chromatography separation (dichloromethane:methanol = 85:15) was performed to obtain alkenyl aspartic acid sulfonic acid potassium salt monomer.

[0035] (3) Under nitrogen atmosphere, 30 mmol of alkenyl aspartic acid sulfonic acid potassium salt monomer and 840 mL of N-methylpyrrolidone were added to a reaction flask equipped with a thermometer, stirred uniformly, 40.5 mmol of polyethylene glycol monomethyl ether 1000 was added, reacted at 100℃ for 5 h, and distilled under reduced pressure to obtain aspartic acid-terminated polyether alkenyl monomer.

[0036] (4) Under nitrogen atmosphere, 25 g of deionized water, 3 g of ammonium persulfate, 5 g of sodium dodecylbenzenesulfonate, and 7 g of OP-10 were added to a reaction flask equipped with a dropping funnel, stirred and dissolved; a mixture of 100 g of methyl methacrylate, 35 g of butyl acrylate, 8 g of acrylic acid, and 3 g of aspartic acid-terminated polyether alkenyl monomer was added to the dropping funnel, 1 / 3 of the mixture was added dropwise, reacted at 80℃ for 3 h, then the remaining mixture was added dropwise, and reacted for another 2 h, after the reaction was completed, ammonia water was added to adjust the pH to 8, and finally 1.5 g of emulsified silicone oil was added to obtain a high-efficiency non-phosphorus gray water scale inhibitor.

[0037] Example 2

[0038] (1) Under nitrogen atmosphere, 42 mmol of L-aspartic acid and 315 mL of methanol were added to a reaction flask, stirred uniformly, 44.8 mmol of 3-(acryloyloxy)propane-1-sulfonic acid potassium salt was added, reacted at 75℃ for 16 h, concentrated under reduced pressure, and column chromatography separation (dichloromethane:methanol:ammonia water = 90:9:1) was performed to obtain aspartic acid sulfonic acid potassium salt monomer.

[0039] (2) Under a nitrogen atmosphere, 108 mmol of aspartic acid sulfonic acid potassium monomer and 1620 mL of N,N-dimethylformamide were added to a reaction flask, and after being uniformly dispersed, 129.6 mmol of acryloyl chloride and 162 mmol of triethylamine were added, and the mixture was reacted at 100°C for 8 h. Deionized water was added to extract the organic phase, and the organic phase was concentrated and separated by column chromatography (dichloromethane:methanol = 85:15) to obtain an aspartic acid sulfonic acid potassium monomer.

[0040] (3) Under a nitrogen atmosphere, 90 mmol of aspartic acid sulfonic acid potassium monomer and 2250 mL of N-methylpyrrolidone were added to a reaction flask equipped with a thermometer, and after being uniformly stirred, 108 mmol of polyethylene glycol monomethyl ether 1000 was added, and the mixture was reacted at 110°C for 3 h. The reaction mixture was distilled under reduced pressure to obtain an aspartic acid-terminated polyether-type alkenyl monomer.

[0041] (4) Under a nitrogen atmosphere, 20 g of deionized water, 2 g of ammonium persulfate, 3 g of sodium dodecylbenzenesulfonate, and 5 g of OP-10 were added to a reaction flask equipped with a dropping funnel, and stirred to dissolve. A mixture of 100 g of methyl methacrylate, 30 g of butyl acrylate, 5 g of acrylic acid, and 6 g of aspartic acid-terminated polyether-type alkenyl monomer was uniformly mixed and added to the dropping funnel. One-third of the mixture was added dropwise, and the mixture was reacted at 90°C for 2 h. The remaining mixture was then added dropwise, and the reaction was continued for 2 h. After the reaction was completed, ammonia water was added to adjust the pH to 7, and 0.5 g of emulsified silicone oil was finally added to obtain a high-efficiency non-phosphorus scale-inhibiting dispersant.

[0042] Example 3

[0043] (1) Under a nitrogen atmosphere, 50 mmol of L-aspartic acid and 500 mL of methanol were added to a reaction flask, and after being uniformly stirred, 55 mmol of 3-(acryloyloxy)propane-1-sulfonic acid potassium was added, and the mixture was reacted at 65°C for 24 h. The reaction mixture was concentrated under reduced pressure and separated by column chromatography (dichloromethane:methanol:ammonia water = 90:9:1) to obtain an aspartic acid sulfonic acid potassium monomer.

[0044] (2) Under a nitrogen atmosphere, 45 mmol of aspartic acid sulfonic acid potassium monomer and 900 mL of N,N-dimethylformamide were added to a reaction flask, and after being uniformly dispersed, 60.75 mmol of acryloyl chloride and 81 mmol of triethylamine were added, and the mixture was reacted at 80°C for 16 h. Deionized water was added to extract the organic phase, and the organic phase was concentrated and separated by column chromatography (dichloromethane:methanol = 85:15) to obtain an aspartic acid sulfonic acid potassium monomer.

[0045] (3) Under nitrogen atmosphere, 40 mmol of the olefinic aspartic acid potassium sulfonate monomer and 1200 mL of N-methylpyrrolidone were added into a reaction flask equipped with a thermometer, stirred uniformly, 60 mmol of polyethylene glycol monomethyl ether 1000 was added, reacted at 90°C for 8 h, and distilled under reduced pressure to obtain the aspartic acid-terminated polyether-type olefinic monomer.

[0046] (4) Under nitrogen atmosphere, 35 g of deionized water, 4 g of ammonium persulfate, 6 g of sodium dodecylbenzenesulfonate and 8 g of OP-10 were added into a reaction flask equipped with a dropping funnel, stirred and dissolved; a mixture of 100 g of methyl methacrylate, 40 g of butyl acrylate, 10 g of acrylic acid and 9 g of the aspartic acid-terminated polyether-type olefinic monomer was added into the dropping funnel, 1 / 3 of the mixture was added dropwise, reacted at 75°C for 5 h, then the remaining mixture was added dropwise, and reacted for another 4 h, after the reaction was completed, ammonia water was added to adjust the pH to 8, and finally 2 g of emulsified silicone oil was added to obtain a high-efficiency phosphorus-free scale inhibition dispersant for water.

[0047] Example 4

[0048] (1) Under nitrogen atmosphere, 12 mmol of L-aspartic acid and 80 mL of methanol were added into a reaction flask, stirred uniformly, 13 mmol of 3-(acryloyloxy)propane-1-sulfonic acid potassium salt was added, reacted at 75°C for 16 h, concentrated under reduced pressure, and separated by column chromatography (dichloromethane:methanol:ammonia water = 90:9:1) to obtain the aspartic acid-based potassium sulfonate monomer.

[0049] (2) Under nitrogen atmosphere, 10 mmol of the aspartic acid-based potassium sulfonate monomer and 185 mL of N,N-dimethylformamide were added into a reaction flask, stirred uniformly, 13.5 mmol of acryloyl chloride and 16 mmol of triethylamine were added, reacted at 95°C for 15 h, deionized water was added for extraction, the organic phase was concentrated, and separated by column chromatography (dichloromethane:methanol = 85:15) to obtain the olefinic aspartic acid potassium sulfonate monomer.

[0050] (3) Under nitrogen atmosphere, 8 mmol of the olefinic aspartic acid potassium sulfonate monomer and 210 mL of N-methylpyrrolidone were added into a reaction flask equipped with a thermometer, stirred uniformly, 10 mmol of polyethylene glycol monomethyl ether 1000 was added, reacted at 105°C for 6 h, and distilled under reduced pressure to obtain the aspartic acid-terminated polyether-type olefinic monomer.

[0051] (4) Under the atmosphere of nitrogen, 30 g of deionized water, 3.5 g of ammonium persulfate, 4.5 g of sodium dodecyl benzene sulfonate and 7 g of OP-10 were added into a reaction flask equipped with a dropping funnel, and stirred and dissolved; 100 g of methyl methacrylate, 32 g of butyl acrylate, 9 g of acrylic acid and 12 g of the mixed solution of aspartic acid-terminated polyether type alkenyl monomer were added into the dropping funnel, 1 / 3 of the mixed solution was added dropwise, and reacted at 80℃ for 5 h, then the remaining mixed solution was added dropwise, and reacted for another 3 h, after the reaction was completed, ammonia water was added to adjust the pH to 8, and finally 1 g of emulsified silicone oil was added to obtain a high-efficiency phosphorus-free scale inhibition dispersant for grey water.

[0052] Example 5

[0053] (1) Under the atmosphere of nitrogen, 25 mmol of L-aspartic acid and 200 mL of methanol were added into a reaction flask, and stirred and uniformly dispersed, then 27 mmol of 3-(acryloyloxy)propane-1-sulfonic acid potassium salt was added, and reacted at 70℃ for 24 h, and concentrated under reduced pressure, and column chromatography separation (dichloromethane:methanol:ammonia water = 90:9:1) was performed to obtain aspartic acid-based sulfonic acid potassium salt monomer.

[0054] (2) Under the atmosphere of nitrogen, 18 mmol of aspartic acid-based sulfonic acid potassium salt monomer and 270 mL of N,N-dimethylformamide were added into a reaction flask, and uniformly dispersed, then 22.5 mmol of acryloyl chloride and 24 mmol of triethylamine were added, and reacted at 85℃ for 16 h, deionized water was added for extraction, the organic phase was concentrated, and column chromatography separation (dichloromethane:methanol = 85:15) was performed to obtain alkenyl aspartic acid sulfonic acid potassium salt monomer.

[0055] (3) Under the atmosphere of nitrogen, 12 mmol of alkenyl aspartic acid sulfonic acid potassium salt monomer and 320 mL of N-methyl pyrrolidone were added into a reaction flask equipped with a thermometer, and stirred and uniformly dispersed, then 16.2 mmol of polyethylene glycol monomethyl ether 1000 was added, and reacted at 105℃ for 7 h, and distilled under reduced pressure to obtain aspartic acid-terminated polyether type alkenyl monomer.

[0056] (4) Under the atmosphere of nitrogen, 32 g of deionized water, 4 g of ammonium persulfate, 5 g of sodium dodecyl benzene sulfonate and 6 g of OP-10 were added into a reaction flask equipped with a dropping funnel, and stirred and dissolved; 100 g of methyl methacrylate, 35 g of butyl acrylate, 7 g of acrylic acid and 15 g of the mixed solution of aspartic acid-terminated polyether type alkenyl monomer were added into the dropping funnel, 1 / 3 of the mixed solution was added dropwise, and reacted at 80℃ for 5 h, then the remaining mixed solution was added dropwise, and reacted for another 3 h, after the reaction was completed, ammonia water was added to adjust the pH to 8, and finally 1.5 g of emulsified silicone oil was added to obtain a high-efficiency phosphorus-free scale inhibition dispersant for grey water.

[0057] Comparative Example 1

[0058] Under nitrogen atmosphere, 25 g of deionized water, 3 g of ammonium persulfate, 5 g of sodium dodecyl benzene sulfonate and 7 g of OP-10 were added into a reaction bottle equipped with a dropping funnel, and stirred and dissolved; a mixture of 100 g of methyl methacrylate, 35 g of butyl acrylate, 8 g of acrylic acid and 3 g of aspartic acid potassium sulfonate monomer (prepared in Example 1) uniformly mixed was added into the dropping funnel, 1 / 3 of the mixture was added dropwise, and reacted at 80℃ for 3 h, then the remaining mixture was added dropwise, and reacted for another 2 h, after the reaction was completed, ammonia water was added to adjust the pH to 8, and finally 1.5 g of emulsified silicone oil was added to obtain a phosphorus-free gray water scale inhibition dispersant.

[0059] Comparative Example 2

[0060] Under nitrogen atmosphere, 25 g of deionized water, 3 g of ammonium persulfate, 5 g of sodium dodecyl benzene sulfonate and 7 g of OP-10 were added into a reaction bottle equipped with a dropping funnel, and stirred and dissolved; a mixture of 100 g of methyl methacrylate, 35 g of butyl acrylate, 8 g of acrylic acid and 3 g of 3-(acryloyloxy) propane-1-sulfonic acid potassium was added into the dropping funnel, 1 / 3 of the mixture was added dropwise, and reacted at 80℃ for 3 h, then the remaining mixture was added dropwise, and reacted for another 2 h, after the reaction was completed, ammonia water was added to adjust the pH to 8, and finally 1.5 g of emulsified silicone oil was added to obtain a phosphorus-free gray water scale inhibition dispersant.

[0061] Comparative Example 3

[0062] Under nitrogen atmosphere, 25 g of deionized water, 3 g of ammonium persulfate, 5 g of sodium dodecyl benzene sulfonate and 7 g of OP-10 were added into a reaction bottle equipped with a dropping funnel, and stirred and dissolved; a mixture of 100 g of methyl methacrylate, 35 g of butyl acrylate, 8 g of acrylic acid was added into the dropping funnel, 1 / 3 of the mixture was added dropwise, and reacted at 80℃ for 3 h, then the remaining mixture was added dropwise, and reacted for another 2 h, after the reaction was completed, ammonia water was added to adjust the pH to 8, and finally 1.5 g of emulsified silicone oil was added to obtain a phosphorus-free gray water scale inhibition dispersant.

[0063] Dispersing performance test: 8 groups of Ca 2+ The solution with a mass concentration of 150 mg / L was added with 100 mg of the gray water scale inhibition dispersant prepared in the examples and comparative examples, and 7 ferrous sulfate heptahydrate to make Fe 2+ = 10 mg / L, and was diluted to 500 mL, and a blank test was performed; sodium tetraborate was used to adjust the pH of the solution to 9; after the pH was stable, it was stirred vigorously for 15 min, and then was placed in a 50℃ water bath for 5 h, the upper clear liquid was taken, and the transmittance T under 420 nm and 3 cm colorimetric cell was measured by visible spectrophotometer, and the smaller the transmittance, the better the dispersing effect.

[0064] Table 1 Dispersing performance test

[0065] Transmittance T (%) Example 1 46.4 Example 2 37.1 Example 3 29.6 Example 4 23.0 Example 5 22.7 Comparative Example 1 50.3 Comparative Example 2 68.2 Comparative Example 3 83.9

[0066] The transmittance reflects the turbidity of the solution, and the dispersing performance of the polymer can be evaluated by the transmittance. The ferrous sulfate heptahydrate generates ferrous hydroxide in the alkaline solution, which is then oxidized to ferric oxide. If the dispersing performance of the polymer is poor, the ferric oxide will precipitate, and the transmittance of the solution will be high. Conversely, the smaller the transmittance, the better the dispersing performance of the polymer.

[0067] From the test results in the above table, it can be seen that the dispersing performance of the grey water scale inhibiting dispersant is gradually enhanced with the increase of the aspartic acid-terminated polyether type alkenyl monomer content. The transmittance in Example 4 is only 23.0%, which is because, on the one hand, the carboxyl and sulfonic acid groups of the aspartic acid-terminated polyether type alkenyl monomer can chelate iron ions, and the hydrophilic groups such as amino and ether groups can make the chelate dissolved or suspended in the solution, thereby preventing the precipitation of ferric oxide and achieving the effect of dispersing ferric oxide; on the other hand, the polyethylene glycol alkyl long chain compound as a solvating chain can form effective steric hindrance to prevent the flocculation and precipitation between particles, thereby realizing the stable dispersion of iron ions in the medium; when the dosage reaches the critical value, enough carboxylic acid and sulfonic acid groups can be ionized from the aspartic acid-terminated polyether type alkenyl monomer to chelate most of the free iron ions in the solution, and the functional groups reach saturation, so the effect of reducing the transmittance is no longer significant.

[0068] The comparative example 1 contains carboxylic acid and sulfonic acid chelating functional groups, but does not contain polyethylene glycol long chain, and has a certain dispersing effect; the comparative example 2 does not contain polyethylene glycol long chain groups, and does not have a synergistic dispersion effect, and the chelation effect is limited; the comparative example 3 does not contain functional groups, and has the worst dispersing performance.

[0069] Scale inhibition performance test: The test is carried out according to the standard HG / T 2024-2009. The principle of the method is that CaCl2 and BaCl2 react with a certain amount of NaHCO3 or Na2SO4 to form CaCO3 and BaSO4 precipitates. Before the reaction to form CaCO3 and BaSO4 precipitates, the prepared grey water scale inhibiting dispersant is added to the solution, and the solution is placed for a period of time without adding the prepared grey water scale inhibiting dispersant. The Ca 2+ and Ba 2+ contents in the clear solution are measured, and the scale inhibition rate is calculated.

[0070] Preparation of CaCl2 solution: 13.86 g of anhydrous calcium chloride is dissolved in water, and the volume is made up to 1 L in a volumetric flask (5 mg / mL in terms of Ca 2+ ).

[0071] Preparation of NaHCO3 solution: 9.92 g of NaHCO3 is dissolved in water, and the volume is made up to 1 L in a volumetric flask (5 mg / mL in terms of HCO3 -Calcium indicator: 0.2 g calcium carboxylate was thoroughly mixed with 100 g calcium chloride and ground to 40-50 mesh.

[0072] EDTA disodium solution: 0.01 mol / L standard solution.

[0073] Calcium indicator: 0.2 g calcium carboxylate was thoroughly mixed with 100 g calcium chloride and ground to 40-50 mesh.

[0074] Test procedure: 200 mL of deionized water was added to a 250 mL volumetric flask, 10 mL of Ca 2+ solution with a mass concentration of 5 mg / mL was added with a burette, 100 mg of the scale inhibitor prepared in the examples and comparative examples was added, 10 mL of HCO3 - solution with a mass concentration of 7.29 mg / mL was added after shaking, deionized water was added to dilute to the calibration mark, shake well, and then the mixture was transferred into a 250 mL stoppered flask, which was kept at 70°C for 10 h. At the same time, an experiment without adding the scale inhibitor was carried out, and the remaining steps were the same, to obtain blank solution 1.

[0075] At the same time, an experiment without adding HCO3 3- solution and the scale inhibitor was carried out, and the remaining steps were the same, to obtain blank solution 2; each stoppered flask was taken out and kept at room temperature, 50 mL of deionized water was taken in a clean conical flask, 25 mL of the filtrate was accurately transferred, mixed well, 10 mL of a sodium hydroxide solution with a mass fraction of 4% and 3 mL of the calcium indicator were added, and the mixture was titrated with 0.01 mol / L EDTA standard solution until it turned pure blue.

[0076] Scale inhibition rate = [p(Ca 2+ 2) - p(Ca 2+ 1)] / [p(Ca 2+ ) - p(Ca 2+ 1)] x 100%.

[0077] In the formula, p(Ca 2+ ) is the Ca 2+ concentration after adding the scale inhibitor, p(Ca 2+ 1) is the Ca 2+ concentration in blank solution 1, and p(Ca 2+ 2) is the Ca 2+ concentration in blank solution 2.

[0078] BaSO4scale inhibition rate test: 200 mL of deionized water was added to a 250 mL volumetric flask, 5 mL of Ba 2+ solution with a mass concentration of 2.81 mg / mL was added with a burette, 100 mg of the scale inhibitor prepared in the examples and comparative examples was added, 5 mL of SO4 2-Solution, add deionized water to dilute to the scale, shake, put into 250 mL flask with stopper, stand for 10 h at 70℃; in the experiment, the experiment without dispersant is carried out at the same time, the rest steps are the same, and blank solution 1 is obtained; in the experiment, the experiment without SO4 2- solution and dispersant is carried out at the same time, the rest steps are the same, and blank solution 2 is obtained.

[0079] Table 2 scale inhibition performance test

[0080]

[0081]

[0082] From the test results in the above table, with the increase of aspartic acid-terminated polyether type alkenyl monomer content, the content of groups that can be chelated with Ca 2+ , Ba 2+ in the dispersant increases, and the scale inhibition performance is obviously improved; through the active carboxyl and sulfonic acid groups in the molecular chain, Ca 2+ , Ba 2+ chelation is inhibited, and the particles can be effectively dispersed on the pipe or container wall, so that the long-term effectiveness of the chelating scale and dispersant is ensured, and the precipitate is not easy to form in the environment with high Ca 2+ , Ba 2+ concentration; the long chain of polyethylene glycol alkyl makes there be a certain mutual repulsion between anions and cations, and the molecular chain is stretched to reduce the probability of mutual collision of BaSO4 and CaCO3 crystal particles, so that the crystal aggregation and precipitation scale are avoided.

[0083] The above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments are not required to be exhausted. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the claims of the present application.

Claims

1. A method for preparing a high-efficiency phosphate-free water scale inhibitor and dispersant, characterized in that, The preparation method includes the following steps: Step (1): Under a nitrogen atmosphere, add the following to a reaction flask equipped with a thermometer: [Structure formula omitted] The alkenyl aspartic acid sulfonate potassium monomer and N-methylpyrrolidone were stirred evenly, and then polyethylene glycol monomethyl ether 1000 was added. The mixture was stirred and reacted. After the reaction was completed, the mixture was distilled under reduced pressure to obtain aspartic acid-terminated polyether alkenyl monomer. Step (2): Under a nitrogen atmosphere, add deionized water, ammonium persulfate, sodium dodecylbenzenesulfonate and OP-10 to a reaction flask equipped with a dropping funnel and stir to dissolve; add a well-mixed mixture of methyl methacrylate, butyl acrylate, acrylic acid and aspartic acid-terminated polyether alkenyl monomers to the dropping funnel, add 1 / 3 of the mixture first, react at 75-90℃ for 2-5 hours, then add the remaining mixture and continue the reaction for 2-4 hours. After the reaction is completed, add ammonia to adjust the pH to 7-8, and finally add emulsified silicone oil to obtain a high-efficiency phosphorus-free water scale inhibitor and dispersant. In step (1), the molar ratio of potassium alkenyl aspartate sulfonate monomer and polyethylene glycol monomethyl ether 1000 is 1:1.2-1.

5.

2. The preparation method of the high-efficiency phosphate-free water scale inhibitor and dispersant according to claim 1, characterized in that, The reaction temperature in step (1) is 90-110℃ and the reaction time is 3-8h.

3. The preparation method of the high-efficiency phosphorus-free water scale inhibitor and dispersant according to claim 1, characterized in that, In step (2), the mass ratio of deionized water, ammonium persulfate, sodium dodecylbenzenesulfonate, OP-10, methyl methacrylate, butyl acrylate, acrylic acid, aspartic acid-terminated polyether alkenyl monomer, and emulsified silicone oil is 20-35:2-4:3-6:5-8:100:30-40:5-10:3-15:0.5-2.

4. The preparation method of the high-efficiency phosphate-free water scale inhibitor and dispersant according to claim 1, characterized in that, The preparation method of the potassium alkenyl aspartate sulfonate monomer in step (1) includes the following steps: Step S1: Under a nitrogen atmosphere, L-aspartic acid and methanol are added to a reaction flask and stirred until homogeneous. Then, potassium 3-(acryloyloxy)propane-1-sulfonate is added and stirred to react. After the reaction is completed, the mixture is concentrated under reduced pressure and separated by column chromatography. The separation solution used for column chromatography is composed of dichloromethane:methanol:ammonia water in a volume ratio of 90:9:1 to obtain potassium aspartic acid sulfonate monomer. Step S2: Under a nitrogen atmosphere, potassium aspartate sulfonate monomer and N,N-dimethylformamide are added to a reaction flask and dispersed evenly. Acryloyl chloride and triethylamine are then added and the mixture is stirred to react. After the reaction is complete, deionized water is added for extraction, the organic phase is concentrated, and column chromatography is performed. The separation solution used for column chromatography is composed of dichloromethane and methanol in a volume ratio of 85:15 to obtain the potassium aspartate sulfonate monomer.

5. The preparation method of the high-efficiency phosphorus-free water scale inhibitor and dispersant according to claim 4, characterized in that, In step S1, the molar ratio of L-aspartic acid and potassium 3-(acryloyloxy)propane-1-sulfonate is 1:1.05-1.

1.

6. The preparation method of the high-efficiency phosphorus-free water scale inhibitor and dispersant according to claim 4, characterized in that, In step S1, the reaction temperature is 65-80℃ and the reaction time is 12-24h.

7. The preparation method of the high-efficiency phosphate-free water scale inhibitor and dispersant according to claim 4, characterized in that, In step S2, the molar ratio of potassium aspartate sulfonate monomer, acryloyl chloride, and triethylamine is 1:1.2-1.35:1.5-1.

8.

8. The preparation method of the high-efficiency phosphorus-free water scale inhibitor and dispersant according to claim 4, characterized in that, In step S2, the reaction temperature is 80-100℃ and the reaction time is 8-16h.

9. A highly efficient phosphate-free water scale inhibitor and dispersant, characterized in that, It is obtained by the preparation method according to any one of claims 1-8.

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