Corrosion inhibition type grey water scale inhibition dispersant and preparation method thereof

Abstract

The invention discloses a corrosion inhibition type grey water scale inhibition dispersant and a preparation method thereof, belongs to the technical field of grey water dispersants, and aims to solve the problems of unstable scale inhibition performance and non-lasting scale inhibition efficiency of a grey water scale inhibition dispersant in the prior art. The technical problem that certain anti-corrosion and corrosion inhibition performance needs to be added to industrial grey water scale inhibition dispersants is urgently needed to be solved. The preparation method comprises the following steps that styrene, acrylamide and acrylic acid serve as raw materials, a polymer wall material is prepared, polyaspartic acid, a modified corrosion inhibitor and vanillin modified chitosan react, a core material is obtained, the core material and the wall material are prepared through a composite coacervation method, and the corrosion inhibition type grey water scale inhibition dispersing agent is obtained. The corrosion inhibition type grey water scale inhibition dispersant prepared by the invention has the advantages of stable and lasting scale inhibition effect and corrosion inhibition.

Description

Technical Field

[0001] The invention relates to the technical field of gray water dispersants, and in particular to a corrosion-inhibiting gray water scale inhibitor dispersant and a preparation method thereof. Background Art

[0002] In various equipment in power plants, scaling in return pumps, pipe valves, and jet nozzles will cause various machines and equipment to not operate normally. It is necessary to add scale inhibitors and dispersants to treat the ash water. The high pH ash water from the slurry pool to the slurry concentration system will explode in contact with the atmosphere in the vibrating screen and concentration tank, which can absorb carbon dioxide in the air and increase the carbonate concentration in the ash water.

[0003] Scale inhibitors use technical means to make heavy metals in fly ash chemically inert or physically coated, reducing their migration into the environment. When added to a supersaturated solution, they can adsorb on the pipe wall to form an adsorption layer, organize particles to deposit on the contact surface, inhibit and dry the growth of scaling, and achieve the purpose of scale inhibition.

[0004] Among various types of power plant equipment, steel materials are mainly used, which are easily corroded during use. How to alleviate the corrosion of mechanical equipment is also a technical problem that needs to be solved urgently. At present, there are many prevention and control measures to reduce metal corrosion losses, such as the use of various organic / inorganic coating technologies, the addition of corrosion inhibitors, and electrochemical protection. However, corrosion inhibitors still have shortcomings in use. For example, slow-release agents such as chromates, mercury salts, and zinc salts are toxic, and various phosphorus-containing compounds can easily cause eutrophication of water bodies. If the gray water scale inhibitor prepared from polymer materials is modified to increase certain corrosion inhibition properties, it can achieve scale inhibition for various types of mechanical equipment while increasing certain anti-corrosion properties. In addition, how to prolong the scale inhibition effect of scale inhibitors and improve the stability of scale inhibition efficiency are also technical problems that need to be solved urgently.

[0005] Patent application CN103708632A discloses a scale inhibitor dispersant for ash water for gasification, including a terpolymer, acrylic acid-hydroxypropyl acrylate, a hydrolyzed maleic anhydride copolymer, a phosphate, etc., wherein the terpolymer is an acrylic acid / 2-methyl-2-acrylamide-propane sulfonic acid copolymer. The prepared scale inhibitor dispersant for ash water for gasification has the advantages of being environmentally friendly and having good dispersing and scale inhibition effects; however, the above-mentioned scale inhibitor dispersant does not have a corrosion inhibition effect and cannot further improve the anti-corrosion performance of various types of mechanical equipment.

[0006] Patent application CN10767885A discloses a phosphorus-free corrosion and scale inhibitor, including itaconic acid-acrylic acid-acrylate copolymer, 2-acrylamide-2-methylpropane sulfonic acid-diethylacrylamide polymer, polyepoxysuccinic acid and hydrolyzed polymaleic anhydride. The phosphorus-free corrosion and scale inhibitor uses active groups to chelate high-valent metal ions and has certain corrosion and scale inhibition properties; however, the above-mentioned gray water scale inhibitor dispersants all use high molecular polymers, the stability of the high molecular scale inhibitor is easily affected by the external environment, and the slow-release effect is not stable and continuous.

[0007] In view of the technical defects in this aspect, a solution is now proposed. Summary of the invention

[0008] The purpose of the present invention is to provide a corrosion-inhibiting gray water scale inhibitor dispersant and a preparation method thereof, which is used to solve the problems of poor stability and unsustainable scale inhibition efficiency of gray water scale inhibitor dispersants in the prior art. How to improve the corrosion inhibition performance of gray water scale inhibitor dispersants is also a technical problem that needs to be solved urgently.

[0009] The purpose of the present invention can be achieved by the following technical scheme: A method for preparing a corrosion-inhibiting gray water scale inhibitor dispersant comprises the following steps:

[0010] S1, styrene, acrylamide, acrylic acid and deionized water are uniformly mixed to obtain a mixture; a dispersant and an initiator are added to the mixture, and the mixture is reacted at room temperature for 10-12 hours to obtain a product; the product is post-processed to obtain a polymer wall material;

[0011] Styrene, acrylamide and acrylic acid are used as monomers. Under the action of dispersants and initiators, a polymer material is obtained through addition polymerization. After acrylamide and acrylic acid are dissolved in water, they carry opposite charges and thus produce electrostatic effects, which reduce solubility and produce phase separation, and condense to form the wall material of the corrosion-inhibiting gray water scale inhibitor dispersant.

[0012] S2. Dissolve the composite anti-scaling dispersant in ethanol to prepare a 10%wt core material solution; dissolve the polymer wall material in deionized water to prepare a 10%wt wall material solution; heat 100mL of the core material solution to 40-45°C, then add 100mL of the wall material solution drop by drop to the core material solution to obtain a mixed solution; the mixed solution is subjected to post-process treatment to obtain a corrosion-inhibiting gray water anti-scaling dispersant.

[0013] The polymer wall material is dissolved in deionized water to prepare a wall material solution, and the composite scale inhibitor is dissolved in ethanol to prepare a core material solution. The pH value of the core material solution is adjusted by using glacial acetic acid, and then the wall material solution is added drop by drop to perform a composite coagulation reaction to obtain a composite coagulation product. The mixed solution is then cooled to a low temperature state to terminate the composite coagulation reaction to allow the wall material to be fully precipitated. The pH value of the composite coagulation product is then adjusted, and formaldehyde is used as a curing cross-linking agent for curing to prepare a corrosion-inhibiting gray water scale inhibitor dispersant.

[0014] Furthermore, the preparation method of the composite scale inhibitor dispersant comprises the following steps:

[0015] A1, chitosan, vanillin and anhydrous ethanol are mixed, refluxed at 70-80°C for 2-3h, and then filtered under reduced pressure to obtain a solid; the solid is vacuum dried at 70-80°C to constant weight to obtain vanillin-modified chitosan;

[0016] Chitosan contains free amino groups, which can react with the aldehyde groups in vanillin to form azomethine characteristic groups, thereby obtaining vanillin-modified chitosan.

[0017] Chitosan and vanillin react to obtain vanillin-modified chitosan as follows:

[0018]

[0019] A2. Mix polyaspartic acid, modified corrosion inhibitor, vanillin modified chitosan and 40-50%wt ethanol solution, reflux at 70-80°C for 10-12h, and then distill at 100-110°C until all liquid is evaporated. The obtained solid is the composite scale inhibitor dispersant.

[0020] The imino and amino functional groups contained in polyaspartic acid and modified corrosion inhibitor solids can undergo hydroxyl amination reaction with the hydroxyl groups in vanillin-modified chitosan to prepare a composite scale inhibitor dispersant.

[0021] The reaction formula of polyaspartic acid, modified corrosion inhibitor solid and vanillin modified chitosan is as follows:

[0022]

[0023] Furthermore, in step A1, the amount ratio of chitosan, vanillin and anhydrous ethanol is 20-40g:15-25g:100mL; in step A2, the amount ratio of polyaspartic acid, modified corrosion inhibitor, vanillin modified chitosan and ethanol solution is 30-50g:30-40g:30-40g:200mL.

[0024] Furthermore, in step A2, the method for preparing the modified corrosion inhibitor comprises the following steps:

[0025] B1, triazole, acetone, potassium carbonate and ethyl chloroacetate were mixed, and refluxed at 80-90°C for 10-12h in a closed system to obtain a mixture; the mixture was filtered and the filtrate was collected; the filtrate was distilled under reduced pressure at -0.1MPa to -0.09MPa to obtain a white solid intermediate A;

[0026] Triazole and ethyl chloroacetate undergo N-alkylation reaction to prepare intermediate A. The reaction formula is as follows:

[0027]

[0028] B2. Mix the intermediate A, hydrazine hydrate and ethanol, and reflux the mixture at 70-80° C. for 10-12 hours to obtain a reaction solution; distill the reaction solution at 75-80° C. until the volume of the precipitated solid is constant, and collect the solid; and vacuum dry the solid at 70-80° C. to a constant weight to obtain a modified corrosion inhibitor.

[0029] Intermediate A reacts with hydrazine hydrate to prepare a modified corrosion inhibitor, and the reaction formula is as follows:

[0030]

[0031] Furthermore, in step B1, the usage ratio of triazole, acetone, potassium carbonate and ethyl chloroacetate is 7-14 g:150 mL:5-10 g:15-20 mL; in step B2, the usage ratio of intermediate A, hydrazine hydrate and ethanol is 25-35 g:5-10 mL:100 mL.

[0032] Furthermore, in step S1, the dosage ratio of styrene, acrylamide, acrylic acid and deionized water is 5-10mL:20-30g:20-30mL:100mL; the dispersant is sodium dodecyl sulfate, and the dosage is 0.15-0.3g; the initiator is potassium persulfate, and the dosage is 0.3-0.5g.

[0033] Furthermore, in step S1, the post-process treatment is specifically: transferring the product into a dialysis bag, dialyzing for 3 days, and obtaining a polymer wall material.

[0034] Furthermore, in step S2, the post-process treatment is specifically as follows: 5%-10wt% glacial acetic acid is added to the mixed solution, the pH value of the mixed solution is adjusted to 3.5-4, and stirred for 10-15min to obtain a composite condensation product; the composite condensation product is naturally cooled to room temperature, and then cooled to 10-15°C in an ice water bath, and then 10%wt NaOH solution is added to adjust the pH value of the composite condensation product to 9-11, and then 2-3mL of formaldehyde is added to solidify for 10-12h to obtain a corrosion-inhibiting gray water scale inhibitor dispersant.

[0035] As another aspect of the present invention, a method for preparing a corrosion-inhibiting gray water scale inhibitor dispersant is provided to prepare the corrosion-inhibiting gray water scale inhibitor dispersant.

[0036] The present invention has the following beneficial effects:

[0037] 1. The composite anti-scaling dispersant prepared by the present invention is prepared with polyaspartic acid, modified corrosion inhibitor and vanillin modified chitosan as monomers. The central atom N of triazole contains unshared electron pairs. When the metal has an empty d orbital, the lone pair of electrons of the central atom of triazole can form a coordination bond with the empty d orbital and adsorb on the metal surface. The above adsorption is chemical adsorption, and it is difficult to desorb once adsorbed. Triazole reacts with ethyl chloroacetate and hydrazine hydrate in sequence to obtain a modified corrosion inhibitor containing imino and amino functional groups, which can react with other monomers. Chitosan is an oligosaccharide formed by connecting 2 to 10 aminoglucose through glycosidic bonds, contains a large number of hydroxyl and amino functional groups, and is non-toxic to the environment and can be completely degraded by microorganisms or fungi. Therefore, it is an environmentally friendly green corrosion inhibitor.

[0038] Chitosan is modified by vanillin to increase carbon-nitrogen double bonds and hydroxide groups. The carbon-nitrogen double bonds contain lone pairs of electrons and have electron-donating properties, so they can also form coordination bonds with empty d orbitals of metals and be adsorbed, thereby improving the corrosion inhibition performance of chitosan. Polyaspartic acid, as a polycarboxylic acid polymer, has both acidic carboxyl groups and basic amide groups in its molecular structure, so polyaspartic acid has both neutral and anionic scale inhibitor properties, and can effectively inhibit calcium carbonate, calcium sulfate, calcium phosphate and barium sulfate scales by means of coagulation and dispersion, lattice distortion, complexation and solubilization, etc., showing an excellent polymerization effect. The modified corrosion inhibitor, vanillin-modified chitosan and polyaspartic acid are reacted to prepare a composite scale inhibitor dispersant with excellent corrosion inhibition effect.

[0039] 2. In order to improve the durability and stability of the scale inhibition performance of the prepared composite scale inhibition dispersant, the present invention uses the composite scale inhibition dispersant as the core material and embeds it into the synthetic polymer wall material to achieve the effect of improving the stability of the substance and controlling the release rate of the substance. The present invention also uses styrene, acrylamide and acrylic acid monomers to obtain a polymer wall material, and disperses the core material into an aqueous solution of the polymer wall material to obtain a self-assembled microcapsule, whose shell layer has uniformly distributed pores, which can embed small molecular substances, and the sustained release effect is durable and stable. In addition, the amide group and carboxyl group contained in the wall material itself have adsorption properties for calcium sulfate and calcium carbonate, so that the wall material and the wall core have excellent scale inhibition performance, realizing dual scale inhibition and sustained release scale inhibition. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Example 1

[0042] This embodiment provides a method for preparing a composite scale inhibitor dispersant for a corrosion-inhibiting gray water scale inhibitor dispersant, comprising the following steps:

[0043] A1. A 250 mL four-necked reaction flask is provided with a stirrer and a reflux condenser. 7 g of triazole, 150 mL of acetone, 10 g of potassium carbonate and 20 mL of ethyl chloroacetate are added to the four-necked reaction flask. The four-necked reaction flask is transferred to a water bath, and then the four-necked reaction flask is sealed. The mixture is heated to reflux at 90° C. and reacted for 12 h to obtain a mixture. The mixture is filtered and the filtrate is collected. The filtrate is distilled under reduced pressure at a pressure of -0.1 MPa to obtain a white solid intermediate A.

[0044] A2. Add 25 g of intermediate A, 5 mL of hydrazine hydrate and 100 mL of ethanol into a 250 mL four-necked reaction flask, which is equipped with a stirrer, a reflux condenser and a thermometer. The four-necked reaction flask is sealed and refluxed at 70° C. at 100 r / min for 10 h to obtain a reaction solution; distill the reaction solution at 75° C. until the volume of the precipitated solid remains unchanged, and collect the solid; dry the solid in a vacuum oven at 70° C. to constant weight to obtain a modified corrosion inhibitor.

[0045] A3, 20 g of chitosan, 15 g of vanillin and 100 mL of anhydrous ethanol were mixed and added into a 250 mL three-necked flask, a stirring bar was arranged inside the flask, one end of the three-necked flask was connected to a reflux condenser, and then the three-necked flask was transferred to a water bath, the temperature of the water bath was set to 70°C, and then the three-necked flask was sealed and refluxed at 200 r / min for 2 h, and then filtered under reduced pressure to obtain a solid; the solid was vacuum dried at 70°C to constant weight to obtain vanillin-modified chitosan.

[0046] A4. Add 30g of polyaspartic acid, 30g of modified corrosion inhibitor, 30g of vanillin modified chitosan and 200mL of 40%wt ethanol solution into a 500mL four-necked reaction bottle, and then seal the four-necked reaction bottle; reflux the reaction at 70°C for 10h with mechanical stirring at 200r / min. After the reaction, distill at 100°C until all the liquid is evaporated, and the obtained solid is the composite scale inhibitor dispersant.

[0047] Example 2

[0048] This embodiment provides a method for preparing a composite scale inhibitor dispersant for a corrosion-inhibiting gray water scale inhibitor dispersant, comprising the following steps:

[0049] A1. A 250 mL four-necked reaction flask is provided with a stirrer and a reflux condenser. 10 g of triazole, 150 mL of acetone, 8 g of potassium carbonate and 17 mL of ethyl chloroacetate are added to the four-necked reaction flask. The four-necked reaction flask is transferred to a water bath, and then the four-necked reaction flask is sealed. The mixture is heated to reflux at 85° C. and reacted for 11 hours to obtain a mixture. The mixture is filtered and the filtrate is collected. The filtrate is distilled under reduced pressure at a pressure of -0.1 MPa to obtain a white solid intermediate A.

[0050] A2. Add 30 g of intermediate A, 6 mL of hydrazine hydrate and 100 mL of ethanol into a 250 mL four-necked reaction flask, which is equipped with a stirrer, a reflux condenser and a thermometer. The four-necked reaction flask is sealed and refluxed at 75° C. and 150 r / min for 11 h to obtain a reaction solution; distill the reaction solution at 76° C. until the volume of the precipitated solid remains unchanged, and collect the solid; dry the solid in a vacuum oven at 75° C. to constant weight to obtain a modified corrosion inhibitor.

[0051] A3, 30 g of chitosan, 20 g of vanillin and 100 mL of anhydrous ethanol were mixed and added into a 250 mL three-necked flask, a stirring bar was arranged inside the flask, one end of the three-necked flask was connected to a reflux condenser, and then the three-necked flask was transferred to a water bath, the temperature of the water bath was set to 75°C, and then the three-necked flask was sealed, and reflux reaction was carried out at 250 r / min for 2.3 h, and then vacuum filtered to obtain a solid; the solid was vacuum dried at 72°C to constant weight to obtain vanillin-modified chitosan.

[0052] A4. Add 40g of polyaspartic acid, 35g of modified corrosion inhibitor, 35g of vanillin modified chitosan and 200mL of 45%wt ethanol solution into a 500mL four-necked reaction bottle, and then seal the four-necked reaction bottle; reflux the reaction at 73°C for 11h with mechanical stirring at 220r / min. After the reaction, distill at 105°C until all the liquid is evaporated, and the obtained solid is the composite scale inhibitor dispersant.

[0053] Example 3

[0054] This embodiment provides a method for preparing a composite scale inhibitor dispersant for a corrosion-inhibiting gray water scale inhibitor dispersant, comprising the following steps:

[0055] A1. A 250 mL four-necked reaction flask is provided with a stirrer and a reflux condenser. 14 g of triazole, 150 mL of acetone, 10 g of potassium carbonate and 20 mL of ethyl chloroacetate are added to the four-necked reaction flask. The four-necked reaction flask is transferred to a water bath, and then the four-necked reaction flask is sealed. The mixture is heated to reflux at 90° C. and reacted for 12 h to obtain a mixture. The mixture is filtered and the filtrate is collected. The filtrate is distilled under reduced pressure at a pressure of -0.09 MPa to obtain a white solid intermediate A.

[0056] A2. Add 35 g of intermediate A, 10 mL of hydrazine hydrate and 100 mL of ethanol into a 250 mL four-necked reaction flask, which is equipped with a stirrer, a reflux condenser and a thermometer. The four-necked reaction flask is sealed and refluxed at 80° C. at 200 r / min for 12 h to obtain a reaction solution; distill the reaction solution at 80° C. until the volume of the precipitated solid remains unchanged, and collect the solid; dry the solid in a vacuum oven at 80° C. to constant weight to obtain a modified corrosion inhibitor.

[0057] A3, 40 g of chitosan, 25 g of vanillin and 100 mL of anhydrous ethanol were mixed and added into a 250 mL three-necked flask, a stirring bar was arranged inside the flask, one end of the three-necked flask was connected to a reflux condenser, and then the three-necked flask was transferred to a water bath, the temperature of the water bath was set to 80°C, and then the three-necked flask was sealed, and reflux reaction was carried out at 300 r / min for 3 hours, and then vacuum filtered to obtain a solid; the solid was vacuum dried at 80°C to constant weight to obtain vanillin-modified chitosan.

[0058] A4. Add 50g of polyaspartic acid, 40g of modified corrosion inhibitor, 40g of vanillin modified chitosan and 200mL of 50%wt ethanol solution into a 500mL four-necked reaction bottle, and then seal the four-necked reaction bottle; reflux the reaction at 80°C for 12h with mechanical stirring at 300r / min. After the reaction, distill at 110°C until all the liquid is evaporated, and the obtained solid is the composite scale inhibitor dispersant.

[0059] Example 4

[0060] This embodiment provides a method for preparing a corrosion-inhibiting gray water scale inhibitor, comprising the following steps:

[0061] 1. Styrene, acrylamide and acrylic acid are passed through 300-mesh alkaline alumina fillers to remove the polymerization inhibitors of each monomer. A 250 mL four-necked flask is selected, and a reflux condenser and a stirring paddle are connected to the four-necked flask. Nitrogen is introduced into the four-necked flask until the inside of the four-necked flask is filled with nitrogen. 5 mL of styrene, 20 g of acrylamide, 20 mL of acrylic acid and 100 mL of deionized water are added to the four-necked flask, and mixed and stirred at 400 r / min for 10 min to obtain a mixture.

[0062] 2. Add 0.15 g of sodium dodecyl sulfate and 0.3 g of potassium persulfate into a four-necked flask and continue the reaction for 10 h to obtain a product. Transfer the product into a dialysis bag and dialyze for 3 days to remove unreacted monomers and related additives to prepare a polymer wall material.

[0063] 3. Dissolve 10g of the composite anti-scaling dispersant prepared in Example 1 in ethanol to prepare a 10%wt core material solution; dissolve 20g of the polymer wall material in deionized water at 45°C to prepare a 10%wt wall material solution; transfer 100mL of the core material solution to a 250mL four-necked flask, heat the four-necked flask to 40°C in a water bath, and then add 100mL of the wall material solution drop by drop into the four-necked flask through a constant pressure dropping funnel to obtain a mixed solution; then add 5%wt of glacial acetic acid to the four-necked flask, adjust the pH value of the mixed solution to 3.5, stir for 10min, and obtain a composite condensation product; then cool the four-necked flask naturally to room temperature, then cool it to 10°C in an ice water bath, then add 10%wt of NaOH solution to the four-necked flask, adjust the pH value of the composite condensation product to 9, and then add 2mL of formaldehyde to solidify for 10h to obtain a corrosion-inhibiting gray water anti-scaling dispersant.

[0064] Example 5

[0065] This embodiment provides a method for preparing a corrosion-inhibiting gray water scale inhibitor, comprising the following steps:

[0066] 1. Styrene, acrylamide and acrylic acid were passed through 300-mesh alkaline alumina fillers to remove the polymerization inhibitors of each monomer. A 250 mL four-necked flask was selected, and a reflux condenser and a stirring paddle were connected to the four-necked flask. Nitrogen was introduced into the four-necked flask until the inside of the four-necked flask was filled with nitrogen. 6 mL of styrene, 25 g of acrylamide, 25 mL of acrylic acid and 100 mL of deionized water were added to the four-necked flask, and mixed and stirred at 450 r / min for 15 min to obtain a mixture.

[0067] 2. Add 0.2 g of sodium dodecyl sulfate and 0.4 g of potassium persulfate into a four-necked flask and continue the reaction for 11 h to obtain a product. Transfer the product into a dialysis bag and dialyze for 3 days to remove unreacted monomers and related additives to prepare a polymer wall material.

[0068] 3. Dissolve 15g of the composite anti-scaling dispersant prepared in Example 2 in ethanol to prepare a 10%wt core material solution; dissolve 26g of the polymer wall material in deionized water at 46°C to prepare a 10%wt wall material solution; transfer 100mL of the core material solution to a 250mL four-necked flask, heat the four-necked flask to 42°C in a water bath, and then add 100mL of the wall material solution dropwise into the four-necked flask through a constant pressure dropping funnel to obtain a mixed solution; then drop 6%wt of glacial acetic acid into the four-necked flask, adjust the pH value of the mixed solution to 3.8, stir for 12min, and obtain a composite condensation product; then cool the four-necked flask naturally to room temperature, then cool it to 12°C in an ice water bath, then add 10%wt of NaOH solution to the four-necked flask, adjust the pH value of the composite condensation product to 10, and then add 2.3mL of formaldehyde to cure for 11h to obtain a corrosion-inhibiting gray water anti-scaling dispersant.

[0069] Example 6

[0070] This embodiment provides a method for preparing a corrosion-inhibiting gray water scale inhibitor, comprising the following steps:

[0071] 1. Styrene, acrylamide and acrylic acid were passed through a 300-mesh alkaline alumina filler to remove the polymerization inhibitor of each monomer. A 250 mL four-necked flask was selected, and a reflux condenser and a stirring paddle were connected to the four-necked flask. Nitrogen was introduced into the four-necked flask until the inside of the four-necked flask was filled with nitrogen. 10 mL of styrene, 30 g of acrylamide, 30 mL of acrylic acid and 100 mL of deionized water were added to the four-necked flask, and mixed and stirred at 500 r / min for 20 min to obtain a mixture.

[0072] 2. Add 0.3 g of sodium dodecyl sulfate and 0.5 g of potassium persulfate into a four-necked flask and continue the reaction for 12 h to obtain a product. Transfer the product into a dialysis bag and dialyze for 3 days to remove unreacted monomers and related additives to prepare a polymer wall material.

[0073] 3. Dissolve 20g of the composite anti-scaling dispersant prepared in Example 3 in ethanol to prepare a 10%wt core material solution; dissolve 30g of the polymer wall material in 50°C deionized water to prepare a 10%wt wall material solution; transfer 100mL of the core material solution to a 250mL four-necked flask, heat the four-necked flask to 45°C in a water bath, and then add 100mL of the wall material solution drop by drop into the four-necked flask through a constant pressure dropping funnel to obtain a mixed solution; then drop 10wt of glacial acetic acid into the four-necked flask, adjust the pH value of the mixed solution to 4, stir for 15min, and obtain a composite condensation product; then cool the four-necked flask naturally to room temperature, then cool it to 15°C in an ice water bath, then add 10%wt of NaOH solution to the four-necked flask, adjust the pH value of the composite condensation product to 11, and then add 3mL of formaldehyde to solidify for 12h to obtain a corrosion-inhibiting gray water anti-scaling dispersant.

[0074] Comparative Example 1

[0075] Compared with Example 6, this comparative example uses styrene and acrylic acid monomers to prepare a polymer wall material.

[0076] Comparative Example 2

[0077] Compared with Example 6, in this comparative example, no modified corrosion inhibitor was added when preparing the composite scale inhibitor and dispersant.

[0078] Comparative Example 3

[0079] Compared with Example 6, in this comparative example, chitosan was not modified with vanillin when preparing the composite scale inhibitor and dispersant.

[0080] Performance Testing:

[0081] 1. According to GB / T16632-2008 "Determination of scale inhibition performance of water treatment agents - calcium carbonate precipitation method", the scale inhibition rate of the corrosion-inhibiting gray water scale inhibitor dispersant prepared in Examples 4-6 and Comparative Examples 1-3 on calcium carbonate at 6h and 12h was calculated; wherein the dosage of the scale inhibitor was 15 mg / L.

[0082] 2. Add a certain volume of the prepared calcium chloride standard solution and sodium sulfate standard solution and the corrosion-inhibiting gray water scale inhibitor prepared in Examples 4-6 and Comparative Examples 1-3 into a 500 mL volumetric flask, dilute with deionized water, shake well, and prepare the final solution of Ca 2+ Concentration is 2000mg / L, SO4 2- The concentration was 4800 mg / L. The prepared solution was transferred to a conical flask and placed in a 70°C constant temperature water bath for 6 h and 12 h respectively. After natural cooling, 3 mL of the filtrate was filtered and placed in a conical flask. Water was added to 30 mL and Ca was determined by EDTA titration. 2+Concentration, record the scale inhibition rate of calcium sulfate respectively, the calculation method is the same as the calculation formula of the scale inhibition rate of calcium carbonate.

[0083] 3. 7B04 aluminum alloy was used as the sample, and the sample size was 1cm×1cm×0.5cm. Before the experiment, the aluminum alloy sample was ultrasonically cleaned in alcohol to remove surface grease. Then it was immersed in a 3.5%wt NaCl solution containing 60mg / L corrosion-inhibiting gray water scale inhibitor and dispersant for 14 days, and its corrosion inhibition rate was calculated by electrochemical detection. The calculation formula of the corrosion inhibition rate is as follows:

[0084] η=(I 0 corr -I corr ) / I corr

[0085] Where I 0 corr and I corr Represent the corrosion current in blank solution and test solution respectively.

[0086] Table 1- Sample performance test data table

[0087]

[0088]

[0089] Data Analysis:

[0090] A comparative analysis of the data in Table 1 above shows that the corrosion-inhibiting gray water scale inhibitor dispersants prepared in Examples 4-6 of the present invention have excellent scale inhibition efficiency for both calcium carbonate and calcium sulfate and the scale inhibition effect is sustained. Acrylamide and acrylic acid have opposite charges and thus electrostatic action occurs, and they can interact with each other to improve the fastness of the prepared polymer wall material and further improve their own slow-release effect, which is manifested in that the prepared corrosion-inhibiting gray water scale inhibitor dispersants have excellent scale inhibition efficiency for both calcium carbonate and calcium sulfate within 12 hours; however, in Comparative Example 1, acrylamide monomer was not added when preparing the polymer wall material, the fastness and stability of the polymer wall material were reduced, and the slow-release effect was weakened, which is manifested in that the slow-release efficiency is high in a relatively short period of time, while the scale inhibition efficiency is not further improved after 12 hours.

[0091] The corrosion-inhibiting gray water scale inhibitor dispersants prepared in Examples 4-6 of the present invention use a composite scale inhibitor dispersant as the core material, and the modified corrosion inhibitor constituting the composite scale inhibitor dispersant has a certain corrosion inhibition effect; however, in Comparative Example 2, when preparing the composite scale inhibitor dispersant, no modified corrosion inhibitor was added, and the modified corrosion inhibitor contained a nitrogen azole group, which itself had a corrosion inhibition effect, resulting in a decrease in the corrosion inhibition rate of the corrosion-inhibiting gray water scale inhibitor dispersant prepared in Comparative Example 2; in Comparative Example 3, when preparing the composite scale inhibitor dispersant, chitosan was not modified with vanillin, and the carbon-nitrogen double bond itself has electron-donating properties, which can improve the corrosion inhibition properties of chitosan, resulting in a decrease in the corrosion inhibition efficiency of the composite scale inhibitor dispersant prepared in Comparative Example 3, which is manifested as a decrease in the corrosion inhibition rate.

[0092] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

[0093] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0094] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a corrosion-inhibiting gray water scale inhibitor dispersant, characterized in that: The following steps are involved: S1, styrene, acrylamide, acrylic acid and deionized water are uniformly mixed to obtain a mixture; a dispersant and an initiator are added to the mixture, and then reacted at room temperature for 10-12 hours to obtain a product; the product is post-processed to obtain a polymer wall material; S2. The composite anti-scaling dispersant is dissolved in ethanol to prepare a 10%wt core material solution; the polymer wall material is dissolved in deionized water to prepare a 10%wt wall material solution; 100mL of the core material solution is heated to 40-45°C, and then 100mL of the wall material solution is added dropwise to the core material solution to obtain a mixed solution; the mixed solution is subjected to post-process treatment to obtain a corrosion-inhibiting gray water anti-scaling dispersant.

2. The method for preparing a corrosion-inhibiting gray water scale inhibitor dispersant according to claim 1, characterized in that: The preparation method of the composite scale inhibitor dispersant comprises the following steps: A1, chitosan, vanillin and anhydrous ethanol are mixed, refluxed at 70-80°C for 2-3h, and then filtered under reduced pressure to obtain a solid; the solid is vacuum dried at 70-80°C to constant weight to obtain vanillin-modified chitosan; A2. Mix polyaspartic acid, modified corrosion inhibitor, vanillin modified chitosan and 40-50%wt ethanol solution, reflux at 70-80°C for 10-12h, and then distill at 100-110°C until all the liquid is evaporated. The obtained solid is the composite scale inhibitor dispersant.

3. The method for preparing a corrosion-inhibiting gray water scale inhibitor dispersant according to claim 2, characterized in that: In step A1, the amount ratio of chitosan, vanillin and anhydrous ethanol is 20-40g:15-25g:100mL; in step A2, the amount ratio of polyaspartic acid, modified corrosion inhibitor, vanillin modified chitosan and ethanol solution is 30-50g:30-40g:30-40g:200mL.

4. The method for preparing a corrosion-inhibiting gray water scale inhibitor dispersant according to claim 2, characterized in that: In step A2, the method for preparing the modified corrosion inhibitor comprises the following steps: B1, triazole, acetone, potassium carbonate and ethyl chloroacetate were mixed, and refluxed at 80-90°C for 10-12h in a closed system to obtain a mixture; the mixture was filtered and the filtrate was collected; the filtrate was distilled under reduced pressure at -0.1MPa to -0.09MPa to obtain a white solid intermediate A; B2. Mix the intermediate A, hydrazine hydrate and ethanol, and reflux the mixture at 70-80° C. for 10-12 hours to obtain a reaction solution; distill the reaction solution at 75-80° C. until the volume of the precipitated solid is constant, and collect the solid; and vacuum dry the solid at 70-80° C. to a constant weight to obtain a modified corrosion inhibitor.

5. The method for preparing a corrosion-inhibiting gray water scale inhibitor dispersant according to claim 4, characterized in that: In step B1, the usage ratio of triazole, acetone, potassium carbonate and ethyl chloroacetate is 7-14 g:150 mL:5-10 g:15-20 mL; in step B2, the usage ratio of intermediate A, hydrazine hydrate and ethanol is 25-35 g:5-10 mL:100 mL.

6. The method for preparing a corrosion-inhibiting gray water scale inhibitor dispersant according to claim 1, characterized in that: In step S1, the dosage ratio of styrene, acrylamide, acrylic acid and deionized water is 5-10mL:20-30g:20-30mL:100mL; the dispersant is sodium dodecyl sulfate, and the dosage is 0.15-0.3g; the initiator is potassium persulfate, and the dosage is 0.3-0.5g.

7. The method for preparing a corrosion-inhibiting gray water scale inhibitor dispersant according to claim 1, characterized in that: In step S1, the post-process treatment is specifically: transferring the product into a dialysis bag, dialyzing for 3 days, and obtaining a polymer wall material.

8. The method for preparing a corrosion-inhibiting gray water scale inhibitor dispersant according to claim 1, characterized in that: In step S2, the post-process treatment is specifically as follows: 5%-10wt of glacial acetic acid is added to the mixed solution, the pH value of the mixed solution is adjusted to 3.5-4, and stirred for 10-15min to obtain a composite condensation product; the composite condensation product is naturally cooled to room temperature, and then cooled to 10-15°C in an ice water bath, and then 10%wt of NaOH solution is added to adjust the pH value of the composite condensation product to 9-11, and then 2-3mL of formaldehyde is added to solidify for 10-12h to obtain a corrosion-inhibiting gray water scale inhibitor dispersant.

9. A corrosion-inhibiting grey water scale inhibitor dispersant, characterized in that: The corrosion-inhibiting grey water scale inhibitor dispersant is prepared by the preparation method of the corrosion-inhibiting grey water scale inhibitor dispersant as described in any one of claims 1 to 8.

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