Biodegradable non-phosphorus scale and corrosion inhibitor and preparation method thereof

Abstract

The application discloses a phosphorus-free scale and corrosion inhibitor easy to be biodegraded and a preparation method thereof, and belongs to the technical field of water treatment. The phosphorus-free scale and corrosion inhibitor comprises the following components in parts by weight: 360-400 parts of water, 30-40 parts of modified polyepoxysuccinic acid, 20-30 parts of a composite adsorption corrosion inhibitor, 20-25 parts of hydrolyzed polymaleic anhydride, 8-15 parts of sodium gluconate, 4-6 parts of alanine, 2-5 parts of sodium alginate and 1-3 parts of sodium carboxymethyl cellulose. The composite adsorption corrosion inhibitor is formed by a complex of plant polyphenol and hydroxypropyl-beta-cyclodextrin, and then is reacted with sodium tartrate, sodium citrate and polyaspartic acid to obtain the composite adsorption corrosion inhibitor. The modified polyepoxysuccinic acid is obtained by modifying epoxysuccinic acid with urea, N-hydroxymaleimide and citraconimide. The phosphorus-free scale and corrosion inhibitor prepared by the application is easy to be biodegraded and has good scale and corrosion inhibition performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of water treatment, and particularly relates to a phosphorus-free scale and corrosion inhibitor easy to be biodegraded and a preparation method thereof. BACKGROUND

[0002] Traditional scale and corrosion inhibitors can only play a good scale and corrosion inhibition effect in a specific pH range. When the pH value of water exceeds the range, the performance of the scale and corrosion inhibitor will be greatly reduced, which cannot stably guarantee the normal operation of equipment in a complex water quality environment and cannot meet the adaptability requirement of different industrial production and water treatment scenes to the pH change of water quality. In some high-temperature industrial circulating water systems or hot water treatment equipment, the existing scale and corrosion inhibitor is prone to decomposition, volatilization or performance degradation under high-temperature conditions. Not only the scale and corrosion inhibition effect is greatly reduced, but also new impurities are generated due to the change of components, which affects the normal operation of the water system and even causes additional damage to the equipment.

[0003] Therefore, the application develops a phosphorus-free scale and corrosion inhibitor easy to be biodegraded and a preparation method thereof to solve the technical problems of the existing scale and corrosion inhibitor, such as containing phosphorus, not easy to be biodegraded and poor stability of a compounded system. SUMMARY

[0004] The application aims to provide a phosphorus-free scale and corrosion inhibitor easy to be biodegraded and a preparation method thereof to solve the technical problems of the existing scale and corrosion inhibitor, such as containing phosphorus, not easy to be biodegraded and poor stability of a compounded system.

[0005] In order to achieve the above-mentioned purpose, the application adopts the following technical scheme:

[0006] The phosphorus-free scale and corrosion inhibitor easy to be biodegraded comprises the following components in parts by weight: 360-400 parts of water, 30-40 parts of modified polyepoxysuccinic acid, 20-30 parts of a composite adsorption corrosion inhibitor, 20-25 parts of hydrolyzed polymaleic anhydride, 8-15 parts of sodium gluconate, 4-6 parts of alanine, 2-5 parts of sodium alginate and 1-3 parts of sodium carboxymethyl cellulose; the composite adsorption corrosion inhibitor is formed by a complex of plant polyphenol and hydroxypropyl-beta-cyclodextrin, and then reacts with sodium tartrate, sodium citrate and polyaspartic acid to obtain; the modified polyepoxysuccinic acid is synthesized by reacting a sodium hydroxide solution, a maleic anhydride solution and hydrogen peroxide to obtain epoxysuccinic acid, and then modified by urea, N-hydroxymaleimide and citraconimide.

[0007] As a preferred, the preparation method of the composite adsorption corrosion inhibitor comprises the following steps:

[0008] Q1, plant polyphenol solution is added into a saturated aqueous solution of hydroxypropyl-beta-cyclodextrin, stirred, ultrasonically treated, cooled, placed, filtered, washed, dried to obtain a complex;

[0009] Q2, adding the inclusion compound, sodium tartrate and sodium citrate into water, adjusting the pH value to 8-9, heating and stirring to react, obtaining a reaction solution, cooling to room temperature, adding polyaspartic acid solution and N,N-dicyclohexyl carbodiimide into the reaction solution, stirring to react, adding dilute hydrochloric acid to adjust the pH value to 6-7, filtering, collecting the filtrate, adding the filtrate into anhydrous ethanol to obtain a precipitate, washing, drying, and obtaining the composite adsorption corrosion inhibitor.

[0010] As preferred, the volume ratio of the plant polyphenol solution to the saturated aqueous cyclodextrin solution in Q1 is 1:6-8, the plant polyphenol is a mixture of tea polyphenol and tannic acid, the mass ratio of tea polyphenol to tannic acid is 1:1-2, and the plant polyphenol solution is prepared by mixing plant polyphenol and ethanol according to a mass ratio of 1:5-8; the ultrasonic power is 100-300 W, the ultrasonic temperature is 30-50℃, the ultrasonic time is 30-60 min, the cooling temperature is room temperature, the standing temperature is 2-8℃, and the standing time is 12-24 h.

[0011] As preferred, the mass ratio of the inclusion compound, sodium tartrate, sodium citrate and water in Q2 is 1:2-3:1-2:10-20, the pH value is adjusted to 8-9 by 1 mol / L NaOH, the heating temperature is 50-70℃, the stirring speed is 300-500 r / min, the stirring reaction time is 2-4 h, the mass concentration of the polyaspartic acid solution is 10-30 wt%, the ratio of the reaction solution, the polyaspartic acid solution and N,N-dicyclohexyl carbodiimide is 10 g:50-100 mL:0.05-0.3 g, the room temperature stirring reaction time is 4-6 h, the concentration of the dilute hydrochloric acid is 0.1-1 mol / L, and the volume ratio of the filtrate to anhydrous ethanol is 1:10-20.

[0012] As preferred, the preparation method of the modified polyepoxysuccinic acid comprises the following steps:

[0013] S1, adding sodium hydroxide solution dropwise into maleic anhydride solution, stirring, adding a catalyst, and adding hydrogen peroxide dropwise to react, obtaining an epoxysuccinic acid solution; adding an initiator into the epoxysuccinic acid solution, heating, and obtaining polyepoxysuccinic acid;

[0014] S2, dissolving the polyepoxysuccinic acid in N,N-dimethylformamide, respectively adding urea, N-hydroxymaleimide, citraconimide, p-toluenesulfonic acid, dicyclohexyl carbodiimide and 4-dimethylamino pyridine, heating to react, after the reaction, cooling, filtering, collecting the filtrate, pouring the filtrate into deionized water to obtain a precipitate, filtering, washing and drying, and obtaining the modified polyepoxysuccinic acid.

[0015] Preferably, the concentration of the maleic anhydride solution in S1 is 0.5-2 mol / L, the concentration of the sodium hydroxide solution is 1-3 mol / L, the catalyst is silicotungstic acid, the mass concentration of the hydrogen peroxide is 30 wt%, the dosage ratio of the maleic anhydride solution, the sodium hydroxide solution, the silicotungstic acid and the hydrogen peroxide is 100 mL: 50-100 mL: 0.05-0.2 g: 30-40 mL, the reaction temperature is 65-70 DEG C, and the reaction time is 2-3 h; the initiator is an equal-mass mixture of sodium hydroxide and potassium hydroxide, the dosage ratio of the initiator and the epoxy succinic acid solution is 0.1-0.5 g: 100 mL; the heating temperature is 85-90 DEG C, and the reaction time is 3-4 h.

[0016] Preferably, the dosage ratio of the polyepoxysuccinic acid, N,N-dimethylformamide, urea, N-hydroxymaleimide, citraconimide, p-toluenesulfonic acid, dicyclohexyl carbodiimide and 4-dimethylamino pyridine in S2 is 10 g: 100-200 mL: 1-2.5 g: 1-2.5 g: 1-2 g: 0.1-0.3 g: 10-12 g: 0.1-0.5 g, the heating temperature is 80-100 DEG C, the heating reaction time is 4-6 h, the cooling temperature is 20-25 DEG C, and the reaction time is 12-24 h.

[0017] Further, the preparation method of the easily biodegradable phosphorus-free scale and corrosion inhibitor comprises the following steps:

[0018] (1) mixing the modified polyepoxysuccinic acid and the hydrolyzed polymaleic anhydride to obtain a mixture one, grinding the composite adsorption corrosion inhibitor, adding the composite adsorption corrosion inhibitor into the mixture one, and stirring to obtain a mixture two;

[0019] (2) adding the sodium carboxymethyl cellulose into water, stirring and dissolving to obtain a sodium carboxymethyl cellulose solution; adding the sodium alginate and the sodium gluconate into the sodium carboxymethyl cellulose solution respectively, stirring and dissolving to obtain a mixed solution; adding the mixed solution into the mixture two, stirring uniformly, and finally adding the alanine, and stirring to obtain the easily biodegradable phosphorus-free scale and corrosion inhibitor.

[0020] Preferably, the particle size of the composite adsorption corrosion inhibitor in step (1) is 10-100 microns, the stirring speed is 200-400 r / min, and the stirring time is 30-60 min.

[0021] As described above, the present application has the following advantages due to the adoption of the above technical solutions:

[0022] 1、The invention is through the synergistic effect of modified polyepoxysuccinic acid, composite adsorption corrosion inhibitor, sodium polyacrylate, hydrolyzed polymaleic anhydride, sodium carboxymethyl cellulose, sodium gluconate and other components, wherein the modified polyepoxysuccinic acid, hydrolyzed polymaleic anhydride and sodium gluconate act as metal organic chelating agents, which can effectively prevent the formation of scale layer by calcium, magnesium and other ions in water, has the effect of softening water quality and slowing down the rate of scale formation, at the same time, forms a protective film on the metal surface, inhibits the corrosion of metal, prolongs the service life of equipment. The components in the scale and corrosion inhibitor have good biodegradability, and the synergistic effect of each component forms a stable compounded system, which is not prone to delamination, precipitation and other phenomena during storage and use.

[0023] 2、The invention is through the formation of inclusion compound by plant polyphenol and hydroxypropyl-β-cyclodextrin, not only improves the stability and solubility of plant polyphenol, but also makes it more easily adsorbed on the metal surface. The introduction of sodium tartrate and sodium citrate forms a complex with metal ions, further enhances the stability and density of the protective film. In addition, the addition of polyaspartic acid forms an adsorption network with rich pore structure and active sites, which has good adsorption performance and chelating ability, can synergize with plant polyphenol and other components, improve the adhesion of corrosion inhibitor on the metal surface and the barrier ability to corrosion medium, thereby significantly enhancing the corrosion inhibition effect of phosphorus-free scale and corrosion inhibitor.

[0024] 3、The invention is through the reaction of sodium hydroxide solution, maleic anhydride solution and hydrogen peroxide to synthesize epoxy succinic acid, and then modified by urea, N-hydroxymaleimide and citraconimide, introducing various active groups into the molecular structure of polyepoxysuccinic acid, enhancing the chelating ability to calcium, magnesium, iron and other metal ions, which can more effectively prevent the formation of scale deposits by metal ions. At the same time, the modified molecular structure has a stronger interference effect on the growth of scale crystals, inhibiting the aggregation and growth of scale crystals, thereby significantly improving the scale inhibition performance of phosphorus-free scale and corrosion inhibitor. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the invention are described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the invention, not all the embodiments. Based on the embodiments in the invention, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the invention.

[0026] Embodiment 1:

[0027] The embodiment provides a preparation method of composite adsorption corrosion inhibitor, comprising the following steps:

[0028] Q1, a plant polyphenol solution is obtained by mixing plant polyphenols and ethanol at a mass ratio of 1:5, the mass ratio of tea polyphenols and tannic acid being 1:1, 100 mL of the plant polyphenol solution is added to 600 mL of a saturated aqueous solution of hydroxypropyl-β-cyclodextrin, stirring, ultrasonic treatment, ultrasonic power being 100 W, ultrasonic temperature being 30°C, ultrasonic time being 30 min, cooling to room temperature, standing temperature being 2°C, standing time being 12 h, filtration, washing, and drying to obtain an inclusion compound;

[0029] Q2, 10 g of the inclusion compound, 20 g of sodium tartrate, and 10 g of sodium citrate are added to 100 g of water, the pH value is adjusted to 8 by using 1 mol / L NaOH, heated stirring reaction, heating temperature being 50°C, stirring speed being 300 r / min, stirring reaction time being 2 h to obtain a reaction solution, cooling to room temperature, 50 mL of a 10 wt% polyaspartic acid solution and 0.05 g of N,N-dicyclohexyl carbodiimide are added to 10 g of the reaction solution, room temperature stirring reaction time being 4 h, 0.1-1 mol / L dilute hydrochloric acid is added to adjust the pH value to 6, filtration, the filtrate is collected, 50 mL of the filtrate is added to 500 mL of anhydrous ethanol to obtain a precipitate, washing, and drying to obtain a composite adsorption corrosion inhibitor.

[0030] The embodiment provides a preparation method of modified polyepoxysuccinic acid, including the following steps:

[0031] S1, 1 mol / L 50 mL of a sodium hydroxide solution is added dropwise to 0.5 mol / L 100 mL of a maleic anhydride solution, stirring, 0.05 g of tungstosilicic acid is added, 30 mL of 30 wt% hydrogen peroxide is added dropwise for reaction, the reaction temperature is 65°C, and the reaction time is 2 h to obtain an epoxysuccinic acid solution; 0.05 g of sodium hydroxide and 0.05 g of potassium hydroxide are added to 100 mL of the epoxysuccinic acid solution, heating, the heating temperature is 85°C, and the reaction time is 3 h to obtain polyepoxysuccinic acid;

[0032] S2, 10 g of the polyepoxysuccinic acid is dissolved in 100 mL of N,N-dimethylformamide, 1 g of urea, 1 g of N-hydroxymaleimide, 1 g of citraconimide, 0.1 g of p-toluenesulfonic acid, 10 g of dicyclohexyl carbodiimide, and 0.1 g of 4-dimethylaminopyridine are added, heating reaction, the heating temperature is 80°C, and the heating reaction time is 4 h, after the reaction is completed, the reaction is cooled, the cooling temperature is 20°C, and the reaction time is 12 h, filtration, the filtrate is collected, the filtrate is poured into deionized water to obtain a precipitate, and the precipitate is filtered, washed, and dried to obtain modified polyepoxysuccinic acid.

[0033] The embodiment provides an easily biodegradable phosphorus-free scale and corrosion inhibitor, which comprises the following components by weight: 360 g of water, 30 g of modified polyepoxysuccinic acid, 20 g of a composite adsorption corrosion inhibitor, 20 g of hydrolyzed polymaleic anhydride, 8 g of sodium gluconate, 4 g of alanine, 2 g of sodium alginate and 1 g of sodium carboxymethyl cellulose.

[0034] The preparation method of the easily biodegradable phosphorus-free scale and corrosion inhibitor comprises the following steps:

[0035] (1) mixing the modified polyepoxysuccinic acid and the hydrolyzed polymaleic anhydride to obtain a mixture one, grinding the composite adsorption corrosion inhibitor, the particle size of the composite adsorption corrosion inhibitor being 100 microns, adding the composite adsorption corrosion inhibitor into the mixture one, stirring at a stirring speed of 200 r / min for 30 min to obtain a mixture two;

[0036] (2) adding the sodium carboxymethyl cellulose into water, stirring and dissolving to obtain a sodium carboxymethyl cellulose solution, adding the sodium alginate and the sodium gluconate into the sodium carboxymethyl cellulose solution respectively, stirring and dissolving to obtain a mixed solution, adding the mixed solution into the mixture two, stirring uniformly, finally adding the alanine, and stirring to obtain the easily biodegradable phosphorus-free scale and corrosion inhibitor.

[0037] Embodiment 2:

[0038] The embodiment provides a preparation method of a composite adsorption corrosion inhibitor, which comprises the following steps:

[0039] Q1, a plant polyphenol solution is obtained by mixing plant polyphenols and ethanol according to a mass ratio of 1:6, the mass ratio of tea polyphenols and tannic acid is 1:1.2, 100 mL of the plant polyphenol solution is added into 650 mL of a hydroxypropyl-β-cyclodextrin saturated aqueous solution, stirring, ultrasonic treatment, the ultrasonic power is 180 W, the ultrasonic temperature is 35 DEG C, the ultrasonic time is 35 min, cooling to room temperature, the temperature of standing is 4 DEG C, the standing time is 16 h, filtering, washing, drying to obtain an inclusion compound;

[0040] Q2, 10 g of the inclusion compound, 22 g of sodium tartrate and 14 g of sodium citrate are added into 120 g of water, the pH value is adjusted to 8.3 by using 1 mol / L NaOH, heating and stirring reaction, the heating temperature is 55 DEG C, the stirring speed is 350 r / min, the stirring reaction time is 2.5 h, to obtain a reaction liquid, cooling to room temperature, 60 mL of 15 wt% polyaspartic acid solution and 0.1 g of N,N-dicyclohexyl carbodiimide are added into 10 g of the reaction liquid, the stirring reaction time is 5 h at room temperature, 0.4 mol / L dilute hydrochloric acid is added to adjust the pH value to 6.2, filtering, collecting the filtrate, 50 mL of the filtrate is added into 600 mL of anhydrous ethanol to obtain a precipitate, washing and drying to obtain the composite adsorption corrosion inhibitor.

[0041] The embodiment provides a preparation method of modified polyepoxysuccinic acid, and comprises the following steps:

[0042] S1, 1.6mol / L 60mL sodium hydroxide solution is added dropwise into 0.8mol / L 100mL maleic anhydride solution, stirring, 0.1g tungstosilicic acid is added, 33mL 30wt% hydrogen peroxide is added dropwise for reaction, the reaction temperature is 66℃, the reaction time is 2.5h, and an epoxysuccinic acid solution is obtained; 0.1g sodium hydroxide and 0.1g potassium hydroxide are added into 100mL epoxysuccinic acid solution, heating, the heating temperature is 86℃, the reaction time is 3.2h, and polyepoxysuccinic acid is obtained;

[0043] S2, 10g polyepoxysuccinic acid is dissolved in 120mL N,N-dimethylformamide, 1.5g urea, 1.5g N-hydroxymaleimide, 1.2g citraconimide, 0.15g p-toluenesulfonic acid, 10.5g dicyclohexyl carbodiimide and 0.2g 4-dimethylaminopyridine are added respectively, heating reaction, the heating temperature is 85℃, the heating reaction time is 4.5h, after the reaction is completed, the reaction is cooled, the cooling temperature is 21℃, the reaction time is 16h, filtration is carried out, the filtrate is collected, the filtrate is poured into deionized water, a precipitate is obtained, and the precipitate is filtered, washed and dried to obtain modified polyepoxysuccinic acid.

[0044] The embodiment provides a biodegradable phosphorus-free scale and corrosion inhibitor, which comprises the following components by weight: 370g water, 32g modified polyepoxysuccinic acid, 22g composite adsorption corrosion inhibitor, 21g hydrolyzed polymaleic anhydride, 10g sodium gluconate, 4g alanine, 3g sodium alginate and 1g sodium carboxymethyl cellulose.

[0045] The preparation method of the biodegradable phosphorus-free scale and corrosion inhibitor comprises the following steps:

[0046] (1) mixing the modified polyepoxysuccinic acid and the hydrolyzed polymaleic anhydride to obtain a mixture one, grinding the composite adsorption corrosion inhibitor, the particle size of the composite adsorption corrosion inhibitor is 40 microns, adding the composite adsorption corrosion inhibitor into the mixture one, stirring, the stirring speed is 250r / min, and the stirring time is 40min, to obtain a mixture two;

[0047] (2) adding the sodium carboxymethyl cellulose into water and stirring and dissolving to obtain a sodium carboxymethyl cellulose solution; adding the sodium alginate and the sodium gluconate into the sodium carboxymethyl cellulose solution respectively and stirring and dissolving to obtain a mixed solution; adding the mixed solution into the mixture two and stirring uniformly, and finally adding the alanine and stirring to obtain the biodegradable phosphorus-free scale and corrosion inhibitor.

[0048] Embodiment 3:

[0049] The embodiment provides a preparation method of a composite adsorption corrosion inhibitor, which comprises the following steps:

[0050] Q1, the plant polyphenol solution is obtained by mixing plant polyphenols and ethanol at a mass ratio of 1:7, and the mass ratio of tea polyphenols to tannic acid is 1:1.8. 100 mL of the plant polyphenol solution is added to 750 mL of a saturated aqueous solution of hydroxypropyl-β-cyclodextrin, stirred, ultrasonically treated at an ultrasonic power of 250 W and an ultrasonic temperature of 45℃ for 50 min, cooled to room temperature, and left to stand at a temperature of 6℃ for 16 h. After filtration, washing, and drying, the inclusion compound is obtained;

[0051] Q2, 10 g of the inclusion compound, 28 g of sodium tartrate, and 18 g of sodium citrate are added to 180 g of water, and the pH value is adjusted to 8.5 with 1 mol / L NaOH. After heating and stirring for 3 h at a temperature of 60℃ and a stirring speed of 400 r / min, a reaction solution is obtained. After cooling to room temperature, 90 mL of a 20 wt% polyaspartic acid solution and 0.2 g of N,N-dicyclohexyl carbodiimide are added to 10 g of the reaction solution, and stirring is performed at room temperature for 5 h. After adjusting the pH value to 6.8 with 0.8 mol / L dilute hydrochloric acid, filtration is performed, and the filtrate is collected. After 50 mL of the filtrate is added to 800 mL of anhydrous ethanol, a precipitate is obtained. After washing and drying, the composite adsorption corrosion inhibitor is obtained.

[0052] The embodiment provides a preparation method of modified polyepoxysuccinic acid, and the method comprises the following steps:

[0053] S1, 90 mL of a 2 mol / L sodium hydroxide solution is added dropwise to 100 mL of a 1.5 mol / L maleic anhydride solution, stirred, and 0.15 g of tungstosilicic acid is added. After 38 mL of 30 wt% hydrogen peroxide is added dropwise for reaction at a temperature of 68℃ for 3 h, an epoxysuccinic acid solution is obtained. After 0.2 g of sodium hydroxide and 0.2 g of potassium hydroxide are added to 100 mL of the epoxysuccinic acid solution, heating is performed at a temperature of 89℃ for 4 h, and polyepoxysuccinic acid is obtained.

[0054] S2, 10 g of the polyepoxysuccinic acid is dissolved in 180 mL of N,N-dimethylformamide, and 2 g of urea, 2 g of N-hydroxymaleimide, 1.8 g of citraconimide, 0.2 g of p-toluenesulfonic acid, 11 g of dicyclohexyl carbodiimide, and 0.4 g of 4-dimethylaminopyridine are added. After heating reaction at a temperature of 95℃ for 5 h, cooling reaction is performed at a temperature of 24℃ for 16 h. After filtration, the filtrate is collected, poured into deionized water, and a precipitate is obtained. After filtration, washing, and drying, the modified polyepoxysuccinic acid is obtained.

[0055] The embodiment provides an easily biodegradable phosphorus-free scale and corrosion inhibitor, which comprises the following components by weight: 390 g of water, 38 g of modified polyepoxysuccinic acid, 26 g of a composite adsorption corrosion inhibitor, 24 g of hydrolyzed polymaleic anhydride, 13 g of sodium gluconate, 5 g of alanine, 4 g of sodium alginate and 2 g of sodium carboxymethyl cellulose.

[0056] The preparation method of the easily biodegradable phosphorus-free scale and corrosion inhibitor comprises the following steps:

[0057] (1) mixing the modified polyepoxysuccinic acid and the hydrolyzed polymaleic anhydride to obtain a mixture one, grinding the composite adsorption corrosion inhibitor, the particle size of the composite adsorption corrosion inhibitor being 30 microns, adding the composite adsorption corrosion inhibitor into the mixture one, stirring at a stirring speed of 300 r / min for 50 min to obtain a mixture two;

[0058] (2) adding the sodium carboxymethyl cellulose into water, stirring and dissolving to obtain a sodium carboxymethyl cellulose solution, adding the sodium alginate and the sodium gluconate into the sodium carboxymethyl cellulose solution respectively, stirring and dissolving to obtain a mixed solution, adding the mixed solution into the mixture two, stirring uniformly, finally adding the alanine, and stirring to obtain the easily biodegradable phosphorus-free scale and corrosion inhibitor.

[0059] Embodiment 4:

[0060] The embodiment provides a preparation method of a composite adsorption corrosion inhibitor, which comprises the following steps:

[0061] Q1, a plant polyphenol solution is obtained by mixing plant polyphenols and ethanol at a mass ratio of 1:8, the mass ratio of tea polyphenols and tannic acid is 1:2, 100 mL of the plant polyphenol solution is added into 800 mL of a hydroxypropyl-β-cyclodextrin saturated aqueous solution, stirring, ultrasonic treatment, the ultrasonic power is 300 W, the ultrasonic temperature is 50 DEG C, the ultrasonic time is 60 min, cooling to room temperature, the temperature of standing is 8 DEG C, the standing time is 24 h, filtering, washing, drying to obtain an inclusion compound;

[0062] Q2, 10 g of the inclusion compound, 30 g of sodium tartrate and 20 g of sodium citrate are added into 200 g of water, the pH value is adjusted to 9 by using 1 mol / L NaOH, heating and stirring reaction, the heating temperature is 70 DEG C, the stirring speed is 500 r / min, the stirring reaction time is 4 h, a reaction solution is obtained, cooling to room temperature, 100 mL of 30 wt% polyaspartic acid solution and 0.3 g of N,N-dicyclohexyl carbodiimide are added into 10 g of the reaction solution, the stirring reaction time is 6 h at room temperature, 1 mol / L dilute hydrochloric acid is added to adjust the pH value to 7, filtering, collecting the filtrate, 50 mL of the filtrate is added into 1000 mL of anhydrous ethanol to obtain a precipitate, washing, drying to obtain the composite adsorption corrosion inhibitor.

[0063] The embodiment provides a preparation method of modified polyepoxysuccinic acid, and comprises the following steps.

[0064] S1, 3mol / L 100mL sodium hydroxide solution is added dropwise into 2mol / L 100mL maleic anhydride solution, stirring, 0.2g tungstic acid is added, 40mL 30wt% hydrogen peroxide is added dropwise for reaction, the reaction temperature is 70℃, the reaction time is 3h, and an epoxysuccinic acid solution is obtained; 0.25g sodium hydroxide and 0.25g potassium hydroxide are added into 100mL epoxysuccinic acid solution, heating, the heating temperature is 90℃, the reaction time is 4h, and polyepoxysuccinic acid is obtained;

[0065] S2, 10g polyepoxysuccinic acid is dissolved in 200mL N,N-dimethylformamide, 2.5g urea, 2.5g N-hydroxymaleimide, 2g citraconimide, 0.3g p-toluenesulfonic acid, 12g dicyclohexyl carbodiimide and 0.5g 4-dimethylaminopyridine are added respectively, heating reaction, the heating temperature is 100℃, the heating reaction time is 6h, after the reaction is completed, the reaction is cooled, the cooling temperature is 25℃, the reaction time is 24h, filtration is carried out, the filtrate is collected, the filtrate is poured into deionized water, a precipitate is obtained, and the precipitate is filtered, washed and dried to obtain modified polyepoxysuccinic acid.

[0066] The embodiment provides a biodegradable phosphorus-free scale and corrosion inhibitor, which comprises the following components by weight: 400g water, 40g modified polyepoxysuccinic acid, 30g composite adsorption corrosion inhibitor, 25g hydrolyzed polymaleic anhydride, 15g sodium gluconate, 6g alanine, 5g sodium alginate and 3g sodium carboxymethyl cellulose.

[0067] The preparation method of the biodegradable phosphorus-free scale and corrosion inhibitor comprises the following steps.

[0068] (1) The modified polyepoxysuccinic acid and the hydrolyzed polymaleic anhydride are mixed to obtain a mixture one, the composite adsorption corrosion inhibitor is ground, the particle size of the ground composite adsorption corrosion inhibitor is 10 microns, the composite adsorption corrosion inhibitor is added into the mixture one, stirring is carried out, the stirring speed is 200r / min, and the stirring time is 30min, to obtain a mixture two.

[0069] (2) The sodium carboxymethyl cellulose is added into water and stirred and dissolved to obtain a sodium carboxymethyl cellulose solution; the sodium alginate and the sodium gluconate are added into the sodium carboxymethyl cellulose solution respectively and stirred and dissolved to obtain a mixed solution; the mixed solution is added into the mixture two and stirred uniformly, finally, the alanine is added and stirred to obtain the biodegradable phosphorus-free scale and corrosion inhibitor.

[0070] Comparative example 1

[0071] Compared with Example 3, in the preparation process of the easily biodegradable non-phosphorus scale and corrosion inhibitor, the comparative example 1 does not add the composite adsorption corrosion inhibitor, and other conditions are unchanged.

[0072] Comparative example 2:

[0073] Compared with Example 3, in the preparation process of the easily biodegradable non-phosphorus scale and corrosion inhibitor, the comparative example 2 does not add the modified polyepoxy succinic acid, and other conditions are unchanged.

[0074] Experimental example:

[0075] The easily biodegradable non-phosphorus scale and corrosion inhibitors prepared by Examples 1-4 and Comparative Examples 1-3 are subjected to performance test, and the water quality indexes of the water sample used for the test at 25℃ are as follows: Ca 2+ 183mg / L, Mg 2+ 140mg / L, Cl - 230mg / L, HCO3 - 125mg / L, SO4 2- 99mg / L, pH is 9.4, and the dissolved oxygen is 12.8mg / L; the dosing concentration is 20mg / L during the test, the water temperature is 80℃, and the test duration is 16h; the scale inhibition rate is tested according to GB / T16632-2019 “Determination of Scale Inhibition Performance of Water Treatment Agent-Calcium Carbonate Deposition Method”, and the corrosion inhibition rate is tested according to GB / T18175-2014 “Determination of Corrosion Inhibition Performance of Water Treatment Agent-Rotating Hanging Piece Method” (the standard corrosion hanging piece is 20# carbon steel, the constant temperature is 40℃, the rotating speed is 75r / min, and the rotation time is 72h), and the test results are shown in Table 1:

[0076] Table 1

[0077] Group Carbonate scale inhibition rate (%) Sulfate scale inhibition rate (%) Corrosion inhibition rate (%) Example 1 99.13 99.02 92.04 Example 2 99.18 99.06 92.11 Example 3 99.32 99.28 92.23 Example 4 99.27 99.19 92.16 Comparative Example 1 90.02 84.57 68.25 Comparative Example 2 71.21 70.50 84.24

[0078] According to the test results in Table 1, the scale and corrosion inhibition performance of the easily biodegradable non-phosphorus scale and corrosion inhibitor prepared by Examples 1-4 of the application is compared with Comparative Examples 1-2, and it is found that the addition of the composite adsorption corrosion inhibitor and the modified polyepoxy succinic acid can significantly improve the scale and corrosion inhibition performance of the non-phosphorus scale and corrosion inhibitor.

[0079] The above is only the preferred specific implementation of the application, but the protection scope of the application is not limited to this, any person skilled in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the application within the technical range disclosed by the application, which should be covered in the protection scope of the application.

[0080] The preferred embodiments of the application disclosed above are only to facilitate the elucidation of the application. The preferred embodiments do not describe all the details of the application and limit the application to the specific embodiments. Obviously, many modifications and variations can be made in light of the teachings above. The description is chosen and described in order to provide the best illustration of the application and its practical application to those skilled in the art and to enable those skilled in the art to utilize the application in its best mode. The application is only limited by the claims and their full scope and equivalents.

Claims

1. A readily biodegradable, phosphorus-free scale and corrosion inhibitor, characterized in that, The product comprises the following components by weight: 360-400 parts water, 30-40 parts modified polyepoxysuccinic acid, 20-30 parts composite adsorbent corrosion inhibitor, 20-25 parts hydrolyzed polymaleic anhydride, 8-15 parts sodium gluconate, 4-6 parts alanine, 2-5 parts sodium alginate and 1-3 parts sodium carboxymethyl cellulose. The preparation method of the composite adsorbent corrosion inhibitor includes the following steps: Q1. Add the plant polyphenol solution to a saturated aqueous solution of hydroxypropyl-β-cyclodextrin, stir, sonicate, cool, let stand, filter, wash, and dry to obtain the inclusion complex. Q2. Add the inclusion complex, sodium tartrate, and sodium citrate to water, adjust the pH to 8-9, heat and stir to react, obtain a reaction solution, cool to room temperature, add polyaspartic acid solution and N,N-dicyclohexylcarbodiimide to the reaction solution, stir to react, add dilute hydrochloric acid to adjust the pH to 6-7, filter, collect the filtrate, add the filtrate to anhydrous ethanol to obtain a precipitate, wash, dry, and obtain the composite adsorption corrosion inhibitor; The preparation method of the modified polyepoxysuccinic acid includes the following steps: S1. Add sodium hydroxide solution dropwise to maleic anhydride solution, stir, add catalyst, add hydrogen peroxide dropwise to react and obtain epoxy succinic acid solution; add initiator to epoxy succinic acid solution, heat to obtain polyepoxy succinic acid; S2. Polyepoxysuccinic acid is dissolved in N,N-dimethylformamide, and urea, N-hydroxymaleimide, citrileimide, p-toluenesulfonic acid, dicyclohexylcarbodiimide and 4-dimethylaminopyridine are added respectively. The mixture is heated to react, and after the reaction is completed, the mixture is cooled, filtered, and the filtrate is collected. The filtrate is poured into deionized water to obtain a precipitate, which is then filtered, washed and dried to obtain modified polyepoxysuccinic acid.

2. The readily biodegradable phosphorus-free scale and corrosion inhibitor according to claim 1, characterized in that, The volume ratio of the plant polyphenol solution to the saturated aqueous solution of cyclodextrin in Q1 is 1:6-8. The plant polyphenol is a mixture of tea polyphenol and tannic acid, and the mass ratio of tea polyphenol to tannic acid is 1:1-2. The plant polyphenol solution is prepared by mixing plant polyphenol and ethanol at a mass ratio of 1:5-8.

3. The readily biodegradable phosphorus-free scale and corrosion inhibitor according to claim 1, characterized in that, In Q2, the mass ratio of the inclusion compound, sodium tartrate, sodium citrate, and water is 1:2-3:1-2:10-20. The pH value is adjusted to 8-9 with 1 mol / L NaOH. The mass concentration of the polyaspartic acid solution is 10-30 wt%. The ratio of the amount of reaction solution, polyaspartic acid solution, and N,N-dicyclohexylcarbodiimide is 10 g: 50-100 mL: 0.05-0.3 g.

4. The readily biodegradable phosphorus-free scale and corrosion inhibitor according to claim 1, characterized in that, In S1, the concentration of maleic anhydride solution is 0.5-2 mol / L, the concentration of sodium hydroxide solution is 1-3 mol / L, the catalyst is silicotungstic acid, the mass concentration of hydrogen peroxide is 30 wt%, and the ratio of maleic anhydride solution, sodium hydroxide solution, silicotungstic acid and hydrogen peroxide is 100 mL: 50-100 mL: 0.05-0.2 g: 30-40 mL.

5. The readily biodegradable phosphorus-free scale and corrosion inhibitor according to claim 1, characterized in that, The initiator is a mixture of equal masses of sodium hydroxide and potassium hydroxide, and the ratio of initiator to epoxy succinic acid solution is 0.1-0.5 g: 100 mL.

6. The readily biodegradable phosphorus-free scale and corrosion inhibitor according to claim 1, characterized in that, The ratio of polyepoxysuccinic acid, N,N-dimethylformamide, urea, N-hydroxymaleimide, citrileimide, p-toluenesulfonic acid, dicyclohexylcarbodiimide, and 4-dimethylaminopyridine in S2 is 10g:100-200mL:1-2.5g:1-2.5g:1-2g:0.1-0.3g:10-12g:0.1-0.5g.

7. The method for preparing the readily biodegradable phosphorus-free scale and corrosion inhibitor according to claim 1, characterized in that, Includes the following steps: (1) Mix modified polyepoxysuccinic acid and hydrolyzed polymaleic anhydride to obtain mixture one. Grind the composite adsorbent corrosion inhibitor and add it to mixture one. Stir to obtain mixture two. (2) Add sodium carboxymethyl cellulose to water and stir to dissolve it to obtain a sodium carboxymethyl cellulose solution; Sodium alginate and sodium gluconate were added separately to sodium carboxymethyl cellulose solution and stirred to dissolve, resulting in a mixed solution. Add the mixed solution to mixture two, stir well, and finally add alanine and stir to obtain a phosphorus-free scale and corrosion inhibitor that is easily biodegradable.

8. The method for preparing the readily biodegradable phosphorus-free scale and corrosion inhibitor according to claim 7, characterized in that, In step (1), the composite adsorbent corrosion inhibitor has a grinding particle size of 10-100 micrometers.