LU501613B1

LU501613B1 - Phosphorus-free reverse osmosis scale inhibitor per-pamam and preparation methods thereof

Info

Publication number: LU501613B1
Application number: LU501613A
Authority: LU
Inventors: Feifei Shi; Shuguang Zhang
Original assignee: Univ Shandong Technology
Priority date: 2022-03-08
Filing date: 2022-03-08
Publication date: 2023-09-08

Abstract

The disclosure belongs to field of water treatment chemicals, and specifically involves a phosphorus-free reverse osmosis scale inhibitor PER-PAMAM and preparation methods thereof. Performing a Michael addition reaction between pentaerythritol and acrylonitrile in alkaline environment, performing an esterification reaction between the Michael addition reaction product and alcohol compound in acidic condition, and reacting the esterification product with diamine compound in organic solvent to obtain a 1.0 generation scale inhibitor PER-PAMAM; and reacting 1.0 generation scale inhibitor PER-PAMAM with unsaturated fatty acid ester in organic solvent; and reacting the product with diamine compound in organic solvent to obtain 2.0 generation scale inhibitor PER-PAMAM. The chemical of the invention has small dosage and does not contain phosphorus to avoid serious bacterial and algae breeding problems; and it has excellent scale inhibition performance for CaCO3 scale and CaSiO3 scale; and the disclosure also provides preparation methods thereof without "three-waste" discharges throughout production process.

Description

BL-5380

PHOSPHORUS-FREE REVERSE OSMOSIS SCALE INHIBITOR PER-PAMAM 10501613

AND PREPARATION METHODS THEREOF

TECHNICAL FIELD

[01] The disclosure belongs to field of water treatment chemicals, and specifically involves a phosphorus-free reverse osmosis scale inhibitor PER-PAMAM and preparation methods thereof.

BACKGROUND ART

[02] It is well known that the pollution and lack of water resources seriously restricts the sustainable development of China. Circulating cooling water accounts for a large proportion of industrial water with the continuous development of economic society, so the circulation of cooling water has become the main way to save water. Due to the recycling of industrial cooling water, the concentration of inorganic ions such as Ca””, Mg?*, CO3”, SO4” and silicates in water increases gradually with the continuous evaporation and concentration of water, and the deposition of insoluble salts and scale in large amount affects the working efficiency and service life of reverse osmosis membranes. In inorganic scale, the deposition of silica and silicates is an extremely painful problem. Since the silica scale is hard in texture, it is difficult to remove once formed. Although adding hydrofluoric acid can effectively remove silica scale, this method will seriously reduce the service life of reverse osmosis membrane and bring great disadvantages to industrial production.

[03] In recent years, scale inhibitors have been widely used due to their advantages such as good synergistic effect, scale inhibition performance and less environmental pollution, and adding scale inhibitors to circulating cooling water is undoubtedly a simple, efficient, green and inexpensive scale inhibition method in order to reduce the formation of silica scale. However, most of the common scale inhibitors in the market are phosphorus-containing, and large-scale use causes water eutrophication and environmental damage.

[04] The components of the reverse osmosis membrane scale inhibitor disclosed in Chinese patent CN 101352655 are as follows by weight percentage: 25-50% organic phosphonic acid, 20-40% sulphonate copolymer, 5-15% pH regulator, and the balance deionized water. The components of the reverse osmosis membrane scale inhibitor disclosed in Chinese patent CN 102167451 A are as follows by weight percentage: 5-15% sodium polyepoxysuccinate, 5-15% sodium polyaspartate, 3-10% polymaleic acid, 1-5% 2-phosphonobutane-1, 2, 4-tricarboxylic acid, 8-15% hexapotassium hexamethylenediamine tetramethyl phosphate and polyamidoamine with hexamethylene diamine as the core, and the balance being water. These scale inhibitors can effectively control silica scale and calcium scale but they contain organic phosphonates, which are easy to hydrolyze and cause water eutrophication and environmental pollution. Chinese patent CN 102585196 A discloses a method for synthesizing a scale and corrosion inhibitor sodium polyepoxysuccinate, and the sodium polyepoxysuccinate can well control calcium scale, but the scale inhibiting effect on silica scale is not ideal.

SUMMARY

[05] In view of the deficiencies of the prior art, the purpose of the present disclosure is to provide a phosphorus-free reverse osmosis scale inhibitor PER-PAMAM, which has a low dosage, does not contain phosphorus compared with traditional organic phosphonic acid 1

BL-5380 (phosphate) scale inhibitors, does not have the problem of excessive phosphorus discharge in concentrated water, and also does not provide nutrients for microorganisms in the membrane, LUS01613 so as to avoid causing serious bacterial and algae breeding problems; and it has excellent scale inhibition performance for CaCO; and CaSiO; scale. The present disclosure also provides preparation methods thereof, wherein the whole production process has no "three wastes" discharged, and has good economic benefits and wide social benefits.

[06] According to the phosphorus-free reverse osmosis scale inhibitor PER-PAMAM of the present disclosure, performing a Michael addition reaction between pentaerythritol and acrylonitrile in alkaline environment, performing an esterification reaction between the Michael addition reaction product and alcohol compound in acidic condition, and reacting the esterification reaction product with diamine compound in organic solvent to obtain a 1.0 generation scale inhibitor PER-PAMAM.

[07] Pentaerythritol has four hydroxyl functional groups in the molecular structure, and the structure is completely symmetrical, which is very suitable for constructing dendritic macromolecules. At present, there are relatively few studies on novel dendrimer silica scale inhibitors based on pentaerythritol and derivatives thereof as the core. Compared with the traditional organic phosphonic acid (phosphate) scale inhibitor, the dosage of the chemical is less and does not contain phosphorus, and there is no problem of excessive phosphorus discharge in concentrated water.

[08] Wherein: the molar ratio of pentaerythritol to acrylonitrile is 1:4-1:7; and the molar ratio of the Michael addition reaction product to alcohol compound is 1:8-1:12; and the molar ratio of the esterification product to diamine compound is 1:14-1:18.

[09] Preferably, reacting the 1.0 generation scale inhibitor PER-PAMAM with unsaturated fatty acid ester in organic solvent; and reacting the reaction product with diamine compound in organic solvent to obtain 2.0 generation scale inhibitor PER-PAMAM. The scale inhibitor of 2.0 generation has more amine end groups and better scale inhibition performance compared with that of 1.0 generation.

[10] The molar ratio of the 1.0 generation scale inhibitor PER-PAMAM to the unsaturated fatty acid ester is 1:22-1:28, and the molar ratio of the reaction product to the diamine compound is 1:30-1:36.

[11] Wherein:

[12] performing the Michael addition reaction in a two-phase system of aqueous metal hydroxide solution and organic solvent; and the metal hydroxide is alkali metal hydroxide or alkaline earth metal hydroxide; the alkali metal hydroxide is lithium hydroxide, potassium hydroxide or sodium hydroxide; the alkaline earth metal hydroxide is calcium hydroxide, strontium hydroxide or barium hydroxide; and the organic solvent is one or more of branched or unbranched alkane, alkyl-substituted aromatic solvent, alcohol or ether which is water- immiscible or partially water-miscible, preferably the organic solvent is one or more of methanol, ethanol, butanediol, benzene, toluene, xylene, 1,4-dioxane, diethyl ether, tetrahydrofuran, dichloromethane, or triethanolamine. Side reactions of acrylonitrile can be suppressed by using this two-phase system.

[13] The temperature of the Michael addition reaction is 0 °C-70 °C and the time is 10-12 hours; and the temperature of the esterification reaction is 50 °C-90 °C and the time is 2-6 hours. 2

BL-5380

[14] The alcohol compound is methanol, ethanol or propanol; and the diamine compound is ethylenediamine, propane diamine or butanediamine. LU501613

[15] The unsaturated fatty acid ester is methyl acrylate or methyl methacrylate, containing unsaturated bonds and ester groups, capable of both Michael addition and amidation reactions.

[16] According to a preparation method of the phosphorus-free reverse osmosis scale inhibitor PER-PAMAM of the present disclosure, performing a Michael addition reaction between pentaerythritol and acrylonitrile in alkaline environment, performing an esterification reaction between the Michael addition reaction product and alcohol compound in acidic condition, and reacting the esterification reaction product with diamine compound in organic solvent to obtain a 1.0 generation scale inhibitor PER-PAMAM in the preparation method of the phosphorus-free reverse osmosis scale inhibitor PER-PAMAM.

[17] Preferably, a preparation method of the phosphorus-free reverse osmosis scale inhibitor

PER-PAMAM according to the disclosure comprises the following steps:

[18] (1) Performing the Michael addition reaction between pentaerythritol and acrylonitrile in a two-phase system of aqueous metal hydroxide solution and organic solvent, and controlling the pH of the whole system at 8-10;

[19] (2) Mixing the reaction product obtained in step (1) with alcohol compound, introducing HCI gas, and the pH value is 2-3 to perform an esterification reaction;

[20] (3) Reacting the reaction product obtained in step (2) with diamine compound in organic solvent to obtain 1.0 generation scale inhibitor PER-PAMAM,;

[21] (4) Reacting the 1.0 generation scale inhibitor PER-PAMAM with unsaturated fatty acid ester in organic solvent.

[22] (5) Reacting the reaction product obtained in step (4) with diamine compound in organic solvent; and obtaining 2.0 generation scale inhibitor PER-PAMAM.

[23] More preferably, a preparation method of the phosphorus-free reverse osmosis scale inhibitor PER-PAMAM according to the disclosure comprises the following steps:

[24] (1) Adding pentaerythritol and acrylonitrile into a three-neck flask in the molar ratio of 1:4-1:7, and creating alkaline environment using 40% KOH aqueous solution, using 1,4- dioxane as a solvent, controlling the pH of the whole system at 8-10, and performing the reaction at room temperature for 10-12 hours and purifying to obtain an intermediate tetranitrile.

[25] (2) Adding the intermediate tetranitrile and methanol into a four-neck flask in the molar ratio of 1:8-1:12, introducing HCI gas, the pH value is 2-3, and performing the reaction at 50 °C- 90 °C for 2-6 hours and purifying to obtain 0.5 generation PER-PAMAM scale inhibitor.

[26] (3) Adding 0.5 generation PER-PAMAM scale inhibitor and ethylenediamine into a three-neck flask in the molar ratio of 1:14-1:18, using methanol as solvent, reacting at room temperature for 10-12 hours and purifying to obtain 1.0 generation PER-PAMAM scale inhibitor. 3

BL-5380

[27] (4) Adding 1.0 generation PER-PAMAM scale inhibitor and methyl acrylate into a three-neck flask in the molar ratio of 1:22-1:28, using methanol as solvent, and reacting at room LU501613 temperature for 10-12 hours and purifying to obtain 1.5 generation PER-PAMAM scale inhibitor.

[28] (5) Adding the 1.5 generation PER-PAMAM scale inhibitor and ethylenediamine into a three-neck flask in the molar ratio of 1:30-1:36, using methanol as solvent, and reacting at room temperature for 10-12 hours and purifying to obtain 2.0 generation PER-PAMAM scale inhibitor.

[29] The present disclosure has the following advantages compared to the prior art:

[30] (1) The present disclosure provides a novel non-phosphorus environment-friendly reverse osmosis scale inhibitor, comprising a 1.0 generation scale inhibitor PER-PAMAM and a 2.0 generation scale inhibitor PER-PAMAM, which are both novel polyamidoamine dendrimer scale inhibitors for scale treatment of water quality, and compared with traditional organic phosphonic acid (salt) scale inhibitors, the dosage of the scale inhibitor is less and does not contain phosphorus, is biodegradable, and there is no problem of excessive phosphorus discharge in concentrated water, and also does not provide nutrients for microorganisms in the membrane, so as to avoid causing serious bacterial and algae breeding problems.

[31] (2) The scale inhibitor of the present disclosure has a more excellent scale inhibition performance for CaCO; scale and CaSiOs scale in addition to the excellent scale inhibition performance for these conventional scales such as calcium scale. The phosphorus-free reverse osmosis scale inhibitor PER-PAMAM of the present disclosure has a higher scale inhibition effect at a lower dosage than the disclosed scale inhibitor.

[32] (3) The preparation methods provided by the present disclosure have no "three-waste" discharge in the whole production process, and the scale inhibition process for treating complex water quality is simple, small dosage in use, low in cost, good in effect, and has very good economic benefits and wide social benefits; it has the advantages of good scale inhibition performance, green pollution-free and low price.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[33] The disclosure will be further described in detail with reference to the accompanying drawings and embodiments.

Embodiment 1

[34] 20 g pentaerythritol and acrylonitrile in the molar ratio of 1:6 were added into a three- neck flask, alkaline environment was created using 40% KOH aqueous solution, 1,4-dioxane was used as solvent, the pH of the whole system was controlled to 9, magnetic stirring was performed, and acrylonitrile was slowly added dropwise via a constant pressure addition funnel.

The reaction was maintained at room temperature for 10 hours after the addition. The reaction mixture was dissolved in appropriate amount of dichloromethane and extracted several times with small amount of deionized water after completion of the reaction. The organic phase was dried using anhydrous sodium sulphate, and then the solvents DCM, 1,4-dioxane and excess acrylonitrile were removed by rotary distillation to give tetranitrile in 85% yield.

[35] 20 g tetranitrile and methanol were added into a four-neck flask in the molar ratio of 4

BL-5380 1:10 with the temperature controlled at 85 °C, reflux was conducted, HCI gas was introduced, the pH value was 2.5, and the reaction was stirred for 4 hours. Excess methanol was removed LU501613 by rotary evaporation, washed with water, added ethyl acetate, extracted and separated. The ethyl acetate extract was then washed with deionized water, dried using anhydrous sodium sulphate, filtered and concentrated to obtain 0.5 generation PER-PAMAM scale inhibitor in 88% yield.

[36] 20 g 0.5 generation product and methanol were added into a three-neck flask, ethylenediamine was added dropwise into the flask in the molar ratio of the 0.5 generation product to ethylenediamine 1:18, after the completion of the dropwise addition, the reaction was carried out at room temperature for 10 hours, and after the reaction was completed, rotary distillation was completed to remove excess methanol and ethylenediamine to obtain 1.0 generation PER-PAMAM scale inhibitor in 87% yield.

[37] 20 g 1.0 generation product and methanol were added into a three-neck flask, and methyl acrylate was added dropwise in the molar ratio of 1.0 generation product to methyl acrylate 1:26, and reacted at room temperature for 10 hours; after the reaction was completed, rotary evaporation purification was performed to obtain 1.5 generation PER-PAMAM scale inhibitor in 89% yield.

[38] Methanol and 20 g 1.5 generation product were added into a three-neck flask, and ethylenediamine was added in the molar ratio of 1.5 generation product to ethylenediamine 1:32, and reacted at room temperature for 10 hours. After completion of the reaction, it was purified by rotary evaporation to obtain 2.0 generation PER-PAMAM scale inhibitor in 90% yield.

Embodiment 2

[39] 20 g pentaerythritol and acrylonitrile were added into a three-neck flask in the molar ratio of 1:6, alkaline environment was created with 40% KOH aqueous solution, 1,4-dioxane was used as solvent, the pH of the whole system was controlled to 9, magnetic stirring was performed, and acrylonitrile was slowly added dropwise via a constant pressure addition funnel.

The reaction was maintained at room temperature for 12 hours after the addition. The reaction mixture was dissolved in appropriate amount of dichloromethane and extracted several times with small amount of deionized water after completion of the reaction. The organic phase was dried using anhydrous sodium sulphate, and then the solvents DCM, 1,4-dioxane and excess acrylonitrile were removed by rotary distillation to give tetranitrile in 90% yield.

[40] 20 g tetranitrile and methanol were added into a four-neck flask in the molar ratio of 1:10 with the temperature controlled at 85 °C, reflux was conducted, HCI gas was introduced, the pH value was 2.5, and the reaction was stirred for 6 hours. Excess methanol was removed by rotary evaporation, washed with water, added ethyl acetate, extracted and separated, and then the ethyl acetate extract was washed with deionized water, dried using anhydrous sodium sulphate, filtered and concentrated to obtain 0.5 generation PER-PAMAM scale inhibitor in 89% yield.

[41] 20 g 0.5 generation product and methanol were added into a three-neck flask, ethylenediamine was added dropwise into the flask in the molar ratio of the 0.5 generation product to ethylenediamine 1:18, after the completion of the dropwise addition, the reaction was carried out at room temperature for 12 hours, and after the reaction was completed, rotary distillation was completed to remove excess methanol and ethylenediamine to obtain 1.0

BL-5380 generation PER-PAMAM scale inhibitor in 95% yield.

LU501613

[42] 20 g 1.0 generation product and methanol were added into a three-neck flask, and methyl acrylate was added dropwise in the molar ratio of 1.0 generation product to methyl acrylate 1:26, and reacted at room temperature for 12 hours; after the reaction was completed, rotary evaporation purification was performed to obtain 1.5 generation PER-PAMAM scale inhibitor in 97% yield.

[43] Methanol and 20 g 1.5 generation product were added into a three-neck flask, and ethylenediamine was added in the molar ratio of 1.5 generation product to ethylenediamine 1:32, and reacted at room temperature for 12 hours. After completion of the reaction, it was purified by rotary evaporation to obtain 2.0 generation PER-PAMAM scale inhibitor in 96% yield.

Embodiment 3

[44] 20 g pentaerythritol and acrylonitrile were added into a three-neck flask in the molar ratio of 1:6, alkaline environment was created with 40% KOH aqueous solution, 1,4-dioxane was used as solvent, the pH of the whole system was controlled to 9, magnetic stirring was performed, and acrylonitrile was slowly added dropwise via a constant pressure addition funnel.

The reaction was maintained at 50 °C for 12 hours after the addition. The reaction mixture was dissolved in appropriate amount of dichloromethane and extracted several times with small amount of deionized water after completion of the reaction. The organic phase was dried using anhydrous sodium sulphate, and then the solvents DCM, 1,4-dioxane and excess acrylonitrile were removed by rotary distillation to give tetranitrile in 80% yield.

[45] 20 g tetranitrile and methanol were added into a four-neck flask in the molar ratio of 1:10 with the temperature controlled at 85 °C, reflux was conducted, HCI gas was introduced, and the reaction was stirred for 6 hours. Excess methanol was removed by rotary evaporation, washed with water, added ethyl acetate, extracted and separated. The ethyl acetate extract was then washed with deionized water, dried using anhydrous sodium sulphate, filtered and concentrated to obtain 0.5 generation PER-PAMAM scale inhibitor in 89% yield.

[46] 20 g of 0.5 generation product and methanol were added into a three-neck flask.

Ethylenediamine was added dropwise into the flask in the molar ratio of the 0.5 generation product to ethylenediamine 1:18, after the completion of the dropwise addition, the reaction was carried out at 50 °C for 12 hours, and rotary distillation was completed to remove excess methanol and ethylenediamine to obtain 1.0 generation PER-PAMAM scale inhibitor in 82% yield.

[47] 20 g 1.0 generation product and methanol were added into a three-neck flask, and methyl acrylate was added dropwise in the molar ratio of 1.0 generation product to methyl acrylate 1:26, and reacted at 50 °C for 12 hours; after the reaction was completed, rotary evaporation purification was performed to obtain 1.5 generation PER-PAMAM scale inhibitor in 83% yield.

[48] Methanol and 20 g 1.5 generation product were added into a three-neck flask, and ethylenediamine was added in the molar ratio of 1.5 generation product to ethylenediamine 1:32, and reacted at 50 °C for about 12 hours. After completion of the reaction, it was purified by rotary evaporation to obtain 2.0 generation PER-PAMAM scale inhibitor in 85% yield. 6

BL-5380

[49] The performance of scale inhibitors prepared in embodiments 1-3 was tested:

LU501613

[50] 1. Determination of silica scale inhibition performance

[51] Static silicate inhibition method: Sample preparation process is as follows: deionized water was used to prepare the sodium silicate solution with SiO, concentration of 600 mg/L, and appropriate amount of scale inhibitor was added, then hydrochloric acid and sodium hydroxide were used to adjust the pH value of the solution to 7.0+0.1, and then a certain amount of calcium chloride was added to make the calcium ion concentration in the solution to 500 mg/L. Then the pH value was adjusted to 7.0+0.1. All samples prepared in this way were placed in a multihole thermostatic water bath, the temperature was set at 40 °C. À certain amount of water samples were filtered at regular intervals, and the content of silicate ions was determined by spectrophotometry and the scale inhibition rate was calculated. Calculation formula:

E, = Pı7Po 100%

P -Po

Wherein: Er-- Silica scale inhibition rate, % p1 -- Content of silicate ion in dosing solution, mg/L po --Content of silicate ion in blank solution, mg/L p --Content of initial silicate ion in solution, mg/L.

[52] The amount of scale inhibitor added and the test results are shown in Table 1.

[53] 2. Determination of calcium carbonate scale inhibition performance

[54] 3 mL of 40 g/L. calcium chloride solution was sequentially added into a 500 mL volumetric flask, 5 mL of 48.8 g/L. sodium bicarbonate solution and suitable amount of scale inhibitor, and deionized water was added to constant volume and shake well. The volumetric flasks were placed into a multihole thermostatic water bath, the temperature was set at 80 °C, heated for 10 hours, then the volumetric flasks were taken out to cool naturally, then the upper clear liquid was drawn for analysis and the content of calcium ion was determined. A blank control test was also carried out.

[55] A pipette was used to measure 10 mL of test solution, 50 mL of deionized water and 5 mL of 20% potassium hydroxide solution were successively added into the conical flask; and the solution showed green after adding appropriate amount of calcein indicator into the conical flask, and then EDTA standard solution was used for titration; it can be found that the green gradually disappears and it is the end point of titration when the green completely disappeared and the purple red happened to appear. The concentration X (mg/L) of calcium ion (Ca””) can be calculated according to the following formula: x- Crpra XV, x40.48x1000

V

Wherein: X-Concentration of calcium ion (Ca**), mg/L 7

BL-5380

C-Concentration of EDTA standard solution, mol/L

LU501613

V1-Volume of EDTA solution consumed, ml 40.48-Molar mass of calcium ion, g/mol.

[56] Calculation method for the scale inhibition rate 0 of calcium carbonate: 0 =[(Ca1**- Car”*)/( Cao”*-Caz*)] x100%

Wherein: Cao”*-Concentration of calcium ion before scale inhibition reaction, mg/L

Ca1*”*-Remaining concentration of calcium ion after scale inhibition reaction with the presence of scale inhibitor, mg/L

Ca»*”*-Remaining concentration of calcium ion after scale formation in blank test, mg/L,

The amount of scale inhibitor added and test results are shown in Table 1.

[57] Comparative Embodiment: The scale inhibition effect of HEDP (hydroxyethylidene diphosphonate) used alone.

Table 1 Calculation results of scale inhibition performance test

Adding Scale Adding Scale

Let amount of inhibition amount of | Inhibition rate

Scale inhibitor Cale inhibitor Tate Of SiOz scale inhibitor Of CaCOs (mg/L) (%) (mg/L) (%) 1.0 generation 60 78.9 18 28.6 . scale inhibitor ; ;

Embodiment 1 ; 2.0 generation 60 85.6 18 03.7 scale inhibitor 1.0 generation 60 81.7 18 02.8 . scale inhibitor

Embodiment 2 ; 2.0 generation 60 88.7 18 06.7 scale inhibitor 1.0 generation 60 75.3 18 85.3 . scale inhibitor

Embodiment 3 ; 2.0 generation 60 83.5 18 89.7 scale inhibitor 8

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Comparative HEpp 60 478 20 78.2 LU501613

Example

[58] As can be seen from Table 1, the scale inhibitor of the present disclosure has excellent scale inhibition performance against both silica scale and calcium scale. Meanwhile, the phosphorus-free reverse osmosis scale inhibitor PER-PAMAM of the present disclosure has a higher scale inhibition effect at a lower dosage than other disclosed scale inhibitors.

[59] Furthermore, the novel reverse osmosis scale inhibitor PER-PAMAM of the present disclosure does not contain phosphorus and has no problem of excessive phosphorus discharge in concentrated water and is an environment-friendly reverse osmosis scale inhibitor. 9

Claims

BL-5380 WHAT IS CLAIMED IS: LU501613

1. À phosphorus-free reverse osmosis scale inhibitor PER-PAMAM, characterized in that: performing a Michael addition reaction between pentaerythritol and acrylonitrile in alkaline environment, performing an esterification reaction between the Michael addition reaction product and alcohol compound in acidic condition, and reacting the esterification reaction product with diamine compound in organic solvent to obtain a 1.0 generation scale inhibitor PER-PAMAM.

2. The phosphorus-free reverse osmosis scale inhibitor PER-PAMAM according to claim 1, characterized in that: the molar ratio of pentaerythritol to acrylonitrile is 1:4-1:7; and the molar ratio of the Michael addition reaction product to alcohol compound is 1:8-1:12; and the molar ratio of the esterification product to diamine compound is 1:14-1:18.

3. The phosphorus-free reverse osmosis scale inhibitor PER-PAMAM according to claim 1, characterized in that: reacting the 1.0 generation scale inhibitor PER-PAMAM with unsaturated fatty acid ester in organic solvent; and reacting the reaction product with diamine compound in organic solvent to obtain 2.0 generation scale inhibitor PER-PAMAM.

4. The phosphorus-free reverse osmosis scale inhibitor PER-PAMAM according to claim 3, characterized in that: the molar ratio of the 1.0 generation scale inhibitor PER-PAMAM to the unsaturated fatty acid ester is 1:22-1:28, and the molar ratio of the reaction product to the diamine compound is 1:30-1:36.

5. The phosphorus-free reverse osmosis scale inhibitor PER-PAMAM according to claim 1, characterized in that: performing the Michael addition reaction in a two-phase system of aqueous metal hydroxide solution and organic solvent; wherein the metal hydroxide is alkali metal hydroxide or alkaline earth metal hydroxide; the alkali metal hydroxide is lithium hydroxide, potassium hydroxide or sodium hydroxide; the alkaline earth metal hydroxide is calcium hydroxide, strontium hydroxide or barium hydroxide; and the organic solvent is one or more of methanol, ethanol, butanediol, benzene, toluene, xylene, 1,4-dioxane, diethyl ether, tetrahydrofuran, dichloromethane, or triethanolamine.

6. The phosphorus-free reverse osmosis scale inhibitor PER-PAMAM according to claim 1, characterized in that: the temperature of the Michael addition reaction is 0 °C-70 °C and the time is 10-12 hours; and the temperature of the esterification reaction is 50 °C-90 °C and the time is 2-6 hours.

7. The phosphorus-free reverse osmosis scale inhibitor PER-PAMAM according to claim 1 or 3, characterized in that: the alcohol compound is methanol, ethanol or propanol; and the diamine compound is ethylenediamine, propane diamine or butanediamine.

8. The phosphorus-free reverse osmosis scale inhibitor PER-PAMAM according to claim 3, characterized in that: the unsaturated fatty acid ester is methyl acrylate or methyl methacrylate.

9. A preparation method of the phosphorus-free reverse osmosis scale inhibitor PER- PAMAM according to any one of claims 1 to 6, characterized in that: performing a Michael addition reaction between pentaerythritol and acrylonitrile in alkaline environment, performing an esterification reaction between the Michael addition reaction product and alcohol compound

BL-5380 in acidic condition, and the esterification product reacts with diamine compound in organic solvent to obtain a 1.0 generation scale inhibitor PER-PAMAM. LU501613

10. The preparation method of the phosphorus-free reverse osmosis scale inhibitor PER- PAMAM according to claim 9, characterized in that, it comprises the following steps: (1) Performing the Michael addition reaction between pentaerythritol and acrylonitrile in a two-phase system of aqueous metal hydroxide solution and organic solvent, and controlling the pH of the whole system at 8-10; (2) Mixing the reaction product obtained in step (1) with alcohol compound, introducing HCI gas, and the pH value is 2-3 to perform an esterification reaction; (3) Reacting the reaction product obtained in step (2) with diamine compound in organic solvent to obtain 1.0 generation scale inhibitor PER-PAMAM,; (4) Reacting the 1.0 generation scale inhibitor PER-PAMAM with unsaturated fatty acid ester in organic solvent. (5) Reacting the reaction product obtained in step (4) with diamine compound in organic solvent; and obtaining 2.0 generation scale inhibitor PER-PAMAM. 11

BL-5380 LU501613 ANSPRÜCHE

1. Phosphorfreier Umkehrosmose-Kesselsteininhibitor PER-PAMAM, dadurch gekennzeichnet: Durchführen einer Michael-Additionsreaktion zwischen Pentaerythrit und Acrylnitril in einer alkalischen Umgebung, Durchführen einer Veresterungsreaktion zwischen dem Michael-Additionsreaktionsprodukt und einer Alkoholverbindung in einem sauren Zustand und Reagieren des Veresterungsreaktionsprodukts mit einer Diaminverbindung in einem organischen Lôsungsmittel, um einen Kesselsteininhibitor PER-PAMAM der Generation 1.0 zu erhalten.

2. Phosphorfreier Umkehrosmose-Kesselsteininhibitor PER-PAMAM nach Anspruch 1, dadurch gekennzeichnet, dass: das Molverhältnis von Pentaerythrit zu Acrylnitril 1:4—1:7 beträgt und das Molverhéltnis des Michael- Additionsreaktionsprodukts zu der Alkoholverbindung 1:8—1:12 beträgt und das Molverhältnis des Veresterungsprodukts zu der Diaminverbindung 1:14—1:18 betragt.

3. Phosphorfreier Umkehrosmose-Kesselsteininhibitor PER-PAMAM nach Anspruch 1, dadurch gekennzeichnet: Reagieren des Kesselsteininhibitors PER- PAMAM der Generation 1.0 mit einem ungesâttigten Fettsäureester in einem organischen Lösungsmittel und Reagieren des Reaktionsprodukts mit einer Diaminverbindung in einem organischen Lösungsmittel, um einen Kesselsteininhibitor PER-PAMAM der Generation 2.0 zu erhalten.

4. Phosphorfreier Umkehrosmose-Kesselsteininhibitor PER-PAMAM nach Anspruch 3, dadurch gekennzeichnet, dass: das Molverhältnis des Kesselsteininhibitors PER-PAMAM der Generation 1.0 zu dem ungesattigten Fettsäureester 1:22—1:28 beträgt und das Molverhaltnis des Reaktionsprodukts zu der Diaminverbindung 1:30—1:36 betragt. 1

BL-5380 LU501613

5. Phosphorfreier Umkehrosmose-Kesselsteininhibitor PER-PAMAM nach Anspruch 1, dadurch gekennzeichnet: Durchführen der Michael- Additionsreaktion in einem Zwei-Phasen-System von einer wässrigen Metallhydroxidlésung und einem organischen Lösungsmittel; wobei das Metallhydroxid ein Alkalimetallhydroxid oder ein Erdalkalimetallhydroxid ist; das Alkalimetallhydroxid Lithiumhydroxid, Kaliumhydroxid oder Natriumhydroxid ist; das Erdalkalimetallhydroxid Calciumhydroxid, Strontiumhydroxid oder Bariumhydroxid ist und es sich bei dem organischen Lösungsmittel um eines oder mehrere von Methanol, Ethanol, Butandiol, Benzol, Toluol, Xylol, 1,4-Dioxan, Diethylether, Tetrahydrofuran, Dichlormethan oder Triethanolamin handelt.

6. Phosphorfreier Umkehrosmose-Kesselsteininhibitor PER-PAMAM nach Anspruch 1, dadurch gekennzeichnet, dass: die Temperatur der Michael- Additionsreaktion 0 °C — 70 °C beträgt und die Zeit 10—12 Stunden beträgt und die Temperatur der Veresterungsreaktion 50 °C — 90 °C beträgt und die Zeit 2— 6 Stunden beträgt.

7. Phosphorfreier Umkehrosmose-Kesselsteininhibitor PER-PAMAM nach Anspruch 1 oder 3, dadurch gekennzeichnet, dass: die Alkoholverbindung Methanol, Ethanol oder Propanol ist und die Diaminverbindung Ethylendiamin, Propandiamin oder Butandiamin ist.

8. Phosphorfreier Umkehrosmose-Kesselsteininhibitor PER-PAMAM nach Anspruch 3, dadurch gekennzeichnet, dass: der ungesättigte Fettsäureester Methylacrylat oder Methylmethacrylat ist.

9. Herstellungsverfahren für den phosphorfreien Umkehrosmose- Kesselsteininhibitor PER-PAMAM nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet: Durchführen einer Michael-Additionsreaktion zwischen Pentaerythrit und Acrylnitril in einer alkalischen Umgebung, Durchführen einer Veresterungsreaktion zwischen dem Michael-Additionsreaktionsprodukt und einer Alkoholverbindung in einem sauren Zustand, und wobei das 2

BL-5380 LU501613 Veresterungsprodukt mit einer Diaminverbindung in einem organischen Lösungsmittel reagiert, um einen Kesselsteininhibitor PER-PAMAM der Generation 1.0 zu erhalten.

10. Herstellungsverfahren für den phosphorfreien = Umkehrosmose- Kesselsteininhibitor PER-PAMAM nach Anspruch 9, dadurch gekennzeichnet, dass es die folgenden Schritte umfasst: (1) Durchführen der Michael-Additionsreaktion zwischen Pentaerythrit und Acrylnitril in einem Zwei-Phasen-System von einer wässrigen Metallhydroxidldsung und einem organischen Lösungsmittel und Regulieren des pH-Werts des gesamten Systems auf 8-10; (2) Mischen des in Schritt (1) erhaltenen Reaktionsprodukts mit einer Alkoholverbindung, Einbringen von HCI-Gas, und wobei der pH-Wert 2-3 beträgt, um eine Veresterungsreaktion durchzuführen; (3) Reagieren des in Schritt (2) erhaltenen Reaktionsprodukts mit einer Diaminverbindung in einem organischen Lösungsmittel, um einen Kesselsteininhibitor PER-PAMAM der Generation 1.0 zu erhalten; (4) Reagieren des Kesselsteininhibitors PER-PAMAM der Generation 1.0 mit einem ungesâttigten Fettsäureester in einem organischen Lösungsmittel; (5) Reagieren des in Schritt (4) erhaltenen Reaktionsprodukts mit einer Diaminverbindung in einem organischen Lösungsmittel und Erhalten eines Kesselsteininhibitors PER-PAMAM der Generation 2.0. 3