Scale inhibitor based on dendritic macromolecules and application thereof

Abstract

The invention discloses a scale inhibitor based on dendritic macromolecules and application of the scale inhibitor. The scale inhibitor is prepared from a dendrimer and water, the dendrimer is a polyamide-amine PAMAM (Polyamidoamine) series dendrimer taking alkyl diamine as a core. According to the invention, the influence of the type, concentration and system temperature of the scale inhibitor on the performance of the scale inhibitor is fully researched, and the scale inhibitor is compared with a commercial product under the optimal condition. Results show that the PAMAM scale inhibitor with a specific structure can effectively reduce pollution or damage caused by silicate scale and calcium sulfate scale in industrial water, and particularly, the silicate scale inhibition performance of the PAMAM scale inhibitor is obviously superior to that of a commercial product.

Description

Technical Field

[0001] The invention belongs to the field of water treatment chemicals, and in particular relates to a scale inhibitor based on dendritic macromolecules and application thereof. Background Art

[0002] In industrial water treatment systems, Ca in water 2+ Mg 2+ Easy with CO3 2- 、SO4 2- 、SiO3 2- PO4 3- Scale is formed and deposited on the metal surface inside pipes and equipment, causing pipe blockage, increased energy consumption, reduced productivity, and increased operating costs. Among them, silica scale and calcium sulfate scale are difficult to clean. Scale inhibitors can effectively prevent the formation of various types of scale, especially those containing phosphonates and polyphosphates. However, these scale inhibitors are prone to cause environmental problems. Therefore, the research and development of environmentally friendly scale inhibitors has a good application prospect.

[0003] Dendrimers are a new type of polymer with a three-dimensional structure, high branching and high order. During its synthesis, it can be strictly controlled at the molecular level to design the molecular size, shape, structure and functional groups. The products are generally highly symmetrical and monodisperse. The internal cavity of the molecule, the functional groups on the surface and the highly branched structure have chelating and encapsulation effects, and have good application prospects in the application research of host-guest chemistry, demulsification and solubilization, catalysts, etc.

[0004] In response to the demand for environmentally friendly antiscalants and combining the characteristics of dendrimers, a scale inhibitor based on polyamide-amine (PAMAM) dendrimers with rich amino groups at the end groups was proposed to overcome the shortcomings of current antiscalants, such as low antiscaling rate and short life. Summary of the invention

[0005] Purpose of the invention: The purpose of the present invention is to provide a dendritic macromolecule-based scale inhibitor and its application in view of the shortcomings of the prior art. The scale inhibitor of the present invention is a high-performance phosphorus-free scale inhibitor for calcium silicate and calcium sulfate in water, which has a high scale inhibition rate and is suitable for inhibiting silica scale and calcium sulfate scale in industrial water, thereby extending the operating cycle and life of the system.

[0006] Technical solution: The purpose of the present invention is achieved through the following technical solution:

[0007] The invention provides a scale inhibitor based on dendritic macromolecules. The scale inhibitor is prepared from dendritic macromolecules and water. The dendritic macromolecules are polyamide-amine PAMAM series dendritic macromolecules with alkyl diamine as the core.

[0008] The scale inhibitor of the present invention is a PAMAM dendritic macromolecule scale inhibitor based on a specific alkyl diamine as a core. The dendritic macromolecule with a specific structure has the characteristics of being green, environmentally friendly, temperature-resistant and compatible. In particular, the number of functional groups and the nature of the end groups can effectively inhibit the growth of silica scale in high-silicon cooling water.

[0009] Preferably, the core molecule of the polyamidoamine PAMAM series dendrimer is one of ethylenediamine, propylenediamine, butylenediamine or hexamethylenediamine.

[0010] Preferably, the generation number of the polyamidoamine PAMAM series dendritic macromolecules is one of 0.5G, 1G, 1.5G or 2G.

[0011] Preferably, the terminal groups of the polyamidoamine PAMAM series dendrimers are methyl or amino groups.

[0012] The PAMAM dendrimer used in the present invention can inhibit the nucleation of calcium sulfate crystals, and delay or prevent the formation of scale by affecting the nucleation rate and crystallization rate of calcium sulfate and inducing changes in the crystal morphology.

[0013] A preferred embodiment of the present invention is that the polyamidoamine PAMAM series dendritic macromolecules are prepared by the following method: synthesizing PAMAM dendritic macromolecules by a divergent method, preparing dendritic macromolecules with different alkyl diamines as the core, or different generations of dendritic macromolecules with 1,6-hexanediamine as the reaction core through Michael addition and amidation condensation reactions.

[0014] Furthermore, the alkyl diamine is 1,2-ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine or 1,6-hexanediamine.

[0015] With 1,2-ethylenediamine as the core, the specific preparation method is as follows:

[0016] The divergent synthesis method was adopted, with anhydrous ethylenediamine as the initiating core unit and anhydrous methanol as the solvent to react with methyl acrylate to undergo Michael addition reaction to obtain a 0.5G product, and then the ester group was subjected to an amidation condensation reaction with ethylenediamine to obtain a 1G product.

[0017] The reaction principle is as follows:

[0018] (1) Synthesis of 0.5G-PAMAM:

[0019]

[0020] (2) Synthesis of 1G-PAMAM:

[0021]

[0022] 1.5G, 2G, 2.5G and 3G-PAMAM can be synthesized by repeating the above steps.

[0023] The method for preparing PAMAM dendrimers with 1,3-propylenediamine, 1,4-butylenediamine or 1,6-hexanediamine as the core is similar to the above method.

[0024] The present invention also provides application of the scale inhibitor in an industrial circulating water cooling system and / or a high-temperature water system.

[0025] The scale inhibitor is used for preventing silicate scale and / or calcium sulfate scale.

[0026] The dosage concentration of the scale inhibitor for silicate scale is 10-80 mg / L. After 24 hours, the retention rate of SiO2 is tested. When the optimal dosage concentration of the agent is 40 mg / L, the retention rate can reach more than 87%, which is significantly better than commercial products.

[0027] The scale inhibitor has a dosing concentration of 2-20 mg / L for calcium sulfate scale inhibition. After 25 hours, the scale inhibition rate of calcium sulfate was tested. When the optimal agent dosing concentration was 10 mg / L, the scale inhibition rate could reach more than 95%, which is similar to the effect of commercial products.

[0028] In the studied temperature range of 20-100℃, for calcium sulfate scale, when the concentration of the agent is 20mg / L, the scale inhibition rate of PAMAM for CaSO4 is close to 100%, indicating that the dendrimer is not only suitable for industrial circulating water cooling systems, but also for high-temperature water systems.

[0029] Beneficial effects:

[0030] The scale inhibitor based on dendritic macromolecules provided by the present invention can effectively reduce the pollution or damage caused by silicate scale and calcium sulfate scale in industrial water, effectively extend the cleaning cycle and operating life of the system, and greatly reduce the operating cost of the system. The agent is a uniform liquid product and is easy to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Infrared spectra of 0.5G-PAMAM, 1.5G-PAMAM and 2.5G-PAMAM;

[0032] Figure 2 Infrared spectra of 1.0G-PAMAM, 2.0G-PAMAM and 3.0G-PAMAM;

[0033] Figure 3 It is 1.0G-PAMAM NMR carbon spectrum;

[0034] Figure 4 It is 1.5G-PAMAM NMR carbon spectrum;

[0035] Figure 5 This is the 3.0G-PAMAM nuclear magnetic carbon spectrum. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is described in detail below through specific embodiments, but the protection scope of the present invention is not limited to the embodiments.

[0037] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0038] The experimental methods in the following examples are conventional methods unless otherwise specified. The experimental materials used in the following examples are commercially available products unless otherwise specified.

[0039] Example 1 High performance scale inhibitor

[0040] Its composition is: 1G product of PAMAM-1G-Eth, a PAMAM series dendrimer macromolecule with 1,2-ethylenediamine as the core, added to the water sample at a concentration of 40 mg / L and prepared with ionized water.

[0041] The specific preparation steps are as follows:

[0042] (a) Synthesis of 0.5G-PAMAM

[0043] Place a 250mL round-bottom flask in ice water to cool, then add 70.0g (0.814mol) of methyl acrylate, then add 40.0mL of anhydrous methanol as solvent, under nitrogen protection, slowly add 10.0g (0.166mol) of ethylenediamine dissolved in 40mL of anhydrous methanol solution while stirring, with a drop rate of about 1 drop / s. After the addition is complete, stir the reaction in an ice-water bath for 30min, then warm to room temperature and continue stirring for 48h. After stirring, transfer the product to a distillation flask, remove the solvent by vacuum rotary evaporation at 40°C, and dry at 50°C and 13.3Pa to obtain a light yellow oily liquid.

[0044] (b) Synthesis of 1G-PAMAM-NH2 (i.e. PAMAM-1G-Eth)

[0045] Place a 500mL round-bottom flask in ice water for cooling, then add 150.0g (2.496mol) of ethylenediamine, and then add 200.0mL of anhydrous methanol as solvent. Under nitrogen protection and strong stirring, slowly drop 20.0g (0.050mol) of 0.5G-PAMAM dissolved in 40.0mL of anhydrous methanol into the flask using a constant pressure dropping funnel. The dropping speed is about 1 drop / s. During the dropping process, the temperature must be controlled below 10°C. After the dropping is completed, the temperature is raised to room temperature and the reaction is continued with stirring for 96h. After the reaction is completed, the product is transferred to a distillation flask, and the solvent is first removed by vacuum rotary evaporation at 40°C, and then the excess ethylenediamine is removed by rotary evaporation at 72°C. Trace ethylenediamine can be removed by azeotropic distillation with 100mL of toluene / methanol (V / V=9:1) solution, and then dried at 50°C and 13.3Pa to obtain a light yellow oily liquid.

[0046] Similarly, 1.5G, 2G, 2.5G, and 3G products are synthesized according to the same steps and processing methods as above.

[0047] 0.5G-PAMAM, 1.5G-PAMAM, 2.5G-PAMAM infrared spectra Figure 1 .

[0048] The half-generation PAMAM products have the same structural features except that 0.5G does not have an amide group, and the infrared spectra are also very similar. -1 The strong absorption peak at 1437cm is the asymmetric stretching vibration of -CH2-. -1 The corresponding -CH2- bending vibration absorption peak appeared at 1735cm -1 The strongest characteristic absorption peak of carbonyl ester appeared at 1648 cm -1 、1541cm -1 、1328cm -1 The absorption peak is the third amide band, 1255 cm -1 、1174cm -1 The corresponding absorption peaks are the asymmetric and symmetric stretching vibrations of CN, 1198 cm -1 、1045cm -1 The corresponding absorption peaks are the asymmetric and symmetric stretching vibrations of CO.

[0049] 1.0G-PAMAM, 2.0G-PAMAM, 3.0G-PAMAM infrared spectra Figure 2 .

[0050] The infrared spectra of 1G, 2G and 3G generations of PAMAM products are very similar. -1 , 3075cm-1 The strong absorption peaks appearing are the asymmetric and symmetric stretching vibrations of NH, 2934 cm -1 , 2865cm -1 The strong absorption peaks at 1460cm -1 , 1437cm -1 The corresponding -CH2- bending vibration absorption peak appeared at 1735cm -1 The disappearance of the absorption peak at 1644 cm -1 、1557cm -1 、1358cm -1 The absorption peak is the third amide band, 1127 cm -1 、1035cm -1 The corresponding absorption peaks are the asymmetric and symmetric stretching vibrations of CN (secondary carbon).

[0051] 1.0G-PAMAM NMR carbon spectrum data see Figure 3 , 1.5G-PAMAM NMR carbon spectrum data see Figure 4 , 3 .0G-PAMAM NMR carbon spectrum data see Figure 5 .

[0052] PAMAM 1G 1 The corresponding relationship between the H-NMR absorption peaks is as follows Figure 3 As shown: a 2.46; b 2.75 (N- CH 2-CH2CO); c, e 2.34; d 3.25(-CONH- CH 2-); f 1.50(-NH2); g 8.10~8.20ppm(-CON H ).

[0053] PAMAM AG1.5 1 The corresponding relationship between the HNMR absorption peaks is as follows Figure 4 Shown: a, c, e, g 2.33~2.55; b, f2.75(N- CH 2-CH2CO); d 3.26(-CONH- CH 2-); h 3.65(-CO2- CH 3); i 7.3(-CON H )ppm.

[0054] Example 2-4 High performance scale inhibitor

[0055] Its composition is: 1G products of PAMAM series dendrimer macromolecules (PAMAM-1G-Prop, PAMAM-1G-But and PAMAM-1G-Hex) with 1,3-propylenediamine, 1,4-butylenediamine and 1,6-hexanediamine as cores, respectively, added to the water sample at a concentration of 40 mg / L and prepared with ionized water.

[0056] The preparation method of 1G products of PAMAM-1G-Prop, PAMAM-1G-But and PAMAM-1G-Hex refers to Example 1.

[0057] Example 5 Scale inhibition test performance evaluation

[0058] In this example, the PAMAM-1G-Eth, PAMAM-1G-Prop, PAMAM-1G-But and PAMAM-1G-Hex series of dendritic macromolecules were used as scale inhibitors to evaluate the performance of concentrated scale inhibition experiments on a high silicon solution with a pH value of 7±0.1, a reaction temperature of 30°C and a SiO2 concentration of 500 mg / L.

[0059] The scale inhibition effect of the scale inhibitor prepared in Examples 1-4 on colloidal silicon was investigated by a static method. Na2SiO3·9H2O was dissolved in deionized water to prepare a high silicon solution with a SiO2 concentration of 500 mg / L, which was then placed in several polyethylene volumetric bottles. The pH value was then adjusted to 7±0.1 with hydrochloric acid, and the solution was stirred evenly and then placed in a water bath at 30°C.

[0060] The performance test method of the calcium silicate scale inhibitor prepared in the above Examples 1-4 is: referring to GB / T 12149-2007 "Determination of silicon in industrial circulating cooling water and boiler water - spectrophotometry", a silicon dioxide standard curve is drawn. The scale inhibitor is directly added and uniformly mixed with the high silicon solution of deionized water; the water bath is kept for a total of 24 hours, and the concentration of soluble silica in the filtrate is determined by the molybdenum silica yellow photometry, and a portion is retained as a blank.

[0061] The experimental results are shown in Table 1.

[0062] Table 1 Experimental results of Example 1-Example 4

[0063] type <![CDATA[Residual SiO2 concentration (mg / L)]]> Retention rate % blank 159 31.8 PAMAM-1G-Eth 402 80.4 PAMAM-1G-Prop 435 87.0 PAMAM-1G-But 407 81.4 PAMAM-1G-Hex 406 81.2

[0064] It can be seen from Table 1 that the scale inhibition rate of different types of PAMAM-1G products is very high.

[0065] Example 6 Evaluation of the performance of concentrated scale inhibition experiments with different concentrations of scale inhibitors

[0066] This example is a concentrated scale inhibition test performance evaluation of the PAMAM series dendritic macromolecules as scale inhibitors at different concentrations on a high silicon solution with a pH value of 7±0.1, a reaction temperature of 30°C, and a SiO2 concentration of 500 mg / L.

[0067] PAMAM-1G-Eth, PAMAM-1G-Prop, PAMAM-1G-But and PAMAM-1G-Hex prepared in Examples 1-4 were added to the water samples respectively to prepare solutions with concentrations of 30, 50 and 60 mg / L using deionized water.

[0068] The anti-scaling effect of the scale inhibitor on colloidal silica was investigated by the static method. Na2SiO3·9H2O was dissolved in deionized water to prepare a high-silicon solution with a concentration of 500 mg / L SiO2, which was then placed in several polyethylene volumetric bottles. The pH value was then adjusted to 7±0.1 with hydrochloric acid, and the solution was stirred evenly and placed in a water bath at 30°C.

[0069] The scale inhibitor was added directly and uniformly mixed with the high silicon solution of deionized water. The water bath was kept for a total of 12 hours. After sampling, the concentration of soluble silicate in the filtrate was determined by the molybdenum-silicon yellow photometry, and a portion was retained as a blank.

[0070] The experimental results are shown in Table 2.

[0071] Table 2 Experimental results

[0072]

[0073] It can be seen from Table 2 that different PAMAM-1G antiscalants can obviously achieve a scale inhibition rate of more than 77% when added in amounts of 30, 50, and 60 mg / L.

[0074] Example 7 Comparison of the Stabilizing Effect of Antiscalants on Soluble Silica

[0075] The scale inhibitor is composed of PAMAM-1G-Prop, with a concentration of 40 mg / L, prepared with deionized water. The stabilizing effect of commercial aminotri(methylenephosphonic acid) (ATMP) and polyacrylic acid (PAA) on soluble silica is compared with the same concentration.

[0076] The static method was used to examine the scale inhibition effect of the scale inhibitor on colloidal silicon. Anhydrous sodium silicate was dissolved in deionized water to prepare a high silicon solution with a concentration of 500 mg / L SiO2. The solution was placed in several polyethylene volumetric bottles and the required amount of scale inhibitor was added. The pH value was then adjusted to 7±0.1 with hydrochloric acid or sodium hydroxide solution and the temperature was kept at 30°C.

[0077] The method of using the above PAMAM scale inhibitor is as follows: the scale inhibitor is directly added and uniformly mixed with the high silicon solution of deionized water; after a total of 24 hours of water bathing, the concentration of soluble silicate in the filtrate is determined by the molybdenum-silicon yellow photometry.

[0078] The product PAMAM-1G-Prop was compared with commercial aminotri(methylenephosphonic acid) (ATMP) and polyacrylic acid (PAA) in terms of their stabilizing effect on soluble silica. The experimental performance evaluation conditions were pH 7±0.1, reaction temperature 30°C, and a high silicon solution with a SiO2 concentration of 500 mg / L. The experimental results are shown in Table 3. The concentration was 40 mg / L and was prepared with deionized water.

[0079] Table 3 Experimental results

[0080] type <![CDATA[Residual SiO2 concentration (mg / L)]]> Retention rate % PAMAM-1G-Prop 435 87.0 ATMP 171 34.2 PAA 178 35.6

[0081] It can be seen from Table 3 that the scale inhibition effect of PAMAM type scale inhibitor is significantly better than that of ATMP and PAA.

[0082] Example 8

[0083] Its composition is: 0.5G product of PAMAM-0.5G-Hex, a PAMAM series dendritic macromolecule with 1,6-hexanediamine as the core, added to the water sample at a concentration of 2, 10, and 20 mg / L, and prepared into a scale inhibitor with ionized water.

[0084] The preparation of PAMAM-0.5G-Hex is as described in Example 1, except that the core molecule is 1,6-hexanediamine.

[0085] Example 9

[0086] Its composition is: 1.5G product of PAMAM-1.5G-Hex, a PAMAM series dendritic macromolecule with 1,6-hexanediamine as the core, added to the water sample at a concentration of 2, 10, and 20 mg / L, and prepared into a scale inhibitor with ionized water.

[0087] The preparation of PAMAM-1.5G-Hex is as described in Example 1, except that the core molecule is 1,6-hexanediamine.

[0088] Example 10

[0089] Its composition is: 2G product of PAMAM-2G-Hex, a PAMAM series dendritic macromolecule with 1,6-hexanediamine as the core, added to the water sample at a concentration of 2, 10, and 20 mg / L, and prepared into a scale inhibitor with ionized water.

[0090] The preparation of PAMAM-2G-Hex is as described in Example 1, except that the core molecule is 1,6-hexanediamine.

[0091] Example 11 Evaluation of scale inhibition performance of scale inhibitors against CaSO4 scale

[0092] According to SYT5673-93 "Method for evaluating the performance of scale inhibitors for oil fields", the scale inhibition performance of the dendrimers prepared in Examples 4 and 8-10 against CaSO4 scale was evaluated.

[0093] The initial test solution contained 3000 mg / L Ca 2+ and 7200mg / L SO4 2- , PAMAM scale inhibitors of different concentrations were added by direct dosing and mixed evenly with the solution; the pH value of the solution was adjusted to 9.0 with borax buffer (0.01 mol / L), and the mixed solution was placed in a water bath at 70°C for 25 hours. The mixed solution was cooled to room temperature, filtered with a 0.22 μm filter membrane, and Ca was titrated with a 0.01 mol / L sodium ethylenediaminetetraacetic acid (EDTA) standard solution using a calcein phenolphthalein mixed indicator as an indicator. 2+ At the same time, a blank test was used as a reference to conduct experiments without antiscalant.

[0094] PAMAM-0.5G-Hex, PAMAM-1G-Hex, PAMAM-1.5G-Hex and PAMAM-2G-Hex dendrimers were used as scale inhibitors. The pH value was 9.0, the reaction temperature was 70°C, and the initial test solution contained 3000 mg / LCa. 2+ and 7200mg / LSO4 2- The antiscaling test performance was evaluated under the following conditions. The experimental results are shown in Table 4, and the antiscaling agent concentration is 2-20 mg / L.

[0095] Table 4 Experimental results

[0096]

[0097] It can be seen from Table 4 that when the scale inhibitor concentration is 2-20 mg / L, it has a scale inhibition effect on CaSO4 scale.

[0098] Example 12 Comparison of scale inhibition effects of scale inhibitors on calcium sulfate at different temperatures

[0099] PAMAM-1.5G-Hex dendrimers were added to water samples at concentrations of 2, 10, and 20 mg / L, and the temperature test range was 30-90° C. The method in Example 11 was used to evaluate the scale inhibition effect of the scale inhibitor on calcium sulfate at different temperatures.

[0100] At different temperatures, PAMAM-1.5G-Hex dendrimers with concentrations of 2, 10, and 20 mg / L were added to the water sample as a scale inhibitor to evaluate the scale inhibition performance of high-concentration calcium sulfate under pH 9.0 water conditions. The experimental results are shown in Table 5, with a concentration of 2 to 20 mg / L and a temperature test range of 30 to 90°C.

[0101] Table 5 Experimental results

[0102]

[0103] It can be seen from Table 5 that the scale inhibitor has a scale inhibition effect on CaSO4 scale when the temperature is between 30 and 90°C. Example 13 Comparison of scale inhibition effect of scale inhibitor on calcium sulfate

[0104] PAMAM-1.5G-Hex dendrimer was compared with a commercial hexamethylenediaminetetramethylenephosphonic acid (HDTMPA) CaSO4 scale inhibitor at the same concentration. The concentration added to the water sample was 4, 8, and 10 mg / L. The method in Example 11 was used for evaluation.

[0105] The product PAMAM-1.5G-Hex and commercial hexamethylenediaminetetramethylenephosphonic acid (HDTMPA) were compared for their antiscaling performance against CaSO4 at the same concentration. The experimental performance evaluation conditions were pH 9.0, reaction temperature 70°C, and the initial test solution contained 3000 mg / L Ca 2+ and 7200mg / L SO4 2- The scale inhibition performance was evaluated under the following conditions. The experimental results are shown in Table 6, with a concentration of 4-10 mg / L and prepared with deionized water.

[0106] Table 6 Experimental results

[0107]

[0108] It can be seen from Table 6 that when the PAMAM type scale inhibitor is used at a concentration of 8 to 10 mg / L, it has a scale inhibition effect close to that of the commercialized phosphorus-containing hexamethylenediaminetetramethylenephosphonic acid (HDTMPA).

[0109] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the present invention itself. Various changes in form and details may be made without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A scale inhibitor based on dendritic macromolecules, characterized in that: The scale inhibitor is prepared from dendritic macromolecules and water; the dendritic macromolecules are polyamide-amine PAMAM series dendritic macromolecules with alkyl diamine as the core.

2. The scale inhibitor according to claim 1, characterized in that The core molecule of the polyamide-amine PAMAM series dendritic macromolecules is one of ethylenediamine, propylenediamine, butylenediamine or hexamethylenediamine.

3. The scale inhibitor according to claim 1, characterized in that: The generation number of the polyamidoamine PAMAM series dendritic macromolecules is one of 0.5G, 1G, 1.5G or 2G.

4. The scale inhibitor according to claim 1, characterized in that: The terminal groups of the polyamide-amine PAMAM series dendritic macromolecules are methyl or amino.

5. The scale inhibitor according to claim 1, characterized in that: The polyamide-amine PAMAM series dendritic macromolecules are prepared by the following method: synthesizing PAMAM dendritic macromolecules by a divergent method, and preparing dendritic macromolecules with different alkyl diamines as cores or different generations of dendritic macromolecules with 1,6-hexanediamine as reaction cores through Michael addition and amidation condensation reactions.

6. The scale inhibitor according to claim 5, characterized in that: The alkyl diamine is 1,2-ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine or 1,6-hexanediamine.

7. Use of the scale inhibitor according to any one of claims 1 to 6 in an industrial circulating water cooling system and / or a high-temperature water system.

8. The use according to claim 7, characterized in that: The scale inhibitor is used for preventing silicate scale and / or calcium sulfate scale.

9. The use according to claim 8, characterized in that: The dosage concentration of the scale inhibitor for silicate scale is 10-80 mg / L.

10. The use according to claim 7, characterized in that: The dosage concentration of the scale inhibitor for inhibiting calcium sulfate scale is 2-20 mg / L.

Images