Polyaspartic acid derivatives modified with hydroxybenzhydrazide, preparation method and application thereof

Abstract

The application discloses a polyaspartic acid derivative modified by hydroxybenzoyl hydrazine, a preparation method and application thereof, and adopts a graft copolymerization method to introduce the hydroxybenzoyl hydrazine into a peptide chain of polyaspartic acid, and synthesizes three derivatives. 2+ The derivatives can be combined with Ca 2+ Metal ions to generate water-soluble complexes, have good scale inhibition and bacteriostatic performance, and have certain corrosion inhibition effect. In addition, the derivatives have good inhibition effect on escherichia coli, which is the main pollution source in circulating cooling water. The derivatives also have good optical properties, which are convenient for real-time monitoring of the concentration of the derivatives in the circulating cooling water pipeline in cooperation with a fluorescence monitor in industrial production, and optimization of the industrial production process. Therefore, the polyaspartic acid derivative modified by the hydroxybenzoyl hydrazine significantly improves the scale inhibition, corrosion inhibition and bacteriostatic performance, avoids application of a phosphorus-containing compound, and effectively reduces negative influence on the environment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of industrial circulating water treatment, and particularly relates to a polyaspartic acid derivative based on hydroxybenzoyl hydrazine modification, a preparation method and application thereof. BACKGROUND

[0002] Cooling water circulation systems are widely used in industrial production, but the presence of calcium ions, sulfate ions, carbonate ions and other anions and cations in the circulation system causes scale deposition and pipe corrosion during the circulation of cooling water. Ion exchange membranes, ion exchange resins, and the addition of water treatment agents are commonly used in industry to solve this problem. However, ion exchange membrane and ion exchange methods require regular replacement of ion exchange membranes and ion exchange resins, which is costly. Therefore, the most popular and convenient method is to add water treatment agents.

[0003] Polyaspartic acid is widely concerned in the field of industrial circulating water due to its non-toxic, non-polluting and biodegradable properties. Current research focuses on improving scale inhibition, corrosion inhibition and antibacterial properties by modifying its structure. Hydroxybenzoic acid has the ability to complex with metal ions and certain bactericidal ability. The hydroxyl group on the benzene ring is easily oxidized, which also suggests that it may have good corrosion inhibition performance as a circulating cooling water treatment agent. At the same time, hydroxybenzoic acid has excellent optical properties, which makes it possible to realize real-time monitoring as a water treatment agent. Literature reports that the lone pair of electrons on the amide bond can adsorb microcrystals in the solution that have a tendency to form scale, causing these microcrystals to aggregate and all have negative charges. The repulsive force between the same charges can effectively hinder the formation of large crystals, thereby playing an important role in scale inhibition. Based on this mechanism, the present application innovatively introduces the hydroxybenzoyl hydrazine structure fragment into the peptide chain of polyaspartic acid through an amide bond, aiming to prepare a multifunctional water treatment agent that combines scale inhibition, corrosion inhibition, bacteriostasis and fluorescence properties. SUMMARY

[0004] In view of the deficiencies in the prior art, the present application aims to provide a polyaspartic acid derivative based on hydroxybenzoyl hydrazine modification, a preparation method and application thereof. The polyaspartic acid derivative provided by the present application has effective functional groups such as phenolic hydroxyl groups, amide bonds and aromatic rings, and simultaneously has scale inhibition, corrosion inhibition, bacteriostasis and fluorescence properties.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] In a first aspect, the present application introduces functional structure fragments into the polyaspartic acid peptide chain by using hydroxybenzoyl hydrazine to open the ring of poly succinimide under alkaline conditions, and synthesizes three polyaspartic acid derivatives based on hydroxybenzoyl hydrazine modification, the structural formula is as shown below:

[0007]

[0008] wherein R2 is -OH, R1 and R3 are H or -OH; A represents an unmodified unit, the polymerization degree of which is n, B represents a modified unit, the polymerization degree of which is m, m+n represents the total polymerization degree, m / (m+n) x 100% = 10-40%, that is, the polymerization degree of hydroxybenzoyl hydrazine accounts for 10-40% of the total polymerization degree, preferably, the polymerization degree of hydroxybenzoyl hydrazine accounts for 40% of the total polymerization degree.

[0009] The present application takes poly succinimide (PSI), 4-hydroxybenzoyl hydrazine (4-HBH), 3,4-dihydroxybenzoyl hydrazine (3,4-DHBH), and 3,4,5-trihydroxybenzoyl hydrazine (3,4,5-THBH) as main raw materials. The hydroxybenzoyl hydrazine is subjected to ring-opening modification of poly succinimide under alkaline conditions to obtain the target product poly aspartic acid-hydroxybenzoyl hydrazine. The specific reaction route is shown as follows:

[0010]

[0011] R2 is -OH, R1 and R3 are H or -OH.

[0012] comprising the following steps:

[0013] The hydroxybenzoyl hydrazine and poly succinimide are dissolved in dimethyl sulfoxide, then the pH value of the reaction solution is adjusted to weak alkalinity by using a sodium hydroxide solution, and the reaction is heated and stirred at 60-90℃ for 20-30h. During the reaction, the pH value of the reaction solution is kept weak alkalinity by continuously adding the sodium hydroxide solution. After dialysis and distillation of the solvent, the target product is obtained.

[0014] Further, the molar ratio of hydroxybenzoyl hydrazine to monomers in poly succinimide is (2.5-3.5):1. 1mmol of poly succinimide monomers and 2.5-3.5mmol of hydroxybenzoyl hydrazine need to be dissolved in 4mL of dimethyl sulfoxide.

[0015] Further, the concentration of the sodium hydroxide solution used is 1mol / L-2mol / L.

[0016] Further, the pH value of the dimethyl sulfoxide solution of hydroxybenzoyl hydrazine and poly succinimide is 8-9; and the pH value of the reaction solution is kept at 8-9 by continuously adding the sodium hydroxide solution during the reaction.

[0017] Further, the molecular weight cut-off of the dialysis bag during dialysis is 500-2000Da, and the dialysis is performed in distilled water until the conductivity of the distilled water is 1.5-2.5μS / cm.

[0018] Specifically, water bath heating is used during the reaction, and the water bath temperature is 75-80℃.

[0019] The hydroxybenzoyl hydrazine modified polyaspartic acid derivative prepared by the preparation method has the functions of scale inhibition, corrosion inhibition, bacteriostasis and fluorescence.

[0020] The application of the hydroxybenzoyl hydrazine modified polyaspartic acid derivative as a multifunctional water treatment agent with the functions of scale inhibition, corrosion inhibition, bacteriostasis and fluorescence.

[0021] The application of the hydroxybenzoyl hydrazine modified polyaspartic acid derivative as a scale inhibitor or a bacteriostatic agent.

[0022] The application of the hydroxybenzoyl hydrazine modified polyaspartic acid derivative as a corrosion inhibitor.

[0023] The application of the hydroxybenzoyl hydrazine modified polyaspartic acid derivative as a fluorescent tracer.

[0024] The raw material ratio is optimized by adjusting the formula and controlling the polymerization degree, so that the water treatment agent achieves the optimal scale inhibition effect. The hydroxybenzoyl hydrazine structure fragment is introduced into the polyaspartic acid peptide chain, so that the scale inhibition performance, the corrosion inhibition performance and the bacteriostasis performance are improved. The application of the multifunctional polyaspartic acid derivative with the functions of scale inhibition, corrosion inhibition, bacteriostasis and fluorescence is provided.

[0025] The polyaspartic acid derivative with the functions of scale inhibition, corrosion inhibition, bacteriostasis and fluorescence is prepared by modifying the poly succinimide through ring-opening reaction. Compared with the prior art, the hydroxybenzoyl hydrazine structure fragment is introduced into the polyaspartic acid peptide chain, so that a new type of water treatment agent is synthesized.

[0026] 1) The hydroxybenzoyl hydrazine structure fragment is introduced into the polyaspartic acid peptide chain, so that a new type of water treatment agent is synthesized.

[0027] 2) The polymerization degree of the modified structure unit accounts for 50% of the total polymerization degree by adjusting the formula ratio, so that the water treatment agent synthesized under the polymerization degree has the optimal scale inhibition performance.

[0028] 3) First, the structure of the water treatment agent can combine with calcium ions in the solution to form a water-soluble complex, so that the concentration of calcium ions in the industrial circulating cooling water is reduced, and the scale inhibition effect is achieved.

[0029] 4) The synthetic step of the present application is simple, and the product synthesized is a new type of phosphorus-free water treatment agent, which can be used to directly detect the concentration of water treatment agent in the pipeline by using its optical activity with a fluorescence tracer instrument, and has good industrial application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 Mw of PASP prepared in the present application 1 H NMR spectrum; b is the H NMR spectrum of PASP-THBH prepared in the present application 1 H NMR spectrum; c is the H NMR spectrum of PASP-DHBH prepared in the present application 1 H NMR spectrum; d is the H NMR spectrum of PASP-HBH prepared in the present application 1 H NMR spectrum;

[0031] Figure 2 The scale inhibition effect of PASP, PASP-THBH, PASP-DHBH and PASP-HBH prepared in the present application on calcium carbonate scale;

[0032] Figure 3 The scale inhibition effect of PASP, PASP-THBH, PASP-DHBH and PASP-HBH prepared in the present application on calcium carbonate scale;

[0033] Figure 4 The antibacterial activity of PASP and PASP-THBH prepared in the present application was detected by coating method;

[0034] Figure 5 The antibacterial activity of PASP and PASP-THBH prepared in the present application was detected by coating method;

[0035] Figure 6 The fluorescence spectrum of PASP-THBH prepared in the present application. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0037] In the following examples and comparative examples, the raw materials used are all directly purchased ordinary commercially available products or can be prepared by using conventional methods in the art, unless otherwise specified.

[0038] The poly succinimide used in the following examples and comparative examples has a molecular weight of 7000-8000 and is purchased from Shanghai Maikelin Biochemical Technology Co., Ltd.

[0039] Example 1

[0040] Synthesis of PASP-THBH

[0041] PASP-THBH was synthesized by adding 10 mmol (0.984 g) of polysuccinimide (PSI) and 30 mmol (5.52 g) of 3,4,5-trihydroxybenzhydrazide (THBH) into a 100 mL round-bottom flask, adding 40 mL of DMSO to completely dissolve them, then adding 2 mol / L aqueous sodium hydroxide solution to adjust the pH of the reaction solution to 8-9, and then stirring the reaction at 75°C in a water bath for 24 h, continuously adding 2 mol / L aqueous sodium hydroxide solution to maintain the pH of the reaction solution at 8-9 during the reaction. After the reaction was completed, the reaction solution was loaded into a dialysis bag with a molecular weight cut-off of 1000 Da, dialyzed in distilled water, and dialyzed until the conductivity of the distilled water decreased to about 2 μS / cm. The solution was evaporated under reduced pressure to obtain the target product PASP-THBH.

[0042] Synthesis of PASP-DHBH

[0043] PASP-DHBH was synthesized by adding 10 mmol (0.984 g) of polysuccinimide (PSI) and 30 mmol (5.05 g) of 3,4-dihydroxybenzhydrazide (DHBH) into a 100 mL round-bottom flask, adding 40 mL of DMSO to completely dissolve them, then adding 2 mol / L aqueous sodium hydroxide solution to adjust the pH of the reaction solution to 8-9, and then stirring the reaction at 80°C in a water bath for 24 h, continuously adding 2 mol / L aqueous sodium hydroxide solution to maintain the pH of the reaction solution at 8-9 during the reaction. After the reaction was completed, the reaction solution was loaded into a dialysis bag with a molecular weight cut-off of 1000 Da, dialyzed in distilled water, and dialyzed until the conductivity of the distilled water decreased to about 2 μS / cm. The solution was evaporated under reduced pressure to obtain the target product PASP-DHBH.

[0044] Synthesis of PASP-HBH

[0045] PASP-HBH was synthesized by adding 10 mmol (0.984 g) of polysuccinimide (PSI) and 30 mmol (4.56 g) of 4-hydroxybenzhydrazide (HBH) into a 100 mL round-bottom flask, adding 40 mL of DMSO to completely dissolve them, then adding 2 mol / L aqueous sodium hydroxide solution to adjust the pH of the reaction solution to 8-9, and then stirring the reaction at 85°C in a water bath for 48 h, continuously adding 2 mol / L aqueous sodium hydroxide solution to maintain the pH of the reaction solution at 8-9 during the reaction. After the reaction was completed, the reaction solution was loaded into a dialysis bag with a molecular weight cut-off of 1000 Da, dialyzed in distilled water, and dialyzed until the conductivity of the distilled water decreased to about 2 μS / cm. The solution was evaporated under reduced pressure to obtain the target product PASP-HBH.

[0046] PASP Synthesis

[0047] 10 mmol (0.984 g) of polysuccinimide (PSI) was added to 10 mL of distilled water and placed in a 40 °C water bath. 10 mL of 1 mol / L sodium hydroxide aqueous solution was slowly added dropwise with stirring. After reacting at this temperature for 24 h, the resulting solution was placed in a dialysis bag with a molecular weight cutoff of 1000 Da and dialyzed in distilled water until the conductivity of the distilled water decreased to about 2 μS / cm. The retentate was evaporated to dryness under reduced pressure to obtain 1.11 g of the target product PASP, with a yield of 95.68%.

[0048] Figure 1 'a' represents PASP 1 The H NMR spectrum showed typical characteristic peaks of the methine and methylene groups of PASP at δ4.47 and δ2.75, proving that PASP was successfully synthesized.

[0049] Figure 1 b represents the target product PASP-THBH 1 The 1H NMR spectrum shows typical characteristic peaks of the methine and methylene groups of PASP at δ4.47 and δ2.75, and a characteristic peak on the benzene ring at δ6.75, proving the successful preparation of PASP-THBH. Figure 1 Based on the integral area calculation of the hydrogen on the benzene ring at a mid-shift of approximately δ6.75 and the hydrogen on the methylene side chain of PASP-THBH at approximately δ2.75, the grafting rate of the target product PASP-THBH is 40%.

[0050] Figure 1 c represents the target product PASP-DHBH 1 The 1H NMR spectrum shows typical characteristic peaks of the methine and methylene groups of PASP at δ4.47 and δ2.75, and characteristic peaks of the benzene ring at δ6.8 and δ7.2, proving the successful preparation of PASP-DHBH. Figure 1 Based on the integral area calculation of the hydrogen on the benzene ring at mid-shifts of approximately δ6.8 and δ7.2 and the hydrogen on the methylene side chain of PASP-DHBH at approximately δ2.75, the grafting rate of the target product PASP-DHBH is 40%.

[0051] Figure 1 d represents the target product PASP-HBH 1 The 1H NMR spectrum shows typical characteristic peaks of the methine and methylene groups of PASP at δ4.47 and δ2.75, and characteristic peaks of the benzene ring at δ6.9 and δ7.7, proving the successful preparation of PASP-HBH. Figure 1The grafting rate of the target product PASP-HBH was 20% calculated by the integral area of the hydrogen on the benzene ring at about δ6.9 and δ7.7 and the hydrogen on the methylene side chain of PASP-HBH at about δ2.75.

[0052] Example 2

[0053] The anti-calcium carbonate scale rate of the product of Example 1 was tested by static scale inhibition method

[0054] According to GB / T 16632-2019 "Determination of scale inhibition performance of water treatment agent by calcium carbonate deposition method", the scale inhibition performance of PASP-THBH on calcium carbonate scale was determined by static scale inhibition method.

[0055] (1) Take 9 250mL conical flasks numbered from 1 to 8, add 6mg / mL CaCl2 aqueous solution 10mL, 3.8g / L Na2B4O7·10H2O aqueous solution 10mL (adjust the initial pH to 9.0), 18.3mg / mL NaHCO3 solution 10mL to each flask;

[0056] (2) Then add a certain amount of 1mg / mL PASP-THBH aqueous solution to the 3-8 conical flasks, so that the final concentration of PASP-THBH in the 3-8 conical flasks is 10, 20, 30, 40, 50, 60mg / L respectively, while adding distilled water to the 1-8 conical flasks to make the total volume of the solution 250mL;

[0057] (3) Take 25mL of the solution in flask 1 and titrate with 0.01mol / L EDTA-2Na standard solution to calibrate the concentration of Ca 2+ in it, and the volume of the standard solution consumed is recorded as V0.

[0058] (4) Then, 2-8 conical flasks were reacted in a 80℃ water bath for 10h, after the reaction was completed, the filtrate was filtered, and 25mL of the filtrate was titrated with 0.01mol / L EDTA-2Na standard solution to calibrate the concentration of Ca 2+ in it, and the volume of the standard solution consumed by the filtrate in flask 2 is recorded as V1, and the volume of the standard solution consumed by the filtrate in flasks 3-8 is recorded as V2.

[0059] (5) Scale inhibition efficiency The scale inhibition rate of the product of Example 1 was tested by static scale inhibition method

[0060]

[0061] Repeat the above steps, replace PASP-THBH with PASP-DHBH, PASP-HBH, PASP to test its scale inhibition rate on calcium carbonate scale, and the scale inhibition rate of PASP on calcium carbonate scale is used as a control.

[0062] Figure 2 The scale inhibition rate of different concentrations of PASP and PASP-THBH, PASP-DHBH, and PASP-HBH on calcium carbonate scale can be seen from the figure. Under the same conditions, the scale inhibition effect of PASP-THBH, PASP-DHBH, and PASP-HBH on calcium carbonate scale increases with the increase of hydroxyl groups on the benzene ring. The scale inhibition rate of PASP-THBH gradually increases with the increase of concentration. When the concentration is 60 mg / L, the scale inhibition rate can reach 91.00%. Compared with the scale inhibition rate of 60 mg / L of PASP (67.73%), the scale inhibition rate is significantly improved.

[0063] Example 3

[0064] The scale inhibition effect of the product of Example 1 on calcium sulfate scale was tested by static scale inhibition method.

[0065] According to SY / T 5673-2020 "General Technical Conditions for Scale Inhibitors for Oilfields", the scale inhibition performance of PASP-THBH on calcium sulfate scale was determined by static scale inhibition method.

[0066] (1) Take 8 250 mL conical flasks, number them from 1 to 8, and then add 7.35 mg / mL CaCl2 solution 50 mL, 10.4 g / L Na2B4O7·10H2O solution 25 mL, and 7.1 mg / mL Na2SO4 solution 25 mL;

[0067] (2) Add a certain amount of 1 mg / mL PASP-THBH aqueous solution to the 3-8 conical flasks, so that the final concentration of PASP-THBH in the 3-8 conical flasks is 1, 2, 3, 4, 5, 6 mg / L, respectively. At the same time, add distilled water to the 1-8 conical flasks to make the total volume of the solution reach 250 mL;

[0068] (3) Take 5 mL of the solution in the 1 conical flask and titrate with 0.025 mol / L EDTA-2Na standard solution to calibrate the Ca2+ concentration in the solution. The volume of the standard solution consumed is recorded as V0. 2+

[0069] (4) Put the 2-8 conical flasks in a 70°C water bath for 6 h, filter, and then take 5 mL of the filtrate and titrate with 0.025 mol / L EDTA-2Na standard solution to calibrate the Ca2+ concentration in the filtrate. The volume of the standard solution consumed by the filtrate in the 2 conical flask is recorded as V1, and the volume of the standard solution consumed by the filtrate in the 3-8 conical flasks is recorded as V2. 2+

[0070] (5) Scale inhibition efficiency It can be calculated according to formula (1) in Example 2.

[0071] ​​Repeat the above steps, replace PASP-THBH with PASP-DHBH, PASP-HBH, PASP to measure their calcium sulfate scale inhibition rate, wherein the calcium sulfate scale inhibition rate of PASP as a control.

[0072] Figure 3 For different concentrations of PASP and PASP-THBH, PASP-DHBH, PASP-HBH, the calcium sulfate scale inhibition rate of calcium sulfate scale, it can be seen from the figure that the PASP-THBH with 3 hydroxyl groups on the benzene ring and the PASP-HBH with 1 hydroxyl group have the same scale inhibition performance as PASP, both of which can reach about 100% at a lower concentration of 6 mg / L; but when the benzene ring of the molecule has 2 hydroxyl groups, the calcium sulfate scale inhibition effect of PASP-DHBH is lower than that of PASP, PASP-THBH and PASP-HBH.

[0073] Example 4

[0074] The corrosion inhibition performance of the product of Example 1 was determined by the rotating coupon method.

[0075] According to GB / T1875-2014 "Determination of Corrosion Inhibition Performance of Water Treatment Agent-Rotating Coupon Method", the corrosion inhibition performance of PASP-THBH was determined by the rotating coupon method.

[0076] (1) Preparation of standard solution: take 0.05 mol (7.35 g) CaCl2·H2O, 0.02 mol (4.93 g) MgSO4·7H2O, 0.11 mol (6.58 g) NaCl in 7 L water; take 0.02 mol (1.68 g) NaHCO3 in 1 L water; then mix the two solutions, dilute with water to 10 L to obtain the standard solution;

[0077] (2) Preparation of acid and alkali washing solution: prepare 1.5 mol / L NaOH solution 1000 mL as alkali washing solution; take 0.057 mol (8 g) hexamethyl tetramine in 1000 mL mixed solution of V 浓盐酸(37％) :V H2O = 1:4 as acid washing solution;

[0078] (3) Pretreatment of test pieces: take 7 groups of 20 # carbon steel test pieces, wipe off the rust grease with filter paper, then wash in anhydrous ethanol, dry with filter paper after washing, dry in a forced air drying oven at 60°C for 4 h, cool and weigh, record as m1 (accurate to four decimal places), and store in a desiccator for use;

[0079] (4) Test solution preparation: 2000 mL of PASP-THBH solution with concentrations of 0, 10, 20, 30, 40, 50 mg / L respectively were prepared using the standard solution prepared in step (1); similarly, 2000 mL of PASP solution with concentrations of 0, 10, 20, 30, 40, 50 mg / L respectively were prepared using the standard solution prepared in step (1);

[0080] (5) The beakers containing the test solution were heated on the rotating coupon apparatus, and when the temperature of the test solution reached 45°C, 1-6 groups of carbon steel test pieces treated in step (3) were hung in the six beakers respectively, and were completely immersed in the test solution, the rotating speed was adjusted to 94 r / min, and the reaction was carried out at 45°C for 72 h (according to the test situation, the standard solution was added in time during the reaction to keep the volume of the test solution at 2000 mL);

[0081] (6) After 72 h, the test was stopped, the test pieces in the beakers on the rotating coupon apparatus were taken out, washed clean with a brush, cleaned in the pickling solution prepared in step (2) for 30 s, taken out, rinsed with tap water, quickly immersed in the alkaline cleaning solution for 30 s, taken out, rinsed with tap water, distilled water, dried with filter paper, then immersed in anhydrous ethanol for 3 min, taken out, dried with filter paper, dried in a forced air drying oven at 60°C for 4 h, cooled, weighed, and recorded as m2 (accurate to four decimal places). The 7th group of test pieces (treated in step (3), without step (5) experiment) also underwent the above pickling, alkaline cleaning, ethanol cleaning, drying and other operations, and were weighed and recorded as m2.

[0082] The corrosion rate is denoted by υ, and the unit is mm / a (millimeter per year), which is calculated according to formula (2):

[0083]

[0084] In the formula:

[0085] m - the mass loss of the 1-6 groups of test pieces (m2-m1), in grams (g);

[0086] m0 - the mass loss of the 7th group of test pieces (m2-m1), in grams (g);

[0087] s - the surface area of the test piece, in square centimeters (cm 2 );

[0088] p - the density of the test piece, in grams per cubic centimeter (g / cm 3 );

[0089] t - the test time, in hours (h);

[0090] 8760 - the number of hours corresponding to a year, in hours per year (h / a);

[0091] 10 - millimetres equivalent to 1 cm, in millimetres per centimetre (mm / cm).

[0092] The corrosion inhibition rate η is calculated according to formula (3):

[0093]

[0094] In the formula:

[0095] υ0 - the corrosion rate of the test piece at a sample concentration of 0 mg / L, in millimetres per year (mm / a);

[0096] υ1 - the corrosion rate of the test piece at a sample concentration of 10-50 mg / L, in millimetres per year (mm / a).

[0097] The test results are shown in Table 1:

[0098] Table 1 Corrosion inhibition efficiency of different concentrations of PASP-THBH

[0099]

[0100]

[0101] Table 2 Corrosion inhibition rate of different concentrations of PASP

[0102]

[0103] Example 4 is to investigate the corrosion inhibition effect of different concentrations of PASP and PASP-THBH by the rotating hanging piece method. It can be seen from the table that the corrosion inhibition efficiency of PASP-THBH has obvious concentration dependence when the concentration is 0-20 mg / L, and when the concentration exceeds 20 mg / L, the corrosion inhibition efficiency gradually decreases with the increase of the concentration, but is higher than that of PASP at the same concentration. The corrosion inhibition rate of PASP-THBH is as high as 43.52% at a concentration of 20 mg / L, which is about twice that of PASP at the same concentration.

[0104] Example 5

[0105] Determination of the bacteriostatic activity of PASP-THBH

[0106] (1) Plate coating counting method for determining the bacteriostatic activity of PASP-THBH on E. coli

[0107] PASP and PASP-THBH mother liquor with a mass concentration of 500 mg / mL were prepared with LB liquid medium as the solvent to explore the inhibition effect of PASP and PASP-THBH on E. coli.

[0108] Strain activation: Escherichia coli (E. coli) strain stored in -80℃ refrigerator was streaked on fresh solid LB plate (containing 10 g of tryptone, 5 g of yeast extract, 10 g of NaCl and 1.6 g of agar powder per 1 liter) and incubated at 30℃ for 24 h.

[0109] The single colony was inoculated in 5 mL of LB liquid medium and incubated at 30℃ and 220 r / min for 24 h. After sterilization, 80 μL of the bacterial solution cultured for 24 h was added to 8 mL of PASP or PASP-THBH solution and diluted to a final concentration of 20, 40, 60, 80 and 100 mg / mL, respectively. Then, 50 μL of the bacterial solution was taken out after 2 h of incubation at 37℃ and spread on a solid LB medium. After incubation at 37℃, the number of colonies on the solid medium was recorded and the experimental results were photographed.

[0110] Figure 4 For the bacteriostatic activity of different concentrations of PASP-THBH on E. coli, it can be seen from the figure that the survival rate of E. coli decreased significantly with the increase of the concentration of PASP-THBH. In comparison, the survival rate of E. coli decreased slowly with the increase of the concentration of PASP. Overall, the inhibitory effect of PASP-THBH on E. coli was better than that of PASP at the same concentration. When the concentration of PASP-THBH was 100 mg / mL, the survival rate of E. coli was only 33%.

[0111] (2) Inhibition zone method for measuring the bacteriostatic activity of PASP-THBH on E. coli

[0112] Strain activation: Escherichia coli (E. coli) strain stored in -80℃ refrigerator was streaked on fresh solid LB plate (containing 10 g of tryptone, 5 g of yeast extract, 10 g of NaCl and 1.6 g of agar powder per 1 liter) and incubated at 30℃ for 24 h.

[0113] The single colony was inoculated in 5 mL of LB liquid medium and incubated at 30℃ and 220 r / min for 24 h.

[0114] Take 1 mL of overnight culture and transfer to 100 mL of LB semi-liquid medium (0.7 g of agar powder), mix well, and pour into a pre-prepared LB solid plate. After 30 min, place sterilized round filter paper pieces with a diameter of 0.7 mm on the LB medium, and drop different concentrations of PASP and PASP-THBH solution onto the filter paper pieces, with a compound dose of 50 μL on each filter paper piece, and repeat three times for each sample. After standing for 30 min, place the above plate in a 30°C constant temperature incubator for overnight culture. Observe and measure the diameter of the inhibition zone. If there is a clear colony inhibition zone around the filter paper pieces coated with the drug, it is determined that PASP or PASP-THBH has an inhibitory effect on the tested strain. Among them, the antibacterial effect of PASP is used as a control group.

[0115] Figure 5 The antibacterial activity of PASP and PASP-THBH on E. coli. The antibacterial diameters of 50 mg / mL and 100 mg / mL of PASP on E. coli are both 8.1 mm; while the antibacterial diameters of PASP-THBH on E. coli are 26.4 mm at a concentration of 100 mg / mL and 24.4 mm at a concentration of 50 mg / mL, which is significantly better than PASP.

[0116] Example 6

[0117] Fluorescence spectrum of PASP-THBH

[0118] Prepare PASP-THBH aqueous solutions with concentrations of 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100 mg / L, respectively, and mark them as test solutions. Fix the excitation wavelength at 325 nm (the optimal absorption of PASP-THBH is 325 nm, which is tested by ultraviolet light), set the excitation slit and emission slit at 20 nm and 10 nm, respectively, and use a fluorescence spectrophotometer to detect the emission wavelength and corresponding fluorescence intensity of PASP-THBH at different concentrations.

[0119] Figure 6 The relationship between the concentration of PASP-THBH and the fluorescence intensity. As can be seen from the figure, the fluorescence intensity of PASP-THBH increases with the increase of concentration, showing a good linear relationship, so the content of water treatment agent in circulating water can be estimated according to the fluorescence intensity of the aqueous solution in the circulating water pipeline in industrial production.

[0120] The above embodiments only express the implementation of the present application, which is described in more detail and in more detail, but cannot be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present application patent should be subject to the appended claims.

[0121] It should be noted that the above examples and control examples belong to the same inventive concept, and the description of the examples and control examples has its own emphasis. The description of the examples and control examples is not exhaustive, and can be referred to the description of other examples and control examples.

Claims

1. A method for preparing a polyaspartic acid derivative modified with hydroxybenzoylhydrazine, characterized in that, The process is as follows: Hydroxybenzoyl hydrazide and polysuccinimide are dissolved in dimethyl sulfoxide, and then the pH of the reaction solution is adjusted to weakly alkaline with sodium hydroxide solution. The reaction is heated and stirred at 60~90℃ for 20~30 h. During the reaction, sodium hydroxide solution is continuously added to maintain the pH of the reaction solution at a weakly alkaline level. The solvent is removed by dialysis and evaporation to obtain the target product. The hydroxybenzoyl hydrazide is one or a mixture of two or more of 4-hydroxybenzoyl hydrazide, 3,4-dihydroxybenzoyl hydrazide and 3,4,5-trihydroxybenzoyl hydrazide in any proportion, and the molar ratio of hydroxybenzoyl hydrazide to the repeating unit in polysuccinimide is (2.5~3.5):

1.

2. The method for preparing polyaspartic acid derivatives modified with hydroxybenzoylhydrazine according to claim 1, characterized in that, The concentration of sodium hydroxide solution is 1 mol / L to 2 mol / L.

3. The method for preparing polyaspartic acid derivatives modified with hydroxybenzoylhydrazine according to claim 1, characterized in that, Weak alkalinity refers to a pH value of 8-9.

4. The method for preparing polyaspartic acid derivatives modified with hydroxybenzoylhydrazine according to claim 1, characterized in that, During dialysis, the molecular weight cutoff of the dialysis bag is 500~2000 Da. Dialysis is performed in distilled water, and the conductivity of the distilled water is 1.5~2.5 μS / cm.

5. A polyaspartic acid derivative based on hydroxybenzoylhydrazine modified by the preparation method according to any one of claims 1 to 4.

6. The application of the polyaspartic acid derivative modified with hydroxybenzoyl hydrazine as described in claim 5 as a multifunctional water treatment agent with scale inhibition, corrosion inhibition, antibacterial and fluorescence properties.

7. The application of the polyaspartic acid derivative modified with hydroxybenzoylhydrazine as described in claim 5 as a scale inhibitor or antibacterial agent.

8. The application of the polyaspartic acid derivative modified with hydroxybenzoylhydrazine as described in claim 5 as a corrosion inhibitor.

9. The application of the polyaspartic acid derivative modified with hydroxybenzoylhydrazine as described in claim 5 as a fluorescent tracer.

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