Quaternized chitosan benzisothiazolinone derivative as well as preparation and application thereof

Abstract

The invention discloses a quaternized chitosan benzisothiazolinone derivative as well as a preparation method and application of the quaternized chitosan benzisothiazolinone derivative in efficient antibacterial performance. The derivative has a structure as shown in a formula 1. The preparation method comprises the following steps: reacting chitosan with glycidyl trimethyl ammonium chloride at 60-100 DEG C for 6-48 hours to obtain a product 1, namely hydroxypropyl trimethyl ammonium chloride chitosan (HACC); the preparation method comprises the following steps: reacting 1, 2-benzisothiazolin-3-one with sodium chloroacetate at the temperature of 110-140 DEG C for 12-36 hours to obtain a product 2: 2-(3-carbonyl benzo [d] isothiazole-2-(3H)-yl) acetic acid (BITCOOH); and reacting the product 1 with the product 2 under a neutral condition for 12-48 hours to obtain the quaternized chitosan benzisothiazolinone derivative (HACCBIT). The derivative has a broad-spectrum antibacterial property, and has a killing effect on a plurality of bacteria, such as staphylococcus aureus, escherichia coli, salmonella salmonella salmonella, lactobacillus paracasei, lysinibacillus sphaericus, acinetobacter lwoffii and the like, and the derivative can be used for killing a plurality of bacteria, such as the staphylococcus aureus, the escherichia coli, the salmonella salmonella salmonella, the lactobacillus paracasei, the lysinibacillus sphaericus, the acinetobacter lwoffii and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of antibacterial materials, and particularly relates to a quaternized chitosan benzisothiazolinone derivative, a preparation method thereof and an application thereof in an antibacterial agent. Background Art

[0002] During the production, storage and use of daily chemical products, the problem of bacterial contamination leading to the corruption of daily chemical products has been around for a long time. In addition, the cases of harmful microorganisms adhering to the surface of materials and forming biofilms on the surface of medical devices, which cause chronic infections and device degradation, are also increasing year by year. Antimicrobial agents control product corruption and disease transmission by inhibiting or destroying the growth of pathogenic microorganisms. The use of antimicrobial agents to resist bad microorganisms and corruption is one of the most common means at present, and is widely used in industries such as daily chemical products and hospital treatment. The irrational use and abuse of antimicrobial agents are becoming more and more serious. Once antimicrobial resistance similar to antibiotic resistance occurs, the bactericidal effect becomes poor or even ineffective. Resistant bacteria resist bacteria and develop resistance by changing targets, producing specific enzymes, reducing membrane permeability, expressing efflux pumps, and forming biofilms. Therefore, exploring new antimicrobial agents and enriching the types of antimicrobial products are important directions for market traction and social demand.

[0003] 1,2-Benzisothiazolin-3-one (BIT) is a highly efficient, broad-spectrum non-oxidizing fungicide, which is currently mainly used in the sterilization of circulating water systems, papermaking, cosmetics, coatings and other industries. Benzisothiazolin-3-one is not easily soluble in water and has certain toxicity. It is irritating to the human respiratory system, central nervous system and skin. When used, direct contact and inhalation are harmful to human health. In addition, as a fungicide, it is irritating to human skin and often causes skin allergic reactions. How to modify 1,2-benzisothiazolin-3-one to improve its solubility, biocompatibility, safety and antibacterial properties is an important direction to improve the application of 1,2-benzisothiazolin-3-one. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the shortcomings of existing product technology, the present invention provides a quaternized chitosan benzisothiazolinone derivative and a preparation method and application thereof, so as to solve the problems of skin sensitization of the above-mentioned 1,2-benzisothiazolin-3-one (BIT) and insolubility in existing daily chemical water-based products and water-based coatings. The prepared antibacterial agent has the advantages of high biocompatibility and no effect on the performance of aluminum alloy materials, thereby improving the technical problem of applicability of product applications.

[0006] (II) Technical solution

[0007] 1,2-Benzisothiazoline-3-one is bonded to the side chain end of chitosan quaternary ammonium salt by electronic splicing to obtain a quaternary chitosan benzisothiazoline derivative, the general structural formula of which is shown in Formula 1:

[0008]

[0009] Where n = 100 to 5000

[0010] The preparation method of the quaternized chitosan benzisothiazolinone derivative comprises the following steps:

[0011] a: chitosan and glycidyl trimethyl ammonium chloride are added in a molar ratio of 1:3-6, reacted at 60-100°C for 6-48h, filtered, concentrated, dialyzed, concentrated, ethanol precipitated and vacuum dried to obtain product 1;

[0012] b: 1,2-Benzisothiazoline-3-one and sodium chloroacetate are added in a molar ratio of 1:2-10, reacted at 110-140°C for 12-36h, and product 2 is obtained through acid precipitation, washing and vacuum drying.

[0013] c: The molar ratio of product 1 to product 2 is 1:4-10 and the reaction is carried out under neutral conditions for 12-48 hours. The final derivative is obtained through dialysis, concentration and freeze-drying.

[0014] Preferably, the chitosan and glycidyl trimethyl ammonium chloride are reacted at a molar ratio of 1:3-6 at 80° C. for 6-48 hours, and then the product 1 is obtained by anhydrous ethanol precipitation and vacuum drying.

[0015] Preferably, chitosan and isopropanol are mixed in a molar ratio of 2 to 4:1, stirred at 30 to 60°C for 3 to 5 hours, and chitosan is uniformly dispersed in the isopropanol system to obtain solution A. Glycidyl trimethyl ammonium chloride is dissolved in purified water to obtain solution B. Solution A and solution B are added according to the molar ratio of chitosan to glycidyl trimethyl ammonium chloride of 1:3 to 6, and stirred at 60 to 100°C for 6 to 48 hours. After cooling, anhydrous ethanol is added to precipitate, and the precipitate is rinsed with anhydrous ethanol and dried to obtain product 1 (HACC).

[0016] Preferably, the product 2 is prepared by dissolving 1,2-benzisothiazolin-3-one in a 3-5% potassium hydroxide aqueous solution, immediately heating to 110-140° C., adding a sodium chloroacetate aqueous solution at a molar ratio of 1:2-10, reacting for 12-36 hours, returning to room temperature after the reaction is completed, concentrating, acid precipitating, washing the precipitate with purified water, anhydrous ethanol and the like solvents, and drying to obtain product 2 (BITCOOH).

[0017] Preferably, the final product described in step c is prepared by adding product 1 and product 2 in an aqueous solution at a molar ratio of 1:4-10, reacting at 25-28° C. for 12-36 hours, placing the reaction solution in a 1000Da dialysis bag, and dialyzing with pure water for 48 hours. After the solution is concentrated, it is dried to obtain the final product HACCBIT, wherein the degree of substitution of benzisothiazolinone is 40-60%.

[0018] Preferably, the quaternized chitosan benzisothiazolinone derivative is used in antibacterial agents. The application direction is to use it in the form of addition or spraying for antiseptic of daily chemical products, sterilization of medical devices, antibacterial of materials or antibacterial application in coatings.

[0019] The quaternized chitosan benzisothiazolinone derivative has a broad-spectrum antibacterial activity, especially has a killing effect on bacteria such as Staphylococcus aureus, Escherichia coli, Sediminibacterium salmoneum, Lacticaseibacillus paracasei, Lysinibacillus sphaericus and Acinetobacter lwoffi, and can be used as an antibacterial agent for bacteria such as Staphylococcus aureus, Escherichia coli, Sediminibacterium salmoneum, Lacticaseibacillus paracasei, Lysinibacillus sphaericus and Acinetobacter lwoffi.

[0020] The quaternized chitosan benzisothiazolinone derivative is used as an antibacterial active ingredient, and the addition amount varies according to different fields, wherein the addition amount for daily chemical products is 0.1-10%, the addition amount for spraying or soaking medical devices is 0.1-15%, and the addition amount for other fields is 0.1-20%.

[0021] The daily chemical products mentioned above include cleaning and hygiene cosmetics, skin care cosmetics, beauty cosmetics, hair care cosmetics, etc. Medical devices refer to preparations used on the outer surface of metal or non-metal materials of diagnostic and therapeutic equipment. The materials include metal materials, knitted materials, etc. The coatings are water-based coatings, powder coatings, etc.

[0022] Beneficial effects of the present invention

[0023] Compared with the prior art, the present invention provides a quaternized chitosan benzisothiazolinone derivative and its preparation and application, which has the following beneficial effects:

[0024] 1. The quaternized chitosan benzisothiazolinone derivative prepared by the present invention has excellent antibacterial activity and has a killing effect on Staphylococcus aureus, Escherichia coli, salmon sediment rod-shaped bacteria, Lactobacillus paracasei, spherical lysine Bacillus and Acinetobacter lwoffii. Under the condition of low use concentration, the bactericidal activity is strong and the affinity-penetration-rupture-death efficient bactericidal process is completed through synergistic action. It has great potential for application as an antibacterial agent in daily chemical products, materials and medical devices.

[0025] 2. The quaternized chitosan benzisothiazolinone derivative prepared by the present invention is easily soluble in water, can form a uniform aqueous solution, has good compatibility with a variety of daily chemical products, has no effect on the performance of metal materials, and greatly improves the practicality of the present invention.

[0026] 3. The quaternized chitosan benzisothiazolinone derivative prepared by the present invention is non-toxic to human epidermal cells and has high biocompatibility, thereby improving the safety of the present invention in daily use. At the same time, the method of the present invention is simple, the experimental materials are easily available, and it is convenient for mass preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is the hydrogen nuclear magnetic resonance spectrum of the quaternized chitosan benzisothiazolinone derivative of the present invention;

[0028] Figure 2 is the infrared spectrum of the quaternized chitosan benzisothiazolinone derivative of the present invention;

[0029] Figure 3 This is a microscopic morphology diagram of the quaternized chitosan benzisothiazolinone derivative of the present invention;

[0030] Figure 4 This is a graph showing the inhibition of bacterial growth curves by the quaternized chitosan benzisothiazolinone derivatives of the present invention;

[0031] Figure 5 This is a microscopic morphology of bacteria after being treated with the quaternary ammonium chitosan benzisothiazolinone derivative of the present invention;

[0032] Figure 6 This is a test diagram of the toxicity of the quaternized chitosan benzisothiazolinone derivative of the present invention to HaCaT cells;

[0033] Figure 7 This is a graph showing the effect of the quaternized chitosan benzisothiazolinone derivative of the present invention on the electrochemical properties of 7050 stainless steel;

[0034] Figure 8This is a diagram of the preparation method of the quaternized chitosan benzisothiazolinone derivative of the present invention. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Example 1

[0037] Preparation of a highly effective antibacterial agent of quaternized chitosan benzisothiazolinone derivative

[0038] a: 2 mol chitosan was mixed with 1 mol isopropanol solution and stirred at 40°C for 5 h until chitosan was evenly dispersed in the isopropanol system to obtain solution A. 6 mol glycidyl trimethylammonium chloride was dissolved in 30 mL purified water to obtain solution B. Solution A and solution B were stirred and reacted at 80°C for 24 h. After cooling, anhydrous ethanol was added to precipitate, the precipitate was rinsed with anhydrous ethanol, and then dried to obtain product 1;

[0039] b: 10 mol of 1,2-benzisothiazolin-3-one was dissolved in 3% potassium hydroxide aqueous solution, and the temperature was immediately raised to 140°C. 50 mol of sodium chloroacetate aqueous solution was added. After the reaction was allowed to react for 18 hours, the reaction was terminated and cooled to room temperature. Product 2 was obtained after acid precipitation, washing and drying.

[0040] c: 2 mol of product 1 and 8 mol of product 2 were stirred in an aqueous solution at 25°C for 24 hours. The reaction solution was placed in a 1000Da dialysis bag and dialyzed with pure water for 48 hours. The solution was concentrated and dried to obtain the final product LHACCBIT.

[0041] Example 2

[0042] Preparation of a highly effective antibacterial agent of quaternized chitosan benzisothiazolinone derivative

[0043] a: 4 mol of chitosan was added to 1 mol of isopropanol solution and stirred at 60°C for 4 h. After chitosan was evenly dispersed in the isopropanol system, it was reacted with 6 mol of glycidyl trimethylammonium chloride at 90°C for 20 h. After cooling to room temperature, anhydrous ethanol was added to precipitate the product, which was filtered and dried to obtain product 1.

[0044] b: Dissolve 16 mol of 1,2-benzisothiazolin-3-one in 4% potassium hydroxide aqueous solution, add 160 mol of sodium chloroacetate aqueous solution, react at 120°C for 36 hours, then cool to room temperature to precipitate the product under acidic conditions. Wash the solid with purified water and anhydrous ethanol, and dry to obtain product 2.

[0045] c: 1 mol of product 1 and 8 mol of product 2 were mixed evenly in an aqueous solution, reacted at 28°C for 36 hours, the reaction solution was placed in a 1000Da dialysis bag, and dialyzed with pure water for 48 hours. After the solution was concentrated, it was dried to obtain the final product, quaternized chitosan benzisothiazolinone derivative (HACCBIT).

[0046] Example 3

[0047] Determination of the degree of substitution of isothiazolinone in quaternized chitosan benzisothiazolinone derivatives

[0048] Method: The changes of functional groups of the products were analyzed by nuclear magnetic resonance spectroscopy. Chitosan and the samples obtained in Examples 1 and 2 were dissolved in deuterated water / deuterated acetic acid, respectively. 1 The H NMR test was measured using a Bruker AVIII-600 nuclear magnetic resonance spectrometer. Since the degree of substitution of the product of Example 2 was higher than that of the product of Example 1, the sample of Example 2, i.e., HACCBIT, was used in subsequent experiments.

[0049] Results: H NMR spectrum Figure 1 As shown. The chemical shifts of chitosan skeleton proton H at 1.9, 3.0, 3.3-4.0 ppm and 4.5 ppm are attributed to the protons of glucosamine units H2, H3-H6. The characteristic signal of HACCBIT at 7.1-7.8 ppm is the proton on the benzene ring of 1,2-benzisothiazolin-3-one, and the characteristic signal at 3.3 ppm is the proton of -CH2-. The characteristic signals observed at 4.3, 2.8-3.0 are the characteristic peaks -N retained by HACCBIT. + (CH3)3. Further analysis was performed by nuclear magnetic resonance hydrogen spectrum, and the results showed that the quaternized chitosan benzisothiazolinone derivative shown in formula 1 was successfully synthesized, and the peak integrated area at 7.1-7.8 ppm of Example 2 was higher than that of Example 1, proving that the degree of substitution of benzisothiazolinone in Example 2 was higher than that in Example 1. The structural formula of HACCBIT was obtained as follows:

[0050]

[0051] Example 4

[0052] Structural Characterization and Physicochemical Properties of Quaternary Ammonium Chitosan Benzisothiazolinone Derivatives

[0053] ① The chemical properties of the sample obtained in Example 2 were characterized by using a Nicolet IS 50 Fourier transform infrared spectrometer (FTIR) from Thermo Corporation of the United States at 25°C. The sample was mixed with KBr and pressed into a pellet. -1 The measurement is done within a specific wavenumber range.

[0054] ② Microscopic morphology of chitosan (CS) and quaternary ammonium chitosan benzisothiazolinone derivative (HACCBIT). Take appropriate amount of CS and HACCBIT powder, use conductive glue to fix the sample to be tested on the stage, gently blow away the powder not adhering to the conductive glue with an ear-cleaning bulb, spray gold under vacuum conditions, place the stage in a scanning electron microscope, and observe the surface microstructure of chitosan and quaternary ammonium chitosan benzisothiazolinone derivative with an electron beam acceleration voltage of 5kV.

[0055] ③ Water solubility of HACCBIT and BIT under different pH conditions. The two compounds were dissolved in 5 mL of pure water under different pH conditions at room temperature until insoluble matter was observed. The solution was centrifuged at 4000 rpm for 10 minutes to separate the insoluble components. After centrifugation, 2 mL of the supernatant was freeze-dried and the water solubility was calculated by the weight of the dried solid.

[0056] Results: ① FTIR of chitosan and its derivatives Figure 2 As shown. Product 1 (HACC) was prepared by chitosan quaternization method. The spectrum of HACC is at 1477cm -1 -N(CH3)3 appears + The sharp peak indicates that the quaternary ammonium salt has been formed. The spectrum of product 2 (BITCOOH) contains C=O (1718 cm -1 )、CO(1201cm -1 ) clearly shows the formation of BITCOOH carboxylic acid bonds. In the FTIR spectrum of HACCBIT, 1608 cm -1 The peak at is related to the -C=O- stretching vibration. Figure 2 It can be seen that HACCBIT not only has the absorption peak of BITCOOH, but also contains the characteristic absorption peak of HACC at 1477cm -1 .

[0057] ② The results of scanning electron microscopy are as follows Figure 3As shown in the figure, the chitosan after derivatization changes from the original crystal morphology to a smooth film, with a granular and porous structure on the surface. It can be seen that the aggregation state of the chitosan molecular chain has changed significantly after chemical modification. This leads to a significant change in the entanglement degree and crystallinity between the molecular chains, thereby reducing the intermolecular interaction between the chitosan molecular chains, thereby improving the water solubility and showing better film-forming properties.

[0058] ③ The water solubility results of BIT and HACCBIT under different pH conditions are shown in Table 1. Due to the enhanced interaction between OH- ions and BIT molecules under alkaline conditions, the water solubility of BIT is significantly improved, but compared with HACCBIT, the water solubility of HACCBIT is significantly higher than that of BIT and is not affected by the pH value of the solution.

[0059] Table 1 Water solubility under different pH conditions

[0060]

[0061] Among them, * represents the statistical significance of water solubility under different pH conditions, P < 0.05.

[0062] Example 5

[0063] HACCBIT Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) Determination

[0064] Method: Take the sterilized LB medium and dilute the bacterial solution to a concentration of (1-5)×10 6 CFU / mL. Take a 96-well plate, inoculate 50μL of bacterial solution in each well, and add 50μL of HACCBIT with a final concentration of 1024mg / L, 512mg / L, 256mg / L, 128mg / L, 64mg / L, 32mg / L, 16mg / L, 8mg / L, 4mg / L, 2mg / L, and 1mg / L. After incubation at 37℃ for 20h, the concentration without obvious turbidity observed by naked eye is the minimum inhibitory concentration (MIC). The liquid in different wells is inoculated onto LB solid culture medium. After incubation at 37℃ for 24h, the concentration without colony appearance is the minimum bactericidal concentration (MBC).

[0065] result:

[0066] The minimum bactericidal concentration and minimum inhibitory concentration of HACCBIT for 6 bacteria are shown in Table 2. The MIC of HACCBIT for Sediminibacterium salmoneum, Lysinibacillus sphaericus, Lactobacillus paracasei, and Acinetobacter lwoffi was 64 mg / L, and the MBC was 128 mg / L; the MIC of HACCBIT for Escherichia coli and Staphylococcus aureus was 32 mg / L, and the MBC was 64 mg / L.

[0067] Table 2 MIC and MBC of chitosan benzisothiazolinone derivative (HACCBIT) against different bacteria

[0068]

[0069] Example 6

[0070] Antibacterial activity of HACCBIT against different bacterial species

[0071] Methods: Different strains were taken and revived for 24 hours. After centrifugation at 4000 rpm for 10 minutes, the supernatant was removed and the bacterial solution was diluted with PBS to a concentration of 0.5 in a McFarland turbidimetric tube. At this time, the bacterial concentration was about 1.5-2.5×10 8 CFU / mL. Add LB liquid culture medium and adjust the bacterial concentration to 1.5-2.5×10 5 CFU / mL. 50 μL of bacterial solution and 50 μL of sample (blank group is water, sample group HACCBIT final concentration is MIC concentration) were added to the 96-well plate, placed in a microplate reader, incubated at 37°C, and continuously monitored for 15 hours at 600 nm for changes in absorbance.

[0072] result:

[0073] The results are as follows Figure 4 As shown in the figure, under normal conditions, the number of bacteria (turbidity) increases with time. After being treated with HACCBIT at the MIC concentration, the growth of the six bacteria was significantly inhibited, and the turbidity at OD600nm was relatively low, indicating that HACCBIT prolonged the growth cycle of each bacteria and inhibited its logarithmic growth phase. Figure 4 The figure d in the figure shows that HACCBIT has the strongest inhibitory effect on Staphylococcus aureus, and the bacterial growth did not reach the logarithmic growth phase within 9 hours. Figure 4It can be seen from the af in that within 15 hours of treatment, HACCBIT has a significant inhibitory effect on the growth of all six bacteria. In summary, HACCBIT has a broad-spectrum antibacterial activity.

[0074] Example 7

[0075] Effect of HACCBIT on bacterial morphology

[0076] Method: The bacterial concentration was adjusted to 1×10 8 CFU / mL, water was added as a blank control group, and HACCBIT with the minimum inhibitory concentration was added as a sample group, and then the bacteria were cultured at 37°C for 20 hours. After cultivation, the culture medium was discarded, and the samples were washed three times with PBS (10×), then centrifuged at 10,000rpm for 5 minutes, and fixed in 5% glutaraldehyde for 2 hours. Subsequently, 30%, 50%, 70%, 80%, 90%, and anhydrous ethanol gradients were used for dehydration. After the samples were dried at the critical point of carbon dioxide, they were sprayed with gold and observed under a field emission scanning electron microscope.

[0077] result:

[0078] like Figure 5 As shown in the figure, the changes in the microstructure of each bacteria before and after co-culture with HACCBIT were observed by electron scanning microscopy. The results showed that the morphology of each bacteria in the blank group showed a complete and plump rod-shaped or spherical morphology. After 20 hours of HACCBIT treatment, Sediminibacterium salmoneum showed cell shrinkage and collapse, and Lysinibacillus sphaericus, Escherichia coli, Lysinibacillus sphaericus, Lacticaseibacillusparacasei, and Acinetobacter lwoffii showed obvious wrinkles, deformation, and even ruptures in their microstructure, which showed that HACCBIT acted on the microbial membrane structure, destroyed the structural integrity of the bacteria, and caused the bacteria to rupture and die.

[0079] Example 8

[0080] Toxicity test of HACCBIT and BIT on HaCaT cells (human immortalized epidermal cells)

[0081] Methods: The sample solution was diluted to 512 μg / mL with complete culture medium, and then diluted to 256, 128, 64, and 32 mg / L, for a total of 5 gradient concentrations. HaCaT cells cultured to the logarithmic phase were taken, washed twice with PBS, and digested with trypsin. After centrifugation at 11000 rpm for 4 min, the supernatant was discarded, and 1 mL of complete culture medium containing 10% fetal bovine serum was added and blown evenly. 10 μL was taken and counted using a hemocytometer, and 1×10 4 Cells / well (100 μL per well) were inoculated in a 96-well plate, incubated at 37°C for 24 hours, and the culture medium was discarded. Different concentrations of HACCBIT and BIT were added: 512, 256, 128, 64, and 32 mg / L. Only complete culture medium was added to the blank group. Each experimental group was repeated for 3 wells and incubated for another 24 hours. After incubation, 10 μL MTT solution (5 mg / mL) was added to each well, and then incubated at 37°C for another 4 hours to observe the appearance of purple crystals at the bottom of the 96-well plate. The 96-well plate was removed, the supernatant was gently aspirated and discarded, 150 μL DMSO was added to each well and placed on a shaker to shake for 10 minutes until the crystals dissolved. The mixed solution was measured at 570 nm using an enzyme marker. The cell viability of the blank group was set as 100%, and the cell viability of the treated group was calculated relative to the blank group.

[0082] Cell viability (%) = absorbance of cells in the treatment group / absorbance of cells in the control group * 100

[0083] result:

[0084] like Figure 6 As shown, when the concentration of BIT is higher than 64 mg / L, the cell survival rate is only 6%, and when it is 32 mg / L, the cell survival rate is about 40%, indicating that BIT has strong cytotoxicity to human epidermal cells. The concentration of HACCBIT is dose-dependent with the cell survival rate. When the concentration is 256 mg / L and below, the cell survival rate is about 80%, indicating that HACCBIT has no cytotoxicity to HaCaT cells when the concentration is lower than 256 mg / L, and has higher biocompatibility and safety compared with BIT.

[0085] Example 9

[0086] Effect of HACCBIT on the properties of metal materials

[0087] Method: The electrochemical experiment adopts a three-electrode system, with a platinum electrode of 20mm×20mm×2mm as the auxiliary electrode, a saturated calomel electrode as the reference electrode, and a metal material of 7050 aluminum alloy. 1) The open circuit potential is completed by the electrochemical workstation CS100 (Wuhan Cost). Before the electrochemical measurement, the closed system is polarized at constant potential, and the electrochemical measurement is carried out after the system is stable. 2) The electrochemical alternating current impedance (EIS) is completed by the electrochemical workstation CS100 (Wuhan Cost). 10mV is selected as the amplitude of the sinusoidal AC voltage, and the scanning frequency is 10 5 Hz to 10 -2 Hz, and the results were fitted and analyzed using ZsimpWin software. 3) Potentiodynamic polarization curves with a potential scanning rate of 0.1 mV·S -1 The experimental results were analyzed by C-view software.

[0088] result:

[0089] Depend on Figure 7 From the a in the figure, we can see that the three-electrode system is stable. According to the characteristics of the impedance spectrum, Figure 7 The d fitting circuit in Figure 7 The impedance spectrum after adding HACCBIT is consistent with the impedance spectrum of the blank group, and the capacitance arc radius has no significant change, indicating that HACCBIT has no corrosive effect on 7050 aluminum alloy. Figure 7 From c in FIG. 3 , we can see that the corrosion rate (Corrision Rate) is obtained by fitting the potentiodynamic polarization curve data as shown in Table 3 below. The corrosion rate results show that the corrosion rate of HACCBIT on 7050 aluminum alloy is 0.0041 mm / year, indicating that HACCBIT has almost no effect on metal materials.

[0090] Table 3 Corrosion rate data of 7050 aluminum alloy under polarization potential

[0091]

[0092] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A quaternized chitosan benzisothiazolinone derivative (HACCBIT), characterized in that: HACCBIT has a structure as shown in Formula 1: Among them, n=100~5000.

2. A method for preparing a quaternized chitosan benzisothiazolinone derivative, characterized in that: The following steps are involved: a: chitosan and glycidyl trimethyl ammonium chloride were added in a molar ratio of 1:3-6, reacted at 60-100°C for 6-48h, and product 1 (HACC) was obtained by filtration, concentration, dialysis, concentration, ethanol precipitation and drying; b: 1,2-Benzisothiazoline-3-one and sodium chloroacetate are added in a molar ratio of 1:2-10, reacted at 110-140°C for 12-36h, and then acid precipitated, washed and dried to obtain product 2 (BITCOOH); c: The molar ratio of product 1 to product 2 is 1:4-10, and the reaction is carried out under neutral conditions for 12-48 hours to obtain the final derivative (HACCBIT).

3. The method for preparing a quaternized chitosan benzisothiazolinone derivative according to claim 2, characterized in that: The preparation of the product 1 in step a is as follows: chitosan and isopropanol are mixed in a molar ratio of 2 to 4:1, stirred at 30 to 60°C for 3 to 5 hours, so that the chitosan is evenly dispersed in the isopropanol system to obtain solution A; glycidyl trimethyl ammonium chloride is dissolved in purified water to obtain solution B with a final concentration of 1.0 g / mL; solution A and solution B are added in a molar ratio of chitosan to glycidyl trimethyl ammonium chloride of 1:3 to 6, and reacted at 60 to 100°C for 6 to 48 hours; after the reaction is completed, the mixture is cooled to room temperature, anhydrous ethanol is added to precipitate, the precipitate is rinsed with anhydrous ethanol, and then dried to obtain product 1.

4. The method for preparing a quaternized chitosan benzisothiazolinone derivative according to claim 2, characterized in that: The preparation method of the product 2 in step b is as follows: 1,2-benzisothiazolin-3-one is dissolved in a 3-5% potassium hydroxide aqueous solution, the temperature is immediately raised to 110-140° C., a sodium chloroacetate aqueous solution is added in a molar ratio of 1:2-10, the reaction is carried out for 12-36 hours, the reaction is completed and the mixture is cooled to room temperature, concentrated under reduced pressure, and precipitated with acid. The precipitate is washed three times with purified water, anhydrous ethanol or the like solvent, and then dried to obtain the product 2.

5. The method for preparing a quaternized chitosan benzisothiazolinone derivative according to claim 2, characterized in that: The preparation of the final derivative in step c is as follows: product 1 and product 2 are mixed in an aqueous solution at a molar ratio of 1:4-10, reacted at 25-28° C. for 12-48 hours, and then the reaction solution is placed in a 1000Da dialysis bag, dialyzed with pure water for 48 hours, and the solution is concentrated and dried to obtain the final product, a quaternized chitosan benzisothiazolinone derivative, wherein the degree of substitution of benzisothiazolinone is 40-100%.

6. Use of the quaternized chitosan benzisothiazolinone derivative according to claim 1 in the preparation of an antibacterial agent, characterized in that: Quaternized chitosan benzisothiazolinone derivatives can be used as broad-spectrum antibacterial agents.

7. The use according to claim 6, characterized in that: Quaternized chitosan benzisothiazolinone derivatives have a killing effect on bacteria such as Staphylococcus aureus, Escherichia coli, Sediminibacterium salmoneum, Lacticaseibacillus paracasei, Lysinibacillus sphaericus and Acinetobacter lwoffi, and can be used as a broad-spectrum antibacterial agent.

8. The use according to claim 6, characterized in that: The quaternized chitosan benzisothiazolinone derivative is used as an antibacterial agent or as an active ingredient in daily chemical products, medical devices, antibacterial materials or coatings as an antibacterial agent.

9. The use according to claim 7, characterized in that: The addition amount of the quaternized chitosan benzisothiazolinone derivative is different, among which the addition amount for daily chemical products is 0.1-10%, the addition amount for spraying or soaking of medical devices is 0.1-15%, and the addition amount for other fields is 0.1-20%.

Images