Preparation method of modified betaine and antibacterial cellulose ether containing modified betaine

Abstract

The invention relates to a preparation method of modified betaine and an antibacterial cellulose ether containing modified betaine, and belongs to the technical field of antibacterial cellulose ether. The invention comprises the following steps: using bromopropyne and an azide reagent as raw materials and monovalent copper ions as catalysts for reaction, adjusting the pH of the system to alkalinity, filtering to obtain a triazole derivative; dropping a betaine solution with a weakly acidic pH into the triazole derivative for reaction to obtain a modified betaine solution; then in the granulation stage of the cellulose ether, spraying the modified betaine solution on the surface of the HPMC gel material after filter pressing, and then granulating and low-temperature crushing to obtain a powdered antibacterial cellulose ether. The invention adopts a click chemistry reaction catalyzed by monovalent copper to modify the betaine molecule by a nucleophilic substitution reaction of a bromine end group, prepares a novel functional antibacterial agent, realizes the synergistic antibacterial of triazole and electrostatic action, and greatly improves the antibacterial performance and mildew resistance of HPMC.

Description

Technical Field

[0001] The invention relates to a preparation method of modified betaine and antibacterial cellulose ether containing the modified betaine, belonging to the technical field of antibacterial cellulose ether. Background Art

[0002] People's requirements for daily necessities are constantly increasing. When ensuring the quality of daily chemical products, they are also required to have certain antibacterial and disinfection capabilities. Hydroxypropyl methylcellulose (HPMC), as a commonly used daily chemical thickener, has the characteristics of being renewable, recyclable, non-toxic, inexpensive, biodegradable, and having excellent biocompatibility. However, as a non-ionic cellulose ether, HPMC itself does not have a significant weakening and resistance to pathogens. When preparing daily chemical products, in order to improve the antibacterial properties of daily chemical products, other antibacterial ingredients need to be added to achieve the purpose, which will not only increase costs, but also some effective ingredients of antibacterial agents will cause damage to the environment. For example, the invention patent document with application number 200680038712.6 discloses an antibacterial composition comprising a cationic polymer with limited antibacterial activity (e.g., a hydrophobically modified quaternary ammonium cellulose ether) and an antibacterial compound (e.g., one or more compounds selected from the following: diiodomethyl-p-tolylsulfone, o-phenylphenol, sodium pyrithione, zinc pyrithione, 3-iodo-2-propynyl butyl carbamate, 2-methyl-4-isothiazoline-3-one, 1,2- -benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 1-(3-chloroallyl)-3,5,7-triaza-1-azoniadiantane chloride, 2-(4-thiazolyl)-benzimidazole, β-bromo-β-nitrostyrene, 2,4,4′-trichloro-2-hydroxyphenyl ether, chloroxylenol, chlorocresol, p-tert-amylphenol, N-(4-chlorophenyl)-N′-(3,4-dichlorophenyl)-urea, or p-hydroxybenzoic acid esters). Summary of the invention

[0003] The present invention aims to solve the above problems, thereby providing a modified betaine. The present invention synthesizes a triazole antibacterial functional group modified betaine molecule through a click chemistry reaction catalyzed by monovalent copper to prepare a novel functional antibacterial agent with excellent antibacterial performance; the present invention mixes the prepared novel functional antibacterial agent with HPMC, utilizes a low-temperature crushing process, combines the advantages and antibacterial mechanism of betaine and triazole, and prepares a novel functional antibacterial cellulose ether with excellent antibacterial performance, good decontamination effect and the ability to improve the biocompatibility of detergents.

[0004] The technical solution of the present invention to solve the above problems is as follows:

[0005] The preparation method of modified betaine comprises the following steps:

[0006] S1. Add propidium bromide and azide reagent solution into the reaction kettle, stir, add a solution containing cuprous ions as a catalyst and continue stirring, and set the reaction time;

[0007] S2. After the reaction is completed, the pH of the system is adjusted to alkaline, and the triazole derivative is obtained by filtration;

[0008] S3, dissolving betaine, adjusting the pH to be weakly acidic, and preparing a betaine solution;

[0009] S4, adding the betaine solution dropwise to the triazole derivative, starting stirring, turning on the oil bath for heating, and heating the mixture to react;

[0010] S5. After the reaction is completed, a modified betaine solution is obtained.

[0011] Betaine is widely found in plants in nature, such as beets, malt, and spinach. Betaine is a natural substance, and because its chemical structure is similar to that of amino acids, it belongs to quaternary ammonium water-soluble alkaloids. Betaine is an amphoteric organic compound and therefore has the property of double charge. It contains anionic groups and cationic groups in the same structural unit. As an amphoteric organic compound, betaine itself has the characteristics of non-toxicity and pollution-free, extremely high biocompatibility, high water solubility, acid resistance, high temperature resistance, alkali resistance, strong antioxidant properties, etc., and it is simple to operate and safe to use, so it has a very wide range of uses, such as animal husbandry, medicine, agriculture and forestry, food, and daily chemicals. Due to its amphoteric characteristics, betaine can easily damage the surface of bacteria through surface charge adsorption, penetrate the bacterial biomass membrane, destroy its protease, and thus inhibit the reproduction of bacteria. At the same time, due to its positive charge, it will also resist the attachment of some bacteria with positive charges on the surface, achieving the purpose of antibacterial.

[0012] Betaine, as a commonly used antibacterial agent, is usually added directly to the products used to achieve antibacterial purposes. However, some other chemical derivatives that come with it during the production process increase its toxicity, pose safety hazards to users, and increase the burden of environmental management.

[0013] Triazole is a five-membered heterocyclic ring containing three nitrogen atoms, which can easily form a coordination bond to bind to a biological molecule target. Triazole compounds are five-membered heterocyclic compounds formed by replacing a carbon atom in imidazole with a nitrogen atom. They can actively participate in the formation of hydrogen bonds and have high tolerance to hydrolysis, redox and other reactions. The bactericidal properties of triazole mainly kill bacteria by inhibiting the formation of microbial cell membranes. Due to its special antibacterial agent system, triazole is widely used in medicine, pesticides, daily chemicals and food.

[0014] The present invention adopts a click chemistry reaction catalyzed by monovalent copper. The alkynyl group forms a highly electrophilic complex with the monovalent copper. The azide group added in addition is easy to coordinate with the complex to achieve bonding and synthesize a triazole compound. The reaction has a high degree of completion. The click chemistry reaction catalyzed by monovalent copper can find a binding site and complete the reaction even when the concentration of the reactants is extremely low. At the same time, the nucleophilic substitution reaction of the bromine end group is used to modify the betaine molecule to prepare a new functional antibacterial agent, realizing the synergistic antibacterial effect of triazole and electrostatic action.

[0015] As a preferred embodiment of the above technical solution, in step S1, the molar ratio of the azide reagent to propyne bromide is 1:1.

[0016] As a preferred embodiment of the above technical solution, in step S1, the amount of catalyst added is 0.01% of the total mass, and the catalyst is CuSO4·5H2O / sodium ascorbate or CuBr.

[0017] As a preferred embodiment of the above technical solution, in step S1, the azide reagent is sodium azide and the solvent used is water.

[0018] As a preferred embodiment of the above technical solution, in step S2, a sodium hydroxide aqueous solution with a mass concentration of 4-5% is used to adjust the pH to 8.0-10.0.

[0019] As a preferred embodiment of the above technical solution, in step S2, dilute hydrochloric acid with a mass concentration of 8-10% is used to adjust the pH to 3.0-6.0.

[0020] As a preferred embodiment of the above technical solution, in step S1, the stirring rate is 40-80 r / min, the temperature during stirring is controlled at 30-100° C.; and the reaction time is set to 24-48 h.

[0021] As a preferred embodiment of the above technical solution, in step S4, the feeding rate of the betaine solution is 10-100 mL / min, the speed of the agitator is set to 40-80 r / min, the temperature is raised to 80-100° C., and the reaction time is 8-12 h.

[0022] Another object of the present invention is to provide an antibacterial cellulose ether.

[0023] An antibacterial cellulose ether is prepared by a method comprising the following steps:

[0024] The modified betaine solution obtained according to the preparation method of the modified betaine is sprayed on the surface of the filtered HPMC gel material to obtain granular antibacterial cellulose ether; then the granular antibacterial cellulose ether is crushed at low temperature to obtain powdered antibacterial cellulose ether.

[0025] The present invention adopts low-temperature crushing technology to combine HPMC and a novel functional antibacterial agent obtained by triazole-modified betaine molecules, which greatly improves the antibacterial performance and mildew resistance of HPMC, while also ensuring the activity of the antibacterial agent, and provides a novel environmentally friendly antibacterial functional cellulose ether for the daily chemical market.

[0026] As a preferred embodiment of the above technical solution, the spraying rate of the modified betaine solution is 100 mL / min.

[0027] As a preferred embodiment of the above technical solution, the low-temperature crushing is performed by controlling the crushing temperature to be 70-80°C.

[0028] As a preferred embodiment of the above technical solution, the low-temperature pulverization uses low-temperature dry gas for cooling during the process.

[0029] In summary, the present invention has the following beneficial effects:

[0030] 1. The present invention adopts a click chemistry reaction catalyzed by monovalent copper. The alkynyl group will form a highly electrophilic complex with the monovalent copper. The added azide group is easy to coordinate with the complex to achieve bonding and synthesize triazole compounds. The reaction has a high degree of completion. The click chemistry reaction catalyzed by monovalent copper can find the binding site and complete the reaction even when the concentration of the reactants is extremely low. At the same time, the nucleophilic substitution reaction of the bromine end group is used to modify the betaine molecule to prepare a new functional antibacterial agent, realizing the synergistic antibacterial effect of triazole and electrostatic action;

[0031] 2. The present invention adopts low-temperature crushing technology, combines the advantages and antibacterial mechanisms of betaine and triazole, combines HPMC and triazole-modified betaine antibacterial agent, and prepares a product with excellent antibacterial performance, which greatly improves the antibacterial performance and mildew resistance of HPMC; at the same time, it also ensures the activity of the antibacterial agent, and provides a new type of environmentally friendly antibacterial functional cellulose ether for the daily chemical market. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is the reaction technology roadmap of the present invention;

[0033] Figure 2 1 is a graph showing the antibacterial performance test results of Examples 1 to 5;

[0034] Figure 3 It is a graph showing the antibacterial performance test results of comparative examples 1-2 and a blank control group;

[0035] Figure 4 It is a graph showing the anti-mildew performance test results of Examples 1 to 5, Comparative Examples 1 to 2 and a blank control group. DETAILED DESCRIPTION

[0036] The present invention is further explained below in conjunction with the accompanying drawings.

[0037] This specific implementation is only an explanation of the present invention, not a limitation of the present invention. Any changes made by those skilled in the art after reading the specification of the present invention will be protected by the patent law as long as they are within the scope of the claims.

[0038] Example 1

[0039] Open the reactor, inject a measured amount of sodium azide aqueous solution, and then inject propargyl bromide, the molar ratio of propargyl bromide to sodium azide is 1:1; set the stirrer speed to 80 rpm, add 0.01% of the catalyst CuSO4·5H2O / sodium ascorbate while stirring, set the reaction temperature to 80°C, react for 24 hours, after the reaction is completed, use 5% NaOH to adjust the pH value to 8, and filter to obtain the triazole derivative. The reaction technology route is as follows: Figure 1 shown.

[0040] Betaine was dissolved, and the pH value was adjusted to 4 with 10% dilute hydrochloric acid to prepare a betaine solution; the feeding rate of the betaine solution was set to 20 mL / min, and it was slowly added to the triazole derivative obtained above, and the molar ratio of the added amount of betaine to propyne bromide was 1.5:1; the stirring rate of the reactor was set to 80 rpm, the stirring temperature was set to 50 °C, and the reaction was carried out for 12 hours. After the reaction was completed, a solution of triazole-modified betaine was obtained; the reaction technology route is as follows Figure 1 shown.

[0041] The triazole-modified betaine solution was sprayed on the surface of the HPMC gel after filter pressing at a rate of 100 mL / min, and the mass ratio of the solution to the gel was about 1:20; then, granulation was performed to obtain granular antibacterial cellulose ether, and finally low-temperature crushing was performed at a temperature of 70°C to obtain powdered antibacterial cellulose ether.

[0042] Example 2

[0043] Open the reactor, inject a measured sodium azide aqueous solution, and then inject propargyl bromide, the molar ratio of propargyl bromide to sodium azide is 1:1; set the stirrer speed to 80 rpm, add 0.01% of the catalyst CuBr while stirring, set the reaction temperature to 80°C, react for 24 hours, after the reaction is completed, use 5% NaOH to adjust the pH value to 8, and filter to obtain the triazole derivative. The reaction technology route is as follows: Figure 1 shown.

[0044] Betaine was dissolved, and the pH value was adjusted to 4 with 10% dilute hydrochloric acid to prepare a betaine solution; the feeding rate of the betaine solution was set to 20 mL / min, and it was slowly added to the triazole derivative obtained above, and the molar ratio of the added amount of betaine to propyne bromide was 1.5:1; the stirring rate of the reactor was set to 80 rpm, the stirring temperature was set to 50 °C, and the reaction was carried out for 12 hours. After the reaction was completed, a solution of triazole-modified betaine was obtained; the reaction technology route is as follows Figure 1 shown.

[0045] The triazole-modified betaine solution was sprayed on the surface of the HPMC gel after filter pressing at a rate of 100 mL / min, and the mass ratio of the solution to the gel was about 1:20; then, granulation was performed to obtain granular antibacterial cellulose ether, and finally low-temperature crushing was performed at a temperature of 70°C to obtain powdered antibacterial cellulose ether.

[0046] Example 3

[0047] Open the reactor, inject a measured sodium azide aqueous solution, and then inject propargyl bromide, the molar ratio of propargyl bromide to sodium azide is 1:1; set the stirrer speed to 80 rpm, set the reaction temperature to 80 ° C, and react for 24 hours. After the reaction is completed, use 5% NaOH to adjust the pH value to 8, and filter to obtain a triazole derivative. The reaction technology route is as follows: Figure 1 shown.

[0048] Betaine was dissolved, and the pH value was adjusted to 4 with 10% dilute hydrochloric acid to prepare a betaine solution; the feeding rate of the betaine solution was set to 20 mL / min, and it was slowly added to the triazole derivative obtained above, and the molar ratio of the added amount of betaine to propyne bromide was 1.5:1; the stirring rate of the reactor was set to 80 rpm, the stirring temperature was set to 50 °C, and the reaction was carried out for 12 hours. After the reaction was completed, a solution of triazole-modified betaine was obtained; the reaction technology route is as follows Figure 1 shown.

[0049] The triazole-modified betaine solution was sprayed on the surface of the HPMC gel after filter pressing at a rate of 100 mL / min, and the mass ratio of the solution to the gel was about 1:20; then, granulation was performed to obtain granular antibacterial cellulose ether, and finally low-temperature crushing was performed at a temperature of 70°C to obtain powdered antibacterial cellulose ether.

[0050] Example 4

[0051] Open the reactor, inject a measured amount of sodium azide aqueous solution, and then inject propargyl bromide, the molar ratio of propargyl bromide to sodium azide is 1:1; set the stirrer speed to 80 rpm, add 0.01% of the catalyst CuSO4·5H2O / sodium ascorbate while stirring, set the reaction temperature to 80°C, react for 48 hours, after the reaction is completed, use 5% NaOH to adjust the pH value to 8, and filter to obtain a triazole derivative. The reaction technology route is as follows: Figure 1 shown.

[0052] Betaine was dissolved, and the pH value was adjusted to 4 with 10% dilute hydrochloric acid to prepare a betaine solution; the feeding rate of the betaine solution was set to 20 mL / min, and it was slowly added to the triazole derivative obtained above, and the molar ratio of the added amount of betaine to propyne bromide was 1.5:1; the stirring rate of the reactor was set to 80 rpm, the stirring temperature was set to 50 °C, and the reaction was carried out for 12 hours. After the reaction was completed, a solution of triazole-modified betaine was obtained; the reaction technology route is as follows Figure 1 shown.

[0053] The triazole-modified betaine solution was sprayed on the surface of the HPMC gel after filter pressing at a rate of 100 mL / min, and the mass ratio of the solution to the gel was about 1:20; then, granulation was performed to obtain granular antibacterial cellulose ether, and finally low-temperature crushing was performed at a temperature of 70°C to obtain powdered antibacterial cellulose ether.

[0054] Example 5

[0055] Open the reactor, inject a measured amount of sodium azide aqueous solution, and then inject propargyl bromide, the molar ratio of propargyl bromide to sodium azide is 1:1; set the stirrer speed to 80 rpm, add 0.01% of the catalyst CuSO4·5H2O / sodium ascorbate while stirring, set the reaction temperature to 80°C, react for 24 hours, after the reaction is completed, use 5% NaOH to adjust the pH value to 8, and filter to obtain the triazole derivative. The reaction technology route is as follows: Figure 1 shown.

[0056] Betaine was dissolved, and the pH value was adjusted to 4 with 10% dilute hydrochloric acid to prepare a betaine solution; the feeding rate of the betaine solution was set to 20 mL / min, and it was slowly added to the triazole derivative obtained above, and the molar ratio of the added amount of betaine to propyne bromide was 1.5:1; the stirring rate of the reactor was set to 80 rpm, the stirring temperature was set to 50 °C, and the reaction was carried out for 12 hours. After the reaction was completed, a solution of triazole-modified betaine was obtained; the reaction technology route is as follows Figure 1 shown.

[0057] The triazole-modified betaine solution was sprayed on the surface of the HPMC gel after filter pressing at a rate of 100 mL / min, and the mass ratio of the solution to the gel was about 1:20; then, granulation was performed to obtain granular antibacterial cellulose ether, and finally low-temperature crushing was performed at a temperature of 80°C to obtain powdered antibacterial cellulose ether.

[0058] Comparative Example 1

[0059] Open the reactor, inject a measured sodium azide aqueous solution, and then inject propidyl bromide, the molar ratio of propidyl bromide to sodium azide is 1:1; set the stirrer speed to 80 rpm, add 0.01% catalyst CuSO4·5H2O / sodium ascorbate while stirring, set the reaction temperature to 80°C, react for 24 hours, after the reaction is completed, use 5% NaOH to adjust the pH value to 8, and filter to obtain a triazole derivative.

[0060] The solution of triazole derivatives is sprayed on the surface of the HPMC gel after filter pressing at a rate of 100 mL / min, and the mass ratio of the solution to the gel is about 1:20; then, granulation is performed to obtain granular antibacterial cellulose ether, and finally low-temperature crushing is performed at a temperature of 70°C to obtain powdered antibacterial cellulose ether.

[0061] Comparative Example 2

[0062] The betaine solution was sprayed on the surface of the HPMC gel after filter pressing at a rate of 100 mL / min, and the mass ratio of the solution to the gel was about 1:20; then, granulation was performed to obtain granular antibacterial cellulose ether, and the amount of betaine used was the same as that in Example 1; finally, low-temperature crushing was performed at a temperature of 70° C. to obtain powdered antibacterial cellulose ether.

[0063] Examples 1 to 5, Comparative Examples 1 to 2 and a blank control group were tested for antibacterial properties, wherein coliform bacteria, Staphylococcus aureus and Pseudoalteromonas were tested using the 24-hour plate count method. The specific test results are shown in Tables 1 and Figure 2~3 .

[0064] The plate count method is as follows:

[0065] The first step is to use the liquid culture medium prepared in the laboratory to culture the bacteria in a constant temperature shaker for 48 hours to reach a concentration of 10^8 CFU / mL, and prepare the solid culture medium at the same time;

[0066] The second step is to dilute the bacterial solution that has reached a bacterial concentration of 10^8 CFU / mL with 0.9% saline, select 900 μL of the bacterial solution diluted to 10^6 CFU / mL, take 100 μL of the diluted bacterial solution and mix it with the sample, and shake it on a mixer for 1 min;

[0067] The third step is to evenly coat the mixed bacterial solution and sample on the surface of the pre-prepared solid culture medium using a triangular coating glass rod, incubate the culture medium upside down in a constant temperature incubator for 24 hours, and then count the number of colonies.

[0068] Table 1 Antibacterial performance test results of each group

[0069] Escherichia coli group (units) Staphylococcus aureus group (unit) Pseudoalteromonas group (individuals) Example 1 0 0 1 Example 2 1 7 2 Example 3 50 83 64 Example 4 76 72 70 Example 5 96 330 244 Comparative Example 1 203 238 302 Comparative Example 2 196 270 231 Blank Group 256 1329 379

[0070] The mildew resistance of Examples 1 to 5, Comparative Examples 1 to 2 and the blank control group was tested. 2 g of the sample was dissolved into a 1.0% aqueous solution and placed in a constant temperature and humidity incubator for 3 months to observe whether there was mildew on the surface. The specific test results are shown in Tables 2 and Figure 4 .

[0071] Table 2 Test results of mildew resistance of each group

[0072] Is it moldy? Example 1 no Example 2 no Example 3 yes Example 4 yes Example 5 yes Comparative Example 1 yes Comparative Example 2 yes Blank Group yes

[0073] It can be seen from the results in Table 1 and Table 2 that the novel functional antibacterial thickener prepared in the present invention has excellent antibacterial properties, especially the antibacterial rate and mildew resistance rate of Example 1 can almost reach 100%.

Claims

1. A method for preparing modified betaine, comprising the following steps: S1. Add propidium bromide and azide reagent solution into a reaction kettle, stir, add a solution containing cuprous ions as a catalyst, continue stirring, and set the reaction time; S2. After the reaction is completed, the pH of the system is adjusted to alkaline, and the triazole derivative is obtained by filtration; S3, dissolving betaine and adjusting the pH to weak acidity to prepare a betaine solution; S4, adding the betaine solution dropwise to the triazole derivative, starting stirring, turning on the oil bath for heating, and heating the mixture to react; S5. After the reaction is completed, a modified betaine solution is obtained; In step S1, the molar ratio of the azide reagent to propyne bromide is 1:1; In step S1, the amount of catalyst added is 0.01% of the total mass, and the catalyst is CuSO4·5H2O / sodium ascorbate or CuBr; In step S1, the azide reagent is sodium azide and the solvent used is water; In step S4, the molar ratio of betaine added to propyne bromide is 1.5:1, the feeding rate of betaine solution is 10-100 mL / min, the stirrer speed is set to 40-80 r / min, the temperature is raised to 80-100° C., and the reaction time is 8-12 h.

2. The method for preparing modified betaine according to claim 1, characterized in that: In step S2, a sodium hydroxide aqueous solution with a mass concentration of 4-5% is used to adjust the pH to 8-10.

3. The method for preparing modified betaine according to claim 1, characterized in that: In step S2, the pH is adjusted to 3.0-6.0 using dilute hydrochloric acid with a mass concentration of 8-10%.

4. The method for preparing modified betaine according to claim 1, characterized in that: In step S1, the stirring rate is 40-80 r / min, the temperature during stirring is controlled at 30-100° C., and the reaction time is set to 24-48 h.

5. Antimicrobial cellulose ether is prepared by a method comprising the following steps: spraying a modified betaine solution obtained by the method for preparing modified betaine according to any one of claims 1 to 4 on the surface of a filtered HPMC gel material, granulating to obtain granular antimicrobial cellulose ether; and then low-temperature crushing the granular antimicrobial cellulose ether to obtain a powdered antimicrobial cellulose ether.

6. The antimicrobial cellulose ether according to claim 5, characterized in that: The temperature of the low temperature pulverization is 70-80°C.

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