CN102229689B - Preparation method of absorbent resin with bacteriostasis function - Google Patents

Abstract

The invention discloses a preparation method of a water-absorbent resin with antibacterial performance, which comprises the following process steps: 1) fully dissolving potassium hydroxide in deionized water, slowly adding acrylic acid solution; adjusting the neutralization degree to 50-90%, Stir continuously to make the reaction complete, and cool the neutralizing solution for later use; 2) Add the neutralizing solution to the chitosan solution, stir well and then add the initiator and cross-linking agent to carry out the graft copolymerization reaction; stir the reaction in an aqueous solution at 65°C , react until the product is viscous, stop stirring, and continue to react for 2 to 3 hours to obtain a water-absorbing resin with antibacterial properties. The product prepared by the preparation method of the invention not only has high water absorption performance, but also has good antibacterial effect.

Description

A kind of preparation method of water-absorbent resin with antibacterial performance

technical field

The invention relates to a preparation method of a water-absorbing resin with antibacterial performance, which belongs to the field of high-molecular polymer-based composite materials.

Background technique

As a natural, non-toxic, biocompatible, degradable, renewable and abundant resource, chitosan has attracted increasing attention and has been successfully used in many fields such as medicine.

Chitosan with different molecular weights has different inhibitory mechanisms on different microorganisms:

(1) For Gram-negative bacteria (Escherichia coli), the main reason is that chitosan, a small molecule, penetrates into the microbial cells, adsorbs the negatively charged cytoplasm in the cells, and flocculates, disrupting the normal physiological activities of the cells. , thereby killing bacteria;

(2) For Gram-positive bacteria (Staphylococcus aureus), it is mainly due to the adsorption of macromolecular chitosan on the surface of microbial cells to form a layer of polymer film, which prevents the transport of nutrients into the cells until the bacteria die.

Chitin is one of the most abundant natural organic compounds in nature, its quantity is second only to cellulose, and it is also the largest nitrogen-containing natural organic compound on the earth except protein, accounting for almost 8% of the global aquatic organisms The materials are rich in chitin, including shrimp, crab, squid, oyster and cuttlefish, etc. Marine waste produces more than 80 million tons of chitin every year. It is of great significance to develop and utilize this marine resource. Chitosan, the product of deacetylation of chitin, is composed of most of D-glucosamine and a small amount of N-acetyl-D-glucosamine, and is directly linked by β-(1,4) glycosidic bonds. Chain polysaccharide, its structure is similar to cellulose, because of its unique molecular structure, chitosan is the only alkaline amino polysaccharide that exists in large quantities in natural polysaccharides, its chemical properties are relatively active, it is easy to carry out various chemical modifications, and it is soluble in acidic aqueous solution , has good biocompatibility and biodegradability. Because of its protonated ammonium, chitosan can interact with the negatively charged cell membrane of bacteria, interfere with the function of the bacterial cell membrane, cause the loss of cytoplasm in the bacteria, disrupt the normal physiological metabolism of the cells, and achieve the purpose of sterilization.

At present, in the domestic preparation of water-absorbent resins with antibacterial properties (patent publication number: CN101559234A), water-absorbent resin particles are added to a dispersion containing silver ions, zinc ions, titanium oxide and a mixture thereof, stirred and left to stand, and the Dried to become a composite material containing an antimicrobial agent. Due to the water solubility of silver ions, this kind of composite material containing silver ions is easily soluble in water when it encounters water and does not adhere to the surface of the water-absorbing material; for zinc ions and titanium oxide composite materials, it needs to be under photocatalytic conditions to have antibacterial function. The present invention uses chitosan grafted acrylic synthetic resin, the bacteriostatic material is always in the water-absorbing material, and the product with bacteriostatic and water-absorbing properties becomes the key point of the present invention.

Contents of the invention

The object of the present invention is to provide a method for preparing a water-absorbent resin with antibacterial properties. The product prepared by the preparation method of the invention not only has high water absorption performance, but also has good antibacterial effect.

In order to achieve the above object, the solution of the present invention is:

A method for preparing a water-absorbent resin with antibacterial properties, comprising the following process steps: 1) Potassium hydroxide is weighed and fully dissolved in deionized water, and an acrylic acid solution is slowly added, wherein the ratio of the amount of potassium hydroxide to acrylic acid is expressed by weight It is calculated as potassium hydroxide: acrylic acid=(40～73.5): 100; adjust the degree of neutralization to be 50-90%, keep stirring to make the reaction complete, and cool the neutralizing solution for subsequent use; 2) add the neutralizing solution to the chitosan solution And liquid, after fully stirring, add initiator, cross-linking agent and carry out graft copolymerization reaction, wherein the ratio of the addition of chitosan, neutralizing liquid, initiator and cross-linking agent is chitosan by weight: neutralization Liquid: Initiator: Crosslinking agent = (0.1～3.75g): (40～73.5g): (0.0625～0.5g): (0.0125～0.118g); Stir and react in 65°C aqueous solution until the product is viscous The stirring is stopped, and the reaction is continued for 2 to 3 hours to obtain a water-absorbent resin with antibacterial properties.

The ratio of the add-on of described potassium hydroxide and acrylic acid is preferably potassium hydroxide by weight: acrylic acid=62.5: 100, the ratio of the add-on of chitosan, neutralizing liquid, initiator and linking agent, with The weight is preferably chitosan: neutralizing solution: initiator: crosslinking agent=2.0: 62.5: 0.25: 0.025.

The water-absorbent resin product with antibacterial properties is dried in an oven at 65°C until the quality is constant, and then pulverized to obtain a powder product.

The chitosan dissolving solution is made of chitosan with a deacetylation degree of 50.0--95.0% as a raw material, and the chitosan dissolving solution is obtained after adding an acid solution and stirring until fully dissolved; wherein the amount of chitosan and acid solution is Ratio, by weight, chitosan:acid solution=1:100.

The concentration of the acid solution is 1.0 mol/L, and one of acetic acid, oxalic acid, acrylic acid, citric acid or hydrochloric acid is used.

Described initiator adopts potassium persulfate and sodium bisulfite.

The crosslinking agent adopts N, N-methylenebisacrylamide.

The beneficial effects of the present invention are: a preparation method of chitosan-grafted acrylic acid water-absorbent resin of the present invention, using acrylic acid as the matrix, and chitosan-grafted acrylic acid water-absorbent resin, the material not only has high water absorption performance but also has Good antibacterial effect, the water absorption rate of the resin is 685g/g, and the antibacterial rate against Escherichia coli and Staphylococcus aureus reaches more than 70%. It can be used in the field of hygiene, such as baby diapers, adult incontinence diapers, women's hygiene Towels and other sanitary care products.

Description of drawings

Fig. 1 is a process flow diagram of the present invention;

Fig. 2 is the colony diagram after chitosan resin inhibits Escherichia coli (bacteria concentration 10 ⁻⁷ );

Fig. 3 is the bacteriostatic colony figure to Escherichia coli (bacterial concentration 10 ⁻⁷ ) of the blank test that does not contain chitosan resin;

Fig. 4 is the bacteriostatic colony figure of chitosan resin to Staphylococcus aureus (bacteria concentration 10 ⁻⁷ );

Fig. 5 is a colony diagram after a blank test containing no chitosan resin inhibits Staphylococcus aureus (bacteria concentration 10 ^-7 ).

Detailed ways

Example 1

As shown in Figure 1, in this embodiment, 40g of potassium hydroxide was weighed and fully dissolved in deionized water, and 100g of acrylic acid was slowly added to adjust the degree of neutralization to 50%, stirring continuously to complete the reaction, and the neutralizing solution was cooled for subsequent use; 0.1g of chitosan with a degree of deacetylation of 50.0--95.0%, add 100g of acetic acid solution and stir until fully dissolved to form a chitosan solution. The concentration of the acetic acid solution is 1.0mol/L. Add 40g neutralizing solution in chitosan solution, add 0.0625g potassium persulfate and sodium bisulfite as initiator, 0.0125g N, N-methylenebisacrylamide as cross-linking agent after fully stirring, at 65 Stir and react in an aqueous solution at ℃, stop stirring until the product becomes viscous, and continue to react for 2 to 3 hours to obtain the product; dry the product in an oven at 65°C until the quality is constant, and then pulverize to obtain a powdery superabsorbent resin product. The performance of the synthetic resin was measured, and its water absorption rate was 440g/g.

Example 2

As shown in Figure 1, in this embodiment, 62.5g of potassium hydroxide was weighed and fully dissolved in deionized water, and 100g of acrylic acid was slowly added to adjust the degree of neutralization to 80%, stirring continuously to complete the reaction, and the neutralizing solution was cooled for later use; Add 2.0g of chitosan with a deacetylation degree of 50.0--95.0%, add 100g of acrylic acid or citric acid solution and stir until fully dissolved to form a chitosan solution. The concentration of acrylic acid or citric acid solution is 1.0mol/L. Add 62.5g neutralizing solution in chitosan solution, add 0.25g potassium persulfate and sodium bisulfite as initiator, 0.025g N, N-methylenebisacrylamide as cross-linking agent after fully stirring, Stir and react in an aqueous solution at 65°C, stop stirring until the product becomes viscous, and continue to react for 2 to 3 hours to obtain the product; dry the product in an oven at 65°C until the quality is constant, and then pulverize to obtain a powdery superabsorbent resin product. The performance of the synthetic resin was measured, and it was a water absorption ratio of 804 g/g.

Example 3

As shown in Figure 1, in this embodiment, 73.5g of potassium hydroxide was weighed and fully dissolved in deionized water, and 100g of acrylic acid was slowly added to adjust the degree of neutralization to 90%, stirring continuously to complete the reaction, and the neutralizing solution was cooled for subsequent use; 3.75g of chitosan with a deacetylation degree of 50.0--95.0%, add 100g of hydrochloric acid solution and stir until fully dissolved to form a chitosan solution. The concentration of the hydrochloric acid solution is 1.0mol/L. Add 73.5g neutralizing solution in chitosan solution, add 0.5g potassium persulfate and sodium bisulfite as initiator, 0.118g N, N-methylenebisacrylamide as cross-linking agent after fully stirring, Stir and react in an aqueous solution at 65°C, stop stirring until the product becomes viscous, and continue to react for 2 to 3 hours to obtain the product; dry the product in an oven at 65°C until the quality is constant, and then pulverize to obtain a powdery superabsorbent resin product. The performance of the synthetic resin was measured, and it was a water absorption ratio of 850 g/g.

Example 4

Resin antibacterial performance test:

The concentrations of the bacteria solution containing Escherichia coli and the bacteria solution containing Staphylococcus aureus were prepared respectively (dilute the bacteria solution to a concentration of 10 ^-1 ~ 10 ^-9 m ^-1 ), so that the initial concentration of bacteria in the solution was about On the order of 10 ^-7 ml ^-1 , add 0.10 g of the resin sample prepared according to the method of Example 2, 18 ml of normal saline solution and 1 ml of LB medium into a 50 ml Erlenmeyer flask, and add 1 ml of cultured bacterial solution after autoclaving Place on a shaker (37°C, 150rpm) and shake for 8 hours, pipette 0.5ml bacterial solution from the Erlenmeyer flask to make 10 ^-6 , 10 ^-7 dilutions and spread on the plate, and coat three Petri dishes for each dilution. Cultivate in a 37°C incubator for 24 hours, observe the growth of bacteria, and calculate the antibacterial rate of the resin according to the formula η=(N ₁ -N ₂ )/N ₁ , where N ₁ represents the average number of colonies on the blank control culture dish, and N ₂ represents Add the average number of colonies on the petri dish of the bacterium-containing liquid after the resin sample treatment, and calculate the resin bacteriostatic rate. The blank control was the same as above but without adding resin. As shown in Figures 1, 2, 3, and 4, Fig. 2 is a colony diagram after chitosan resin inhibits Escherichia coli (bacterial concentration 10 ^-7 ); Bacillus (bacteria concentration 10 ^-7 ) colony diagram after inhibition; Figure 4 is the colony diagram after chitosan resin inhibited Staphylococcus aureus (bacteria concentration 10 ^-7 ); Figure 5 is the blank test without chitosan resin Colony diagram after inhibition of Staphylococcus aureus (bacteria concentration 10 ^-7 ). Through calculation, the bacteriostatic rate to Escherichia coli reaches 76-88%; the bacteriostatic rate to Staphylococcus aureus is 72-77%.

Claims (7)

1. A method for preparing a water-absorbing resin with antibacterial properties, characterized in that it comprises the following process steps: 1) taking potassium hydroxide and fully dissolving it in deionized water, slowly adding an acrylic acid solution, wherein the amount of potassium hydroxide and acrylic acid The ratio, by weight, is potassium hydroxide: acrylic acid=(40～73.5): 100, adjust the degree of neutralization to be 50-90%, keep stirring to make the reaction complete, and cool the neutralizing liquid for subsequent use; 2) in chitosan Add neutralizing solution to the dissolving solution, add initiator and crosslinking agent after fully stirring to carry out graft copolymerization reaction, wherein the ratio of the addition amount of chitosan dissolving solution, neutralizing solution, initiator and crosslinking agent is by weight Chitosan: neutralizing solution: initiator: crosslinking agent=(0.1～3.75): (40～73.5): (0.0625～0.5): (0.0125～0.118); stirring reaction in 65 ℃ aqueous solution, reacting to When the product is viscous, stop stirring and continue to react for 2 to 3 hours to obtain a water-absorbing resin with antibacterial properties. 2. a kind of preparation method with bacteriostatic property water-absorbing resin as claimed in claim 1 is characterized in that: the ratio of the add-on of described potassium hydroxide and acrylic acid is potassium hydroxide by weight: acrylic acid=62.5 : 100, the ratio of the amount of addition of chitosan, neutralizing solution, initiator and crosslinking agent is chitosan by weight: neutralizing solution: initiator: crosslinking agent=2.0: 62.5: 0.25: 0.025. 3. A method for preparing a water-absorbent resin with antibacterial properties as claimed in claim 1, characterized in that: the product of the water-absorbent resin with antibacterial properties is dried in an oven at 65°C until the quality is constant, and then pulverized to obtain powder shaped products. 4. a kind of preparation method with bacteriostatic property water-absorbing resin as claimed in claim 1 is characterized in that: described chitosan dissolving solution is raw material with the chitosan of degree of deacetylation 50.0--95.0%, adds The acid solution is stirred until fully dissolved to form a chitosan solution; wherein the ratio of the amount of chitosan to the acid solution, by weight, is chitosan:acid solution=1:100. 5. A method for preparing a water-absorbing resin with antibacterial properties as claimed in claim 4, characterized in that: the concentration of the acid solution is 1.0mol/L, and acetic acid, oxalic acid, acrylic acid, citric acid or hydrochloric acid are used One of. 6. A method for preparing a water-absorbent resin with antibacterial properties as claimed in claim 1, characterized in that: potassium persulfate and sodium bisulfite are used as the initiator. 7. A method for preparing a water-absorbing resin with antibacterial properties as claimed in claim 1, characterized in that: said cross-linking agent is N, N-methylenebisacrylamide.

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