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CN-121975160-A - Zinc ion/carboxymethyl chitosan crosslinked high-strength and high-toughness antibacterial polyvinyl alcohol film and preparation method thereof

CN121975160ACN 121975160 ACN121975160 ACN 121975160ACN-121975160-A

Abstract

The invention discloses a zinc ion/carboxymethyl chitosan crosslinked high-strength and high-toughness antibacterial polyvinyl alcohol film and a preparation method thereof. The method comprises the steps of dissolving polyvinyl alcohol in deionized water to prepare PVA solution, preparing carboxymethyl chitosan aqueous solution and zinc salt aqueous solution respectively, synchronously dripping CMC solution and zinc salt solution into the PVA solution under the conditions of stirring and heating, constructing a PVA-Zn-CMC ternary dynamic coordination network by taking Zn 2+ as a coordination center, and performing ultrasonic defoaming, tape casting and drying to form a film. The invention does not need to use traditional aldehyde cross-linking agent and acid solvent, the preparation process is full-aqueous phase, acid-free and aldehyde-free, and the unique network structure is formed by synchronous dripping, so that the film has excellent mechanical property and synergistic antibacterial property. In addition, the film is soluble and recoverable in hot water and forms a film again based on reversibility of coordination bonds, has remarkable environmental protection value, and is suitable for the fields of biomedical and green packaging.

Inventors

  • LI JINCHUN
  • SHI JIAZHEN
  • LIU HANCHAO
  • SHAN XUEYING
  • JIANG XINTONG

Assignees

  • 常州大学

Dates

Publication Date
20260505
Application Date
20260209

Claims (8)

  1. 1. The preparation method of the zinc ion/carboxymethyl chitosan crosslinked high-strength and high-toughness antibacterial polyvinyl alcohol film is characterized by comprising the following steps of: (1) Dissolving polyvinyl alcohol in deionized water, heating, stirring and dissolving to obtain a polyvinyl alcohol solution; (2) Respectively preparing carboxymethyl chitosan aqueous solution and zinc salt aqueous solution; (3) Under the condition of stirring, adding the carboxymethyl chitosan aqueous solution and the zinc salt aqueous solution in the step (2) into the polyvinyl alcohol solution in the step (1) in a synchronous dropwise adding mode, and carrying out coordination crosslinking reaction to obtain a polyvinyl alcohol composite solution; (4) And (3) after carrying out ultrasonic treatment on the polyvinyl alcohol composite solution, pouring the solution into a mould, and drying the solution in an oven to form a film.
  2. 2. The preparation method of the zinc ion/carboxymethyl chitosan crosslinked high-strength and high-toughness antibacterial polyvinyl alcohol film according to claim 1, wherein in the step (1), the dosage ratio of the polyvinyl alcohol to deionized water is 1-20 g/100 mL.
  3. 3. The preparation method of the zinc ion/carboxymethyl chitosan crosslinked high-strength and toughness antibacterial polyvinyl alcohol film according to claim 1, wherein in the step (2), the dosage of the carboxymethyl chitosan is 1% -8% of the mass of the polyvinyl alcohol.
  4. 4. The preparation method of the zinc ion/carboxymethyl chitosan crosslinked high-strength and toughness antibacterial polyvinyl alcohol film according to claim 1, wherein in the step (2), the zinc salt is zinc chloride, and the mass ratio of the zinc chloride to the polyvinyl alcohol is 0.004-0.016:1.
  5. 5. The method for preparing the zinc ion/carboxymethyl chitosan crosslinked high-strength and toughness antibacterial polyvinyl alcohol film according to claim 1, wherein in the step (3), the temperature of the coordination crosslinking reaction is 80-100 ℃, and the reaction time is 2-3 hours.
  6. 6. The method for preparing the zinc ion/carboxymethyl chitosan crosslinked high-strength and high-toughness antibacterial polyvinyl alcohol film according to claim 1, wherein in the step (4), the drying temperature of the oven is 50-60 ℃ and the drying time is 24-48 hours.
  7. 7. A zinc ion/carboxymethyl chitosan crosslinked high-strength and high-toughness antibacterial polyvinyl alcohol film, which is characterized in that the film material is prepared by the preparation method of any one of claims 1-6.
  8. 8. Use of the polyvinyl alcohol film material according to claim 7 for the preparation of food packaging materials, biomedical dressings or recyclable packaging materials.

Description

Zinc ion/carboxymethyl chitosan crosslinked high-strength and high-toughness antibacterial polyvinyl alcohol film and preparation method thereof Technical Field The invention relates to the technical field of film materials, in particular to a super-tough, antibacterial, green and pollution-free polyvinyl alcohol film material crosslinked by metal ions and a preparation method thereof. Background Polyvinyl alcohol (PVA) is a water-soluble high polymer material with a large number of hydroxyl groups distributed on side chains, and has been applied to the field of film materials for packaging PVA materials due to excellent film forming property, biocompatibility and degradability. By virtue of the abundant hydroxyl, PVA can form crosslinking with aldehyde substances through acetal reaction, so that the performance is improved. However, the PVA material crosslinked by covalent bonds cannot be recycled. In addition, in the preparation process, cross-linking agents such as formaldehyde and the like are easy to volatilize, release toxic gases, harm health and pollute the environment. This is a hindrance to its wide application. Secondly, the PVA material has a single general function, and other multifunctional characteristics such as antibacterial property and the like cannot be considered after the mechanical property is improved, so that the application range of the PVA film material is severely limited. In view of the above problems, the PVA is crosslinked by other means, and the PVA film material tends to develop by imparting material functionality. Although related art has been disclosed in the prior art, how to achieve multi-performance and functional coordination of reinforcement, toughening, bacteriostasis, recycling and the like of PVA films remains a challenge. To develop an environmentally friendly PVA film, those skilled in the art have attempted to introduce natural polymers (e.g., chitosan, cellulose) or to physically crosslink with metal ions. For example, patent CN 118994665A discloses the preparation of an antibacterial polyvinyl alcohol film, but the mechanical properties are not improved. Patent CN 116496518A discloses a PVA film material crosslinked by dynamic boron ester bonds, which has a remarkably improved tensile strength, but a non-ideal elongation at break, and no multifunctional properties. In the research of preparation and performance of CS-PAA/Zn 2+ composite network hydrogel, chitosan/polyacrylic acid/zinc ion hydrogel prepared by ultraviolet irradiation method, an author forms a first network by polyacrylic acid and chitosan, and forms a second network by polyacrylic acid and Zn 2+. Therefore, how to prepare a special coordination network by simply blending components on the premise of not using covalent cross-linking agent (no aldehyde) and complex in-situ polymerization process, so that the PVA film can realize high strength, ultrahigh toughness, excellent antibacterial property and recoverability at the same time is the technical problem to be solved by the invention. Disclosure of Invention Aiming at the prior art, the invention aims to provide a super-tough, antibacterial and green pollution-free polyvinyl alcohol film material crosslinked by metal ions. According to the invention, carboxymethyl chitosan is adopted to increase the antibacterial property of the film material, zn 2+ ions are added to enhance the mechanical property, and meanwhile, a synergistic antibacterial system is formed by utilizing the antibacterial property of Zn 2+ and carboxymethyl chitosan. The invention adopts the coordination and crosslinking of the metal ion and the carboxylic acid group of carboxymethyl chitosan and the side chain hydroxyl of PVA to form a multi-stage crosslinking structure of hydroxyl-metal ion-carboxyl. Instead of aldehydes, the substituted aldehydes interact with PVA macromolecules to form a crosslinked network structure. The invention does not need to add aldehyde cross-linking agent or acid catalyst to react, solves the problems that the traditional PVA film material is harmful to human body and environment due to aldehyde cross-linking, improves the mechanical property, increases the antibacterial property of the material, and wastes resources due to the fact that the traditional PVA material cannot be recycled. In order to achieve the above object, the present invention adopts the following technical scheme. (1) Dissolving polyvinyl alcohol in deionized water, heating, stirring and dissolving to obtain a polyvinyl alcohol solution; (2) And synchronously dripping the carboxymethyl chitosan aqueous solution and the zinc chloride aqueous solution into the polyvinyl alcohol solution, carrying out coordination crosslinking reaction, and fully stirring and reacting for 2-3 hours to obtain the polyvinyl alcohol composite solution. (3) And (3) after carrying out ultrasonic treatment on the prepared polyvinyl alcohol composite solution, pouring the solution into a mould, and putting