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CN-121975059-A - Hydrogel based on acrylonitrile-acrylamide copolymerization system and preparation method thereof

CN121975059ACN 121975059 ACN121975059 ACN 121975059ACN-121975059-A

Abstract

The invention relates to the technical field of hydrogels, in particular to a hydrogel based on an acrylonitrile-acrylamide copolymerization system and a preparation method thereof. The preparation method comprises the steps of preparing a copolymer liquid by taking an acrylonitrile monomer and an acrylamide monomer as raw materials, wherein the molar ratio of the acrylonitrile monomer to the acrylamide monomer is 3:7-5:5, adding an initiator into the copolymer liquid, and carrying out polymerization reaction at 40-50 ℃ to obtain organogel, wherein the initiator consists of dibenzoyl peroxide and N, N-dimethylaniline with the molar ratio of 1:1, and replacing a solvent in the organogel with water. Compared with the prior art, the method utilizes acrylamide to construct a network skeleton with high hydrophilicity and high entanglement, ensures that the material has good flexibility and ductility, introduces an acrylonitrile monomer containing strong polar cyano groups, dynamically constructs a high-strength physical crosslinking area under the action of external force through dipole-dipole interaction formed by the acrylonitrile monomer, and realizes network dynamic enhancement and strain hardening response.

Inventors

  • ZHAO CHUANZHUANG
  • WU WENJUAN
  • GAO LU

Assignees

  • 宁波大学

Dates

Publication Date
20260505
Application Date
20260403

Claims (9)

  1. 1. The preparation method of the hydrogel based on the acrylonitrile-acrylamide copolymerization system is characterized by comprising the following steps of: S1, preparing a copolymer liquid by taking an acrylonitrile monomer and an acrylamide monomer as raw materials, wherein the molar ratio of the acrylonitrile monomer to the acrylamide monomer is 3:7-5:5; S2, adding an initiator into the copolymerization liquid, and performing polymerization reaction at 40-50 ℃ to obtain organogel, wherein the initiator consists of dibenzoyl peroxide and N, N-dimethylaniline in a molar ratio of 1:1; And S3, replacing the solvent in the organogel with water by adopting a solvent replacement method to obtain the hydrogel based on the acrylonitrile-acrylamide copolymerization system.
  2. 2. The method according to claim 1, wherein in the step S1, the copolymer solution further contains a crosslinking agent, the crosslinking agent is N, N' -methylenebisacrylamide, and the molar amount of the crosslinking agent is 0.0008 to 0.0012% based on the total molar amount of the acrylonitrile monomer and the acrylamide monomer.
  3. 3. The preparation method of claim 2, wherein the specific operation of the step S1 is that firstly, acrylonitrile monomer is dissolved in solvent and stirred uniformly, then acrylamide monomer is added, and after mixing uniformly, cross-linking agent is added and stirred uniformly, so as to obtain copolymer liquid.
  4. 4. The method according to claim 1, wherein in the step S1, the solvent of the copolymer solution is dimethyl sulfoxide.
  5. 5. The method according to claim 1, wherein in the step S1, the total monomer concentration of the acrylonitrile monomer and the acrylamide monomer in the copolymer liquid is not less than 40% by weight in terms of mass percent.
  6. 6. The method according to claim 1, wherein in the step S2, the molar amount of the initiator is 0.0002 to 0.00025% of the total molar amount, based on the total molar amount of the acrylonitrile monomer and the acrylamide monomer.
  7. 7. The method according to claim 1, wherein in the step S2, the polymerization is carried out under a sealed condition for 24 to 28 hours.
  8. 8. The method according to claim 1, wherein in the step S3, the solvent replacement method is performed by placing the organogel in excess deionized water, and replacing the organogel with deionized water at intervals of 6 to 10 hours for 9 to 12 times.
  9. 9. A hydrogel based on an acrylonitrile-acrylamide copolymer system, obtainable by the process according to any one of claims 1 to 8, characterized in that the hydrogel has a breaking strength of not less than 10MPa and a strain hardening degree E max /E 0 >15.

Description

Hydrogel based on acrylonitrile-acrylamide copolymerization system and preparation method thereof Technical Field The invention relates to the technical field of hydrogels, in particular to a hydrogel based on an acrylonitrile-acrylamide copolymerization system and a preparation method thereof. Background The hydrogel material has excellent flexibility, good biocompatibility and adjustable mechanical property, and has wide application prospect in the fields of biomedicine, flexible electronics, soft robots and the like. With the development of advanced technologies such as deep sea detection, motion protection and impact monitoring, higher requirements are put on the mechanical reliability of the hydrogel material under complex working conditions, and particularly, the hydrogel material needs to have high deformability and high strength when bearing high load and high-speed impact so as to maintain structural integrity and functional stability. However, conventional hydrogels often suffer from the contradiction that high elongation and high modulus are difficult to combine, making them limited in protective and load bearing applications. To improve the mechanical properties of hydrogels, researchers have developed various strategies such as building dual networks, introducing nanocomposite systems, or utilizing highly entangled topologies. Although these methods can improve strength or toughness to some extent, they rely on static crosslinking or a single reinforcement mechanism, and it is difficult to achieve high flexibility, high toughness, and dynamic response characteristics at the same time. In recent years, strategies based on the synergy of dynamic non-covalent interactions (such as hydrogen bonding, ionic coordination, hydrophobic association) and entangled networks have received attention, and dynamic crosslinking and energy dissipation can be induced during deformation, thereby improving toughness and recovery. Nevertheless, there is still a lack of systematic and intensive research on how to achieve significant strain hardening effects and ultra-high strength through controlled molecular design, especially by using strong polar monomers to build high density dipole interactions, and in conjunction with highly entangled networks. In nature, many biological tissues (such as skin, artery and jellyfish) have strain hardening characteristics, can keep soft at the initial stage of deformation, and harden rapidly under large strain to resist damage, thus providing important inspiration for bionic material design. Previous studies have simulated such mechanical behavior in hydrogels by modulating network structure or introducing microphase separation, and achieved high stretchability. However, the absolute mechanical strength of the existing bionic hydrogel is still generally low, the requirements of high-strength impact-resistant scenes are difficult to meet, and meanwhile, the accurate regulation and control means of stress-strain behaviors of the existing bionic hydrogel are limited, so that the performance adaptation of the material in different application environments is restricted. Disclosure of Invention To overcome the above drawbacks of the prior art, a first object of the present invention is to provide a method for preparing hydrogels based on acrylonitrile-acrylamide copolymer systems, comprising in particular the following steps: S1, preparing a copolymer liquid by taking an acrylonitrile monomer and an acrylamide monomer as raw materials, wherein the molar ratio of the acrylonitrile monomer to the acrylamide monomer is 3:7-5:5; S2, adding an initiator into the copolymerization liquid, and performing polymerization reaction at 40-50 ℃ to obtain organogel, wherein the initiator consists of dibenzoyl peroxide and N, N-dimethylaniline in a molar ratio of 1:1; And S3, replacing the solvent in the organogel with water by adopting a solvent replacement method to obtain the hydrogel based on the acrylonitrile-acrylamide copolymerization system. Compared with the prior art, the invention provides a preparation method of high-strength and high-toughness strain hardening hydrogel based on AN Acrylonitrile (AN) and Acrylamide (AM) copolymerization system. The invention utilizes acrylamide to construct a network skeleton with high hydrophilicity and high entanglement, ensures that the material has good flexibility and ductility, introduces an acrylonitrile monomer containing strong polar cyano, dynamically constructs a high-strength physical crosslinking area under the action of external force through dipole-dipole interaction formed by the acrylonitrile monomer, and realizes network dynamic enhancement and strain hardening response. By regulating the monomer proportion, the entanglement density and the dipole action strength can be systematically regulated, so that the accurate 'coding' of the stress-strain behavior of the material is realized, the hydrogel with high breaking strength and obvious str