Method for preparing high-strength hydrogel with macromolecular microgel composite structure

Abstract

The invention discloses a method for preparing high-strength hydrogel with a macromolecular microgel composite structure. The method comprises the following steps of: (1) adding 10 to 20 mmol of N-isopropylacrylamide serving as a first monomer, 0.4 to 0.8 mmol of cross linker, 0.5 to 1.0 g of surfactant and 0.1 to 0.2 mmol of initiator into every 100 mL of water; adding the N-isopropylacrylamide, the cross linker, the surfactant, the initiator and the water into a reaction container, mixing uniformly, charging nitrogen to remove oxygen, sealing the reaction container, reacting for 10 to 60 minutes with stirring at the temperature of between 40 and 60 DEG C, and cooling the reaction product to the temperature of below 20 DEG C by using cooling water of below 15 DEG C; and (2) adding poly (N-isopropylacrylamide) microgel aqueous dispersion prepared in the step (1) and a second monomer into the reaction container, charging nitrogen to remove oxygen after the second monomer is dissolved and mixed uniformly, sealing the reaction container, reacting for 24 to 48 hours at the temperature of between 0 and 25 DEG C, and thus obtaining the high-strength hydrogel with the macromolecular microgel composite structure, wherein the ratio of the volume of the poly (N-isopropylacrylamide) microgel aqueous dispersion to the mass of the second monomer is 2: (0.1-0.5).

Description

technical field [0001] The invention belongs to a preparation method of high-strength hydrogel, in particular to a preparation method of high-strength hydrogel with a composite structure. Background technique [0002] Hydrogel is a material composed of a cross-linked three-dimensional polymer network and can hold a large amount of water. It can be used as a super absorbent for soil water retention, baby diapers, hygiene products, etc., and can be used as a tool for plastic surgery, cell culture and tissue engineering. Scaffold materials can be used for drug delivery carriers, sensing elements, micromachines, chemical and biochemical reactors, etc. Hydrogels need to have higher strength in use, but conventional hydrogels cross-linked with small molecule chemical cross-linking agents have lower strength due to the different lengths of network chains in the structure and the random distribution of cross-linking points. Poor and tends to show brittle characteristics. Introduci...

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Problems solved by technology

[0003] In the prior art, methods for improving the strength of hydrogels by introducing composite structures of polymer particles include: physically filling polymer particles into hydrogels (Zhou CJ, Wu QL, Zhang QG. Dynamic rheology studies of in situ polymerization process of polyacrylamide-cellulose nanocrystal composite hydrogels. Colloid and Polymer Science. 2011, 289(3): 247-255), although this method is simple to operate, it has poor effect on improving the mechanical properties of hydrogel; Polymer microspheres prepared by copolymerization of photoinitiators and hydrophobic monomers trigger hydrophilic monomers to obtain hydrogels with increased strength (see Chinese patent application 201010159507.3 for the preparation of chemically cross-linked nanocomposite hydrogels; Wu YT, Xia MG, Fan QQ, Zhu MF. Designable synthesis of nanocomposite hydrogels with excellent mechanical properties based on chemical cross-linked interactions. Chemical Communications. 2010, 46(41): 7790-7792), this method requires the use of specially synthesized cocoa Polymerization of photoinitiators and only photoinitiated polymerization can be used for hydrogel synthesis; nanoparticles formed in acetone / water using starches containing polymerizable unsaturated double bonds (see Tan Y, Xu K, Wang PX, Li WB, Sun SM, Dong LS. High mechanical strength and rapid response rate of poly(N-isopropylacrylamide) hydrogel crosslinked by starch-based nanospheres. Soft Matter, 2010, 6(7): 1467-1471), or with polymerizable unsaturated double Copolymerized polyacrylamide microparticles with hydrophilic monomers to prepare hydrogels with improved mechanical properties (Qin XP, Zhao F, Liu YK, Wang HY, Feng SY. High mechanical strength hydrogels preparation using hydraulic re active microgels as crosslinking agents. Colloid and Polymer Science. 2009, 287(5): 621-625), the preparation process of polymer particles with polymerizable double bonds used in this method is complicated, and requires the use of a variety of organic solvents. Conducive to the application of hydrogel

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