Preparation method of high-strength nano-composite hydrogel with rapid dual responses of pH and temperature

Abstract

The invention relates to a preparation method of high-strength nano-composite hydrogel capable of rapidly responding to pH and temperature. The preparation method taking dimethylaminoethyl methacrylate as a monomer, inorganic nanometer clay and N,N'-methylenebisacrylamide as co-crosslinking agents, and a nanometer cellulose whisker as a gel composite reinforcer comprises the following steps of: stirring the components, carrying out uniform ultrasonic oscillation, carrying out photo-initiation free radical polymerization in 0 DEG C ice-bath, then reacting at -18 DEG C for 24 hours to obtain the final gel product. The hydrogel prepared by the method has the dual responses of temperature and pH and excellent mechanical performance and can rapidly swell and deswell; and the lowest transformation temperature of the hydrogel is close to temperature of human bodies; raw materials are cheap; the preparation method is simple; and the high-strength nano-composite hydrogel has the potential of application in fields such as sustained release of medicines and tissue engineering.

Description

technical field [0001] The invention belongs to a method for preparing a hydrogel, in particular to a method for preparing a nanocomposite hydrogel with high mechanical strength, which can produce rapid response to changes in ambient temperature and pH value, thereby producing volume transformation. Background technique [0002] Polymer gel refers to a system composed of a three-dimensional network structure of polymer compounds and a solvent, in which the polymers are connected by van der Waals force, chemical bond force, physical winding force, hydrogen bond force, etc. Since it is a three-dimensional network structure, it cannot be dissolved by solvents, and at the same time, it can be dispersed in solvents and can maintain a certain shape. Although the solvent cannot dissolve the polymer with a three-dimensional network structure, the solvophilic group in the polymer compound can be affected by the solvent to swell the polymer, which is also the reason for the formation ...

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Problems solved by technology

Chinese patents CN101215350A, CN101319019A and CN101161689B also disclose the preparation of nanocomposite temperature-sensitive hydrogels with modified inorganic nanoclays (such as sodium pyrophosphate-modified lethonite, hectorite) as physical cross-linking agents, but do not involve pH response and dual responsive hydrogels

[0010] And DMAEMA is also widely used in the synthesis of multi-response gels. Its synthesis methods include cross-linking with chemical cross-linking agent BIS and polymerization by ultraviolet cross-linking. However, the mechanical properties of these hydrogel products are still poor. And the lowest critical transition temperature LCST temperature is higher than 40 ℃, this temperature is higher than the human body temperature and does not have the value of being used for drug sustained release