Method for preparing fast responsive temperature-sensitive hydrogel by adopting frontal polymerization technology

Abstract

The invention provides a method for preparing fast responsive temperature-sensitive hydrogel by adopting frontal polymerization technology, which comprises the steps of: (1) preparing prepolymerization solution, namely dissolving a heat-sensitive monomer and a crosslinking agent into a water / dimethylsulfoxide mixed solvent according to certain proportion to obtain uniform solution, and then adding an initiator which accounts for 1.2 to 0.5 percent of the mass of the heat-sensitive monomer into the uniform solution to obtain the prepolymerization solution, wherein the crosslinking agent, namely N,N'-methylene-bis-acrylamide accounts for 1.2 to 0.4 percent of the mass of the heat-sensitive monomer; (2) transferring a reaction mixture of the prepolymerization solution into a reactor for heating to ensure that the initiator is heated and decomposed and a polymerization reaction starts; (3) after the reaction starts, evacuating a heat source, and maintaining the reaction by polymerization exotherm until all raw materials in the whole reactor are entirely transformed into a polymer; and (4) taking the polymer obtained in the step (3) out, and rinsing the polymer with deionized water to obtain a product. The method opens up a new way for industrially producing the fast responsive temperature-sensitive hydrogel.

Description

technical field [0001] The invention belongs to the technical field of preparation of functional polymer materials, and in particular provides a method for preparing rapid-response temperature-sensitive hydrogel by wave polymerization technology. Background technique [0002] Thermosensitive hydrogel is a cross-linked network of hydrophilic polymers, which can sense small changes in external temperature and respond to external stimuli by expanding and contracting its own volume. The above-mentioned characteristics of thermosensitive hydrogels make them widely used in drug control release, substance separation and purification, light-adjusting materials, tissue culture, immobilized enzymes, etc. At present, poly(N-isopropylacrylamide) (hereinafter referred to as PNIPAM) and its derivatives are studied more. The transition temperature is about 32°C, which is very close to the normal body temperature of the human body at about 37°C; when the temperature is lower or higher than...

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Problems solved by technology

But the disadvantage of this method is that the solid porogen CaCO 3 It is difficult to evenly disperse in the reaction mixture, which will easily cause uneven pore structure of the product, and also undergo a complicated process of pickling the porogen, which not only increases the process, but also easily causes environmental pollution

CN1858073A adopts the traditional solution radical polymerization method to prepare a fast-response temperature-sensitive polymer by adding a chain transfer agent. The chain transfer agent added in this method is a toxic organic substance, most of which are insoluble or slightly soluble in water and cannot be washed away with water. Easy to get stuck in the product

[0005] In addition, the common problems of the above technologies are: in order to avoid violent polymerization and facilitate temperature control, the concentration of reaction monomers is generally low (less than 20%), which leads to slow polymerization rate, long preparation time, and the conversion of monomers The efficiency is not high; the whole polymerization process needs water bath heating, so the energy consumption is large and the cost is high

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