Method for preparing polyglutamic acid hydrogel

Abstract

The invention discloses a method for preparing polyglutamic acid hydrogel. In the method, polyglutamic acid is used as a main raw material, glycol diglycidyl ether is used as a crosslinking agent and a pH value of the system is adjusted at regular intervals in the reaction process. The method comprises the following steps of: dissolving 15 to 30 percent of polyglutamic acid into distilled water, adding glycol diglycidyl ether in an amount which is 20 to 50 percent based on the molar amount of of polyglutamic acid monomers, uniformly stirring the mixed solution, adjusting the pH value of the system to 3 to 5, and performing a reaction at the temperature of between 40 and 80 DEG C for 4 to 10 hours, wherein the pH value of the system is adjusted to the initial value every 1 to 2 hours; and performing full swelling dialysis and drying of the prepared hydrogel. The method has the advantages that: the reaction is performed in aqueous solution, which contributes to environmental protection; and the preparation period is short, and the hydrogel prepared by the method is high in water absorption and high in swelling speed, and possesses bio-degradability. The hydrogel prepared by the method can be applied to medicament carriers, medical and hygienic products, water-retaining agents used in farming, forestry and gardening industries, thickening agents for cosmetics and foods, anti-condensation agents, flocculating agents, water treatment chemicals and the like.

Description

Technical field: [0001] The invention relates to a preparation method of a biodegradable polymer water-absorbing agent, in particular to a method for preparing hydrogel with polyglutamic acid as a main raw material. Background technique: [0002] The method of preparing polyglutamic acid hydrogel was found by consulting domestic and foreign literature, including physical cross-linking method and chemical cross-linking method. Among them, compared with chemical cross-linking, physical radiation cross-linking has milder cross-linking conditions and can be carried out at normal temperature and pressure. The production process is simple, no cross-linking agent is needed, the product does not need additional disinfection, and there is no secondary pollution. However, the equipment required for radiation crosslinking is huge, the cost is high, and various side reactions may occur, and the radiation dose and radiation dose rate need to be specially adjusted. In particular, the ins...

AI Technical Summary

Problems solved by technology

However, this method has several deficiencies. In the preparation process, the amount of cross-linking agent used is only 6%, and the maximum cross-linking degree that can be achieved is relatively low. The cross-linking reaction needs 20 hours, and the reaction time is relatively long; the raw materials used are all It is a mixture and crude extract with complex components, which makes the prepared hydrogel not easy to purify, the specific composition is not clear, and there are still deficiencies in the pharmaceutical industry with high requirements; the water absorption rate of the gel is 5000 times, and it needs to go through as long as 120 Hours of swelling time can be achieved, and the hydrogel after swelling for 24 hours can only swell 450 times, which is not enough for applications that require a large amount of imbibition or rapid imbibition