Synthesis method of high-carboxylation-degree oxidized cellulose

Abstract

The invention discloses a synthesis method of high-carboxylation-degree oxidized cellulose, comprising the steps of combining pre-treatment and multistep oxidization to fully oxidize a cellulosic material, namely, first sealing, mixing and ball-milling the cellulosic material and dry ice and exposing a sample to air to realize the pre-treatment process after finishing ball-milling, then adopting NaNO3 and H2SO4 for carrying out primary oxidization on the material, and carrying out secondary oxidization by adopting KCLO4 as an oxidizing agent, wherein a reaction is performed at the temperature of 30 to 40 DEG C and the reaction time is 30 to 60 min; finally, further oxidizing the material subjected to the secondary oxidization by adopting KCLO, wherein the oxidization temperature is 50 to 60 DEG C and the time is 50 to 65 min. An oxidized cellulose product obtained through the synthesis method is relatively high in content of carboxyl, the content of the carboxyl can reach up to 35.6 percent to 48.7 percent, and the product has good application prospect in the technical field of biological medicine materials.

Description

technical field [0001] The invention relates to the technical field of biomedical materials, in particular to a method for synthesizing oxidized cellulose with a high degree of carboxylation. Background technique [0002] Cellulose is a linear semi-rigid natural polymer compound formed by D-glucopyranose anhydrous and β-1,4-glycosidic bonds. There are 3 active hydroxyl groups on each glucosyl ring in its macromolecular chain ( Two secondary hydroxyl groups and one primary hydroxyl group), generally speaking, the oxidation reactions of various forms of cellulose mostly occur on these three hydroxyl groups, which can form aldehyde groups, ketone groups and carboxyl groups. As a polyhydroxy compound, cellulose is easily oxidized by oxidants, and different hydroxyl groups can undergo different oxidation reactions. There are mainly the following possible oxidation methods: ① The primary hydroxyl group is oxidized to an aldehyde group, and can continue to be oxidized to a carboxyl...

AI Technical Summary

Problems solved by technology

For example, the Chinese patent (CN101724078A) uses nitric acid and nitrite or nitrogen dioxide as an oxidant to oxidize cellulose in an inert solution, and the carboxyl content in the final product is 8%-12%; the Chinese patent (CN103864940A) uses An oxidation system containing a hydroxylamine compound catalyst as an oxidizing agent, and using sodium hypochlorite or oxygen as an oxidizing agent to oxidize the cellulose material, the carboxyl content of the final product obtained is 1.1%-5.6%; however, the low carboxyl content limits the application of oxidized cellulose For example, if oxidized cellulose is made into medical absorbable hemostatic gauze, the carboxyl content in the cellulose needs to be more than 18%; if oxidized cellulose is used as an anticoagulant, a higher carboxyl content is required