Preparation method of cellulose acetate propionate mixed ester with high propionyl content

Abstract

The invention relates to a preparation method of cellulose acetate propionate mixed ester with high propionyl content. Cellulose is prepared from the following components in parts by weight: 650g of wood pulp, 2630g of propionic acid, 40g of acetic anhydride, 2070g of propionic anhydride and 19.5-52g of a catalyst, wherein the ratio of a liquid acid catalyst to heteropolyacid catalyst is 4:6 to 6:4. The preparation method comprises the steps of activating, carrying out esterification reaction, mixing, adding a magnesium acetate solution, hydrolyzing and carrying out chromatography; and then, sequentially carrying out conventional filtration, washing and drying to obtain a finished product. The preparation method has the advantages that the finished product of cellulose acetate propionate, prepared by using the method, contains more than or equal to 46% of propionyl content and less than or equal to 2% of acetyl and is stable in performance; the catalyst is a mixture of liquid acid and heteropolyacid, so that the consumption of sulfuric acid is reduced, furthermore, corrosion to process equipment and environment pollution can be reduced, and the process safety can be improved; and meanwhile the heteropolyacid is additionally applied, so that the esterification reaction is accelerated, and hydrolysis reaction is more precise and controllable.

Description

technical field [0001] The invention belongs to the field of cellulose lipid derivatives, in particular to a kind of high propionyl content [0002] The preparation method of cellulose acetate propionate mixed ester. Background technique [0003] Cellulose acetate propionate (CAP for short) is a cellulose organic acid ester prepared by esterification of cellulose, acetic anhydride and propionic anhydride. CAP has excellent toughness, thermal stability and compatibility, and is widely used in auto parts, tool handles, radio and TV parts, steering wheels, films, filters, radio transistors, toys, wall and floor tiles, coatings, spinning and other industries . [0004] At present, the content of propionyl group in cellulose acetate propionate produced in China is relatively low and unstable. Chinese patent application number is: 201110009701.8 patent discloses a kind of preparation method of cellulose acetate propionate, this method uses cellulose as raw material, after activ...

AI Technical Summary

Problems solved by technology

The cellulose acetate butyrate butyryl content that this method prepares is higher, but there are following problems: 1. use the concentrated sulfuric acid as catalyzer in this preparation method, process equipment is had very strong corrosion, and use the concentrated sulfuric acid in a large amount, It will pollute the environment; 2. The esterification reaction time is long, and the hydrolysis reaction control is not precise enough; 3. The reaction stage needs to be cooled by an external jacket, which makes the production cost higher