Synthesis of cellulose acetate butyrate
Raw material preparation
Take an appropriate amount of cellulose as the starting material, which is the foundation of synthesis. Another preparation of acetic anhydride and butyric anhydride, two key acylation reagents, need to be accurately measured to ensure that the reaction ratio is appropriate. At the same time, prepare an appropriate amount of concentrated sulfuric acid as a catalyst, the amount of which has a great impact on the reaction process, and should be carefully controlled.

Reaction process
In a clean reaction vessel, first put the cellulose in, and then slowly add the mixture of acetic anhydride and butyric anhydride, stir well, so that the material is in full contact. Then, add concentrated sulfuric acid dropwise, at this time the temperature of the reaction system will rise slightly, so pay close attention. During As the reaction progresses, the color and viscosity of the system will change. This is a characterization of the reaction process. When carefully observed.

Product Treatment
After the reaction is completed, the reaction solution is poured into a large amount of ice water, and cellulose acetate butyrate will precipitate due to the change in solubility. Subsequently, the filtration operation is carried out to collect the precipitated solid product. The product is washed several times with an appropriate amount of distilled water to remove residual impurities and unreacted reagents. After washing, the product is placed in an oven and dried at a suitable temperature until constant weight to obtain pure cellulose acetate butyrate.

Product Analysis
The chemical structure of the product was analyzed by infrared spectroscopy, and the characteristic absorption peak was observed to confirm whether cellulose acetate butyrate was successfully synthesized. Gel permeation chromatography was used to determine the molecular weight and distribution of the product to evaluate the quality of the product. The thermal stability of the product was studied by thermogravimetric analysis, which provided key parameters for its practical application.