微晶纤维素醋酸酯的合成与工艺研究

以微晶纤维素为原料,浓硫酸为催化剂,制备了一系列不同取代度的纤维素醋酸酯。研究了反应时间、温度、原料配比、催化剂用量对取代度和产率的影响,并通过红外图谱进行了表征。结果表明：随着反应时间、反应温度、原料配比和催化剂用量的增加,产物取代度增大,但产率降低。在温度为85℃,时间为10min,浓硫酸用量为1mL,醋酸酐与微晶纤维素的用量比为25∶1的最佳合成条件下取代度接近3,与理论值相符合。

Study on the Preparation and Technology of Microcrystalline Cellulose Acetates

With using microcrystalline cellulose as raw materials, concentrated sulfuric acid as a catalyst, a series of cellulose acetate with different degrees of substitution were prepared. The effects of reaction time, temperature, raw material proportion, catalyst amount on the degree of substitution and yield were studied and the products were characterized by IR. The results showed that with the rising of the reaction time, temperature, the ratio of raw materials and the amount of catalyst, the degree of substitution of product increased, but the yield decreased. The optimal synthesis conditions were as follow： the reaction temperature was 85℃, time was 10min, the amount of concentrated sulfuric acid was lmL, and the ratio of acetic anhydride to microcrystalline cellulose was 25：1, under these conditions, the degree of substitution was close to 3, in line with the theoretical value.