Marine Pollution Department, Environmental Division, National Institute of Oceanography and Fisheries, Kayet Bey, El-Anfoushy, Alexandria, Egypt.
Marine Pollution Department, Environmental Division, National Institute of Oceanography and Fisheries, Kayet Bey, El-Anfoushy, Alexandria, Egypt.
Carbohydr Polym. 2015 Oct 5;130:41-8. doi: 10.1016/j.carbpol.2015.04.065. Epub 2015 May 8.
This research discusses the acetylation of cotton cellulose with acetic anhydride without solvents. The acetylation was done in the presence of different amounts of N-Iodosuccinimide (NIS) as a catalyst; this took place under mild reaction conditions. The extent of acetylation was measured by the weight percent gain (WPG) that varied from 24.71 to 71.83%. Cotton cellulose acetates, with the degree of substitution (DS) that ranged from 0.89 to 2.84, were prepared in one step. The cellulose triacetate, with a degree of substitution (DS) 2.84, was obtained. The WPG and DS were easily controlled by changing the reaction duration (1-5h), and the concentration of the catalyst (0.05 g, 0.075 g and 0.10 g for 1g of cellulose) in 25 ml of acetic anhydride. NIS was recognized as a novel and more successful catalyst for the acetylation of hydroxyl groups in cotton cellulose. Formation of the acetates and the calculation of the degree of substitution were performed by FT-IR, Raman, and (1)H NMR.
本研究探讨了在无溶剂条件下用乙酸酐对棉纤维素进行乙酰化。在不同量的 N-碘代丁二酰亚胺（NIS）作为催化剂的存在下进行乙酰化；在温和的反应条件下进行。乙酰化程度通过重量百分比增加（WPG）来测量，范围从 24.71 到 71.83%。在一步法中制备了取代度（DS）从 0.89 到 2.84 的棉纤维素醋酸酯。获得了取代度（DS）为 2.84 的三醋酸纤维素。通过改变反应时间（1-5 小时）和催化剂浓度（0.05 g、0.075 g 和 0.10 g 用于 1 g 纤维素）在 25 ml 乙酸酐中，WPG 和 DS 很容易控制。NIS 被认为是一种新型的、更成功的棉纤维素羟基乙酰化催化剂。通过 FT-IR、拉曼和（1）H NMR 进行了醋酸酯的形成和取代度的计算。
