Propylation of cellulose from different sources with propionic anhydride using N-iodosuccinimide (NIS) under solvent-free condition was tested. It was done in the presence of NIS as a new catalyst for propylation using three different amounts of catalyst under mild reaction conditions. The degree of substitution by propionate was experimentally calculated and confirmed by FTIR and 1H NMR analyses. The propylation yields varied from 71.54 to 88.37% with the degree of substitution (DS) ranged from 1.32 to 2.80 for commercial cotton cellulose, 1.76–3.00 for rice husk cellulose, and 1.60–3.0 for wheat straw cellulose. The DS were easily controlled by changing the reaction duration (2–6 h) and the amount of the NIS catalyst (50, 75, and 100 mg for each 1.0 g of cellulose) in 25 mL of propionic anhydride. Prolonging the reaction’s duration has no favorable effect on the propylation process and led to decrease in the cellulose propionate (CP). Also, increasing the amount of NIS catalyst results in decrease the DS and CP yield. NIS was recognized as a novel and more successful catalyst for propylation of the hydroxyl groups of cellulose from different sources in high degree of substitution.

中文翻译：

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以NIS为新型催化剂不同来源合成丙酸纤维素的对比研究

测试了在无溶剂条件下使用 N-碘代琥珀酰亚胺 (NIS) 用丙酸酐对来自不同来源的纤维素进行丙酰化。它是在 NIS 作为一种新的丙基化催化剂的存在下使用三种不同量的催化剂在温和的反应条件下完成的。丙酸酯的取代度通过实验计算并通过 FTIR 和 1 H NMR 分析确认。丙基化产率从 71.54% 到 88.37% 不等，商业棉纤维素的取代度 (DS) 范围为 1.32 到 2.80，稻壳纤维素为 1.76-3.00，麦秸纤维素为 1.60-3.0。通过改变反应持续时间（2-6 小时）和 NIS 催化剂的量（50、75 和 100 毫克，每 1.0 克纤维素）在 25 毫升丙酸酐中，很容易控制 DS。延长反应时间对丙基化过程没有有利影响，并导致丙酸纤维素 (CP) 减少。此外，增加 NIS 催化剂的用量会导致 DS 和 CP 产率降低。NIS 被认为是一种新型且更成功的催化剂，可用于以高取代度对来自不同来源的纤维素的羟基进行丙基化。