氨基甲酰乙基微纤化纤维素的制备及改性

Preparation and Modification of Carbamoylethylated Microfibrillated Cellulose

采用氨基甲酰乙基化反应对阔叶浆进行预处理,再经机械研磨得到了微纤化纤维素,最后分别在酸性和碱性条件下用次氯酸钠对其进行了改性。探讨了预处理条件对产物中氨基甲酰乙基和羧乙基含量的影响,并对预处理产物、微纤化纤维素和次氯酸钠改性产物的结构和热稳定性进行了表征。结果表明,预处理过程中丙烯酰胺和氢氧化钠用量以及反应温度会影响产物中氨基甲酰乙基和羧乙基的含量,经研磨后可得到直径为亚微米级的氨基甲酰乙基微纤化纤维素,再经次氯酸钠改性后可得到N-氯氨甲酰化纤维素产品,改性后纤维素产品的初始分解温度和最大失重温度均明显降低,但其残留率显著增加。

Bleached hardwood kraft pulp was pretreated by carbamoylethyl reaction, microfibrillated by mechanical grinding, and then modified by sodium hypochlorite under acidic and alkaline conditions. The effects of pretreatment conditions on the content of carbamoylethyl and carboxyethyl groups in the products were discussed. The structure and thermal stability of the pretreated products, microfibrillated cellulose, and modified products were characterized. The results showed that the contents of carbamoylethyl and carboxyethyl groups in the pretreated products were affected by the dosage of acrylamide and sodium hydroxide as well as the reaction temperature. Carbamoylethylated microfibrillated cellulose with submicron diameter was obtained after grinding. Microfibrillated cellulose containing N-chloroamide was then produced by modifying carbamoylethylated microfibrillated cellulose with sodium hypochlorite. The initial decomposition temperature and maximum weightlessness temperature of the modified products decreased significantly, but the residue rate increased dramatically.