活化细菌纤维素的结构与性能

Structure and properties of activated bacterial cellulose

分别采用乙二胺和NaOH对BC进行活化,以改善BC在离子液体中的溶解性能,通过正交实验优化了其活化工艺,并研究了活化前后BC的红外光谱、结晶结构、结晶度、聚合度和热分解性能,以及在离子液体[BMIM]Cl中的溶解性能。结果表明,乙二胺活化的最佳工艺为浓度14%,温度60℃,时间90min,氢氧化钠活化的最佳工艺为浓度10%,温度40℃,时间480min。活化后BC分子结构中的氢键作用力减弱,结晶结构发生不完全的转变,结晶度和聚合度下降,热稳定性提高,化学试剂的可及度增加,在离子液体中的溶解时间显著缩短。

Ethylenediamine and NaOH were separately used as activators to activate BC in order to improve the solubility property of bacterial cellulose in ionic liquid Cl.The optimum activation conditions with ethylenediamine as activator were： concentration of ethylenediamine was 14wt%,activation temperature was 60℃ and activation time was 90min.And the optimum activation conditions with NaOH as activator were： concentration of NaOH was 10wt%,activation temperature was 40℃ and activation time was 480min.The structures and thermabl stability of bacterial cellulose and activated bacterial cellulose were characterized by FT-IR,XRD and TGA,and their solubility property in ionic liquid Cl was also studied.The results indicate that the hydrogen bond force is weakened,polymerization degree and crystallinity degree are decreased,and the accessibility to chemical solvent is improved in activated bacterial cellulose.The bacterial cellulose activated with ethylenediamine or NaOH as activator dissolved in shorter time in ionic liquid Cl than unactivated bacterial cellulose.Moreover,the dissolution time of bacterial cellulose activated with NaOH as activator is shorter than that activated with ethylenediamine.