摘要:为研究魔芋葡甘聚糖的改性,采用振动机械力化学的方法对魔芋葡甘聚糖进行脱乙酰基和酯化改性。结果表明,在振动机械力化学处理时,魔芋葡甘聚糖分子结构中的活性基团与碱性改性剂发生皂化反应,可以快速有效地脱去乙酰基;碱性改性剂的碱性越强,脱乙酰基改性的效果越好;脱乙酰基的魔芋葡甘聚糖样品具有较好的黏度稳定性,并随着改性时间的延长而增强。在振动磨机械应力作用下,魔芋葡甘聚糖中的羟基可被磷酸盐基团取代发生酯化反应;经酯化改性,魔芋葡甘聚糖水溶胶的透光率优于原料,吸附金属离子量与原料相比较高。在改性时间为10 min时经酯化改性的魔芋葡甘聚糖样品的透光率和吸附性达到最佳值。魔芋葡甘聚糖大分子链的完整性对其絮凝能力的影响大于磷含量的影响。
关键词:机械力化学;魔芋葡甘聚糖;振动磨
Abstract:The de-acetylation and esterification of konjac glucomannan by mechano-chemical treatment in a vibrating mill were investigated,respectively.The results showed that the mechano-chemical treatment under alkaline condition was efficient to remove the acetyls from konjac glucomannan.The alkalinity of modifier could dominate the efficiency of de-acetylation of konjac glucomannan.The de-acetylated konjac glucomannan treated by KOH exhibited a higher viscosity than that treated by NaOH.The de-acetylated konjac glucomannan samples possessed a greater viscous stability,showing a positive relation with grinding duration.The esterification of konjac glucomannan with sodium hexametaphosphate was stimulated by mechano-chemical treatment in a vibrating mill.The aqueous solutions of konjac glucomannan showed a higher transmittance after mechano-chemically esterification.As a flocculant,the treated konjac glucomannan adsorbed more heavy metallic ions rather than the non-treated konjac glucomannan sample.The optimized duration of mechano-chemical treatment of konjac glucomannan for the superior transmittance and adsorption property was 10 min.It was found that the effect of formation of backbone of konjac glucomannan on the adsorption property of konjac glucomannan dominated over the effect of phosphorus content of konjac glucomannan.
Keywords:mechano-chemical;konjac glucomannan;vibrating mill