微波辅助干法制备阳离子木薯淀粉

采用微波辅助加热法干法制备阳离子淀粉,详细考察了微波功率、微波辐照时间、氢氧化钠用量和3-氯-2-羟丙基三甲基氯化铵醚化剂(CHPTMA)用量等对反应效率及其产品取代度的影响。结果表明:微波干法合成阳离子淀粉,反应时间短,反应效率高;在NaOH分2次加入、NaOH与淀粉质量比为4.0%、醚化剂用量为淀粉质量的4.5%、水用量为淀粉用量的25.0%、微波功率为450 W及微波辐照时间为3.0 min等条件下,阳离子淀粉取代度为0.037 5,阳离子醚化剂反应效率高达93.76%。

Preparation of Cationic Cassava Starch in Dry Process Assisted by Microwave Radiation

A dry process assisted by microwave radiation was used to prepare cationic cassava starch,where the effects of microwave power,microwave radiation time,the dosages of NaOH and 3-chloro-2-hydroxypropyl-trimethyl ammonium chloride（CHPTMA） on the reaction efficiency（RE） and the degree of substitution（DS） were investigated.The results showed that,under the assistance of microwave radiation,reaction time can be shortened while the reaction efficiency can be increased.DS of 0.037 5 and RE of 93.76% were achieved under the following conditions： dosage of NaOH,4.0%（w/w） of starch,where the NaOH was divided into 2 parts and delivered respectively in the starch and the CHPTMA;dosage of CHPTMA,4.5%（w/w） of starch;dosage of water,25%（w/w） of starch;microwave power 450 watt;and radiation time,3.0 minutes.