季铵型阳离子淀粉絮凝剂的制备及其应用

Preparation and application of quaternary ammonium type cationic starch flocculant

以玉米淀粉为原料,3-氯-2-羟丙基三甲基氯化铵为阳离子醚化剂,采用预干燥干法制备高取代度季铵型阳离子淀粉絮凝剂。考察了醚化剂用量、氢氧化钠与醚化剂摩尔比、反应温度及反应时间对取代度和反应效率的影响,优化出制备高取代度阳离子淀粉的最佳工艺条件为:醚化剂的加入量为绝干淀粉量的55%,氢氧化钠与醚化剂摩尔比为1.2,反应温度85℃,反应时间4h。将阳离子淀粉对工业中较难处理的高色值糖蜜酒精废液进行絮凝脱色性能测定,结果表明当阳离子淀粉质量浓度为500mg/L、取代度为0.39、废液初始pH值为9.0时,脱色率达53.6%。

The quaternary amino groups containing cationic starch with a high degree of substitution （DS） was prepared via the reaction of corn starch with 3-chloro-2-hydroxypropyl-trimethyl ammonium chloride （CHPTMA） using pre-drying dry process. The effects of the amount of CHPTMA, the molar ratio of sodium hydroxide to CHPTMA, reaction temperature and time on DS and reaction efficiency were investigated. The optimal reaction conditions of preparing high DS cationic starch were as follows： the amount of CHPTMA was 55% of mass of starch, the molar ratio of sodium hydroxide to CHPTMA was 1.2, reaction temperature was 85℃ and reaction time was 4h.The cationic starch was used to treat molasses alcohol wastewater as flocculant. When the cationic starch concentration was 500 mg/L, DS was 0.39, the initial pH value ofwastewater was 9.0, the decolorization efficiency was up to 53.6%.