三元阳离子淀粉絮凝剂的合成

Synthesis of ternary cationic starch flocculant

以自制的阳离子淀粉醚St-GTA和阳离子单体甲基丙烯酰氧乙基三甲基氯化铵(DMC)为原料,合成了三元阳离子淀粉絮凝剂St-GTA-g-DMC。通过正交实验和单因素实验筛选出St-GTA的最佳合成条件为:n(CTA)∶n(St)=1.2∶1,催化剂NaOH加入量为0.8 g,醚化温度为70℃,醚化时间为3 h。再以硝酸铈铵(CAN)为引发剂,St-GTA与DMC接枝共聚,合成出三元阳离子淀粉絮凝剂St-GTA-g-DMC,并用FT-IR、SEM对产物结构进行了表征。此絮凝剂的特性黏度为0.82 d L/g,取代度为1.087,应用于2%高岭土溶液,在加药质量浓度为5 mg/L时,浊度可降低到53.46 NTU。

The ternary cationic starch flocculant St-GTA-g-DMC is synthesized by using the self-made cationic starch ether St-GTA and the cationic monomer methacrylatoethyl trimethyl ammonium chloride（ DMC） as raw materials.Through orthogonal and single factor experiments,the optimum conditions for the synthesis of St-GTA are as follows： n（ GTA）/n（ starch） = 1. 2 ∶1,m（ Na OH） = 0. 8 g,and etherification lasts for 3 h at 70℃.The prepared DMC is grafted onto St-GTA with cerium ammonium nitrate（ CAN） as initiator to synthesize the ternary cationic starch flocculant StGTA-g-DMC. The structure of the flocculant product is characterized by FTIR and SEM. This flocculant has a characteristic viscosity of 0. 82 d L·g-1,and a substitution degree of 1. 087.When the dosage of St-GTA-g-DMC is 5 mg·L^-1,the turbidity of the 2% kaolin solution can be reduced to 53. 46 NTU.