疏水缔合阳离子改性淀粉-纳米SiO_2絮凝剂CSSADD的制备和性能测试

Preparation and performance of hydrophobically associating cationic starch-nano SiO_2 flocculant CSSADD

通过在糊化淀粉上引入丙烯酰胺(AM)、功能性阳离子单体二甲基二烯丙基氯化铵(DMDAAC)、疏水单体甲基丙烯酰氧乙基二甲基十六烷基溴化铵(C_(16)DMN^+)和纳米SiO_2制备了疏水缔合阳离子改性淀粉-纳米SiO_2复合絮凝剂(CSSADD),对其进行了红外光谱(IR)、X射线衍射(XRD)、热重(TG)及扫描电镜(SEM)分析。采用单因素变量法对反应条件进行优化,结果表明,单体摩尔比n(AM)∶n(DMDAAC)∶n(C_(16)DMN^+)=84.5∶15∶0.5,反应体系的pH=5~6,当改性纳米SiO_2与淀粉质量比为1∶3,淀粉与单体质量比为1∶3,引发剂的加量为单体质量的0.5%,反应温度为45℃,反应时间为3 h时,所制备的絮凝剂的絮凝效果最好。性能测试结果表明:高岭土悬浊液的pH=6,当絮凝剂的投加量3 mg/L时,CSSADD处理后悬浊液的上层透光率为98.3%。

With soluble starch as base materials, the research introducing AM, the functional cationic monomer DMDAAC, hydrophobic monomer C16 DMN ＋ and nano-SiO2 to synthesize a hydrophobically associating cationic starch-nano SiO2 composite polymer flocculant, and then the chemical structure of CSSADD was demonstrated by IR, XRD, TG and SEM. The reaction conditions were optimized by the method of single factor variable, and the study showed that the graft monomers molar ratio was n （AM）： n （ DMDAAC ） ： n （ C16 DMN ＋ ） = 84. 5：15：0. 5, acidity control in pH value was 5 N 6, when nano-SiO2 and starch quality ratio scale was 1：3, starch andmonomers quality ratio scale was 1：3 ,the mass of initiator was 0. 5% of total monomers,the reaction temperature was 45 ℃ ,and the reacting time was 3 hours,the CSSADD＇s performance was best. The performance test indicated that when the pH value of kaolin suspension was 6 and the mass of CSSADD was 3 mg/L,the upper transmittance approached 98.3%.