阳离子型改性淀粉絮凝剂的制备及絮凝性能研究

合成了3种具有不同阳离子化度的阳离子型改性淀粉接枝共聚物絮凝剂ZHYC-n”（n=15，40，70），当丙烯酰胺与淀粉的质量比大于2．0以后，再提高接枝单体对淀粉的比例，不能明显提高接枝频率，但能提高接枝侧链相对分子质量。考察了这3种絮凝剂的絮凝性能并与市售阳离子型聚丙烯酰胺絮凝剂CPAM进行了对比。结果表明，絮凝剂ZHYC叫具有优良的絮凝脱浊效果，随阳离子化度增加絮凝效果显著增加；絮凝剂ZHYC-70的絮凝效率比CPAM的高约30倍。阳离子型絮凝剂分子链上的阳离子电荷密度不是影响絮凝效果的惟一主要因素；阳离子型改性淀粉接枝共聚物具有的多支链型结构可以明显提高絮凝剂的絮凝效果。

Study on preparation and flocculation performance of cationic polyacrylamide-starch graft copolymers

Three cationic polyacrylamide-starch graft copolymer flocculants, ZHYC-n, with different cationic charge density .were prepared. When the mass ratio of acrylamide to starch is more than 2.0, the graft frequency is not increased markedly while the relative molecular mass of side chain is increased. The flocculation performance of these flocculants was determined and compared with the typical cationic flocculant CPAM. The experimental results indicate that the flocculation effect increases with the cationic charge density of the flocculants increasing. The flocculation efficiency of ZHYC-70 is about 30 times more than that of the CPAM. But cationic charge density in molecular chain of flocculants is not unique dominating factor affecting the flocculation effect. Multi-side-chain structure of cationic starch graft copolymer flocculants can improve flocculation effect markedly.