羧甲基纤维素接枝聚丙烯酰胺的制备及其絮凝性能研究

Preparation and flocculation properties of carboxymethyl cellulose-graft-polyacrylamide

以一种性能优越的天然高分子材料羧甲基纤维素为基材,通过接枝改性,以丙烯酰胺为改性剂,制备了一系列不同接枝率的羧甲基纤维素接枝聚丙烯酰胺共聚物.并将其作为絮凝剂应用于对一种阳离子型染料——亚甲基蓝污水的处理中,系统地考察了絮凝剂投加量、溶液pH以及聚丙烯酰胺接枝率对其絮凝性能的影响.

Recently,more attentions have been paid to natural polymer based flocculants in wastewater treatment, since they are believed as wide-resource, nontoxic, environment friendly and high efficient materials. Furthermore, they have been even acclaimed as ＂Green Flocculants of 21^st Century＂. However, disadvantages such as their low reaction activity and poor solubility have limited their practical applications. To improve their performances, graft polymerization have been applied to carboxyrnethyl cellulose（CMC）,one of high performance natural polymers,and acrylamide was used as modifier in this work. A series of carboxymethyl cellulose graft polyacrylamide（CMC-g PAM）samples with various grafting ratios have been obtained. CMC-g PAM has been employed to purify a cationic dye water containing methylene blue （MB）. The effects of dosage, pH, and grafting rate on the flocculation performance were investigated systematically. The experimental results show that flocculation performance of the cellulose based graft copolymers has been improved significantly. In addition, CMC-g PAM flocculants should be prepared with a proper grafting ratio in order to achieve better flocculating properties, which is due to the cooperative effects of the charge neutralization and bridging flocculating mechanisms.