Preparation and properties of composite starch flocculants by inverse emulsion polymerization

Abstract

In order to improve the efficiency of sewage treatment, a new high-efficiency and easily degradable composite starch flocculant was prepared. With starch and acrylamide (AM) monomers as raw materials, the starch grafted acrylamide flocculant (St-PAM) was prepared by inverse emulsion polymerization. Orthogonal experiment was used to investigate the influence of reaction temperature, starch and acrylamide monomer ratio, KPS concentration and reaction time on monomer conversion and grafting rate, and then the optimal preparation process was obtained, and performance test analysis of the optimized samples were carried out. The results show that the best process for the synthesis of St-PAM by inverse emulsion polymerization was the reaction temperature of 60 ℃, the ratio of starch to acrylamide monomer 1∶3.5, the KPS concentration 5 mmol·L-1. The monomer conversion rate of the starch flocculant prepared under this process can reach 92.8%, the grafting rate 86.2%. The St-PAM prepared under this condition has a flocculation rate of 92.1% for kaolin simulated wastewater.

Keywords

• composite starch
• acrylamide
• compound flocculant
• inverse emulsion polymerization
• flocculation rate