Flocculation Behavior of Starch Betainate

Abstract

Starch betainate was applied in flocculation of kaolin suspension. The flocculation efficiency of starch betainate increased with the increase of both DS and molecular weight of starch betainate, which demonstrated that the flocculation was realized mainly by charge neutralization and bridging of the particles. When the dose of crosslinked starch betainate with DS of 0.33 was 3ppm, the removal ratio of turbidity could reach 90.5%, which was similar to the effect of traditional etherified cationic starch. The flocculation efficiency of starch betainate decreased with the increasing amount of salt in the kaolin suspension. Besides, pH of 5-7 was shown reasonable for starch betainate in the application.