Highly branched cationic polyelectrolytes: filler flocculation

Highly branched cationic polyacrylamides of low molecular weight and low cationic charge density were investigated for flocculation of ground calcium carbonate and titanium dioxide particles. They were compared with conventional linear polyelectrolytes with special attention on the effect of polymer concentration and shear condition. Also examined was the microparticle addition effect on filler flocculation. The highly branched polymers produced small flocs with great shear resistance. Results show that adding microparticulate silica could further increase the floc size. Application : a highly branched cationic polyelectrolyte offers promise as a retention aid in a microparticulate retention system.