Polymers and Polyelectrolytes in Wet-end Papermaking

Abstract

Polymers and polyelectrolytes are routinely used in wet-end papermaking as retention, drainage and formation aids. The way they function is still not fully understood. We will discuss polymer adsorption on fibers and the different mechanism by which polymers induce flocculation, either by themselves or with the help of other components. Factors that determine the extent of polymer and polyelectrolyte adsorption are molecular weight, polydispersity, pH, morphology, charge density and ionic strength. Important fiber properties are microstructure and surface charge density. Factors that promote flocculation are polymer-cofactor associations, polyelectrolyte-microparticulate affinity, molecular weight and polymer/polyelectrolyte configurations. The kinetics of flocculation dictates optimum addition points for retention aids.