Surface modification of pigments by adsorption of amphipolar copolyelectrolytes

COLL 382

Claus D. Eisenbach1, Heike Arndt2, Christian Schaller2, Thadaeus Schauer2, and Klaus Dirnberger1. (1) Institut für Angewandte Makromolekulare Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany, (2) Forschungsinstitut für Pigmente und Lacke e.V, Allmandring 37, D-70569 Stuttgart, Germany
The controlled modification of the surface of pigments is important for obtaining stable pigment dispersions. Amphipolar polyelectrolytes are of particular interest because of their effectiveness to stabilize colloidal particles in aqueous media by means of electrosteric stabilization. The study of the adsorption of styrene/acrylic acid based block and graft copolymers on inorganic as well as organic pigments infers an initial step-by-step adsorption of copolymer molecules on the pigment surface followed by layer thickening growth involving copolymer micelles. These phenomena as related to the macromolecular architecture and the colloidal system will be elucidated. The implications for employing amphipolar copolyelectrolytes as dispersion stabilizers will be discussed.