Structure-Property Relationship of Dispersants used in Ceramic Feedstock Development

T. Hanemann(a)(b), R. Heldele(a)(b), J. Haußelt(a)(b)
a: Forschungszentrum Karlsruhe, Institut f. Materialforschung III, 76021 Karlsruhe, Germany
b: Albert-Ludwigs-Universität Freiburg, Institut f. Mikrosystemtechnik (IMTEK), 79110 Freiburg, Germany

Abstract

With respect to polymer-filler composite (feedstock) development for the different variants of powder injection molding the use of dispersants or surfactants is essential for a large filler load and a homogenous feedstock quality. In this paper the influence of a series of citrate derived dispersants on the viscosity of feedstock systems with different binder composition and ceramic fillers will be described. Citrates posses four polar functionalities, which can interact with the hydroxy-groups at the alumina or zirconia surface. The investigated surfactants differ in the extension of the lipophilic end chains (ethyl or butyl) and in the presence of one free hydroxy group, which is masked partially by an acetic acid group. The impact of the dispersant concentration, molecular structure, dipole moment and the used binder composition will be discussed in terms of the resulting composite feedstock flow behaviour, some structure-property relationships can be found.