Dispersing Multi‐Component and Unstable Powders in Aqueous Media Using Comb‐Type Anionic Polymers*

Abstract

We have investigated the effect of polymeric dispersants on the rheological properties and consolidation behavior of concentrated cemented carbide (WC–Co) and magnesia (MgO) suspensions. The relatively novel types of comb‐type anionic polymers with grafted non‐ionic side chains are effective dispersants also in multi‐component powder mixtures with a complex solution and surface chemistry and result in more robust suspensions at significantly higher solids loading compared with e.g., a traditional cationic polyelectrolyte. Direct force measurements on comb‐type dispersants with different lengths of the grafted ethylene oxide side chains showed that the dispersants adsorb onto a MgO surface and infer a repulsion where the range scales with the length of the poly ethylene oxide side chains. The compressibility and the consolidation behavior of MgO particle networks in response to a centrifugal force field could be related to the estimated thickness of the adsorbed comb‐type dispersants.