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The role of ammonium polyacrylate in dispersing concentrated alumina suspensions
journal contribution
posted on 2007-01-22, 11:42 authored by J. Davies, J.G.P. BinnerThe role of low molecular weight ammonium polyacrylate (NHPA) has been characterised as a dispersant for the colloidal
powder processing of high solids content alumina suspensions. It has been found to be a very effective dispersant under the correct
conditions, yielding fluid, highly homogeneous aqueous suspensions. Minimum suspension viscosities, one measure of the degree of
suspension dispersion, were observed at two different NHPA concentrations for each solids loading examined. The first viscosity
minimum was independent of the solids loading; however it produced bodies of relatively low green density. The second viscosity
minimum increased with increasing solids loading and yielded components of the highest green density. Adsorption data revealed
that maximum adsorption of NHPA onto the alumina surface occurred at this secondary minimum concentration. From the evi-
dence presented it is concluded that the ®rst minimum is rather unstable, decaying as the sample is dried. The second minimum is
the more stable, yielding the most favourable properties expected for a dispersed suspension. Predictions of the adsorbed polymer
configuration are offered as an explanation for the presence of the two minima.
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Materials
Pages
623431 bytesCitation
DAVIES and BINNER, 2000. The role of ammonium polyacrylate in dispersing concentrated alumina suspensions. Journal of the European Ceramic Society, 20, pp 1539-1553Publisher
© ElsevierPublication date
2000Notes
This is Restricted Access. This article was published in the journal, Journal of the European Ceramic Society [© Elsevier] and is available at: http://www.sciencedirect.com/science/journal/09552219.ISSN
0955-2219Language
- en