Autori: Luminita Mara, Stefan-Ovidiu Dima, Andrei Sarbu, Liliana Sarbu, Rodica Zavoianu, Octavian Pavel, Dumitru Taloi

Editorial: Revista de Chimie, 62 (10) , p.1017-1022, 2011.

Rezumat:

In this paper are presented the results of experimental research regarding the behaviour of ceramic pastes
based on microcrystalline hydrotalcite [MII 1-xMIIIxOH)2]x+An-x/nmH2O, used for the preparation of monoliths
with circular section through extrusion. The experimental studies regarding the rheological behaviour of
hydrotalcite pastes lubricated with stearin shows that these materials have viscoplastic behaviour. Two
rheological models are proposed (Bingham-Schwedoff and Herschel-Bulkley) for the correlation of
experimental data and for the determination of rheological parameters (n and k). It is shown that Herschel-
Bulkley model is more appropriate than Bingham-Schwedoff model to describe these ceramic mixtures and
that stearin has a lubricating role, improving the flowing parameters. By using the bifactorial analysis of
variance it was also investigated, from the statistical point of view, the influence of the studied factors (the
content of the plasticizer agent and the shear rate .γ).

Cuvinte cheie: hidrotalcit, paste ceramice, extrudate, reologie // hydrotalcite, ceramic pastes, extrudates, rheology