Effects of the calcination temperature and the load of sodium carboxymethyl cellulose in the synthesis of novel bentonite ceramic foams

D. TORRES; J. VILLARROEL-ROCHA; D. BARRERA; A. GUTARRA; K. SAPAG

Avances Investigación en ingenierías

Universidad Libre

Lugar: Bogotá; Año: 2017 vol. 14 p. 133 - 144

Novel ceramic foams were obtained by the replica method, using bentonite as alternative raw material and polyurethane sponge as template, where the latter also controls the distribution of the pore size of these ceramics. The synthesis of the ceramics was carried out using slurries of bentonite clay with different percentages of sodium carboxymethyl cellulose as a binder, and evaluating different calcination temperatures. The effect of these factors on the textural and morphological properties of the ceramic foams was studied. The porosity measured by mercury intrusion showed that the total porosity of the ceramic foams decreases as the calcination tem-perature increases. Furthermore, a small quantity of porosity is generated after the burnout of the binder during the calcination step. This porosity is given by pore sizes from 0.05 to 3 μm and it was increased with the amount of the binder that was increased, which was also confirmed by scanning electron micrographs. The characterization of bentonite clay, polyurethane, coated polyurethane sponge and ceramic foams was also complemented with thermogravimetric analysis, nitrogen adsorption at 77 K, and mechanical strength measurements.