Copolymers dispersions designed to shaping of ceramic materials

Abstract

The paper concerns the synthesis and the characterization of new water-thinnable binder such as poly(acrylic–styrene) with the addition of a new amphiphilic macromonomer and it application in shaping of unmodified and modified (by silanization) Al2O3 by die pressing. The organic additives decomposed thermally to non-toxic gases which is beneficial from ecological point of view. Thus, the careful thermal analysis of synthesized binder was done. To characterize the synthesized binder, the glass transition temperature, wetting angle and diameter of polymer particles size in water were also measured. In the next step of the work, the density, porosity, tensile and bending strength, and microstructure observations have been done for modified and unmodified Al2O3 samples obtained by die pressing. The results confirmed that the synthesized binder is eco-friendly, because it decomposed to non-toxic gases such as carbon dioxide and water vapor during heating up to ca. 527 °C. The synthesized binders are characterized by low glass transition temperatures 5.6 °C and − 0.5 °C which are much lower than that of PVA (42 °C). It provided the high tensile strength (0.22 ± 0.01 MPa) of green bodies, 57% higher than strength of bodies with commercially available PVA and bending strength around 192 MPa. Density of sintered samples was around 95% of TD. Nevertheless, the best results were obtain for bodies based on modified Al2O3 where tensile strength of green bodies and bending strength of sintered samples were 0.30 ± 0.04 MPa and 237 ± 19 MPa, respectively.