Organic additives in gel-tape casting of ceramic powders – A novel approach to the problem of elasticity and cracking of thin tapes

Polymerization reactions are frequently used in fabrication of a wide range of ceramic components, from 3D elements (gelcasting, UV-curing), through thin tapes (gel-tape casting) to porous samples (mechanical foaming coupled with gelcasting). The analysis of the properties of organic additives used in these techniques as well as factors which influence the polymerization reaction in ceramic suspension are seldom described in the scientific literature. For this reason this paper presents the properties of selected monomers and polymers with influence on the elasticity of zirconia tapes obtained by gel-tape casting. The measured parameters were as follows: glass transition temperature of polymers with and without external plasticizers, wetting angle of ceramic substrates by monomers, and viscoelastic properties of zirconia slurries. The issues of oxygen inhibition, polymerization rate and polymerization shrinkage with influence on unwanted cracking of thin tapes are also discussed. The location of polymeric binder in green bodies was analyzed by SEM.