Polymerizing mechanism and technical factors optimization of nanometer tetragonal polycrystalline zirconia slurries for the aqueous-gel-tape-casting process

Comparative studies on properties of scandia-stabilized zirconia synthesized by the polymeric precursor and the polyacrylamide techniques

“…This gel consists of long polymeric chains, crosslinked to create a threedimensional tangled network, soaked with a solution of cations [18]. The polymerization of acrylamide occurs in the following sequence [19,20]: (a) the initiator is decomposed into primary free radicals, which can combine with the monomer molecule to produce monomer-free radicals, which, in turn, can combine with monomers producing chain-free radicals [19][20][21]; this reaction proceeds continuously and acrylamide (AAm) molecules polymerize into polymer chains; (b) a network is formed with the polymer chains by their cross-linking and bridging between polymer chains by N,N -methylenebisacrylamide (bis-AAm) molecules reaction; (c) bis-AAm is added into the monomer solution to polymerize the monomers completely. One of the advantages of the polyacrylamide technique is the reproducibility of the batches for obtaining submicron size ceramic powders in large quantities.…”

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

“…Nevertheless the issues of organic additives properties and analysis of factors which influence the polymerization reaction in ceramic suspension are seldom described in the scientific literature. Most of the attention is paid to optimize the quantity of the activator and initiator of polymerization [18,19] but it is worth to take into account more factors during the selection of organic additives in curing processes [20]. The scientific literature provides also interesting information concerning anisotropic shrinkage of ceramic tapes [21,22], therefore the presented in this paper properties of macromolecules may be useful in this field as well.…”

Properties of Scandia-Doped Zirconia Synthesized by the Polymeric Precursor and the Polyacrylamide Techniques

“…This gel consists of long polymeric chains, crosslinked to create a threedimensional tangled network, soaked with a solution of cations (13). The polymerization of acrylamide occurs in the following sequence (14,15): a) the initiator is decomposed into primary free radicals, which can combine with the monomer molecule to produce monomer-free radicals, which, by their turn, can combine with monomers producing chain-free radicals (14)(15)(16); this reaction proceeds continuously and acrylamide -AAmmolecules polymerize into polymer chains; b) a network is formed with the polymer chains by cross-linking of polymer chains and bridging between polymer chains by N,N'-methylenebisacrylamide -bis-AAm -molecules reaction; c) bis-AAm is added into the monomer solution to polymerize the monomers completely. One of the advantages of the polyacrylamide technique is the reproducibility of the batches for obtaining submicron size ceramic powders in large quantities.…”