Gelation process in low-toxic gelcasting systems

Gelcasting has been recognized as a very high-potential method in fabricating complex three-dimensional ceramic parts. The main component of the original gelcasting system (i.e. acrylamide) is a neurotoxic and industry is reluctant to use gelcasting instead of the other ceramic forming methods. Hence, developing of gelcasting systems with similar or superior properties to the original system and low toxicity is required. In this study, gelation kinetics of acrylic acid-based system as a low-toxic gelcasting system were investigated and compared with the original acrylamide-based system, using the Taguchi statistical method. Statistical analysis showed that in both of the gelcasting systems, initiator and accelerator concentrations had the strongest effects on the gelation behaviour. Also, monofunctional monomers had the same effects on the gelation behaviour in both of the gelcasting systems. Between the rest variables (ceramic loading level and crosslinker concentration) a counter interacting term existed which caused to weak the pure effects of these variables on the gelation behaviour of gelcasting systems. In the acrylic acid-based system, unlike the original one, the precise monitoring of the idle time was possible. In this system, in spite of very low activity in the gelcasting process all of the undesirable neurotoxic effects of the original gelcasting system were omitted. (c) 2005 Elsevier Ltd. All rights reserved.