Monosaccharides derivatives in gelcasting of ceramic powders
|Mikolaj Szafran , Paulina Bednarek , Tadeusz Mizerski|
Warsaw University of Technology, Faculty of Chemistry, Noakowskiego 3, Warszawa 00-664, Poland
High-quality, complex-shaped ceramic elements can be obtained by moulding techniques based on colloidal processes. Among these methods we can distinguish gelcasting, the method in which by means of an in situ polymerization, a macromolecular network is created to hold ceramic particles together. The key role in the process plays the suitable selections of an organic monomer which should be water soluble, cannot negatively influence rheological properties of ceramic slurry and must provide high mechanical strength of received green bodies. The monomer, which fulfils these requirements is acrylamide, but this compound is hazardous, and has probably cancerogenic action. In recent time acrylamide was replaced by other substances, e.g. 2-hydroxyethyl acrylate but the properties of received samples were not satisfactory. That is why new low-toxic monomers are still needful.
The interesting alternative for acrylic monomers can be compounds obtained on the basis on monosaccharides. Saccharides are water-soluble, non-toxic and due to the presence of many hydroxyl groups in a molecule, hydrogen bonds in a polymer network can be formed. As a result a cross-linked polymer network is received without adding any external cross-linking agent and obtained ceramic element is rigid enough. This fact allows reducing the quantity of added organic substances to the ceramic slurry.
The authors have synthesized monomers on the basis on glucose and fructose. One hydroxyl group in a molecule has been replaced by an acrylic group with double bond between carbons. Due to the presence of the double bond in a molecule, the compound after adding an initiator ia able to polymerize in a ceramic slurry. The monomers on the basis on monosaccharides are first of all environment friendly and can also provide high mechanical strength of received elements in the green state.
This work was partially financially supported by Faculty of Chemistry Warsaw University of Technology: Project no. 504G/1020/0787
Presentation: Oral at E-MRS Fall Meeting 2008, Symposium I, by Paulina Bednarek
See On-line Journal of E-MRS Fall Meeting 2008
Submitted: 2008-06-29 23:58 Revised: 2009-06-07 00:48
|© 1998-2021 pielaszek research, all rights reserved||Powered by the Conference Engine|