Journal of the American Ceramic Society, Vol.98, No.1, 71-77, 2015
Synthesis of Biopolymer-Derived Zirconium Carbide Powder by Facile One-Pot Reaction
Zirconium carbide (ZrC) was synthesized by polycondensation and carbothermal reduction reactions from an organic-inorganic hybrid complex. A natural biopolymer Gum Karaya (GK) and zirconyl oxychloride octahydrate (ZOO) were used as the sources of carbon and zirconium, respectively. FTIR of as-synthesized dried complexes revealed formation of Zr-O. Pyrolysis of the complexes at 1200 degrees C/1h under argon resulted in tetragonal and monoclinic zirconia which after heat treatment at 1400 degrees C-1550 degrees C transformed to zirconium carbide. Thermal analysis shows that the GK-ZOO complexes lost less mass than the pristine GK to 600 degrees C. The intensity of exothermic decomposition decreases and shifted to higher temperature for the hybrid complexes indicating that zirconia induced thermal stability. A maximum ZrC yield of similar to 60wt% is obtained for the intermediate GK-ZOO ratio of 1:2. Particles pyrolyzed for 1h at 1550 degrees C were coarser (5-10m) with flakes for lower GK-ZOO weight ratio, but were spheroidal with narrow size distribution (similar to 1m) with increasing GK-ZOO weight ratio.