Synthesis of resins as alpha-alumina precursors by the Pechini method using microwave and infrared heating

• Published in: Journal of the European Ceramic Society Vol. 22; no. 16; pp. 2861 - 2868
• Main Authors: HERNANDEZ, M. T, GONZALEZ, M
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.12.2002; Elsevier
• Subjects: Al 2O 3; Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Chemical industry and chemicals; Exact sciences and technology; Microwave heating; Miscellaneous; Pechini method; Precursors-organic; Technical ceramics; Precursors-organic; Microwave heating; Pechini method; Al 2O 3; Thermogravimetry; Differential thermal analysis; Infrared radiation heating; Experimental study; X ray diffraction; Precursor; Oxide ceramics; Powder; Infrared spectrometry; Chemical preparation; Manufacturing; Microstructure; Alumina
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/S0955-2219(02)00040-7

A polymeric method based on the Pechini process was successfully used to synthesize alpha-alumina. Different resins have been prepared in order to compare the effect of the heating source (microwave or conventional IR radiation) during the polyesterification reaction, the importance of the starting aluminium salt and the ratios between reactants. The resin precursor and the product powders were fully characterized in order to investigate the polymer decomposition and the characteristic of the resulting alumina. It is concluded that the control of the ethylene glycol to citric acid ratio is important to obtain weak agglomerated particles, which are required to achieve soft porous precursors. Comparing with a conventional infrared source, the 2.45 GHz-microwave heating reduces the polyesterification reaction time to a great extent followed by a solid polymeric resin formation; however, the reaction mechanisms do not change. The best final alumina powder was synthesised by applying the microwave radiation to a precursor resin obtained from the thermal reaction of the aluminium lactate with small amounts of ethylene glycol as the polymerizant agent.