Low Temperature Solid-State Zinc Borate Synthesis from ZnO and H3BO3

Zinc borates can be used as multi-functional synergistic additives with flame retardant additives in polymers. Zinc borate is white, non-hygroscopic and powder type product. The most important properties are low solubility in water and high dehydration temperature. Zinc borates dehydrate above 290°C and anhydrous zinc borate has thermal resistance about 400°C. Zinc borates can be synthesized using several methods such as hydrothermal and solidstate processes. In this study, the solid-state method was applied at low temperatures of 600oC and 700oC using the starting materials of ZnO and H3BO3 with several mole ratios. The reaction time was determined as 4 hours after some preliminary experiments. After the synthesis, the crystal structure and the morphology of the products were examined by X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). As a result the forms of ZnB4O7, Zn3(BO3)2, ZnB2O4 were synthesized and obtained along with the unreacted ZnO.

Authors:

• A. S. Kipcak
• N. Baran Acarali
• E. Moroydor Derun
• N. Tugrul
• S. Piskin

Keywords:

• FT-IR
• solid-state method
• zinc borate
• XRD.

References:

[1] M. Gonen, D. Balkose, R. B. Gupta, and S. Ulku, "Super critical
carbondioxide drying of methanol zinc borate mixtures", Ind. Eng.
Chem. Res.,vol. 48, pp. 6869-6876, 2009.
[2] C. Ting, D. Jian-Cheng, W. Long-Shuo, and F. Gang, "Preparation and
characterization of nano-zinc borate by a new method", J. Mater.
Process. Tech., vol. 209, pp. 4076-4079, 2009.
[3] D. G├╝rhan, G. ├û. ├çakal, ─É. Ero─ƒlu, and S. ├ûzkar, Kesikli reaktörde ├ºinko
borat ├╝retimini etkileyen parametrelerin incelenmesi, 1. National Boron
Workshop Symposium Book, April 28-29, Ankara, 2005.
[4] D. Schubert, F. Alam, M. Visi and C. Knobler, "Structural
characterization and chemistry of the industrially important zinc borate
Zn[B3O4(OH)3]", Chem. Mater., vol. 15, pp. 866-871, 2002.
[5] H. E. Eltepe, D. Balköse, and S. ├£lk├╝, "Effect of temperature and time
on zinc borate species formed from zinc oxide and boric acid in aqueous
medium", Ind. Eng. Chem. Res., vol. 46, pp. 2367-2371, 2007.
[6] A. V. Shete, S. B. Sawant, and V. G. Pangarkar, "Kinetics of fluid-solid
reaction with an insoluble product: zinc borate by the reaction of boric
acid and zinc oxide", J. Chem. Technol. Biot., vol. 79, pp. 526-532,
2004.
[7] X. Shi, Y. Xiao, M. Li, L. Yuan, and J. Sun, "Synthesis of an
industrially important zinc borate, 2ZnO┬À3B2O3┬À3H2O, by a rheological
phase reaction method" Powder Technol., vol. 186,pp. 263-266, 2008.
[8] H. Igarashi, H. Sawada, A. Tatebe, and K.Sakao, Patent No: 6780913,
U.S.A., 2002.