Progress in Crystal Growth and Characterization PERGAMON Progress in Crystal Growth and Characterization of Materials (2002) 1-7 of Materials http:l/www.elsevier.comllocatelpcrysgrow Coprecipitation of mixture of CuO and Al203 through NaNOj -KNOJ eutectic mixture and its catalytic activity during the decomposition of Hydroxy terminated poly-butadiene (HTPB) zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJI BY N.B. Sit@* and A.K. Ojha Department of Chemistry, D.D.U. Gorakhpur University, Gorakhpur - 273 009 India Abstract When a mixture of copper sulphate and aluminium sulphate in 1:l molar ratio was heated in NaNOa - KNOa eutectic mixture, a mixture of CuO and Al203 was precipitated. The formation of this mixture was confirmed by powder X-ray diffraction technique. This mixture was found to be a very effective catalyst for the decomposition of hydroxy terminated polybutadiene (HTPB). Key Words: Coprecipitation, Decomposition, Copper sulphate, Aluminum Sulphate and Catalyst 1. Introduction Metal oxides are extensively used as catalysts in number of chemical reactions. However, the catalytic properties depend very much on the nature and surface area of the catalysts. Surface area depends on the method of preparation. There are various methods for the preparation of catalytic materials. It has been reported that when metal salts are heated in nitrate eutectic melts, metal oxides are precipitated comparatively at lower temperatures’-’ and hence are expected to have higher surface area. So far it has not been reported that two metal oxides can be coprecipitated through nitrate eutectic melt. In this paper CuO and Al203 have been coprecipitated through NaNOa - KNO3 eutectic melt and the catalytic property of the mixture of the two oxides has been studied for the degradation of HTPB. 2. Experimental 2.1 Materials and Methods HTPB resin was obtained from (VSCC, Thiruvananthpuram) Isophorone diisocynate (IPDI). (Pluka AG), NaNOa, KNOa, CUSO~SH~O and Alz(SO&. 18HzO all from Qualigenes were used. (1) Preparation of eutectic mixture Dried samples of sodium nitrate and potassium nitrate were mixed in 45 : 55 percent ratio (wt %) in a clean test tube. The mouth of the test tube containing the nitrate mixture was sealed and kept in a furnace at a temperature slightly higher than the melting points of the components. When the entire mass melted, the molten liquid was quenched suddenly to room temperature. The process of heating and cooling was repeated several times and ultimately the solidified material was removed from the test tube and crushed into fine powder. This was carried out to produce a homogeneous mixture of the two components. The melting point of the eutectic mixture was found to be 226’C. 0960-8974/02/$ - see front matter 0 2002 Published by Elsevier Science Ltd. PII: SO960-8974(02)00020-7