Double oxides, structures, thermal

Table 21.18 Structures, thermal data, and molar volumes of metal oxides and hydroxides, and of some double oxides ...

T1 ecent investigations have shown that chromium, manganese, cobalt, nickel, copper, and zinc oxides react with uranium oxides at elevated temperatures to form double oxides with the formulas MUO4 and MU3O10. Table I lists eight compounds for which some structural and thermal stability information has been reported. 

Thermal Oxidation of Double-Gyroid-Structured Metals... 

When the nitrato complex includes an extra cation in the structure, as in the series M2[R(N03)5] nHjO for example, the thermal decomposition scheme becomes more complex. In the case of ammonium compounds the final product, at temperatures well below 1000°C, is R2O3 (or equivalent oxide) but in the case of alkali metals stable double oxides of type MRO2 may be formed. The TG/DTG/DTA patterns for several complex nitrates have been determined by Molodkin and co-workers. 

The double bonds in the chain are the reactive centers responsible for thermal and oxidative polymerization properties of the oils. A quantitative measure of the average degree of unsaturation present in a given oil is expressed by its iodine value (IV), which increases with an increasing number of double bonds. Therefore, highly unsaturated oils having the ability to form a solid or semisolid polymeric structure by means of oxidative or thermal polymerization are invaluable for coatings. 

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