Preparation and thermal decomposition of various forms of strontium oxalate

Article abstract of DOI:10.1016/0040-6031(96)02863-8

Strontium oxalate exists in two different forms: the neutral strontium oxalate hydrate, SrC₂O₄·xH₂O, and the acid salt of strontium oxalate, SrC₂O₄·yH₂C₂O ₄·xH₂O. Depending on the concentration of oxalic acid and ammonium oxalate as precipitating agents, both forms can be obtained. At a sufficiently low pH, the stoichiometric compound SrC₂O₄·1/2H₂C₂O ₄·H₂O is formed. The thermal decomposition of the different strontium oxalates is studied in different atmospheres using DSC, and TGA coupled with FTIR and MS. The TGA-EGA spectra indicate that the anhydrous acid oxalate decomposes with the release of H₂O, CO, CO₂ and formic acid.