Oleochemicals I: Studies on the preparation and the structure of lithium soaps

Lithium stearate, palmitate, myristate, laurate, caprate and caprylate were prepared by means of fusion method. Elementary analysis and the infrared a bsorptions spectra of the prepared lithium soaps as well as their X-ray dif fractions and the thermogravimetric analyses were carried out. The anhydrous lithium salts of fatty acids with 12 carbon atoms or less sho wed thermal stability up to ca. 300 +/- 78 degrees C depending on the chain length. On other hand the salts with 14 carbon atoms or more were decompos ed at 126 +/- 4 degrees C leading to formation of lithium carbonate. The homologous lithium soaps had very similar crystal structure among them and their metal-to-oxygen bonds were similar for the acyl chains between 8 and 18 carbons. However the angle of inclination of the molecular axes to t he basal plane increased with the decreasing of the number of carbon atoms of the fatty acid chain, as determined by X-ray diffraction. In addition, t he ionic character of the metal-to-oxygen bond was enhanced with the decrea se of the number of carbon atoms as shown by infrared spectroscopy.