Polymorphism of crystalline phases of calcium stearate

The structures of the low temperature (T⩽400 K) phases of calcium stearate have been investigated by X-ray diffraction. Several forms are shown to exist at room temperature, depending on hydration and thermal treatment. New transitions at cryogenic temperatures are discussed. Transitions at higher temperatures have been investigated together with their reversibility. Thermogravimetry and two calorimetric techniques have been used as a complement. This data completes the already somewhat complex picture of the phase transitions of calcium stearate.