Spectrochemical Study on the Thermal History of Fatty-Acid Aluminum Salts

Abstract

The chemistry of fatty-acid aluminum salts, particularly stearates, was studied in polypropylene, liquid hydrocarbons, and fluorocarbons. Heating results in a series of related events. The distearate carboxylate coordination bonds are altered from crosslinked to intramolecular, and the Al—O—Al bond is weakened or broken. Stearic acid, which is formed as the aluminum distearate decomposes, changes rapidly from the dimer to the less stable monomer form, with a heat of conversion of 4.9 kcal/mole. The conversion of stearic acid dimer to monomer is unaffected by the presence of the aluminum coordination bonds.