Characterization of potential thermal degradation products from the reactions of aqueous ethylene glycol and propylene glycol solutions with copper metal

Abstract

Aqueous solutions of ethylene glycol and propylene glycol are common heat transfer fluids for solar collector systems. Thermal oxidative degradation produces organic acids which, in turn, generate copper salts through reaction with copper containment systems. Copper (II) salts of the organic acids which may be generated as the result of the degradation of the ethylene glycol and propylene glycol were prepared by reacting aqueous solutions of the acids with copper (II) carbonate. Infrared spectra and X-ray diffraction peak spacings and intensities are presented for the salts. These spectra may be useful in analyzing the servive performance of heat transfer fluids used in solar collector systems. © 1987.