Abstract
Solvates of sulfathiazole with acetone, 2-butanone, 2-pentanone and dioxane were isolated, and their physico-chemical properties were investigated by infrared spectroscopy, X-ray powder diffractometry, differential scanning calorimetry (DSC), thermogravimetry and scanning electron microscopy. The process of desolvation was observed thermo-microscopically and the specific surface areas of the desolvated products were measured by the BET method. The combining ratios of all the solvates were determined to be 1 : 1 from the weight descrease in the thermogravimetric curves. The DSC measurements and the visual observations revealed that these solvates belong to the class of compounds with incongruent melting points. The kinetic analysis of the isothermal desolvation showed that the desolvation proceeded in accordance with the mechanism of random nucleation and two-dimensional crystal growth as represented by the Avrami-Erofeev equation. The effects of desolvating conditions and the molecular volume of the solvent on the particle size and the surface appearance of recovered sulfathiazole were examined in detail.
