Abstract
Adduct formation with NH3 was confirmed with 6 sulfonamides (sulfadimethoxine, sulfamethoxazole, sulfanilamide, sulfaphenazole, sulfisomidine, and sulfisoxazole). The thermal and physico-chemical properties of these adducts were investigated by differential scanning calorimetry, thermogravimetry, X-ray powder diffractometry, infrared spectroscopy, and scanning electron microscopy. It was found that one, two or even three kinds of NH3 adducts were formed by the above sulfonamides. When the specific surface areas of the sulfonamides recovered by desorbing NH3 from the adducts were measured by a gas adsorption (BET) method, their particle sizes were found to have been effectively reduced. In addition, variations often found in the DSC and TG curves of these adducts are discussed.
