Solubility of 1,3,5,7-tetra azatricyclo[3.3.1.13,7]decane (HMT) in water from 275.15 K to 313.15 K

The water solubility of 1,3,5,7-tetra azatricyclo[3.3.1.13,7]decane, hexamethylenetetramine (HMT) or urotropine was determined at temperatures between 275.15 K and 313.15 K. Van’t Hoff graphs of ln msat versus 1/T gave three different straight lines, suggesting the existence of three different forms of the substance in the temperature region studied. Previous work reported both increasing and decreasing solubility with temperature. This work found the solubility does not have a simple behavior.