Solubilities of Hexaphenoxycyclotriphosphazene and Tri(2-cyanoethyl)phosphine in Selected Solvents: Measurement and Correlation

Solubilities of hexaphenoxycyclotriphosphazene and tri(2-cyanoethyl)phosphine in selected solvents were measured in this work using a static analytical method. The solubilities of a series of phosphorus-containing flame retardants in organic solvents and water were recently measured in our laboratory. Based on these data and the solid-liquid equilibrium equation for the solute, the activity coefficients of these flame retardants were derived in pure solvents. The Scatchard-Hildebrand activity coefficient model was used to correlate these activity coefficients and the solubility parameters of the solutes were obtained. With the help of the analysis of the solubility parameters for the solute and solvents, solubility enhancement can be achieved due to the occurrence of the synergetic effect of the mixed solvent.