Solubility Determination and Modeling Analysis of exo-3,6-Epoxy-1,2,3,6-tetrahydrophthalic Anhydride in Mixture Solvents from 278.15 to 323.15 K

Abstract

In this work, solubility of exo-3,6-epoxy-1,2,3,6-tetrahydrophthalic anhydride (ETA) was measured and discussed in acetone + ethanol, methyl acetate + ethanol, 1,4-dioxane + ethanol, and ethyl acetate + ethanol mixture solvents in a temperature range from 278.15 to 323.15 K by a gravimetric method under 0.1 MPa. Experimental results indicated that solubility increased with temperature increasing and declined with the mass fraction increasing of ethanol in four kinds of mixture solvents. The solvent effect and Hansen solubility parameter were adopted to discuss the solubility behavior of ETA in selected solvents. Modeling correlation solubility data about ETA indicated that the Jouyban–Acree–Apelblat model (J–A–A) was more suitable than the Jouyban–Acree–Van’t Hoff model (J–A–V) and Ma and Sun model in mixture solvents. Processing of the dilution crystallization in acetone + ethanol system was chosen to separate and purify ETA on the basis of the solubility and solvent characteristics.

Solubility Measurement and Model Correlating of 6-Propyl-2-Thiouracil in Four Binary Solvents at 278.15–323.15 K

“…The solubility data of 6-propyl-2-thiouracil in DMF mixture solvents was investigated by a gravimetric method based on previous work and the literature ,, from 278.15 to 323.15 K at intervals of 5 K. Excess 6-propyl-2-thiouracil and solvent were added to a double-jacketed glass container (120 cm 3 ). The glass container was connected to a constant-temperature water bath instrument (Shanghai Bilon Instrument Co., Ltd., China, T = ±0.05 K) and was equipped with an electromagnetic stirrer.…”

“…The Van′t Hoff model can be expressed by a simplified formula and is considered the ideal model when the activity coefficient of the solution is an approximate value. − This model shows the linear relationship between the solubility data and temperature. a and b represent the model parameters in eq . …”

“…The technology of powder X-ray diffraction was employed to judge the phenomenon of crystal transformation. The experimental solubility was correlated by thermodynamic models such as the modified Apelblat model, − λh model − Van′t Hoff model, − and Jouyban Acree–Apelblat model − for predicting the dissolution state in a wider temperature range.…”