Study On Solid-liquid Equilibrium Of Pentaerythritol And Dipentaerythritol

Pentaerythritol(PE) and dipentaerythritol(DPE) are both important finechemical materials, and PE and DPE of high-purity even can provide higher addedvalue. The study of solid-liquid equilibrium of PE and DPE is very significant fortheir separation and purification. In this paper, the solid-liquid equilibrium of PE andDPE was researched.In this article, the solubility of PE and DPE in dimethyl sulfoxide, N,N-dimethylformamide and methanol+water, ethanol+water, isopropanol+water,acetone+water within certain temperature range were measured by dynamic methodusing e laser monitoring observation technique.The experimental data were correlated by the λh equation, two-parameterequation and three-parameter equation, and the parameters of these equations wereobtained. The total average absolute deviation of these systems are2.90%,2.59%,1.61%respectively. The solubility of PE and DPE in solvents calculated by thethree-parameter equation was discussed. The standard enthalpy and standard entropyof PE and DPE in solvents were calculated.0solH＞0indicates that the break ofassociation bond between solvent molecules is dominant in the dissolved processand this leads to a endothermic process. S0sol＞0indicates that the array of solventmolecules was disturbed during the dissolution of PE and DPE and randomnessincreases. The dissolution processes of PE and DPE in the studied systems areentropy-driven processes.The results of this work can enrich the basic research of chemical engineeringand provide a theoretical and practical value for separation and purification of PEand DPE.