25℃时MgCl_2-H_2O-酰胺(DMA,DMF,FA)三元体系的相平衡

Phase Equilibria of MgCl_2-H_2O-Amides (DMF, DMA, FA) Systems at 25℃

本文报道三元体系MgCl_2-H_2O-DMA(Ⅰ),MgCl_2-H_2O-DMF(Ⅱ)和MgCl_2-H_2O-FA(Ⅲ)25℃时的溶解度与饱和溶液的折光率、密度和粘度等物理化学性质,给出了这些体系的溶度图和性质图,其中体系Ⅰ和Ⅲ属首次报道,体系Ⅱ的结果能较好地解释文献中存在的分歧。

The solubllities of MgCl_2 in three ternary system MgCl_2-H_2O-DMA (Ⅰ), MgCl_2-H_2O-DMF(Ⅱ) and MgCl_2-H_2O-FA(Ⅲ) bare been studied isothormally and the refractive indices, densities and viscosities of thier saturated solutions have been measured at 25℃. The results indicate that: (ⅰ) there are two solid phases containing amide, MgCl_2.6H_2O. 2DMA and MgCl_2.4DMA observed in the system Ⅰ; (ⅱ) in system Ⅱ three stable solid phases, MgCl_2.6H_2O. 2DMF,MgCl_2. 2H_2O. 4 DMF and MgCl_2. 4 DMF are formed, whichis in agreement with the results obtained by Emons, and a new metable solid phase, MgCl_2. 5H_2O.DMF was observed; (ⅲ) in system Ⅲ MgCl_2.2H_2O.4FA, MgCl_2.6FA and MgCl_2. 8FA are formed but no metastable state occurs. The phase diagrams of these system at 25℃ are given and the data of solubilities, properties of liquid phase are tabulated.