DSC determination of partial ternary phase diagrams of methanol/sodium chloride/water and propylene glycol/sodium chloride/water and their applications for synthesized diagrams

The present study presents partial ternary phase diagrams of methanol/sodium chloride/water and propylene glycol/sodium chloride/water systems with compositions of cryobiological interests (R < 20 and x < 30) by means of differential scanning calorimeter. To synthesize the ternary phase diagram through its relevant binary ones, the partial binary phase diagrams of methanol and propylene glycol aqueous solutions are experimentally determined as well. Ultimately, the equations characterizing the liquid surface of these two kinds of alcohol ternary systems are obtained and the polynomial representations for binary phase diagrams of methanol and propylene glycol aqueous solutions are also published in this study. The results show an excellent agreement between the experimental and synthesized data (less than ±2.5 °C) of these ternary systems. These results will enrich our understanding on the protection mechanism of these two cryoprotectants, as well as providing new evidences of the feasibility of synthesizing ternary phase diagrams of cryobiological interests.