Thermodynamic Study and Experimental Verification on the Product Distribution of the Synthesis of Dipropylene Glycol from Propylene Oxide and Propylene Glycol

By designing isodesmic reactions and combining the results of thermodynamic calculations, the and for the isomers of DPG are obtained, and the relative error is less than 7%. The results show that in the process of preparing DPG by PO and PG, when PO: PG = 1, the reaction temperature ranges from 298.15 K to 413.15 K, and the pressure ranges from 101.325 kPa to 506.325 kPa, the reactions of and are thermodynamically spontaneous.

While the reactions of and are thermodynamically unspontaneous. The optimal reaction temperature and pressure are 413.15 K and 101.325 kPa. The thermodynamic stability of the three isomers is DPG1>DPG2>DPG3 under standard conditions. The accuracy of the computational results is verified through experimental design, and based on this, the factors affecting product distribution are analyzed.