Synthetic Design of Polyester Electrolytes Guided by Hydrophobicity Calculations

Partition coefficients (LogP) help to quantify hydrophobicity, which can be used to guide the design of polymer electrolytes with targeted properties. Thus, this study combined synthetic experiments and molecular modeling to produce polyester electrolytes that solubilize lithium salts. These polyester electrolytes were derived from natural sources and polymerized with different ratios of polyols (diglycerol, glycerol, and diethylene glycol) and citric acid in the presence of lithium salts (LiTf and LiTFSI). The Fisher esterification produced homogeneous, cross-linked films with high optical transparency, whereas the lithium salts increased glass transition temperatures. The LogP values of monomers and the resulting polyesters were predicted using cheminformatics tools and indicate changing diglycerol to glycerol or diethylene glycol alters the hydrophobicity. Comparison of different molecular modeling methods with predicted LogP values demonstrate that LogP values are a reliable means of tailoring physical and chemical properties of these polymer electrolytes. Additionally, LogP values greatly benefit from being extremely less expensive from a computational standpoint as well as more convenient for calculating precursory quantitative information.