Prediction of the variation of PGA strength during hydrolysis by a combination of empirical equation, density functional theory calculation, and molecular dynamics simulation

The strength variation of polyglycolic acid (PGA) during the hydrolysis process was predicted by the Flory-Fox model with all required parameters obtained by the theoretical approach. The density functional theory (DFT) calculation with the simple transition theory was used to derive the degradation rate constants of PGA intermediate at different temperatures and external load. The ultimate strength of PGA with infinite chain length, can be obtained by linearly extrapolating the ultimate strengths of three PGA materials with shorter chains. Although this Flory-Fox model formula combined with DFT calculation and MD simulation can only provide a qualitative comparison to those by experimental approaches, the current theoretical approach can provide an economical and quick way to assess the variation of PGA ultimate strength during hydrolysis.