Hydro-Thermal Degradation: A New and Rapid Method for Evaluating the Bio-degradation Performance of Poly(lactic acid)

In order to evaluate the bio-degradation performance of different kinds of poly(lactic acid) (PLA) rapidly, a new method, called hydro-thermal degradation was developed. Four kinds of commercial grade PLA were analyzed by both bio-degradation and hydro-thermal degradation with their degradation performance investigated via weight loss (%), infrared spectra (IR), size-exclusion chromatography (SEC), and X‑ray diffraction measurements (XRD). The experimental results showed that the bio-degradation performance, which would take several years to degrade totally, could degrade in a short time (2 h) at 170°C by the hydro-thermal degradation. The order of the degradation rate is Revode101 > Revode210 > Revode190 > Revode290, corresponding with the structure characteristics of them. Thus, this new method provides a simple and effective way to degrade the PLA rapidly and to evaluate its bio-degradation performance.