Investigation of the Influence of PLA Molecular and Supramolecular Structure on the Kinetics of Thermal-Supported Hydrolytic Degradation of Wet Spinning Fibres

In this study, differences in the kinetics of thermal-supported hydrolytic degradation of poly(lactic acid) (PLA) sample wet spinning fibres due to material variance in the initial molecular and supramolecular structure were analysed. The investigation was carried out at the microstructural and molecular levels by using readily available methods such as scanning electron microscopy, mass erosion measurement and estimation of intrinsic viscosity. The results show a varying degree of influence of the initial structure on the degradation rate of studied PLA fibres. The experiment shows that hydrolytic degradation at a temperature close to the cold crystallization temperature on a macroscopic level is definitely more rapid for the amorphous material, while on a molecular scale it is similar to a semi-crystalline material. Further, for the adopted degradation temperature of 90 °C, a marginal influence of pH of the degradation medium on the degradation kinetics was also demonstrated