Thermal degradation of poly(ε-caprolactone), poly(L-lactic acid) and their blends with poly(3-hydroxy-butyrate) studied by TGA/FT-IR spectroscopy

The thermal degradation behavior of poly(epsilon-caprolactone) (PCL) and poly(L-lactic acid) (PLA) have been studied in different environment. it was found that these polymers undergo completely different degradation processes in nitrogen and oxygen atmosphere. In oxygen environment PCL and PLA mainly decompose to CO2, CO, water and short-chain acids. In nitrogen atmosphere PCL releases 5-hexenioc acid, CO2, CO and epsilon-caprolactone, whereas PLA decomposes to acetaldehyde, CO2, CO and lactide. The polymer blends of poly(3-hydroxybutyrate) (PHB) with PCL and PLA decompose similar to the individual homopolymers with crotonic acid as the initial decomposition product of PHB.