Authors: Ignazio Blanco
Publish Date: 2014/04/30
Volume: 32, Issue: 6, Pages: 681-689
Abstract
A longterm about nine months isothermal degradation experiment of two different commercial polylactide PLA samples used for food packaging was carried out at a relatively low temperature 423 K Thermooxidative degradations of the same polymers were carried out in a thermogravimetric TG analyser at higher temperatures 453 K ≤ T ≤ 523 K under isothermal heating conditions The obtained set of experimental TG data was used to determine the apparent activation energy E a of degradation through two isothermal kinetic methods The results from longterm experiment evidenced considerable mass loss for both PLA samples in the investigated period but the experimental data were not in agreement with those from the shortterm degradations at higher temperatures thus suggesting a different degradation kinetics and then a low reliability of the lifetime predictions for polymers in service or degradation forecasts for the end of their life based on experiments at higher temperatures
Keywords: