Post-yield Fracture Mechanics as a Measure of the Degradation of Artificially Aged Biodegradable Mulch Films

An accelerated approach to assess the long-term performance of biodegradable agriculture films such as mulch films based on poly(butyrate adipate terephthalate) (PBAT) is presented. PBAT films were aged in water and in air at 80 °C for different times and morphological changes were analysed using Fourier-transform infrared spectroscopy and light microscopy. For exposure in air a Xenon-arc test chamber was applied. The essential work of fracture concept was used to determine the resistance against crack initiation and propagation as a measure of the degree of degradation. Only at wet conditions as in real applications the films degrade easily. Thus, the films can break in increasingly small parts to become a part of the ground.