Mechanical and fracture properties of poly(ethylene terephthalate) with glycol/carbon nanotube nanocomposite films under accelerated weathering conditions

In this study, we developed a nanocomposite with one of the most popular engineering thermoplastics, i.e., poly(ethylene terephthalate) with glycol (PETG), and multi-walled carbon nanotubes (CNT). Commercial PETG pellets were extruded into 50-μm thick films with and without 1.0 and 2.0 weight percentages (wt%) of CNT. PETG films and PETG, CNT nanocomposite films were artificially degraded in a customized ultraviolet (UV) weathering apparatus with UV radiance for a certain temperature. They were analyzed in three stages. In the first stage, we attempted to quantify the effect of the accelerated weathering via ultraviolet-visible spectroscopy (UV-Vis) and x-ray photoelectron spectroscopy analyses (XPS). In the second stage, mechanical and fracture characteristics were examined by tensile tests and essential work of fracture (EWF) tests. Finally, fracture surfaces of PETG films and PETG, CNT nanocomposite films were observed via scanning electron microscope (SEM) images.