The effects of unmodified vermiculite on photooxidation of polyamide 11 nanocomposites under accelerated UV test

Abstract

The effects of unmodified vermiculite (UMVC) clay on the photooxidation of polyamide 11 (PA11) were investigated by accelerated UV test up to 600 h. The clay was incorporated to the polymer at a content ratio of 5 wt. %. The film samples were prepared by melt compounding using cast extrusion process. The study showed that accelerated photo-oxidation induced changes in the chemical structure of both PA11 and PA11 nanocomposite resulting in the formation of imides and carboxylic acids as the main carbonyl products. Furthermore, the carbonyl index increased linearly in the first 360 h of exposure indicating a fast oxidation process before decreasing. The stability of the irradiated samples was also evaluated by the onset oxidation temperature (OOT) determined by DSC and the results corroborated well those obtained by FTIR spectroscopy.