Accelerated UV/condensation weathering, outdoor weathering and influence of aged/reprocessed ratios on mechanical, rheological and morphological properties of polyamide 6 composites: Comparing glass bead and glass fiber

The usage of polymeric materials is rising, and they are exposed to the effects of light, temperature and water and their combination throughout their lifetime. The increased use of them has caused waste problems. From an environmental point of view, polymer reprocessing (recycling) is one of the good solutions to diminish waste problems. Therefore, in current research, the effect of reprocessing on the mechanical properties (tensile, impact, flexural), melt flow index and morphology was determined for aged polyamide 6 (PA6), glass bead reinforced PA6 composites with 15 and 30 wt% content and glass fiber reinforced PA6 composites with 15 and 30 wt% content. Virgin granules of PA6 and its composites were injection molded to understand the mechanical, rheological, and morphological properties. The samples were then exposed to natural weathering for up to a year in Gebze (Turkey) between August 2018 and August 2019 and artificially accelerated UV/condensation ageing for up to 336 hours in the chamber. After ageing process, naturally and UV aged specimens were ground and the ground specimens were mixed with virgin PA6 or its composites at rates of 25%, 50% and 75% by weight. The mixed polymeric materials were re-molded to manufacture test specimens, and then mechanical, rheological, and morphological properties were determined. Briefly, in current research, the mechanical, rheological, and morphological properties of virgin, aged for 12 months in outdoor environment, aged for 336 hours in UV chamber PA6 or its composites and blends of virgin-aged PA6 or its composites were studied. It was concluded that the change in mechanical and rheological properties varied according to the ageing environment and glass bead or glass fiber content. Generally, mechanical properties diminished with natural and accelerated UV/condensation ageing. But some retention in properties could be obtained with the addition of virgin polymer.