According to Plastics Europe, only 18.7% of the 58.8 Mt of plastic produced in Europe in 2022 was made from recycled materials.[1] Furthermore, just 26.9% of the 32.3 Mt of plastic waste generated was successfully recycled.[1] To increase these percentages, advancements in recycling technologies and the development of virgin plastic materials and products designed for recyclability are essential.
This study explored the potential for mechanically recycling post-industrial waste (PIW) high-impact polyamide 6,6 (HI-PA 6,6) in natural and red colors. It examined different suppliers of virgin HI-PA 6,6 (S1 and S2) and various red-colored masterbatches (MB1 and MB2), either alone or in combination. To assess the recyclability of these materials, comparisons were made between samples processed once and those processed ten times for each composition, by analyzing their color, thermal, and rheological properties.
Overall, color darkening and a combination of chain scission and crosslinking phenomena, typical of the thermo-oxidative degradation of PA 6,6,[2] were observed in all compositions. However, both color changes and molecular chain variations were more pronounced in the presence of red-colored masterbatches and were affected differently depending on the specific pairing of supplier and masterbatch. This demonstrates that the composition of the masterbatch, as well as its pairing with a specific supplier, is crucial in designing recyclable plastic.