Investigating thermomechanical recycling of poly(ethylene terephthalate) containing phosphorus flame retardants

Poly(ethylene terephthalate) (PET) has wide usage in packaging and fiber industries thanks to its superior mechanical, thermal, barrier properties. It is also one of the "big five" recyclable plastics with well-established procedures. In many textile film products, flame retardants (FRs) are added PET for fire-safe applications. However, PET/FR products often not designed recycling, downgrade during thermomechanical recycling due polymer degradation. To address this issue, we study behavior containing phosphorus FRs after recycling. Two FRs, namely DOPO-PEPA (DP) Aflammit PCO 900 (AF), by extrusion. The compounds then studied a comprehensive set rheological, chemical experiments investigate their thermo-oxidative, thermo-mechanical degradation mechanisms. results indicate high potential DP add enhanced lubrication, control melt rheology over long periods stabilization. On other hand, AF can boost chain extensions branching PET, which counter scissions some extent. A mechanism proposed suggesting that both release active radicals moieties either quench such as oxygen radicals, or initiate reaction chains leading and/or branching. Finally, process simulated reprocessing extrusion injection molding. mechanical performance before tensile experiments. PET/DP samples preserve ductile whereas PET/AF become completely brittle. This work motivates future research on synthesis new based mixed characteristics improved recyclability products.