Pretreatment Effects of Conventional and Reactive Extrusion on <scp>LLDPE</scp> Waste Pyrolysis

ABSTRACT Pyrolysis is a key technique for recycling polyolefin‐rich plastic waste, and extrusion has recently received attention as a promising pretreatment strategy since cascade processes can provide a globally effective solution for waste. However, the role of reactive extrusion (REX) as a pretreatment strategy to manipulate the performance of pyrolysis reactions remains largely unexplored. For this reason, the present study examines for the first time the influence of REX pretreatment on the pyrolysis of postconsumer linear low‐density polyethylene (LLDPE) under different conditions. Unlike conventional extrusion, REX can be used to actively modify the polymer matrix, directly affecting pyrolysis behavior and product characteristics. Results reveal that co‐feeding of radical initiators (peroxide or polypropylene) during REX pretreatment can affect pyrolysis rates, yields, and condensable product composition. In contrast, the composition of gaseous products remains largely unaffected by extrusion and additive incorporation. These findings highlight the potential of REX pretreatment as a tool for the design of tailored recycling strategies.