Evaluation of PET recyclability and characterization of modified reprocessed‐PET for industrial application

Abstract Polyethylene terephthalate (PET) is used in a variety of packaging applications, such as bottles, films, fibers, for its cost‐effective and excellent physical properties. However, the increase in plastic usage and packaging waste has become major global problems. Therefore, the importance of plastic recycling is being emphasized. In this study, the bottle‐grade PET was repeatedly melt processed up to three times to evaluate of PET recyclability. Intrinsic viscosity (IV) and mechanical properties have significantly decreased due to chain scission during the melt reprocessing. In particular, the IV of 3rP (reprocessing three times) decreased to 0.582 dL/g, and the mechanical properties decreased more than twice compared with 0rP. To enhance the physical properties of reprocessed PET (rP‐PET), it was modified using two chain extenders. The IV of the modified 3rP‐PET increased from 0.645 to 0.737 dL/g. And the tensile strength was improved up to approximately 93% of the 0rP properties, confirming the chain extension effect. Additionally, a biaxial orientation process was applied to confirm the feasibility of modified rP‐PET to various industrial packaging applications. Consequently, as the stretching ratio increased, the physical properties of modified rP‐PET improved, confirming the feasibility of rP‐PET in various packaging fields.