Self-nucleation (SN) and successive self-nucleation and annealing (SSA) as powerful tools to determine the composition of polyolefin post-consumer recycled blends

Abstract

AbstractFor the incorporation of post-consumer recycled (PCR) resins in mechanical recycling processes, it is crucial to determine their composition accurately. The blends of linear low-density polyethylene (LLDPE) and low-density polyethylene (LDPE) in PCR film resins pose a challenge due to their varying ratios. This study introduces a quantitative method that employs the successive self-nucleation and annealing (SSA) technique to analyze commercial PCR LLDPE/LDPE blend compositions. Our method is an efficient way to assess these blend compositions, offering an improved analysis compared with traditional methods. We established a series of calibration curves based on the SSA final melting trace to validate our approach. The SSA technique's efficacy was compared with the robust NMR method, showing that SSA can predict LLDPE contents in the blends with comparable accuracy. We demonstrate that the SSA methodology is an accurate and reliable technique for assessing complex waste streams, thereby facilitating the optimization of recycling processes and advancing the goals of sustainable materials management.