A Review of Additive Usage in Polymer Manufacturing: Case Study Phenolic Antioxidants

Abstract The March 2, 2022, United Nations Resolution 5/14: “End plastic pollution: Towards a legally binding instrument” by 2024 provides an important path forward for addressing global plastic pollution, beginning with monomer design and production through the value chain to the final fate of plastic products, including resource recovery. Of the many goals set for this effort, simplifying the polymer and additive universe is one of the most significant. One of the primary obstacles to resource recovery from plastic waste is the variability of the plastic universe, which renders post-use plastic inherently waste-like and virtually unrecoverable. The toxicity levels of chemical additives in plastics are a significant threat to human and ecosystem health. Another obstacle is leakage of microplastic generated during the recovery and recycling process and is now traceable in our ecosystems, our food, and even our bodies. Thus, while simplification measures will not address microplastic and leaching of chemicals during use of plastic, such as for tires, synthetic fibers and coatings, these measures simplify the plastic universe and mitigate microplastic leakage that is fundamentally critical to ensuring a circular use of plastic in our society. This study provides a proof of concept for simplification of the plastic universe through elimination of additives revealed as problematic due to unnecessary redundancy and variability, as well as persistence, bioaccumulation, and toxicity. Further, this study provides a specific focus on to revealing potential paths toward both simplifying and reducing the variability in polymers, plastic waste streams and ultimately plastic pollution, while preserving critical uses and supporting circularity. This study focuses on phenolic antioxidants to prove this concept, however, the same principles discussed and illustrated herein can be applied to other additive classes.