(493d) Fundamental Insights into Chemical Recycling of Polymer Mixtures

The rapid development of novel processes based on efficient utilization of non-traditional feedstocks which are currently considered as waste such as used plastics is crucial for a sustainable and circular economy. The scientific advancements strongly depend on the systematic and fundamental understanding of the reaction systems, which in turn leads to the successful commercialization of the processes. Plastic waste streams are typically a mixture of various types, such as vinyl polymers, e.g. polyethylene (PE), polypropylene (PP), oxygen-containing polymers, e.g. polyethylene terephthalate (PET), halogenated vinyl polymers, nitrogen-containing polymers, and elastomers, as well as additives, fillers and metals. The fundamental mechanistic understanding of interaction effects during chemical recycling of polymer mixtures is nearly non-existent in the literature except for few studies. In the first part of the presentation, I will be presenting the kinetic analysis and product speciation results obtained through a systematic study performed with single streams of vinyl polymers and heteroatom containing polymers, and their mixtures. In the second part, I will be presenting our efforts on method development for detailed characterization of complex pyrolysis oils through two-dimensional gas chromatography and its importance for development of detailed kinetic models. Finally, I will discuss future insights for chemical recycling of polymer mixtures.