Recycling of Mixed Plastic Waste and Nylon-Based Multilayer Plastic Films Via Solvent-Targeted Recovery and Precipitation (STRAP)

Anisha Sharma¹, Kevin Sánchez-Rivera², George W. Huber²

¹University of Illinois at Urbana-Champaign

²University of Wisconsin-Madison

Plastic waste is a growing concern due to its harmful effects on human health, animals, and the environment. A large obstacle in plastic waste management is that of mixed plastic waste streams. Traditional modes of recycling (mechanical and chemical) cannot easily separate out mixed plastics or polymer components from the same material. Solvent-Targeted Recovery and Precipitation (STRAP) is a process wherein polymers are dissolved in a solvent that is selective towards only one of the polymer components ^[1,2]. That dissolved polymer is then recovered via a temperature change and/or introduction of an antisolvent, along with mechanical filtration. Here, we report a method for employing STRAP to selectively recover 8 different polymers from post-industrial mixed plastic waste as well as 3 different polymers from multilayer nylon films. Using a polymer solubility database, the proper solvents and conditions were determined to successfully separate three nylons from each other as well as polypropylene and high-density polyethylene. ATR-FTIR spectroscopy confirms that the targeted polymers are recovered and are chemically similar to the pure resins. Mass balance calculations indicate high recovered polymer yields for both the post-industrial mixed waste and nylon films.

[1] K. L. Sánchez-Rivera, P. Zhou, M. Kim, L. D. González Chávez, S. Grey, K. Nelson, S. Wang, I. Hermans, V. M. Zavala, R. C. V. Lehn, G. W. Huber. ChemSusChem 2021, 14, 4317–4329.

[2] T. W. Walker, N. Frelka, Z. Shen, A. K. Chew, J. Banick, S. Grey, J. A., Dumesic, R. C. V. Lehn, G. W. Huber, Sci. Adv. 2020, 6 (47), eaba7599.