An estimated 6.3 billion metric tons of post-consumer polymer waste has been produced, with the majority (79%) in landfills or the environment. Recycling methods that utilize these waste polymers could attenuate their environmental impact. For many polymers, recycling via mechanical processes is not feasible and these materials are destined for landfills or incineration. One salient example is the superabsorbent material used in diapers and feminine hygiene products, which contain crosslinked sodium polyacrylates. Here we report an open-loop recycling method for these materials that involves (i) decrosslinking via hydrolysis, (ii) an optional chain-shortening via sonication, and (iii) functionalizing via Fischer esterification. The resulting materials exhibit low-to-medium storage and loss moduli, and as such, are applicable as general-purpose adhesives. A life cycle assessment demonstrates that the adhesives synthesized via this approach outcompete the same materials derived from petroleum feedstocks on nearly every metric, including carbon dioxide emissions and cumulative energy demand.

Microplastic pollution is omnipresenthaving been found in our land, air, food, and water. Over the last two decades, both identifying microplastics and sleuthing their sources has been a major research focus. Moving forward, the next goal should be remediation. Although removing microplastics from the environment is impractical, developing methods that prevent their release into the environment is essential. Herein, we report an approach for removing microplastics from water using a pressuresensitive adhesive. Specifically, we demonstrate that shaking zirconium silicate beads coated with poly(2-ethylhexyl acrylate) in aqueous suspensions containing polystyrene microplastics (10 μm) can remove up to 99% of the microplastics within 5 min. We show that the adhesive molar mass (ranging from 93−950 kg/ mol) is invariant with respect to removal efficiency at 5 min, as quantified by flow cytometry. Preliminary results suggest these adhesives can bind other microplastics as well, including nonpolar polymers (e.g., polyethylene, micronized rubber) and polar polymers (e.g., nylon, polyethylene terephthalate). Overall, this proof-of-concept study demonstrates a promising approach for remediating microplastics from aqueous suspensions using adhesives.

No abstract