An estimated 95% of the economic value of plastics is lost after a single use. Ideally, after use, the plastic waste generated would be recycled into the same material or upcycled into a higher value material. However, the chemical structure of the predominant plastic waste stream, polyolefins, necessitates a C–H functionalization strategy. The direct transformation of unactivated aliphatic C–H bonds to useful functionality is a streamlined and sustainable approach to accessing complex materials with enhanced properties from readily available compounds, like polyolefin waste streams post-industry and post-consumer. To avoid the thermodynamically favorable tertiary hydrogen atom abstraction, a selective radical abstracting agent needed to be designed for site-selective C–H functionalization from branched, commodity polyolefins, thereby mitigating chain scission events and providing opportunity for a diversity of modifications. This presentation will highlight research towards regioselective polyolefin C–H xanthylation, mechanistic understanding of amidyl radical-mediated C–H dithiocarbonylation, and general polyolefin C–H diversification using radical chain transfer. The broad reaction platform ultimately enabled the functionalization of waste plastics via reactive extrusion and the incorporation of ionic functionality onto a branched polyolefin to upcycle the material from a thermoplastic into a tough elastomer with the tensile properties of high-value polyolefin ionomers.

Amidyl radical-mediated polyolefin C–H functionalization

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.