Microdroplet Method Converts Polyethylene to Carboxylic Acids Without Added Catalyst

A research paper published in Nature describes a catalyst-free process that converts waste plastics into carboxylic acids through hydroxyl radicals generated at microdroplet interfaces. The method performs oxidative cleavage on polyolefins and rubbers under mild conditions. The process achieved complete conversion of polyethylene, with selectivity to short-chain diacids reaching 69 percent.

It was tested on mixed commercial plastics and scaled to 300 grams. Radical intermediate analysis showed water mediates the degradation through sequential hydroxyl radical addition to alkyl radicals. This pathway differs from classical liquid-phase aerobic oxidation of alkanes.

By removing catalysts, the strategy avoids deactivation from additives, feedstock variability, and poisoning. The paper states the work supplies a scalable blueprint for industrial microdroplet chemistry. A related article titled "In-line NMR guided orthogonal transformation of real-life plastics" appeared on 25 June 2025.