Alkylidene functionalization produces highly recyclable and scalable polyhydroxyalkanoates
- Li Zhou
- James H. May
- Ravikumar R. Gowda
- Levi J. Hamernik
- Jacob K. Kenny
- Lili Wang
- Christopher D. Stubbs
- Ethan C. Quinn
- Jason S. DesVeaux
- Katrina M. Knauer
- Gregg T. Beckham
- Eugene Y.-X. Chen
2026-05-07
Recyclable polymers that can be produced at scale and readily tuned within the same polymer framework for specific properties are critical to achieving a circular materials economy. To this end, synthetic poly(3-hydroxyalkanoate)s (PHAs) have emerged as high-performance, chemically recyclable variants of biological PHAs, but their difficult monomer syntheses and suboptimal recycling efficiencies pose challenges for large-scale deployment. In this study, we investigated a β-isopropylidene PHA, i -PHA, for which the lactone monomer can be synthesized by existing industrial methods from biomass-derived isobutyric acid. The alkylidene substituent prevents decarboxylative degradation typically observed during PHA depolymerization, enabling near-quantitative chemical recycling to monomer. Controlled hydrogenation of the β-isopropylidene side group produces PHAs with diverse performance metrics that are competitive with a range of commodity polymers, spanning strong fibers to ductile thermoplastics to superglue epoxy resins.