Depolymerization by Photocatalytic Solvolysis

The project aims at solvolytic solution-phase depolymerization of polyolefins at low temperatures, initiated and assisted by photo-oxidation.

In this project, we will explore a novel chemical recycling route for polyolefins conversion into more valuable products. The depolymerization of polyolefins, such as polyethylene (PE) and polypropylene (PP), usually involves energy-intensive processes to break down the strong C-C backbone that lacks heteroatoms. A bifunctional heterogeneous photo-solvolysis catalyst that accelerates both photo-oxidation and solvolysis will be developed. Catalytic photo-oxidation introduces oxygen into the backbone of the polyolefin, creating weak links suitable for solvolytic cleavage. The formation of new functional groups on the plastic solid and soluble degradation products in the solution phase will be investigated by vibrational and optical spectroscopy and a combination of HPLC, GC-MS and NMR analysis respectively. The influences of UV light irradiation, oxygen availability, generated reactive oxygen species and solution conditions will be studied to provide insight into the interplay of the photo-oxidation with solvolysis processes and a variety of factors. This will lay the foundation for the development of a sustainable process for plastics recycling.