Chemically Recyclable, Hydroxycinnamic Acid-Derived Semi-Aromatic Polycarbonates

Abstract

Polycarbonate polymers find widespread use for a variety of applications. Driven by the need to transition away from fossil-based resources, there is increasing interest in exploring bio-based monomers for the synthesis of polycarbonates. One interesting class of molecules that can be isolated from a variety of biological resources, including lignin, are hydroxycinnamic acids. This paper reports the synthesis of a library of aromatic diols using p-coumaric acid, ferulic acid, and sinapic acid as starting materials. Using dimethyl carbonate, these diols can be polymerized to generate a variety of semi-aromatic polycarbonate homo- and copolymers. These polycarbonates can be depolymerized via an organocatalyzed process to afford the starting diols in essentially quantitative yield. The monomers obtained from this depolymerization process could subsequently be repolymerized, with no purification needed, to regenerate the original polymer with essentially identical molecular weight, providing a pathway to the chemical recycling of these materials.