Phenolic Polymers as Model Melanins

Melanins are a class of conjugated biopolymers with varying compositions and functions, which have a variety of potential medical and technical applications. Here, this work examines the conjugated polymers derived from a variety of phenolic monomers (catechol (CAT), levodopa (DOPA), and homogentisic acid (HGA)), using a selection of different analytical chemistry techniques to compare their properties with a view to understanding structure–function relations. The polymers display measurable conductivity, with electronic properties tuned by the functional groups pendant on the polymer backbones (which served as dopants) suggesting their potential for application in electronic devices. Polymerization of a variety of phenolic monomers (CAT, DOPA, or HGA) yields conjugated polymers (polyCATs, polyDOPAs, or polyHGA‐HS, respectively) which are simplified versions of biologically generated melanins. Their chemical, paramagnetic, and electrical properties are analyzed to assess if there may be a correlation between the functional groups pendant on the backbone of the polymers and their properties, which underpin their prospects for use as sustainable resources for advanced electronics.