Post-polymerization modification of bio-based polymers:Maximizing the high functionality of polymers derived from biomass

The renaissance of the bio-based chemical industry over the last 20years has seen an ever growing interest in the synthesis of new bio-based polymers. The building blocks of these new polymers, so called platform molecules, contain significantly more chemical functionality than their petrochemical counterparts (such as ethene, propene and para-xylene). As a result bio-based polymers often contain greater residual chemical functionality in their chains, with groups such as alkenes and hydroxyls commonly observed. These functional groups can act as sites for post-polymerization modification (PPM), thus further extending the range of applications for bio-based polymers by tailoring the polymers' final properties. This mini-review highlights some of the most recent and compelling examples of how to make use of bio-based polymers with residual functional groups for PPM. It also looks at how the emerging interdisciplinary field of enzymatic polymer synthesis allows for increased functionality in polymers by avoiding side-reactions as a result of milder reaction conditions, and additionally offers an alternative means of polymer surface modification.