An overview of green and sustainable polymeric coatings

Synthetic polymers have to be replaced with green counterparts for sustainability needs. Green and sustainable polymeric coatings have progressively undergone development, as functional and protective materials for myriad applications ranging from packaging to biomedicine. Despite such innovative and environmental privileges, they are not adequately competitive in terms of properties to displace synthetic polymeric coatings. Functionalization of the surface and/or the bulk of the green polymeric coatings by functional groups, natural polymers, nanoparticles, crosslinking agents, anti-fouling precursors, and synthetic polymers can strengthen their properties and enlarge their performance window. However, definitions and terms related to green and sustainable coatings have not been systematically addressed. Biomass-, plant oil-, carbohydrate-, protein- and microbial-based polymeric coatings are the main classes of sustainable polymeric coatings briefly overviewed herein. The technological bottlenecks towards commercialization of sustainable coatings and films are also highlighted.