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 benefits, they are not adequately competitive in terms of properties to displace synthetic polymeric coatings. Functionalization of the surface and/or the bulk of green polymeric coatings by functional groups, natural polymers, nanoparticles, cross-linking agents, antifouling precursors and synthetic polymers can strengthen their properties and widen their performance window. However, definitions and terms related to green and sustainable coatings have not been systematically addressed. Biomass-, plant-oil-, carbohydrate-, protein- and microbe-based polymeric coatings are the main classes of sustainable polymeric coatings briefly overviewed herein. The technological bottlenecks toward commercialization of sustainable coatings and films are also highlighted.