In light of the urgency to design novel functional materials derived from renewable and sustainable resources, cellulose has attracted significant interest over the last decades as a high value biopolymer displaying potential as reinforcing element. Located in the plant cell wall, cellulose provides high mechanical strength combined with excellent performance in terms of flexibility. Cellulose-based materials with dimensions in the nanoscale have been developed, resulting in unique features linked to the isolation of highly ordered domains and a large surface area. Within the family of nanocelluloses, cellulose nanofibrils with high aspect ratio (CNFs) have proven to be promising bio-based reinforcing nanofillers for polymeric composites. However, given the hydrophilic nature of native cellulose, surface modification is essential to ensure compatibilization in hydrophobic matrices (such as the polymers commonly employed for industrial applications).<br/>Aiming to address this challenge, various strategies for modifying the CNF surface in aqueous dispersion are explored in the present project. Atom Transfer Radical Polymerization (ATRP) is used as a tool for grafting hydrophobic polymer brushes from the CNF surface, as well as synthesizing copolymers with tailored structure and amphiphilic properties designed to electrostatically adsorb onto negatively charged CNFs and subsequently disperse them within a hydrophobic matrix. The interaction of the compatibilizing agents with the nanofibrils, as well as with the matrix, is investigated and optimized targeting specific composite and coating applications. The dispersion in the resin formulation is enhanced, allowing for the full exploitation of the nanomaterial’s reinforcing properties.

Surface-modified cellulose nanofibrils for composite and coating applications

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.