Research database

MadABio (Sustainable rubber composite MAterials by Dynamic covalent networks And BIO-fillers) deals with the modification of liquid rubbers (LRs) and bio-fillers to design recyclable composites due to reversible crosslinking. Conventional LRs (i.e., low molecular weight elastomeric products in liquid form) harden by an irreversible curing reaction, and thus cannot be reprocessed, becoming non-recyclable waste at the end of their life. The use of bio-based fillers as a substitute for traditional fillers (e.g., carbon black) could further reduce the environmental impact of rubber composites. The project aims at developing recyclable LR compounds with increased renewable content, to address the issue of recyclability and sustainability of rubber products. The project has four research objectives: (i) the synthesis of modified LRs suitable for reversible curing processes exploiting dynamic covalent network chemistries, such as epoxy-diacids, or Diels-Alder reactions; (ii) the synthesis of functionalized bio-fillers (e.g., lignin) by using novel coupling agents, making them compatible and able to form dynamic bonds with the reversible LR matrices; (iii) the preparation of recyclable and reprocessable rubber composites made of reversibly crosslinked LRs and functionalized bio-fillers; (iv) the demonstration of circular and renewable product concepts in one use case by the fabrication of reprocessable rubber materials for flexible electronics. The obtaining of a recyclable rubber material reinforced by a bio-filler is a cutting-edge research not yet reported in scientific literature. Having the aim of developing sustainable-by-design advanced materials and technologies, MadABio is totally coherent with the European Strategic Topic “Circular economy” and the related Cluster 4 “Digital, Industry and Space”. Moreover, the results obtained by MadABio for LRs and bio-fillers are likely to be transferable to the preparation of recyclable/reprocessable high molecular weight elastomers for tires and other rubber products (e.g., for automotive industry). Substituting conventional curing and overall providing sustainable alternatives for rubber compounding, thus promoting the transition to circular economy, is the long-term outcome expected from MadABio.