Sustainable, recyclable and biodegradable castor oil-derived elastomers enabled by dynamic acetoacetyl formed amides

Developing sustainable, recyclable, and biodegradable elastomers with the mechanical properties comparable to commercial polymers presents a formidable challenge. To this end, we synthesize a kind of mechanically robust elastomers cross -linked by acetoacetyl formed amides (AFAs) through reacting biomass -based derivatives castor oil acetoacetates (ACO) and terephthaloyl diazides (TPD). Inspired by the transformation of acyl azides into isocyanates via Curtius rearrangement upon thermal treatment, we show for the first time that the reaction of acetoacetates and acyl azides could afford AFAs as well. The AFAs, which have been demonstrated dynamic in our previous works, impart excellent thermal recyclability and healability to the obtained elastomers. Upon controlling the content of AFAs, the mechanical properties and dielectric properties of the elastomers could be flexibly adjusted. Moreover, the elastomers exhibit notable biodegradability, degrading in soil within 24 weeks. We anticipate that this recyclable and biodegradable elastomer represents a promising alternative to its conventional, nonrecyclable polymer counterparts.