Facile coating of low-molecular-weight stretchable adhesive films leveraging carbodiimide-to-urea conversion and gallic acid for enhanced adhesion

Abstract

We present a simple method for bonding an elastomer substrate using a stretchable, low-molecular-weight adhesive. By mixing 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDC) and gallic acid on an aminated surface, EDC is converted into a urea derivative. This derivative features both hydrogen bond donor and acceptor functionalities, combined with bio-inspired adhesive gallol groups, which collectively enhance adhesiveness through extensive hydrogen bonding. Importantly, the adhesive preserves the stretchability of the elastomer.