Design of interface dynamic cross-linked hybrid network with highly improved mechanical, recycling and adhesive performance

Abstract

Engineering interface dynamic crosslinking is particularly favorable for nanocomposite to acquire intriguing properties such as energy dissipation, recyclability and adhesion, yet it still remains a formidable task. Herein, we report a robust and recyclable nanocomposite hot melt adhesives (HMAs) enabled by employing noncovalent interactions at the interface between core–shell structured silica nanoparticles (T-SiO2 NPs) and carboxylated ethylene vinyl acetate copolymer (EVA-COOH). Through elaborate architecture by hydrogen bonds and Fe-based coordination bonds assembly of interface crosslinking network, the resultant hybrid network exhibits excellent mechanical properties, with tensile strength of 11.34 MPa, modulus of 2.64 MPa and toughness of 104.4 MJ m−3, which are 2.89 times, 1.77 times and 1.80 times that of the neat EVA, respectively. Furthermore, due to the dynamic nature of the network, its mechanical properties could be well maintained (∼100 %) even after multiple generations of recycling. More strikingly, the as-prepared HMAs displayed an outstanding ability to bond diverse substrates tightly. In addition, stable adhesion performance is realized on the aluminum (Al) surface under air and harsh conditions. This inorganic–organic interface crosslinking strategy shows great significance for fabricating low-cost and environmentally adaptive functional materials.