Room temperature healable elastomer composite based on light induced supramolecular chemistry

Abstract

The incorporation of the self-healing feature into commercial elastomers encourages the creation of high-end elastomeric products that have an increased lifetime and maintain their economic viability. Various approaches of self-healing mechanisms are introduced in this elastomeric system. Herein, carboxylated nitrile rubber (XNBR) has been chemically modified with light-sensitive benzylimine-functionalized anthracene (BIFA) moiety. BIFA-modified XNBR composites undergo crosslinking via dimerization of anthracene moiety through π-π interactions in the presence of blue LED light. Again, amine-modified nano-silica was mixed with the BIFA-modified XNBR for tuning the tailored mechanical properties of the composite material. The crosslinked composite film exhibited a desirable self-healing property (healing efficiency of 75%) after keeping it under a blue LED for 8 h at ambient temperature, exhibiting tensile stress of ∼4 MPa. Interestingly, the modified XNBR composite showed different 3D structural shapes. Thus, the visible-light-induced dynamic molecular design strategy of reinforcing silica filler could provide a path for healing at ambient temperature with a good balance of mechanical properties, which could be suitable for next-generation smart elastomeric materials.