Strong and efficient self-healing adhesives based on dynamic quaternization cross-links

Self-healing adhesives (SHAs) are derivatives of self-healing materials with remarkable practical potential for rebondable, adjustable and long-term adhesion. However, reports of SHAs are extremely limited because it is difficult to meet both of the two requirements, high strength and efficient self-healing properties, which may greatly limit their application. In this study, the bottleneck is overcome by introducing alternating rigid and flexible segments in the dynamic quaternization cross-links of poly(1,2,3-triazolium) vitrimer (VPTA) adhesives. In consequence, the VPTA adhesive demonstrates a particularly high adhesive strength of 23.7 MPa, compared to the reported SHAs (<= 7.5 MPa). The adhesive joints of VPTA can self-heal after it is completely broken 20 times, while maintaining strengths all above 10 MPa, which is rarely reported. Furthermore, this adhesive also exhibits excellent solvent resistance, high durability, and good creep resistance. The structural design strategy may serve as a versatile method for polymers to prepare strong and efficient SHAs.