Rigid‐Flexible Coupled Dendritic Molecule Doping: General Approach to Activate Commercial Polymers into Harsh Condition‐Tolerant Multi‐Reusable Strong Supramolecular Adhesives

Developing functional adhesives combining strong adhesion, good recyclability and diverse harsh‐condition adaptability is a grand challenge. Here, we introduce a general dendritic molecule doping strategy to activate commercial polymers into a new family of supramolecular adhesives integrating high adhesion strength, ultralow temperature, water resistant and multi‐reusable properties. Our method involves rational design of a new rigid‐flexible coupled dendritic molecule—M 4 C 8 OH as a versatile dopant, while simple M 4 C 8 OH doping into commercial polymers can modulate internal and external non‐covalent interaction to enable H‐bonding enhanced interchain cross‐linking for tough cohesion along with enhanced interphase interaction. This endows 20 wt % M 4 C 8 OH‐doped polycaprolactone (PCL) adhesives (PCL‐M 4 C 8 OH) with improved adhesion strength on various substrates with the maximum increase up to 2.87 times that of PCL. In particular, the adhesion strengths of PCL‐M 4 C 8 OH on polymethyl methacrylate at 25 °C and −196 °C reach 4.67 and 3.58 MPa—1.9 and 2.3 times those of PCL and superior to diverse commercial adhesives and most reported adhesives. PCL‐M 4 C 8 OH also displays markedly‐improved multi‐usability and tolerance against ultralow temperature and diverse wet environments. Mechanism studies reveal the crucial role of M 4 C 8 OH molecular structures toward superior adhesion. Our method can be expanded to other polymer matrices, yielding diverse new supramolecular adhesives.