Temperature-Enhanced Supramolecular Polymer Adhesion Provided by Concurrent Utilization of Calix[4]Pyrrole and Crown Ether Molecular Recognition

Low molecular weight (LMW) supramolecular polymer adhesives built up from functional small molecules suffer from temperature sensitivity, which limits their utility in applications requiring high temperature ranges. It is reported here a linear supramolecular polymer that incorporates concurrent anion- and cation-recognition in an orthogonal manner by means of calix[4]pyrrole (CP) and crown ether (CE) macrocycle monomers functionalized with secondary alkylammonium and carboxylate functional groups, respectively. The resulting alternating supramolecular polymer, named CPCE, is fully characterized and possesses dynamic non-covalent bonding both in solution and solid state. Its high degree of polymerization provides good processability and temperature-enhanced adhesive property when used on glass and steel substrates with up to 5.09 MPa adhesion strength at 75 °C. Furthermore, this low-molecular-weight (LMW) supramolecular polymer adhesive allows for stable reusability over 10 cycles, as well as good long-term durability. The favorable adhesion performance of the CPCE leads to suggests that it can be useful in high-tech special settings requiring elevated temperatures.