Tunable, reusable, and recyclable perfluoropolyether periodic dynamic polymers with high underwater adhesion strength

Most adhesives lose adhesion in the presence of water. Here, hydro-phobic perfluoropolyether (PFPE) dynamic polymers with periodi-cally embedded hydrogen bonding units operate as effective under-water adhesives by enhancing van der Waals interactions and minimizing bulk water uptake. Optimizing the bonding interactions in the polymers and their bulk dynamics enables high cohesive strength while maintaining a hydrophobic, nanophase-separated morphology to prevent water-based failure mechanisms. The result-ing adhesives have high adhesion strength and can be reversibly applied in fully underwater conditions to polyimide, glass, and steel substrates without any solvent or covalent crosslinking, at room temperature, and without substrate modifications. Moreover, the polymer adhesive can be readily recycled due to the use of dynamic crosslinking to achieve adhesion. This work shows how dynamic PFPE polymers with tunable structures and properties can be de-signed for high-strength recyclable underwater adhesives, which could enable reversibly attachable and detachable waterproof wearable devices.

Automated summary

This study found that hydrophobic perfluoropolyether (PFPE) dynamic polymers can act as effective underwater adhesives by enhancing van der Waals interactions and minimizing water uptake. The optimized bonding interactions and bulk dynamics of the polymers enable high cohesive strength while maintaining a hydrophobic, nanophase-separated morphology. The resulting adhesives can be reversibly applied to various substrates in fully underwater conditions without any solvent or covalent crosslinking.