Adaptive Polyurethane Adhesive with Interfacial Recognition for Robust Bonding of Hydrosilylation-Curable...

Polysiloxane (PSI) coating, prepared via in situ hydrosilylation using divinyl-terminated polydimethylsiloxane (^ViPDMS^Vi) and polymethylhydrosiloxane (PMHS) as base materials, has received escalating attention for high transparency, commendable weatherability, and exceptional antismudge properties imparted by the inherently low surface energy. However, a formidable challenge for PSI coating also arises from this low surface energy, causing extremely poor adhesion to the substrates. Herein, an adaptive polyurethane (PU) adhesive with interfacial recognition that integrates vinyl-terminated polysiloxane segments (VHMS) and catechol units, capable of strong bonding between PSI coating and different substrates, was developed. Specifically, during in situ hydrosilylation of PSI coating, vinyl polysiloxane segments can spontaneously segregate to the interface and react with Si-H groups in PMHS, forming a robust covalent bond between the adhesive and PSI coating, while catechol units engage substrates (metals, glass, engineering plastics) via multiple noncovalent interactions. Attributed to the synergistic action of these two modules, the adhesive serves as an interfacial bridge that firmly anchors the PSI coating onto substrates, achieving the adhesion strength far exceeding the cohesive strength of the PSI coating. This work presents a universal strategy for adhering nonpolar PSI coating to diverse substrates, yielding a composite coating that combines high transparency, antismudge, and strong adhesion, with promising applications in optical devices such as photovoltaic panels.