Interfacially Regulated UV-Curable Modified Graphene Oxide/Polyurethane Acrylate Composite with High Conversion: Synergistic Enhancement of Adhesive Performance and Maze Barrier Effect

A critical challenge in developing graphene oxide-reinforced UV-curable acrylates is to balance the filler barrier potential with its adverse effects on curing kinetics and interfacial adhesion. In this work, we address this issue by synthesizing thiol and silane-functionalized nanoparticles (GO-SH) and incorporating them into a UV-curable polyurethane acrylate (PUA) matrix. The resulting GO-SH-PUA films achieve a high acrylate conversion of 90.50%, an elongation at break of 1474%, strong peel strength on various substrates, and a water vapor transmission rate as low as 0.080 g·d–1·m–2. The thiol and silane groups expand the GO interlayer spacing for better dispersion and a stronger maze effect, and they also participate in the curing process via chain transfer, reducing UV shielding and oxygen inhibition. This work demonstrates that interfacial regulation with thiol and silane-functionalized GO can overcome the inherent limitation of GO modification, offering a practical strategy for high-performance UV-curable composites in demanding applications.