Functionalized Polyolefin With Photoresponsive Surface

The introduction of stimulus‐responsive groups can give polymers some material properties that cannot be realized simply by design and synthesis. Polyolefins, due to their nonpolar nature, suffer from poor compatibility with polar materials; however, directly grafting polar groups like hydroxyls onto their surface via traditional synthesis risks compromising their intrinsic hydrophobicity and is further hindered by challenges such as poisoning effects on catalysts from polar moieties. In this work, a photoresponsive strategy for polyolefins that enables surface introduction of hydroxyl groups without altering the bulk properties has been introduced. By copolymerizing ethylene with acrylate‐based comonomers, we synthesized functional polyolefins capable of undergoing photo‐Fries rearrangement under both UV and natural sunlight irradiation. This process selectively generates reactive phenolic hydroxyl groups at the material surface. The phototreated polymers exhibit significantly improved surface properties, including enhanced hydrophilicity, dyeability, and interfacial adhesion to metals. Additionally, we demonstrate a scalable route to these photoresponsive polyolefins via post‐functionalization of commercial maleic anhydride‐grafted polyolefins, establishing a versatile platform for further customization. This work highlights how light responsiveness can overcome the constraints of traditional synthesis to achieve cross‐scale structural control in polymers.