The fabrication and corrosion resistance of benzotriazole-loaded raspberry-like hollow polymeric microspheres

•BTA can be encapsulated in raspberry-like hollow polymeric microspheres.•The release of BTA can be triggered by the change of pH.•The BTA-encapsulated raspberry-like hollow microspheres can be embedded into WPU film.•The composite WPU film exhibits good anti-corrosive property.

This work presents a synthesis of submicron-sized raspberry-like hollow microspheres loaded with corrosion inhibitor (1H-benzotriazole (BTA)) through a multi-stage emulsion polymerization. The combination of hierarchical raspberry-like surface structure and loading of BTA makes the prepared microspheres have good corrosion resistance. When BTA-loaded raspberry-like hollow microspheres are embedded in a water-borne polyurethane film, the obtained composite film can protect the copper from corrosion both in acidic and alkaline corrosive solutions.