Versatile Fabrication of Polymer Microcapsules with Controlled Shell Composition and Tunable Performance via Photopolymerization

In this work, a series of polymer microcapsules basedon UV-curableprepolymers are prepared by combining an emulsion template and photopolymerization.The modulation of the shell structure is achieved by employing UV-curableprepolymers with different chemical structures (polyurethane acrylates,polyester acrylates, and epoxy acrylates) and functionalities (di-,tetra-, and hex-). The relationships between the shell structure andthe microcapsule properties are investigated in detail. The resultsshow that the properties of the microcapsules can be effectively regulatedby adjusting the composition and cross-linking density of the shell.Epoxy acrylate-based microcapsules exhibit higher impermeability,solvent resistance, and barrier and mechanical properties than polyurethaneacrylate and polyester acrylate-based microcapsules. Using UV-curableprepolymer with high functionality as a shell-forming material couldeffectively improve the impermeability, solvent resistance, and barrierand mechanical properties of microcapsules. In addition, the dispersionof microcapsules in the coating matrix tends to follow the similarcomponent, better compatibility principle, i.e., a uniformdispersion of the microcapsule in the coating matrix is more easilyachieved when the compositions of the microcapsule shell and coatingare similar in structure. The convenient adjustment of the shell structureand the investigation of the structure-propertyrelationship provide guidance for the further controlled design ofmicrocapsules.

Automated summary

In this study, polymer microcapsules based on UV-curable prepolymers were prepared using an emulsion template and photopolymerization. By using UV-curable prepolymers with different chemical structures and functionalities, the shell structure of the microcapsules could be controlled, and the relationship between the shell structure and microcapsule properties was investigated. It was found that adjusting the composition and cross-linking density of the shell could effectively regulate the properties of the microcapsules. Epoxy acrylate-based microcapsules showed superior impermeability, solvent resistance, and barrier and mechanical properties compared to polyurethane acrylate and polyester acrylate-based microcapsules. Using UV-curable prepolymers with high functionality as a shell-forming material could enhance the properties of the microcapsules. The dispersion of microcapsules in the coating matrix was also influenced by the similarity in structure between the microcapsule shell and coating.