Molecular design of reactive polycaprolactone that can be induced into shape-memory materials promotes further functionalization

In this study, polymers with different copolymerization composition ratios of α-chloro-ε-caprolactone (α-ClCL) and ε-caprolactone (ε-CL) were prepared using α-ClCL, which can polymerize on its own. The copolymers were prepared by using trimethylolpropane as the initiator, and acryloyl groups were added to the polymer ends to form macromonomers capable of cross-linking reactions. The functionalized macromonomers were confirmed to possess shape-memory properties when cross-flinked in film form by heat. The composition of the functional groups in the macromonomer could be adjusted by changing the ratio of α-ClCL to ε-CL used in the copolymerization. In addition, the chloro group introduced by α-ClCL was converted into an azide group. Both the cross-linked film with chloro groups and the film converted to azide groups prepared in this study exhibited shape-memory according to the softening point of the film. Through fluorescence microscopy, it was confirmed that the converted azide groups were modified with alkylated rhodamine B based on the click reaction. Furthermore, azide-assisted films are expected to add various functions through click reactions in the future.