Synthesis of Novel Core Cross-Linked Star-Based Polyrotaxane End-Capped via CuAAC Click Chemistry

The first example of core cross-linked star (CCS) polyrotaxane was prepared using the poly(?-caprolactone) (PCL) CCS three-dimensional (3D) scaffold. The 3D CCS polymer was firstly prepared through the arm-first approach. Then, the arms of the resultant PCL CCS polymer were threaded with a-cyclodextrins (a-CDs). The threaded a-CDs were permanently locked by the click reaction of terminal alkyne functionalities of the star polymers with the azide-functionalized end caps to afford the CCS polyrotaxanes. All analytical results confirm the formation of the CCS polyrotaxanes and reveal their characteristics, including fluorescence under UV, a channel-type crystalline structure, a two-step thermal decomposition, and a unique core-shell structure in great contrast to the polymer precursors.