Discrete Star Polymers with Tailored Architectures and Stereoregularity

Branched topological polymers are versatile soft nanomaterials, but synthesizing discrete architectures remains challenging due to multifunctional group coupling. Herein, we present an efficient strategy for discrete polylactide (PLA)-based star polymers with precisely defined arm numbers up to 27, arm lengths up to 32 LA units, and molar masses up to 70972.3 Da. This approach integrates the iterative exponential growth (IEG) technique with RERI-driven (reaction-enhanced reactivity of intermediates) CuAAC click chemistry. The RERI-driven CuAAC reaction was enhanced by CuBr/Me 6 TREN in DMSO using monodisperse dendritic cores bearing 1,3-triazide terminals. The inherent RERI mechanism of the 1,3-triazide terminals ensures quantitative grafting of discrete alkynyl-terminated PLA-based arms in a fast and highly efficient way. Consequently, these discrete star polymers with tailored arm numbers, lengths, and stereoregularities were synthesized in high yields of over 95%. The effects of the arm number, length, and stereoregularity on the physical properties of these discrete star PLAs were examined. Furthermore, discrete core–shell and Janus PLA star polymers with controlled amphiphilic structures and stereoregularity were successfully synthesized. Overall, this study establishes an efficient and versatile strategy that not only enables the efficient construction of discrete star polymers but also provides insights into the precise synthesis of diverse discrete topological architectures.