“Clicking” Amphiphilic Block Copolymers onto POSS Core: A General Approach for “Star-like” Polymers with Different Symmetry

Abstract

“Star-like” macromolecules have been widely studied because of their unique physical and chemical properties, which play a great role in many important application fields. In this study, a library of star-like amphiphilic block copolymers consisting of a polyhedral oligomeric silsesquioxane (POSS) core and polyethylene glycol-bolck-polystyrene (PEG_m-b-PS_n) diblock copolymer arms with an exact arm number were prepared through a robust copper-catalysed azide-alkyne cycloadditions (CuAAC) and strain-promoted azide-alkyne cycloaddition (SPAAC) click reactions. Moreover, homo- and mikto-arms star polymers with different compositions were obtained by precisely regulating the central symmetry of the POSS core. The target polymers and intermediate products were characterized by nuclear magnetic resonance (NMR), size exclusion chromatography (SEC), Fourier transform infrared (FT-IR) spectroscopy, and matrix-assisted laser desorption ionization time-of-flight (MALDI-ToF) mass spectrometry. This study demonstrates the chemical robustness of the novel POSS-based building block and establishes a general and efficient approach to prepare star-like macromolecules, especially for asymmetric heteroarm star-like macromolecules, which serve as important model compounds in the study of their bulk properties as well as self-assembling behaviors.