Preparation of Functional Long‐Subchain Hyperbranched Polystyrenes via Post‐polymerization Modification: Study on the Critical Role of Chemical Stability of Branching Linkage

Post‐polymerization modification (PPM) is one of the most powerful strategy for preparing polymers with functional groups that cannot be synthesized by direct polymerization. So far, numerous experimental efforts have been devoted to the stability issue of monomer structures during the PPM process, but little attention was paid to chemical linkages. However, for hyperbranched polymers, a minor change of linkage unit could lead to a significant influence on the overall stability and performance of polymer materials. In this work, we investigated the chemical stability of long‐subchain hyperbranched polystyrenes with ester, aryl ether, and carbon‐carbon bonds as branching linkages under a few most popular PPM conditions, including NaOH hydrolysis reaction, TFA‐promoted hydrolysis reaction, BBr(3)‐catalyzed methoxy‐hydroxyl conversion reaction, and LiAlH(4) carbonyl reduction reaction. Related results are summarized into a synthetic route map that can provide practical and intuitive guidance for preparing functional long‐subchain hyperbranched polystyrenes and other type of polymers by PPM for future applications.