Design and Synthesis of a Cyclic Double-Grafted Polymer Using Active Ester Chemistry and Click Chemistry via A “Grafting onto” Method

Combing active ester chemistry and click chemistry, a cyclic double-grafted polymer was successfully demonstrated via a “grafting onto” method. Using active ester chemistry as post-functionalized modification approach, cyclic backbone (c-P2) was synthesized by reacting propargyl amine with cyclic precursor (poly(pentafluorophenyl 4-vinylbenzoate), c-PPF4VB(6.5k)). Hydroxyl-containing polymer double-chain (l-PS-PhOH) was prepared by reacting azide-functionalized polystyrene (l-PSN(3)) with 3,5-bis(propynyloxy)phenyl methanol, and further modified by azide group to generate azide-containing polymer double-chain (l-PS-PhN(3)). The cyclic backbone (c-P2) was then coupled with azide-containing polymer double-chain (l-PS-PhN(3)) via CuAAC reaction to construct a novel cyclic double-grafted polymer (c-P2-g-Ph-PS). This research realized diversity and complexity of side chains on cyclic-grafted polymers, and this cyclic double-grafted polymer (c-P2-g-Ph-PS) still exhibited narrow molecular weight distribution (M(w)/M(n) < 1.10).