• atom transfer radical polymerization;
  • cyclic polymer;
  • circulatory extraction–cyclization;
  • Cu-catalyzed azide/alkyne cycloaddition;
  • matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS)


Thumbnail image of graphical abstract

Typically, intramolecular cyclization reactions need to be conducted at high dilution to avoid interchain coupling, which leads to the production of cyclic polymer at an extremely low output. Herein, a high-efficiency Cu-catalyzed azide/alkyne cycloaddition “click” synthesis of cyclic polystyrene (PS) and cyclic poly (methyl methacrylate) (PMMA) is reported via a circulatory technique of evaporation–condensation–extraction–inflow strategy by the utilization of elaborately designed equipment. High-output cyclic PS (one batch, 0.71 g cyclic polymer from 1.0 g linear polymer loading) and cyclic PMMA (one batch, 0.62 g cyclic PMMA from 1.0 g linear polymer loading) are achieved. This promising preparation should be beneficial to the large-scale application and research of cyclic polymers.