Electrostatic Self-Assembly and Covalent Fixation with Cationic and Anionic Telechelic Precursors for New Loop and Branch Polymer Topologies

An electrostatic self-assembly of cationic and anionic polymer precursors and subsequent covalent fixation has been performed to construct a series of loop and branch polymer topologies. The process employed the two cationic polymer precursors (1a and 1b) having two pyrrolidinium salt groups either at both chain ends (1a) or at the designated interior positions (1b), and the two anionic counterparts (2a and 2b) having two carboxylate groups either at both chain ends (2a) or at a single chain end (2b). A series of electrostatic polymer−polymer self-assemblies have been prepared by the combination of cationic and anionic precursors, i.e., 1a/2a, 1a/2b, and 1b/2a, respectively, through simple coprecipitation of the precursor polymer mixture into an aqueous medium. The subsequent covalent conversion of the electrostatically self-assembled products by heating under dilution could produce a ring polymer from 1a/2a, a tadpole polymer from 1a/2b, and a two-tail tadpole, having a loop and two branches, polymer fro...