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 from 1b / 2a, respectively.