Synthesis and Characterization of Amphiphilic Cyclic Diblock Copolypeptoids from N-Heterocyclic Carbene-Mediated Zwitterionic Polymerization of N-Substituted N-Carboxyanhydride

N-Heterocyclic carbene (NHC)-mediated ring-opening polymerization of N-decyl-N-carboxylanhydride monomer (De-NCA) has been shown to occur in a controlled manner, yielding cyclic poly(N-decylglycine)s (c-PNDGs) with polymer molecular weights (MW) between 4.8 and 31 kg mol–1 and narrow molecular weight distributions (PDI < 1.15). The reaction exhibits pseudo-first-order kinetics with respect to monomer concentration. The polymer MW increases linearly with conversion, consistent with a living polymerization. ESI MS and SEC analyses confirm the cyclic architectures of the forming polymers. DSC and WAXS studies reveal that the c-PNDG homopolymers are highly crystalline with two prominent first-order transitions at 72–79 °C (Tm,1) and 166–177 °C (Tm,2), which have been attributed to side chain and main chain melting, respectively. A series of amphiphilic cyclic diblock copolypeptoids [i.e., poly(N-methylglycine)-b-poly(N-decylglycine) (c-PNMG-b-PNDG)] with variable molecular weight and composition were synthesi...