One‐step synthesis of poly(<i>N</i>‐vinylpyrrolidone)‐<i>b</i>‐poly(<scp>l</scp>‐lactide) block copolymers using a dual initiator for RAFT polymerization and ROP

Abstract

ABSTRACT Amphiphilic, biocompatible poly( N ‐vinylpyrrolidone)‐ b ‐poly( l ‐lactide) (PVP‐ b ‐PLLA) block polymers were synthesized at 60 °C using a hydroxyl‐functionalized N,N ‐diphenyldithiocarbamate reversible addition–fragmentation chain transfer (RAFT) agent, 2‐hydroxyethyl 2‐( N,N ‐diphenylcarbamothioylthio)propanoate (HDPCP), as a dual initiator for RAFT polymerization and ring‐opening polymerization (ROP) in a one‐step procedure. 4‐Dimethylamino pyridine was used as the ROP catalyst for l ‐lactide. The two polymerization reactions proceeded in a controlled manner, but their polymerization rates were affected by the other polymerization process. This one‐step procedure is believed to be the most convenient method for synthesizing PVP‐ b ‐PLLA block copolymers. HDPCP can also be used for the one‐step synthesis of poly( N ‐vinylcarbazole)‐ b ‐PLLA block copolymers. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52 , 1607–1613