Preparation of Amphiphilic Diblock Copolymers with Pendant Hydrophilic Phosphorylcholine and Hydrophobic Dendron Groups and Their Self-Association Behavior in Water

Generation 3.5 poly(amido amine) dendron (G3.5) with 16 n-butyl terminal groups containing an acrylamide monomer (AaUG3.5) was prepared by condensation between an amino focal group in G3.5 and 11-acrylamidoundecanoic acid. AaUG3.5 was polymerized using poly(2-methacryloyloxyethyl phosphorylcholine) (pMPC)-based macro-chain transfer agent via reversible addition-fragmentation chain transfer (RAFT) radical polymerization to obtain amphiphilic diblock copolymers with different compositions. The diblock copolymers (PmDn) were composed of a hydrophilic pMPC block and hydrophobic pendant dendron-bearing block, where P and D represent pMPC and pAaUG3.5, respectively, and m and n represent the degree of polymerization for each block, respectively. P296D1 and P98D3 formed vesicles and large compound micelles and vesicles, respectively, which was confirmed by light scattering measurements and transmission electron microscopic (TEM) observations. The large compound micelles formed from P98D3 could not incorporate hydrophilic guest polymer molecules, because the aggregates did not have a hydrophilic hollow core. In contrast, the vesicles formed from P269D1 could incorporate hydrophilic guest polymer molecules into the hollow core. (c) 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 4923-4931