Synthesis and self-assembly of tadpole-shaped organic/inorganic hybrid poly(N-isopropylacrylamide) containing polyhedral oligomeric silsesquioxane via RAFT polymerization

Aminopropylisobutyl polyhedral oligomeric silsesquioxane (POSS) was used to prepare a POSS-containing reversible addition-fragmentation transfer (RAFT) agent. The POSS-containing RAFT agent was used in the RAFT polymerization of N-isopropylacrylamide (NIPAM) to produce tadpole-shaped organic/inorganic hybrid Poly(N-isopropylacrylamide) (PNIPAM). The results show that the POSS-containing RAFT agent was an effective chain transfer agent in the RAFT polymerization of NIPAM, and the polymerization kinetics were found to be pseudo-first-order behavior. The thermal properties of the organic/inorganic hybrid PNIPAM were also characterized by differential scanning calorimetry. The glass transition temperature (Tg) of the tadpole-shaped inorganic/organic hybrid PNIPAM was enhanced by POSS molecule. The self-assembly behavior of the tadpole-shaped inorganic/organic hybrid PNIPAM was investigated by atomic force microscopy and dynamic light scattering. The results show the core-shell nanostructured micelles with a uniform diameter. The diameter of the micelle increases with the molecular weight of the hybrid PNIPAM. Surprisingly, the micelle of the tadpole-shaped inorganic/organic hybrid PNIPAM with low molecular weight has a much bigger and more compact core than that with high molecular weight. © Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7049-7061, 2008