The mechanistic interpretation of kinetic anomalies in reversible addition-fragmentation chain transfer (RAFT)-mediated polymerization is critically reviewed. The main conclusion of this exercise is that available data do not allow model discrimination between the two prevailing mechanistic schemes, i.e., the slow fragmentation model and the intermediate radical termination model. However, assessment of the rate parameters reveals that the incompatibilities may not be as large as previously reported in literature. Dedicated kinetic studies on model compounds should be performed to shed further light on the seemingly incompatible data that currently exists in literature.

This study describes the synthesis of well‐defined nanocapsules via the miniemulsion technique. Pentaerythritol tetrakis(3‐mercaptopropionate) (TetraThiol) or 1,6‐hexanediol di(endo, exo‐norborn‐2‐ene‐5‐carboxylate) (DiNorbornene) is used as the oil phase. TetraThiol is encapsulated via the miniemulsion technique without polymerization, as this monomer would simultaneously act as a chain‐transfer agent, and DiNorbornene is encapsulated via miniemulsion polymerization of styrene. Various styrene‐maleic anhydride (PSMA) copolymers and poly(styrene‐maleic anhydride)‐block‐polystyrene (PSMA‐b‐PS) block copolymers were used as surfactant for the synthesis of well‐defined nanocapsules with TetraThiol as the core material. The nanocapsules had a diameter of 150–350 nm and the particle size distribution was narrow. The use of PSMA‐b‐PS block copolymers as surfactant in combination with post‐addition of formaldehyde provided improved stability to the nanocapsules. DiNorbornene was encapsulated via miniemulsion polymerization of styrene, and a stable latex with a bimodal particle size distribution was obtained. The distribution of small particles had a size of 60 nm and the distribution of large particles had a size of 150 nm. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010