Figure 2.

Kinetics of polymerization of HPMA via RAFT aqueous dispersion polymerization at 50 °C and 10% w/w solids. A PEG₁₁₃-PHPMA₃₀₀ diblock copolymer was targeted using a [PEG₁₁₃-DB]/[AIPD] molar ratio of 3.0. The semilogarithmic plot shows three regimes: an initial induction period up to 50 min, a slow rate of solution polymerization between 50 and 60 and 120 min, and a relatively fast rate of polymerization after 120 min. The latter time corresponds to the onset of micellar nucleation, which occurs at an HPMA conversion of around 45%. The inset shows the GPC curves obtained for a subset of these kinetic data, indicating a linear evolution of M_n and a gradual reduction in copolymer polydispersity with monomer conversion.