New method to determine the recombination rate constant between nitroxides and macroradicals

International audienc

Nitroxide-mediated polymerization of methyl methacrylate using an SG1-based alkoxyamine : How the penultimate effect could lead to uncontrolled and unliving polymerization

International audienceThe nitroxide‐mediated polymerization (NMP) of MMA initiated with a new crowded SG1‐based alkoxyamine was performed. Contrary to the results expected after a kinetic analysis (Fischer's diagram), the polymerization of MMA at 45 °C with SG1 showed only partial control and livingness during the first 15% of conversion. Simulations using PREDICI highlighted that the kinetic rate constants currently in use had not been correctly estimated and that a strong penultimate effect drastically increased the equilibrium constant K (7 × 10−7), preventing a well‐controlled polymerization. Experimental determination of the kc value (1.4 × 104 L · mol−1 · s−1) confirmed a strong penultimate effect on the recombination reaction, whereas for the dissociation reaction this effect is lower (kd = 10−2 · s−1)

3.10 - Nitroxide-Mediated Polymerization

International audienceThis chapter covers the main achievements in nitroxide-mediated polymerization (NMP) from its discovery to late 2010. The various synthetic approaches to nitroxides and alkoxyamines are first presented. The range of monomers for NMP, kinetic features, as well as polymerization in aqueous dispersed media are also discussed. Finally, functionalization strategies of NMP-derived polymers, macromolecular architectures, and biomaterials are detailed

First Effective Nitroxide-Mediated Polymerization of Methyl Methacrylate.

International audienc

Nitroxide mediated polymerization, : the pivotal role of the k(d) value of the initiating alkoxyamine and the importance of the experimental conditions.

International audienc