Laboratory of Polymer Chemistry, Eindhoven Polymer Laboratories, Eindhoven University of Technology, P. O. Box 513, 5600 MB Eindhoven, The Netherlands Alkoxyamine-mediated Controlled Radical Polymerization in Emulsion Wilfred Smulders, Christianne Göttgens, Gilles Olive, Steven van Es The increasing need for products with better performance and durability requires the use of speciality polymers with controlled composition and architecture. However, no industrial cost-effective process is presently available to synthesize such polymers. Moreover, current processes are performed in solvent media and need recycling of solvents and thorough removal of organic residuals. Finally, these processes are incompatible with water, while the demand for waterborne systems is growing fast due to environmental concerns. Controlled Radical Polymerization (CRP), especially when applied directly in emulsion, will be able to reconcile these conflicting demands. In CRP all polymer chains allow stepwise addition of monomer throughout the whole process by limiting the extent of chain termination. CRP thereby allows for the sequential radical polymerization of monomers (multi-blocks) and construction of well-defined architectures. The main innovations to be achieved within the project are: increase in polymerization rate at temperatures below 100 °C development of efficient process conditions and modelling controlled radical polymerization in emulsion synthesis of copolymers with controlled composition and architecture targeted to market requirements within the field of PSA Scheme of alkoxyamine-mediated controlled radical polymerization Introduction Results and discussion Bulk polymerizations These plots show that CRP of styrene at 90 °C is possible. These results indicate that an increase in reaction rate is obtained by introducing catalytic groups and open ring structures, while control is maintained. Polydispersities are between 1.2 and 1.4 in all cases. However reaction rates will never be comparable to the rates of uncontrolled polymerizations because the principle of this technique is based on decreasing the radical concentration and thus the polymerization rate. Conclusions Emulsion polymerizations These plots show that in principle it is possible to perform alkoxyamine-mediated CRP in emulsion. Both a linear increase in molecular weight and polydispersities below 1.5 are observed. However in this case the rate is very slow, even compared to the same reaction in bulk. This is probably a consequence of the cage-effect, which does not allow the radical chain to propagate but gives rise to immediate trapping by the nitroxide. results of CRP of styrene at 90 °C in bulk results of CRP of styrene at 90 °C in emulsion There is a considerable effect of both structure and functional groups on kinetics. From this field improvements can be expected. Alkoxyamine-mediated CRP in emulsion is possible, although a considerable increase in reaction rate is necessary. In order to optimize CRP in emulsion and increase the polymerization rate a full theoretical modelling and improved nitroxides are required.