Unusual Kinetics in Aqueous Heterophase Polymerizations

The heterogeneous nature of aqueous heterophase polymerizations is the base for an easy route to unique block copolymers, for the development of new and more effective polymerization strategies, and the abilities to unique studies of radical polymerization kinetics. Thermo‐sensitive double hydrophilic block copolymers and micro‐ or nano‐gel particles of poly(N‐isopropyl acrylamide) as thermo‐responsible block and charged or uncharged hydrophilic polymers can easily be prepared if the polymerization of N‐isopropyl acrylamide is started with the corresponding polymeric radicals. The application of extremely fast microwave heating allows the development of highly effective pulsed thermal polymerization strategies and the production of polymers with desired molecular weight distributions over wide ranges. 2,2′‐azobisisobutyronitrile simultaneously initiates the polymerization in both the monomer and the aqueous phase and leads, even under surfactant‐free conditions, to stable latex particles.