Exploitation of the Nanoreactor Concept for Efficient Synthesis of Multiblock Copolymers via MacroRAFT-Mediated Emulsion Polymerization

Abstract

Multiblock copolymers are a class of polymeric materials with a range of potential applications. We report here a strategy for the synthesis of multiblock copolymers based on methacrylates. Reversible addition–fragmentation chain transfer (RAFT) polymerization is implemented as an emulsion polymerization to generate seed particles as nanoreactors, which can subsequently be employed in sequential RAFT emulsion polymerizations. The segregation effect allowed the synthesis of a high molar mass (>100,000 g·mol–1) decablock homopolymer at a high polymerization rate to an extent not previously achieved. A heptablock copolymer containing seven different 100 unit blocks was also successfully prepared, demonstrating how the strategy can be employed to precisely control the polymer composition at a level hitherto not accessible in environmentally friendly aqueous emulsion polymerization. Importantly, the methodology is a batch process without any intermediate purification steps, thus, rendering industrial scale up more feasible.