Branching in RAFT Miniemulsion Copolymerization of Styrene/Triethylene Glycol Dimethacrylate and Control of Branching Density Distribution

This work reported branching studies in reversible addition-fragmentation chain transfer (RAFT) miniemulsion copolymerization of styrene and triethylene glycol dimethacrylate (TEGDMA), and control of branching density distribution using a model-based computer-programed monomer feeding strategy. Highly branched polystyrenes (PS) were produced with small amount of TEGDMA. The branching density experienced drifting in a batch operation. A semi-batch kinetic model by combining the kinetic model for RAFT miniemulsion copolymerization with a semi-batch reactor model was used to design the monomer feeding rate profiles for targeted branching density distributions. A series of hyperbranched PSs with the designed branching density distributions were synthesized.