(654i) Model-Based Design and Synthesis of Copolymer Sequence Distributions through Programmed Semibatch RAFT Mini-Emulsion Copolymerization of Styrene and Butyl Acrylate

The tactics of targeting copolymer composition and molecular weight via semibatch controlled radical polymerization (CRP) have been extensively studied. However, little effort is made to target copolymer sequence length (CSL) and its triad sequence, which are among the key microstructures determining material properties of the copolymers. This work presents a method to design and synthesize targeted CSL and copolymer triads in a reversible addition–fragmentation transfer (RAFT) mini-emulsion copolymerization system through a semibatch chain and sequence model coupled with Alfrey Mayo model. The kinetic model was first developed and calibrated by correlation with experimental data of the batch copolymerization of styrene (St) and butyl acrylate (BA). The semibatch RAFT model was then employed to design feeding rate profiles for the targeted CSL and their triads. St/BA copolymers with different uniform CSLs and their triads are synthesized through the programmed semibatch (RAFT) mini-emulsion copolymerization processes.