The Synthesis of Acrylate-Based Macromonomers and Structured Copolymers by High-Temperature Semi-Batch Radical Polymerization: The Impact of Acrylate vs. Methacrylate Monomer Choice

High-temperature starved-feed semi-batch radical polymerization is used to produce an isobornyl acrylate (iBoA) polymer solution with high macromonomer content without a mediating agent. The p(iBoA) macromonomer solution serves as an addition-fragmentation agent to synthesize a blocky copolymer in a single-pot sequential feeding process, as has been demonstrated using n-butyl acrylate (BA) as the second monomer. The impact of monomer selection on the copolymer product is investigated by switching the second monomer to n-butyl methacrylate (BMA) while keeping all other aspects of the operating strategy unchanged. Methodologies developed to verify macromonomer incorporation are used to compare the iBoA-BA and iBoA-BMA systems, with two-dimensional liquid chromatography providing a clear contrast between the acrylate and methacrylate (co)polymer products. The comparison demonstrates the effect of monomer structure on the macromonomer addition-fragmentation kinetics, with a blocky copolymer produced using the acrylate macromonomer only when an acrylate is used as the second monomer feed.