Tailoring Polymer Dispersity by RAFT Polymerization: A Versatile Approach

Summary

Dispersity (Ɖ) can significantly affect polymer properties and is a key parameter in materials design. Here, we report a straightforward and versatile batch method based on reversible addition-fragmentation chain transfer (RAFT) polymerization to tailor the molecular weight distributions for a wide range of monomer classes, including acrylates, acrylamides, methacrylates, and styrene. In addition, our methodology is compatible with more challenging monomers, such as methacrylic acid, methyl vinyl ketone, and vinyl acetate. Control over Ɖ is achieved by mixing two RAFT agents with sufficiently different chain-transfer activities in various ratios, affording polymers with monomodal molecular weight distributions over a broad dispersity range (Ɖ ∼ 1.09–2.10). Our experimental findings were supported by simulations through the use of deterministic kinetic modeling, and our method was further demonstrated for the preparation of well-defined block co-polymers, regardless of the initial homopolymer dispersity.