dl‐Methionine‐Mediated Reversible Deactivation Radical Polymerization of Styrene and Methyl Methacrylate

Abstract

Reversible deactivation radical polymerization (RDRP) is a facile and highly efficient technique for the synthesis of well-defined polymer with precise structure. dl-Methionine (Met) as a RDRP control agent is described and assessed for RDRP of styrene (St) and methyl methacrylate (MMA) with AIBN as radical initiator at 75 °C, which enables excellent control of this polymerization. The addition of dl-Methionine significantly decreased the dispersity (Ð) of the polymers for both monomers and first-order linear kinetic plots of polymethyl methacrylate (PMMA) are observed in DMSO. Considering the heat resistance of dl-Methionine, kinetic studies indicate that polymerization develops at a faster rate at higher reaction temperature (100 °C) with the same dl-Methionine content. Well-defined polymethyl methacrylate-block-polystyrene (PMMA-block-PSt) is successfully achieved by the chain extension reaction that demonstrates the high end fidelities of this polymerization approach. The system allows the use of dl-Methionine, a rich source and easily synthesized agent, to mediate RDRP strategy.

Reversible breakage of the C–S bond: function of dl-methionine in PET-RDRP catalyzed by zinc protoporphyrin

“…In our previous work, a chemically-initiated RDRP system with dl -methionine as a control agent was successfully developed for the preparation of polystyrene and polymethyl methacrylate with low dispersity and a high conversion rate. 46 This system, however, needs to be employed under high temperature conditions and requires an additional initiator AIBN. So far, there are no reports in the literature of dl -methionine being used as a control agent for photoinduced electron/energy transfer-reversible-deactivation radical polymerization (PET-RDRP).…”

“…The location of dl -methionine bond breakage has been confirmed in our previous study, so we conjecture that light can break the C–S bond, which has a lower bond energy. 46 To develop PET-RDRP that can be applied to biological systems, we use human hemin to prepare protoporphyrin and then chelate zinc ions to synthesize the photo-catalyst zinc protoporphyrin (ZnPTP). dl -Methionine is used as a control agent and ZnPTP is used as a photo-catalyst for the PET-RDRP reaction of different monomer families (acrylamides, acrylates, methacrylates and acrylic acids) with DMSO and deionized water as solvents, respectively (Scheme 1).…”