Cu(0)-RDRP of 2-hydroxyethyl methacrylate in a non-polar solvent enables rapid synthesis of high-molecular weight homopolymers and direct access to amphiphilic copolymers

摘要

? 2023 Elsevier B.V.2-Hydroxyethyl methacrylate (HEMA) is an important functional monomer affording (co)polymers with numerous applications in different fields. Nevertheless, we still lack a reliable polymerization method for the synthesis of well-defined, high-molecular weight (MW) HEMA homopolymers, as well as for controlled copolymerization of unprotected HEMA with lipophilic comonomers. Herein, we report that rapid and well-controlled (co)polymerization of HEMA can be achieved via metallic copper-mediated reversible-deactivation radical polymerization (Cu(0)-RDRP) in a non-polar solvent (1,4-dioxane) using a chlorine-based initiation/catalytic system. With purified HEMA monomer, this protocol affords very well-defined (? ≤ 1.26) HEMA homopolymers in an unprecedently wide range of molecular weights from 10,000 to 500,000. Conversely, the structurally analogous bromine-based initiation/catalytic system leads to an uncontrolled polymerization. The use of a non-polar solvent enables, for the first time, a direct access to low-dispersity HEMA-rich copolymers with non-polar comonomers, including highly lipophilic ones. This is demonstrated on the successful copolymerization of HEMA with an equimolar amount of 2-ethylhexyl methacrylate and of lauryl methacrylate, yielding well-defined amphiphilic copolymers at quantitative conversion. This work significantly expands the application scope of the HEMA monomer and demonstrates for the first time that Cu(0)-RDRP in a non-polar solvent is applicable also to comparatively polar monomers.