Methacrylate and Styrene Block Copolymer Synthesis by Cu‐Mediated Chain Extension of Acrylate Macroinitiator in a Semibatch Reactor

Abstract A process for the well‐controlled growth of acrylates by Cu‐mediated polymerization has been developed, with macroinitiator synthesized continuously in a copper tubular reactor and subsequently chain‐extended semibatch without additional copper. Extending this to methacrylates styrene, however, proven difficult due significant reduction reaction rate. This barrier overcome chain‐extending low molecular weight ( M n 760 g mol –1 ) poly(methyl acrylate) styrene using PMDETA N , ′, ″, ″‐pentamethyldiethylenetriamine) as ligand. Methyl methacrylate conversions >80% at 70 °C diethylene glycol methyl ether >90% room temperature are achieved 4 h, same conditions successfully applied controlled chain extensions butyl methacrylate. Although slightly lower (60–70%) over h 85 °C, rates substantially higher than other studies. Hydrophobic–hydrophilic triblock structures produced through sequential monomer feeds reactor, keeping total time less 5 h. The ability incorporate and/or into structured block polymers greatly extends range products that can be efficiently levels process.