Macroinitiator halide effects in galactoglucomannan‐mediated single electron transfer‐living radical polymerization

Chloro (Cl)‐ and bromo (Br)‐functionalized macroinitiators were successfully prepared from the softwood hemicellulose O ‐acetylated galactoglucomannan (AcGGM) and then explored and evaluated with respect to their ability and efficiency of initiating single electron transfer‐living radical polymerization (SET‐LRP). Both halogenated species effectively initiate SET‐LRP of an acrylate and a methacrylate monomer, respectively, yielding brushlike AcGGM graft copolymers, where the molecular weights are accurately controlled via the monomer:macroinitiator ratio and polymerization time over a broad range: from oligomeric to ultrahigh. The nature of the halogen does not influence the kinetics of polymerization strongly, however, for acrylate graft polymerization, AcGGM‐Cl gives a somewhat higher rate constant of propagation, while methacrylate grafting proceeds slightly faster when the initiating species is AcGGM‐Br. For both monomers, the macroinitiator efficiency is superior in the case of AcGGM‐Br.