Synthesis of Hydroxy‐Functionalized Polyethylene via Radical Copolymerization of Ethylene with Alkenyl Boronate and Post‐Polymerization Oxidation

Radical copolymerization of ethylene was performed with alkenyl boronate, and post‐polymerization oxidation was conducted to synthesize hydroxy‐functionalized polyethylene (PE). The copolymerization behavior was dependent on the molecular structure of the boron monomer: the copolymerization with α‐methyl substituted monomer carrying boronic acid pinacol ester [isopropenylboronic acid pinacol ester (IPBpin)] afforded copolymers with higher molar masses than the vinyl‐type monomer [i.e., vinylboronic acid pinacol ester (VBpin)]. The content of the boron‐pendant units was up to 7 mol%, and kinetic studies suggested the incorporation of boron‐pendant units in a discrete manner. The post‐polymerization oxidation of the boron pendants on the copolymer proceeded quantitatively, affording a hydroxy‐containing polyethylene. The introduction of a hydroxy group had a significant impact on the crystallization behaviors.