Studies of allyl alcohol radical polymerization by PFG-HMQC and HMBC NMR at 750 MHz

The structures of poly(allyl alcohol) were characterized by one- and two-dimensional gradient-enhanced heteronuclear multiple quantum coherence (gHMQC) and gradient-enhanced heteronuclear multiple-bond connectivity (gHMBC) NMR spectroscopy. Main-chain structures and chain-end structures were identified from the spectra. The polymerization of allyl alcohol can be described by degradative chain transfer to allyl alcohol monomers, which results in distinctive chain ends as well as low molecular weight polymers. After the allylic hydrogen abstraction by initiator radicals, allyl radicals produce chain ends with vinyl groups and aldehyde groups. The chain-end structures were identified by the correlation peaks in gHMQC and gHMBC spectra.