Phosphonates as non-salt-type latent initiators for vinyl ether polymerization

Phosphonates, O,O-di-1-phenylethyl phenylphosphonate (1), O,O-di-tert-butyl phenylphosphonate (2), and O,O-dicyclohexyl phenylphosphonate (3), were examined as non-salt-type latent initiators in the polymerization of isobutyl vinyl ether (IBVE), phenyl vinyl ether (PVE), and tri(ethylene glycol) divinyl ether (DVE-3). The polymerization of IBVE and PVE did not proceed below 90 and 120°C, but rapidly proceeded above these temperatures with 1, respectively. DVE-3 cured with 1 quantitatively at 150°C for 12 h to afford brown gel insoluble in common organic solvents. The phosphonates served as novel non-salt-type latent initiators in the polymerization of the vinyl ether monomers.