Graft copolymerization of methyl acrylate onto poly(vinyl alcohol) initiated by potassium diperiodatocuprate(III)

A novel redox system, potassium diperiodatocuprate(III) [Cu (III)]-poly(vinyl alcohol) (PVA) redox system, was employed to initiate the graft copolymerization of methyl acrylate (MA) onto PVA in alkaline medium. The grafting parameters varied with concentrations of monomer, initiator, macromolecular backbone (DP = 1750, M = 80 000) and temperature. The formation of the graft copolymer was confirmed by Fourier transfer infrared spectroscopy (IR), scanning electron microscope (SEM), X-ray diffraction and thermogravimetric analysis (TGA. It was found that [Cu (III)] PVA system is an efficient redox initiator for this graft copolymerization. A mechanism is introduced to explain the formation of radicals and the initiation. At the same time, the other acrylate monomers, such as methyl methacrylate, ethyl acrylate and n-butyl acrylate, were used as reductant to produce graft copolymerization. It was definitely observed that these reactions could occur in some degree. Thermal stabilities were checked by TGA and this indicated that graft copolymer was resistant to moisture absorption.