SYNOPSISIn this article, the graft copolymerization of methy methacrylate with canna-starch under the initiating of manganic pyrophosphate was investigated systemly. It was found that the percentage of grafting, grafting efficiency, and rate of grafting were all dependent, to some extent, on the concentration of the initiator, monomer and starch, as well as reaction time and temperature. The rate equation of graft copolymerization established from the experimental results was similar to the equation derived from the reaction mechanism. The graft copolymer was investigated with an infered spectroscope, scanning electron microscope, and x-diffraction methods.

ABSTRACT:The initiating ability of the potassium permanganate in the graft copolymerization of acrylonitrile onto starch was studied. The results indicate that the grafting parameters, such as concentrations of potassium permanganate, acrylonitrile, starch, and catalyst acids, all have significant effects on the graft copolymerization and the components of the graft copolymers, and this offers methods to adjust the properties of the graft copolymers. The sources of starch and corn starch derivatives both affected the components of the graft copolymers, which showed the influence of functional group on the grafting ability of starch. The preheat treatment and preoxidation of starch, as well as the adding sequence of the reactants all influenced the graft copolymerization, from which some suggestions about the grafting procession could be obtained.

ABSTRACT:The graft mechanism of acrylonitrile (AN) onto starch under the initiation of potassium permanganate was investigated. The relationships of the grafting rate and the concentrations of potassium permanganate, AN, and backbone starch, as well as the reaction temperature, were established. On this basis, the equation for the rate of the graft copolymerization was derived, and the apparent activation energy for the graft copolymerization was obtained. Through the study of the oxidation reaction of starch with manganic ions, the valence changes of manganic ions during the graft copolymerization, and the grafting ability of different starch derivatives, together with electron spin resonance analysis, the grafting mechanism for the graft copolymerization of AN onto starch under the initiation of potassium permanganate was determined.

SYNOPSISThe graft copolymerization of butyl acrylate onto pullulan using manganic pyrophosphate as initiator in aqueous medium was studied. The effects of concentration of initiator, monomer, pullulan, and sulfuric acid on the percentage of grafting, the grafting efficiency, as well as the rate of graft copolymerization were investigated. The rate equation was derived and a suitable reaction mechanism was proposed. Finally, the grafted samples were characterized by IR spectral measurement.

The ability to graft acrylonitrile (AN) onto starch initiated by various transition metals such as Mn(VII), Cr(VI), V(V) and Fe(II1) were compared in the existence of sulfuric acid in different concentrations. The results showed that the grafting potential of Fe(II1) is the lowest, while Mn(VI1) is the highest of these transition metals discussed. The catalyzing ability of varieties of acids, including perchloric acid, sulfuric acid, nitric acid and hydrochloric acid, in the graft copolymerization of acrylonitrile onto starch was studied; and the graft ability of monomers such as acrylaniide (AM), acrylic acid (AA) and methyl methacrylate (MMA), was compared. The experimental data indicates that the catalytic abilities of acids are related to their capability of providing protons. The granuluar structure of starch and it's graft copolymer were investigated with scanning electron microscopy, infrared spectroscopy, and thermogravietry. 483