| In the presence of crosslinking monomer N-hydroxymethyl acrylamide (N-HMA), the graft copolymerizations of one or two vinyl monomer onto comstarch were carried out using eerie ammounium nitrate as initiator on the basis of different graft efficiency and graft yield. The selective monomers in graft copolymerization are methylacrylate(MA), ethylacrylate(EA), methyl mathacrylate(MMA), ethyl methacrylate(EMA), butyl methacrylate(BMA) and vinyl acetate(VAc).The fourteen kinds of self-crosslinking binary and ternary graft copolymers were synthesized by the graft copolymerization of vinyl monomers onto cornstarch. The experimental results proved that the relationship between monomer structure and graft efficiency was revealed. The reactivity of seven vinyl monomers toward grafting onto starch is MA>MMA>EA>EMA>BA>BMA>VAc.The graft copolymerizations of mixed grafting monomers such as MA, EA, BA, MMA, EMA, BMA, VAc, (MMA+MA), (MMA+EA), (MMA+BA), (VAc +MA), (VAc +EA), (VAc +BA), (VAc +MMA), (EMA+BA) onto grafting skeleton of comstarch have been investigated respectively using eerie ammonium nitrate as initiator. The effects of various factors on the graft copolymerization were studied such as match of mixed monomers, monomer concentration, initiator concentration, reaction temperature, reaction time and nitric acid concentration. The optimum graft copolymerization conditions with higher graft efficiency and graft yield were: [AGU] = 0.123-0.31 mol -L-1; [JV-HMA] = 0.01 mol -L-1; monomer concentration , 0.25-1.75 mol-I/1; [CAN] = 0.3× 10-3~16×10-3 mol-L-1 which was added in molar acid of 0.02-0.2 mol-L-1; reaction temperature, 50~80癈; reaction time, 2.0~3.5h; molar ratio of mixed monomers, l:l(approximation).The self-crosslinking graft copolymers of starch were characterized by IR, SEM, XRD, 1H NMR, GPC and DSC. IR spectra of graft copolymers existed the carbonyl C=O characteristic absorption peak at 1730-1750 cm-1 besides the characteristic absorption peak of starch. The characteristic peaks of starch and link structure of monomer were appeared in *H NMR spectrum of graft copolymer simultaneously. These results proved the existence of grafting. The surface morphology of starch granules was changed, and the reaction mainly took place in the surface of granules. The sequence structure of starch was closed as native granules. The glass transitiontemperature Tg of self-crosslinking starch graft copolymers was varied in comparison with the Tg of homopolymer formed by the grafted monomers respectively. The several diffusion peaks of XRD showed that the starch graft copolymers were the concomitant product of a little crystal and amorphous structure. The mechanism on self-crosslinking graft copolymerization of vinyl monomers onto starch was advanced in the light of characteristics on the binary system of starch graft copolymerization, and its kinetics model was established. The model dealing with simplification could be written as the equation of graft efficiency (GE) withmonomer and initiator concentration: The kinetics of binary self-crosslinking graft copolymerization was also studied by means of Monte Carlo simulation method. The results in agreement on simulated and experimental data verify that the Monte Carlo method is an effect method in describing the kinetics of starch graft copolymerization.The mathematical model of initiator efficiency was obtained by considering the "cage effect" of ternary starch grafting. Some hypotheses were put forward such as coexistence of the copolymerization among two kinds of monomers and monomers grafting onto starch, graft side-chain and copolymer chain to be quadric Markov chain etc. According to the method combined with the kinetics, statistical mechanics, chain structure theory; graph theory, probability theory and mathematical statistics, the mathematical model of ternary self-crosslinking starch graft copolymerization was established on the basis of advanced kinetics scheme.The calculated values from mathematical models of binary and ternary system of sta...
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