The graft copolymerization of acrylonitrile onto corn starch was investigated using manganic pyrophosphate [Mn(H2P2O7)3]3- as initiator. The effects of initiator concentration

monomer concentration

starch concentration and temperature on the grafting reaction have been examined. The results obtained are.1. In the range of [Mn3+] value from 2.0 to 2.5×10-3mol/L)

the grafting reaction was dominantly terminated by polymer radical combinations

the polymerization rate is expressed as:From Arrhenius equation

with least square method Ko was calculated to be 3.37×102(L/mol·s)and activation energy E to be 25.90(kJ/mol).2. When [Mn3+]was increased to 3.0×10-3mol/L

Mn3+ion may terminate the grafting reaction and the rate equation is described as.