Grafting of acrylonitrile onto styrene-maleic acid copolymer by tetravalent cerium ion

The graft copolymerization of acrylonitrile (AN) onto a styrene-maleic acid copolymer (SY-MAc) with ceric ammonium nitrate (CAN) as a redox initiator in an aqueous medium has been studied. The effects of various reaction parameters, including reaction time and temperature, concentrations of initiator, nitric acid, and monomer, on the grafting yields and the rates of polymerization (R_p), graft copolymerization (R_g), and homopolymerization (R_h) were studied systematically. The results are discussed. The kinetic scheme of free-radical graft copolymerization has been proposed and the equations relating the values of R_p, R_g, and R_h are also suggested. The experimental results are found to be in good agreement with the proposed kinetic scheme. The activation energies of graft copolymerization and total polymerization are calculated. © 1995 John Wiley & Sons, Inc.