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 eerie ammonium nitrate (CAN) as a redox initiator in an aqueous medium has been studied. The effects of variou s reaction parameters, including reaction time and temperature, concen trations of initiator, nitric acid, and monomer, on the grafting yield s and the rates of polymerization (R(p)), graft copolymerization (R(g) ), and homopolymerization (R(h)) were studied systematically. The resu lts are discussed. The kinetic scheme of free-radical graft copolymeri zation has been proposed and the equations relating the values of R(p) , R(g), and R(h) are also suggested. The experimental results are foun d to be in good agreement with the proposed kinetic scheme. The activa tion energies of graft copolymerization and total polymerization are c alculated. (C) 1995 John Wiley & Sons, Inc.