Synthesis of polyacrylonitrile (PAN) catalyzed by Ni(II)/glycine chelate complex through emulsion polymerization initiated by monopersulphate

259-263A radical polymer of acrylonitrile (AN) was prepared using a non-conventional complex initiating system Ni(II)/Glycine/KHSO5 in the absence of an added emulsifier. The polymerization reaction was also carried out in the presence of various divalent transition metal salts, certain amino acids and their chelate complexes in atmospheric oxygen. The metal salts and amino acids with free amino and carboxyl groups have a retarding effect on the polymerization reaction, while their chelate complexes have catalytic effect. From among the data, NiCl2/glycine chelate complex was chosen for detailed kinetic study of acrylonitrile polymerization. The stirring of solution produces dispersion of the insoluble monomer in the continuous phase. The rate of polymerization (Rp) was studied for varying concentration of monomer, initiator, glycine, NiCl2 and solvents over a temperature range of 40-70°C. The polymers were characterized by molecular weight determination by GPC and viscosity methods. The overall activation energy was computed to be 5.35 kcal mol-1. From kinetic and spectrophotometric study, the mechanism of KHSO5 decomposition by Ni(II)/glycine complex and initiation of polymerization was suggested