Synthesis of block polymer of Acrylonitrile and Polyethylene glycol with Cerium in Acidic medium. Kinetic study

摘要

Polyethylene glycol(PEG) block Acrylonitrile(AN) (PEG-b-AN) copolymer was synthesized in the presence of Ag(I) using Ce(IV) as an initiator in H2SO4 medium at 313K .The rate of oxidation was determined in the presence and absence of catalyst. and the orders were 0.25 in [Ag(I)], 0.22 in [PEG] in the presence of catalyst. The rate of copolymerization (Rp) and efficiency were determined for [Ag(I)] catalysis. The rate of copolymerization was found to increase with increase in [PEG], [AN] and [Ag(I)] and the orders were 0.50, 1.50 and 0.58 respectively.. A probable mechanism involving the formation of Ag(I) - polymer adduct followed by its oxidation with ceric to Ag(II) - polymer adduct which decomposes to give initiating radicals is proposed to explain the results.