Kinetics of retardation inpersulphate-Fe³⁺-bisulphite initiated polymerization of acrylamide

Abstract

The kinetics of persulphate-Fe³⁺ -bisulphite initiated polymerization has been studied at 30 ± 0.2°C in oxygen atmosphere. It has been found that the polymerization kinetics is significantly altered by Fe³⁺ concentration. At lower concentration (2.0 x 10^-4 mol dm^-3) of Fe³⁺ the rate of polymerization follows the rate equation <i>R</i>_pµ [monomer] [S₂O<img src='http://www.niscair.res.in/jinfo/twobyeight.gif' border=0>] while at higher concentration (8.0 x 10^-4 mol dm^-3) the rate equation becomes <i>R</i>_pµ [M][HSO<img src='/image/spc_char/3_bar.gif' border=0>]. Besides affecting the polymerization kinetics Fe³⁺ also decreases the molecular weight of the resulting polymers. The effects of added salts and temperature on the polymerization process have also been investigated and energy of activation is calcualted to be 42.6 kJ mol^-1. Retarding effect of various aliphatic alcohols, nitro compounds and nitrophenols has been studied in terms of retardation constants.