Polymerisation of Acrylamide initiated by Ce(IV)-Iminodiacetic acid Redox system

Abstract

Polymerisation of acrylamide initiated by ceric ammonium sulphate

Ce(IV) in combination with iminodiacetic acid (IDA) has

been investigated in aqueous solution. Polymerisation behaviour as

a function of the concentration of Ce(IV), IDA and acrylamide as

well as temperature have been studied. The polymerisation is initiated

by the radical produced from the decomposition of the complex

formed between Ce(IV) and IDA. The rate of polymerisation is

found to be first order with respect to the concentration of monomer

and complex. The complex formation constant (K) and disproportionation

constant (k_d) of Ce(IV)-IDA chelated complex are

evaluated and they are 9.043 x 10² and 2.096 x 10^–3 respectively.

The effect of excess of Ce(IV), mineral acid and complex (initiator)

concentrations were studied. The R_p value gradually increases to a

maximum and then decreases with increase of complex concentration.

The kinetic parameters involved were determined.