Study on Aqueous Polymerization of Acrylamide with an Initiator System Composed of Persulfate and Cysteine by pH-Stat Method

Abstract

The redox system composed of cysteine and persulfate ion , which initiates the aqueous polymerization of acrylamide, was investigated with using the pH-stat method, since the hydrogen ion was a product of the redox reaction. The polymerization rate orders for persulfate ion and acrylamide were 1.0 and 1.8, respectively. The rate order on cysteine changed from 0.5 to nil with an increase in the cysteine concentration. The generation rate of hydrogen ion was successfully obtained from the volume of sodium hydroxide solution used for neutralizing hydrogen ion generated during the polymerization in pH-stat apparatus. Hydrogen generation rate orders of sulfate ion, cysteine and acrylamide were 0.92, 1.00 and 0.61, respectively. It is elucidated that the redox initiation in a solution containing cysteine , persulfate ion and acrylamide is influenced by all components of this system .