Vinyl polymerization: Kinetics of Ce(IV)–acetophenone‐initiated polymerization of acrylonitrile in acetic–sulfuric acid mixtures

Abstract

The polymerization of acrylonitrile (M) initiated by the Ce(IV)–acetophenone (AP) redox pair has been studied in acetic–sulfuric acid mixtures in a nitrogen atmosphere. The rate of polymerization is proportional to [M]3/2, [AP]1/2 and [Ce(IV)]1/2. The rate of disappearance of ceric ion,–RCe, is proportional to [AP], [M], and [Ce(IV)]. The effect of certain salts, solvent, acid and temperature on both the rates have been investigated. A suitable kinetic scheme has been proposed, and the composite rate constants kp 2(k/k/t) and k0/ki are reported.

Acrylonitrile polymerization initiated by Ce(IV)–cyclohexanone redox system in presence of surfactant

“…The slope of the bilogarithmic plot of R P (obs) versus [AN] was found to be 1.5. These values are in good agreement with the results published by Santappa et al28 The rate of Ce(IV) consumption, − R Ce , was also linearly dependent on the monomer concentration, since the slope obtained from the log–log plot of − R Ce versus [AN] was approximately one. This may be due to greater number of monomers available in a favorable reaction site, that is, a micellar core or micellar interface.…”

“…Due to the electrostatic attraction of Ce(IV) for the Stern layer of SDS micelles, a greater number of Ce(IV) species were available at the micellar surface on increasing the concentration in the reaction mixture, which ameliorated the free‐radical formation, resulting higher values of R P (obs) . The square‐root dependence of R P (obs) on the Ce(IV) concentration was also reported by other workers earlier 27, 28. The rate of Ce(IV) consumption, − R Ce , has a linear dependence on the Ce(IV) concentration.…”

Vinyl polymerization of acrylonitrile by the Ce(IV)-glucose redox system

“…Termination of vinyl polymerization by metal ions (linear) is now well recognized [12,13]. A perusal of results reported in our earlier publications [8,9] indicates that both types of termination, i. e., mutual and linear are operative.…”

Kinetics of Vinyl Polymerization of Methyl Methacrylate Initiated by Ce(IV)‐Vanillin Redox System

“…Ceric ion has been used in vinyl polymerization in the presence of various organic reducing agents such as alcohols 7 , acids 8 , amides 9 , amines 10 , etc. Rout et al 11 have proposed a linear termination step involving interaction of polymer radicals with ceric ion 12 . The redox system involving complex between both an organic substrate and an inorganic salt was already reported [13][14][15] .…”