Polymerisation of acrylonitrile by V⁵⁺/cyclohexanol‐redox system

Abstract

The effects of the concentrations of monomer, cyclohexanol, V5+, H,SO,, HSO,, SO:-, Cland ionic strength a t 40 to 6OoC on the rate of V5f disappearance and the rate of polymerisation of acrylonitrile were studied. From the experimental results, it was concluded that the organic free radicals formed during the decomposition of the V5f-cyclohexanol complex, initiated polymerisation and that the polymer radicals were terminated by V5+ ion. An appropriate kinetic scheme was proposed and the various rate and energy parameters were evaluated. ZUSAMMENFASSUNG:Die Abhangigkeit der Polymerisationsgeschwindigkeit des Acrylnitrils und der Geschwindigkeit des Verschwindens des V5+ von den Konzentrationen von Monomerem, Cyclohexanol, V5+, H$O, HSO,, SO:-, C1-sowie von der Ionenstiirke wurde untersucht, und zwar bei Temperaturen zwischen 40 und 6OoC. Aus den experimentellen Ergebnissen wird abgeleitet, daB die Polymerisation durch Radikale gestartet wird, die durch Zerfall eines V5+-Cyclohexanol-Komplexes entstehen, und daB die Makroradikale durch das V5+-Ion desaktiviert werden. Die verschiedenen Geschwindigkeits-und Energieparameter w r d e n bestimmt, und es wird ein kinetisches Schema vorgeschlagen.

Polymerization of methyl acrylate initiated by V(V)-cyclohexanone redox system in micellar phase

“…39 Lot of work has been done on the kinetic studies of vinyl polymerization using V(V) -organic substrates as redox systems. [40][41][42][43][44] The presMethod ent piece of work deals mainly with polymerization of methyl acrylate (MA) initiated by a V(V)-…”

Micellar effect on quinquivalent vanadium ion oxidation of D‐glucose in aqueous acid media: A kinetic study

“…Earlier studies 7,38,39 have indicated that the form of the active vanadium(V) species depends on acid types and their concentration range. It has been established by the earlier workers 7,38,39 that in aqueous sulfuric acid media (⩽4.5 mol dm −3 ) the kinetically active species of vanadium(V) is [V(OH) 3 HSO 4 ] + and the equilibrium leading to this active species is given by 7,38–41 In the same way, the results obtained in higher acid concentration range (>4.5 mol dm −3 ), the following equilibria can be considered to be operative 42 for the formation of the active species in this range: The result can be explained by considering the proposed mechanism (Scheme ) The pseudo‐first‐order rate constants ( k obs ) in the presence of various concentrations of different types of surfactants, SDS (sodium dodecyl sulfate, a representative anionic surfactant), CPC ( N ‐cetylpyridinium chloride, a representative cationic surfactant), and TX‐100 (Trion X‐100, a neutral surfactant), are presented in Table I.…”

Effects of surfactants on acrylonitrile polymerization initiated by a Cr(VI)–cyclohexanone redox system: A kinetic study

“…A plot of the reciprocal of R p (obs) versus the Cr(VI) concentration is linear (Fig. 3), indicating linear termination 20 . R Cr also increased with an increasing Cr(VI) concentration in the presence of 0.015 M SDS.…”