Solvation effect in thermal decomposition of 2,2′‐azoisobutyronitrile

Abstract

The solvation effect in the thermal decomposition of a radical initiator (AIBN) in monomer–solvent mixtures is discussed. Equations were derived which comprise the initiator decomposition constant as a function of the monomer mole fraction for chosen types of solvation. In addition, equations were deduced presenting the concentrations and partial relative decomposition rates for the solvated initiator species as a function of the monomer mole fraction. The equations obtained were compared to the experimental literature data and possible dependences of decomposition constants on monomer concentration were simulated for various solvated species. The simulated relationships were found to be straight lines, curves of saturated type (possessing a plateau), S‐shaped curves, and maximum or minimum curves. © 1995 John Wiley & Sons, Inc.

Solvation effect in thermal decomposition of 2,2?-azoisobutyronitrile on theN,N-dimethylformamide/acrylonitrile system

“…It is evident that other explanations are possible but our point of view is consistent with the kinetic consequences in the next stage of polymerization." A solvation hypothesis brings in a conception of spectrum at the thermal decomposition rate constants of solvated forms instead of the decomposition constant of "free" initiator in solution and perhaps brings in notation of the radical reactivity spectrum formed by the decomposition of different solvated 3 forms, which will be an investigation subject of the other reaction of the polymerization of AN/ DMF/AIBN/60°C.…”

Kinetic study of the free‐radical polymerization of vinyl acetate in the presence of deuterated chloroform by 1H‐NMR spectroscopy

“…The solvent concentration dependence of the f value of AIBN has been reported for the homopolymerization of MMA and AN in DMF at 60°C 41, 42. This dependence has been interpreted on the basis of a model of initiator solvation by the monomer and solvent alone as well as by the mixed monomer/solvent 29, 31…”

“…The same results have been reported for the k d of AIBN in various solvent/monomer mixtures, such as N,N ‐dimethylformamide (DMF)/methyl methacrylate (MMA),27 DMF/acrylonitrile (AN),28, 29 and DMF/MMA/AN30 at 60°C. The dependence of the k d of AIBN on the solvent concentration (or equivalent [M]) has been interpreted on the bases of the hypothesis of initiator solvation by the monomer and solvent alone and by the mixed monomer/solvent 29, 31…”

Thermal decomposition of some azo initiators. Influence of chemical structure

“…Numerous experiments on the kinetics of the thermolysis of azo compounds have been reported in the litera-ture [23][24][25][26][27] . Invariably the thermal decomposition follows first order kinetics.…”