Characteristic features of THF polymerizations

Many kinetic studies of the polymerization of THF have been carried out. From these a number of characteristic features of the polymerization have emerged. 

The polymerization of THF approaches an equilibrium between monomer and polymer at every temperature. That is, for every temperature there is an equilibrium monomer concentration, [M]e, that is thermodynamically determined. Also there is a temperature,, above which no polymerization will occur. A value for of 85 2°C was derived for bulk polymerization of THF using PFg counter-ion [72, 73]. Dainton and Ivin [74] have related [M] to the absolute temperature, T, and to the enthalpy change, Affss, and entropy change, AS°, upon the conversion of 

Some readers will be interested in the fact that Huang and Wang [75] in 1972 presented a newer theoretical treatment of the reaction kinetics of reversible polymerization in which this classic derivation of Dainton and Ivin is a special case. The thermodynamics of equilibrium polymerizations have recently been reviewed by Sawada [76]. 

Equation (4) holds for ideal systems but as is well-known most polymer solutions do not behave ideally. Hence the thermodynamic treatment of equilibrium polymerization has been reassessed to take this into account [77—79]. The revised theory has been applied to THE polymerizations in the 15—50°C range [80]. For the purpose of this evaluation the variation of [M] e is expressed by 

Still a different approach toward determining and ASp. has been 

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