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Abstract

Kinetics of isobutyl vinyl ether polymerization initiated by Ph3C+SbCl6 in CH2Cl2 were reexamined by using adiabatic calorimetry and spectrophotometry as previously applied to p-methoxystyrene polymerization. Consumptions of monomer and trityl hexachloroantimonate were followed simultaneously in the temperature range −40° to +25°C. Initiation appeared to be slow (incomplete initiator consumption at temperature equal to or lower than 0°C), and significant transfer and termination processes prevent the system to be considered as “living” (active-centers concentration goes through a maximum during the polymerization). The initiation step was found to be first-order with respect to monomer and to initiator, and an overall second-order with respect to monomer was found for the polymerization. Initiation parameters were separately determined, whereas propagation, transfer to monomer, and termination parameters were computed on the basis of a unimolecular termination process, this leads, for example, to the following rate constants at 0°C and to the activation energies of corresponding reactions:

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