Polymerization of 2-Oxazolines. II. Kinetics of the Cationic Polymerization of 2-Phenyl-2-oxazoline Initiated by Oxazolinium Perchlorate in N, N-Dimethylacetamide Solution

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Abstract
The solution polymerization of 2-phenyl-2-oxazoline in N, N-dimethylacetamide media was carried out at 120-150°C with the use of the oxazolinium salt of monomer and perchloric acid as an initiator. A marked acceleration in rate was observed in the early stage of polymerization. After the period of acceleration the polymerization rate and the moles of polymer chains were shown to remain constant, whereas the number-average degree of polymerization increased almost proportionally with an increase in the degree of conversion. The kinetic discussion, divided into two stages, gave the following results: an early stage of polymerization with slow initiation where the moles of the active propagating species increased, and a later stage with a stationary state where the moles of the active propagating species remained constant and the growth of polymer chains proceeded. The kinetics was reformulated as a function of the differential monomer concentration. The simulation of the kinetics with the use of the rate constants of initiation and propagation reactions obtained experimentally expressed the experimental facts.