Kinetics of Polycycloaddition of Flexible α-Azide-ω-Alkynes Having Different Spacer Length.

Two flexible α-azide-ω-alkynes differing in the length of the hydrocarbon spacers (C 8 vs. C 12 ) between functional groups are synthesized. Their bulk polymerization kinetics is studied by differential scanning calorimetry (DSC) and parameterized with the aid of isoconversional methodology. The monomer with a shorter hydrocarbon spacer has somewhat greater reactivity. The effect is traced to a moderate increase in the effective value of the preexponential factor that arises from the fact that the respective monomer has a higher initial molar concentration in itself. The techniques of GPC and NMR provide additional kinetic and mechanistic insights into the studied reaction.