Kinetics of Polycycloaddition of Flexible & alpha;-Azide-& omega;-Alkynes Having Different Spacer Length

Two flexible a-azide-?-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.