Study of curing kinetics of ladder-like polyepoxysiloxane

Summary

We report on the curing kinetics of three ladder-like polyepoxysiloxanes synthesised by us, namely, AC (with the alkyl groups and epoxy groups grafted to the ladder like main chain), ACP (with the alkyl group, phenyl groups and epoxy groups grafted to the ladder like main chain) and AP (with the phenyl groups and epoxy groups grafted to the ladder like main chain). We also describe the curing behavior of these three polyepoxysiloxanes studied, both in the absence and presence of a curing agent, 1,3-bis(3-aminopropyl)tetramethyldisiloxane. The apparent activation energy required for curing was calculated using the Ozawa method, and was further verified by the Kissinger method. The activation energies follow the order: AC > ACP > AP. The apparent activation energy for AP-CA (AP in the presence of the curing agent) was found to be a little lower than for AP. The curing behavior was also observed using the FTIR technique. Following the curing, the IR bands at 940, 930 and 834 cm⁻¹ that are associated with the epoxy groups disappeared and a new peak appeared at 920 cm⁻¹, which suggests that the epoxy groups reacted completely.