Effect of Grubbs' catalysts on cure kinetics of endo-dicyclopentadiene

The cure kinetics of endo-dicyclopentadiene (endo-DCPD), activated by recrystallized 1st and 2nd generation Grubbs' catalysts, were investigated by dynamic differential scanning calorimetry (DSC). The experimental DSC data were analyzed to evaluate kinetic parameters using model-free isoconversional method and model-fitting method. It revealed that model-free isoconversional method predicted best with the experimental data for endo-DCPD with the 1st and 2nd Grubbs' catalysts. The 2nd generation catalyst system showed a slower initiation rate but a faster polymerization rate than the 1st generation. The activation energy (E) and pre-exponential factor (A) were found to be larger in the 2nd generation system. Furthermore, the variation of E and A values vs. fractional conversion was established in the model-free isoconversional method, from which the reaction mechanisms were discussed.