Cure behavior of UP/Org-MMT/MEKP/cobalt octoate nanocomposites by the Dynamic Torsional Vibration Method

The cure behavior of unsaturated polyester(UP)/organo-montmorillonite (Org-MMT)/methyl ethyl ketone peroxide (MEKP)/cobalt octoate intercalated nanocomposites at varying temperatures and Org-MMT loadings was investigated by the Dynamic Torsional Vibration Method (DTVM). The apparent kinetic parameters of the cure reaction, including the gelation time t_g, apparent activation energy E_a, and curing rate, etc., were estimated by Flory's gelation theory, non-equilibrium thermodynamic fluctuation theory, and Avrami equation. The theoretical prediction is in good agreement with the experimental re suits obtained by the DTVM. The gelation time t_g increases, and the rate of curing reaction decreases, with increasing Org-MMT loadings, but there is no obvious effect of Org-MMT on the apparent activation energy E_a and the curing process of nanocomposites. A two-step cure process of UP was observed due to the addition of Org-MMT.