Optimizing cure cycle of nanoclay-reinforced unsaturated polyester resins considering various curing kinetic models

Abstract

In this research, a method has been presented for optimizing cure cycle of neat unsaturated polyester resin and polyester resin containing 3 wt% nanoclay Cloisite® 10 A (UP/10 A) and nanoclay Cloisite® 30B (UP/30B) in thin components. We refer to this optimization method as the directed grid search method. To model cure behaviour of unsaturated polyester resin, four different kinetic models were considered, including advanced iso-conversional method, Kamal method, Kamal method with Chern diffusion factor, and Kamal method with Sbirrazzuoli diffusion factor. The comparison of our proposed optimized cure cycles indicates that addition of nanoclay to the resin causes the cure cycle duration and also the maximum temperature during the cure to decrease. In addition, by adding nanoclay to the resin, the optimal cure cycle is transformed from a five-stage cure cycle to a four-stage one. Our investigations indicate that optimal cure cycles for the UP/10 A and UP/30B systems do not significantly differ. This is because the pre-exponential factor can influence the optimal cure cycle as much as the activation energy. Our results show that the optimal cure cycle obtained from the Kamal model is much shorter than the optimal cure cycle obtained from the advanced iso-conversional method, while the optimal cure cycle obtained from the Kamal model with Chern diffusion factor is very similar to the cure cycle resulting from the advanced iso-conversional method.