Kinetic analysis of isothermal curing of unsaturated polyester resin catalyzed with tert-butyl peroxybenzoate and cobalt octoate by differential scanning calorimetry

Abstract

The curing kinetic analysis of unsaturated polyester (UP) with tert-butyl peroxybenzoate (TBPB) and cobalt octoate (CoOct) was investigated by differential scanning calorimeter. It was found that apart from enhancing the curing reaction, the less time and lower temperature to cure will be both achieved by the addition of promoter (CoOct). To further study the UP/TBPB/CoOct system, the automatic Kamal model was applied to the experiment. According to the thermokinetic parameters that were evaluated by the automatic Kamal model, the results show that the experimental data fit well with the Kamal model fitting except in the last stage. Considering about the different effects of diffusion control and curing control on the experimental system, a diffusion factor was introduced into the Kamal model; consequently, the fitting results were much better than with Kamal model. Modified Kamal model with diffusion factor was proven to be more suitable for UP resins cured with TBPB and CoOct, since the isothermal runs of differential scanning calorimeter can predict time profiles successfully during the molding process.