Reaction mechanism of an unsaturated polyester system containing thickeners

The thickening process and curing reaction of unsaturated polyester resins were characterized by viscosity measurement and differential scanning calorimetry when a thickener was involved. Various kinetic parameters were determined by means of dynamic and isothermal experimental data and rheological process. The different values of activation energy reflected the different reaction mechanisms occurred in the curing course. Under isothermal conditions, polymerization reaction is one-order and diffusion-controlled reaction becomes significant when high concentration of thickener was applied.