Evaluation of a method for the determination of optimal curing conditions for unsaturated polyesters

By measuring the residual enthalpy of curing of a partially cured unsaturated polyester resin, it is possible to determine the degree of curing. This method has the advantage of directly measuring the chemical process of curing itself and not a secondary property dependent on the degree of curing. Due to the complexity of the reaction, it is not possible to calculate the conditions for an optimal curing. Use of a DSC (differential scanning calorimetry) oven with its precise temperature setting allows complicated curing cycles to be simulated. At any point of the heating curve, the residual enthalpy of curing can be measured and the progress of curing can be monitored. It is also shown that there are differences in the resin systems according to the nature of the initiating radicals, especially with respect to the possibility of interrupting the curing process and starting it again when using C-C-unstable initiators