Master curve and time–temperature–transformation cure diagram of a polyfunctional epoxy acrylic resin

The curing reaction of a well‐defined glycidyl methacrylate‐co‐butyl acrylate statistical copolymer, prepared by atom transfer radical polymerization, and a commercial linear diamine (Jeffamine D‐230) was studied with the objectives of constructing and discussing a time–temperature–transformation isothermal curing for this system. Thermal and rheological analyses were used to obtain the gelation and vitrification times. Differential scanning calorimetry data showed a one‐to‐one relationship between the glass‐transition temperature (Tg) and fractional conversion independent of the cure temperature. As a result, Tg was used as a measurement of conversion. We obtained a kinetically controlled master curve for isothermal curing temperatures from 50 to 100°C by shifting Tg versus the natural logarithm time data to a reference temperature of 80°C. We calculated the apparent activation energy by applying two different methods, gel time measurements versus shift factors, suggesting a good agreement between them. Isoconversion contours were calculated by the numerical integration of the kinetic model.