Kinetic study of phenolic resin cure by IR spectroscopy

The cure reaction of a commercial phenolic resin (FRD-5002, Borden Chimie S.A.) has been studied by IR spectroscopy (Fourier transform IR). A phenomenological approach was used to characterize the kinetic of reaction. Various kinetic models, including homogeneous reactions, diffusion-controlled reactions, phase boundary movement, and nucleation and growth-type kinetic, have been tested. Kinetic analyses using integral procedures on isothermal data indicate that the cure reaction data can be described above 140°C using the homogeneous first-order reaction model. The activation energy has been found to be about 49.6 kJ mol−1. At lower temperature, a diffusive mechanism was active, and the kinetic of reaction was well described by the Jander kinetic model. Because of the simple kinetic control active above 140°C, a mechanistic model for the resol cure at these temperatures has been also proposed.