Cure kinetics of a cyanate ester blended with poly(phenylene oxide)

The cure kinetics and mechanisms of a cyanate ester and its blends with poly(phenylene oxide) (PPO) were studied using differential scanning calorimetry and Fourier transform infrared spectroscopy. The results showed that blending with PPO has an effect on the cure reaction. Reaction rates of the cyanate ester blends were higher in the initial stage than that of the neat cyanate ester; however, the conversion reached decreased with increasing PPO content. Experimental data, showing autocatalytic behavior, were compared with Kamal's model which includes two apparent rate constants and two reaction orders. This model apparently describes well the kinetics, but diffusion control in the vitrified state limits the reactions from going further. By introducing a diffusion factor f(α) into this model, it becomes possible to predict the cure kinetics over the whole range of conversion.