Isothermal kinetics of photopolymerization and thermal polymerization of bis-GMA/TEGDMA resins

The purpose of this work is to analyse certain kinetic features related to thermoinduced and photoinduced isothermal curing in the 25/75 mass% bis-GMA/TEGDMA system. The kinetic parameters associated with photo and thermal curing were determined and compared using an isoconversional procedure and the kinetic model was obtained by means of a reduced master plot. In photocuring, the kinetic results obtained by means of this phenomenological methodology were compared with those obtained on the basis of mechanistic considerations. In this case, we estimated the propagation and termination constants associated with photocuring at different conversions. When the phenomenological procedure is performed, the rate constant decreases slightly during the curing process and the autoacceleration effect of the process is demonstrated in the kinetic model, which is autocatalytic. However, in the mechanistic model, this same effect is noted through an increase in the rate constants, while it is assumed that the kinetic model is in the order of n with n=1. © 2008 Springer Science+Business Media, LLC.