Journal of Applied Polymer Science, Vol.124, No.6, 5122-5129, 2012
Rheokinetic of a gelled resol resin curing by dynamic-temperature rheometry based on rectangular torsion strain
The rheological behavior of a phenolic resol resin during its curing process was studied through a rheological dynamic-temperature analysis. Two heating ramps from 0 to 120 degrees C (1 degrees C/min) and from 0 to 150 degrees C (5 degrees C/min) were performed. The resin's complex viscosity data were obtained by applying a rectangular torsion strain. The overall change of complex viscosity with temperature was due to a combination of thermal softening, described by the Andrade equation, and the resin crosslinking process. The four- and six-parameter Arrhenius rheokinetic model was applied to the profiles obtained for the resin's complex viscosity, and the viscous flow and activation energies of curing kinetics were established. Two calculation methods are proposed to obtain the flow and curing parameters of the material. The six-parameter Arrhenius model was more suitable for predicting changes in the resin's complex viscosity, obtaining an activation energy of similar to 38.0 kJ/mol for the resol resin curing process. (c) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011