Chemorheological study of a polyfurfuryl alcohol resinsystem — Pre-gel curing stage

The rheological and chemorheological behavior of a new biomass-based polyfurfuryl alcohol (FA) resinaimed to be used as a matrix in composite materials is studied in this work. The viscosity dependenceon the shear rate and temperature of the resin is studied under steady and oscillatory conditions. TheFA resin exhibits a Newtonian flow behavior within the shear rate range tested.

The dependence of theviscosity of the uncured resin on temperature is measured and modeled. The flow activation energy, ascalculated by the Arrhenius model, is 63.3 kJ mol−1. The chemorheological study of the curing processshowed that the flow activation energy of the resin is increased when the amount of catalyst is increased.Furthermore, the curing parameters of the FA resin using three amounts of catalyst of 2, 4, and 6% (w/w),are obtained by the Arrhenius model.

The curing activation energy is found to be about 96 kJ mol−1andwith no dependence on the amount of catalyst. However, a significant difference of the logarithm ofthe pre-exponential curing parameter is found. This parameter increases from 28.9 to 30.7 when theamount of catalyst is increased from 2 to 6% (w/w).

Based on the established values of the Arrheniusmodel parameters, predictions are made for the evolution of viscosity of the resin during isothermalcuring with different temperatures, and different amounts of catalyst. This is of great importance inthe design of the curing processes of the FA resin during development and improvement of compositemanufacturing processes.© 2013 Elsevier B.V.

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