Nonisothermal cure kinetics in the synthesis of polybenzoxazine-clay nanocomposites

The ability to understand and model the mechanism of cure kinetics accurately is crucial for the production of thermosetting resin-based nanocomposites. This article reports on work performed to elucidate an accurate model of cure kinetics for the formation of polybenzoxazine-montorillonite nanocomposites through the use of differential scanning calorimetry with nonisothermal methods, including single-heating and multiple-heating methods. The results indicated that both the Kissinger and Ozawa methods for calculating the activation energy gave fairly close results of 115 and 120 kJ/mol, respectively. The reaction order was about 1.31, calculated from the single-heating method based on the autocatalytic method, and a comparison was made of the dynamic curing behaviors in the syntheses of polybenzoxazine and polybenzoxazine-montorillonite nanocomposites. (C) 2003 Wiley Periodicals, Inc.