Modeling of Cure Kinetics and Rheological Behavior of an Epoxy Resin Using DSC and Rheometry

TL;DR

The paper develops and validates models for the curing and rheological behavior of an epoxy resin used in composites.

Contribution

The novel contribution is the development and experimental validation of a rheological model and an autocatalytic curing kinetics model for an epoxy resin.

Findings

The rheological model accurately predicts viscosity evolution with temperature and time.

The autocatalytic curing kinetics model was verified through isothermal experiments.

Both models provide practical guidance for processing and forming epoxy composites.

Abstract

Epoxy resins with excellent overall performance, are widely used in aerospace, automotive, and related fields, frequently in combination with reinforcing fibers to fabricate composites. To enable controllable epoxy processing for prepreg fabrication and composite forming, a rheological model and a curing kinetics model were developed and experimentally validated for an epoxy resin. Rotational rheometry was conducted to quantify the viscosity evolution with temperature and time, enabling construction of a corresponding rheological model. Comparison between model predictions and experimental measurements exhibited a high level of consistency across a wide temperature range. Furthermore, differential scanning calorimetry (DSC) was employed to measure heat-flow curves at different heating rates. The degree of curing was calculated from the heat-flow data, and an autocatalytic curing kinetics model was established based on a reaction kinetics formulation. And the accuracy of the model was verified by isothermal experiments. The developed rheological model provides a theoretical basis and practical guidance for resin processing and prepreg fabrication, whereas the curing kinetics model supports the design and control of curing and forming schedules for epoxy-matrix composites.

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