Nonlinear and complex cure kinetics of ultra-thin glass fiber epoxy prepreg with highly-loaded silica bead under isothermal and dynamic-heating conditions

In the advent of the miniaturized mobile devices, the packaging technology is required utmost high performance of the thin composite laminates in such materials properties as the coefficient of thermal expansion (CTE) and stiffness. Accordingly, the composition of a thermosetting resin becomes extremely complicated often including multiple fillers, monomers and/or catalysts in thermoset-based glass fiber prepregs. The prepreg systems is so complicated that it is usually difficult to obtain a reliable kinetic description and methodology that could be used for the complex thermal cycles including both isothermal and dynamic-heating segments in a facile manner. In this investigation, we propose an isoconversional kinetic using an ultra-thin glass fiber epoxy prepreg with highly loaded silica filler (the ultra-thin glass fiber/silica bead epoxy prepreg) as a model system. The activation energy was determined as a function of the conversion of curing reactions, which was fitted to linear models. The kinetic prediction using the linear models showed an excellent agreement to isothermal experiments. The master curve of a conversion-dependent function which derived from activation energy dependency used to investigate the complex reactions of the ultra-thin glass fiber/silica bead epoxy prepreg.