Controlled composite processing based on off‐stoichiometric thiol‐epoxy dual‐curing systems with sequential heat release (SHR)

Abstract

AbstractControl of curing rate and exothermicity during processing of thermosetting composite materials is essential in order to minimize the formation of internal stresses leading to mechanical and dimensional defects in the samples, especially in thick composite samples. It was recently proposed that sequential heat release, an approach based on the kinetic control of the curing sequence of dual‐curing thermosets, would enable a step‐wise release of the reaction heat and therefore a better control of conversion and temperature profiles during the crosslinking stage. In this article, it is shown experimental proof of this concept obtained by means of an instrumented mold that can be used for the processing of small samples with and without carbon fiber reinforcement. Safe processing scenarios have been defined by numerical simulation using a simplified two‐dimensional heat transfer model and validated experimentally.