In-situ cure monitoring of epoxy/graphene nanocomposites by several spectroscopic techniques

Abstract

Cure protocols of thermoset resins usually comprise two isothermal steps where resins undergo molecular cross-linking processes. The cure conditions are crucial to ensure a consistent and reliable manufacturing of the piece and have been the subject of an important body of research. While most studies have been carried out by traditional calorimetry or infrared spectroscopy under dynamic conditions, the development of new sensors and in-situ characterization techniques has resulted on a renewed interest on the subject under industrial isothermal protocols. Here, we monitor the curing reaction of both un-filled and nanofilled epoxy resin using broadband dielectric spectroscopy (BDS) and correlate the results with in-situ FT-IR and Raman spectroscopy. Hence, the proposed methodology provides complementary information on the chemical reactions and molecular dynamics associated to the cure cycle and can be an efficient tool for real-time monitorization of thermoset composites manufacturing.