Magnetic fiber enabled curing electrogram: Real-time process monitoring for thermosetting polymer materials

The curing behavior of thermosetting polymer materials is crucial to the quality and performance of their composite products, which promotes the development of the curing process monitoring. A novel strategy for real-time monitoring of the curing process of thermosetting resin using magnetic fiber (MF) with sensitive stress impedance effect is proposed. Differential scanning calorimetry and dynamical mechanical analysis are performed to obtain the curing degree, modulus, and glass transition temperature (Tg) as a calibration curve to establish a relationship with the impedance of MF embedded in resin during the curing cycle, which is determined by the internal stresses around the MF mainly induced by the crosslinking reaction and cooling shrinkage of resin. The dynamic physical properties of epoxy resin during curing process can be effectively and continuously monitored in real-time through the curing electrogram from the integrated MF sensor signal output, which can digitalize the evolution of resin crosslinking reaction and capture the gelation point, Tg and local mechanical state. The MF sensors for curing process monitoring is a promising technology to be developed into a life-cycle structural health monitoring of polymer composites and instrumental to their smart manufacturing advancement. [Display omitted]