An out-of-oven curing technique for epoxy resin via magnetic particle-induced in situ heating

Out-of-oven curing of epoxy resins with economical and energy-efficient techniques is vital for manufacturing advanced composite structures. In this study, the effects of a magnetic particle (MP)-induced in situ heating technique on the heating temperatures and mechanical properties of epoxy resins were investigated. The results showed that the proposed technique quickly increased the epoxy resin temperature and steadily heated the polymer until it was fully cured. With increasing MP concentrations from 6 wt% to 22 wt%, a notable increase in the heating ratio from 3.27 °C/min to 8.96 °C/min and steady increases in the heating temperature from 92.61 °C to 115.03 °C were observed. Surface modification of the MPs improved the homogeneity of the heating field and cross-linking and also increased the heating ratio and steady heating temperature. With merely 2.5 h of induction heating, the flexural moduli and strengths of functionalized MP/epoxy samples with MP loads of 6 wt%, 13 wt% and 22 wt% were 45.1%, 42.8%, 40.5% and 6.3%, 33.5%, 39.4% higher than those of oven-cured control samples. These findings provide essential knowledge for fabricating advanced polymeric composite structures without an oven.