Novel self‐healing Diels–Alder (DA) polymer and the corresponding semi‐interpenetrated polymer networks (semi‐IPNs) were synthesized and characterized. Initially, a furan‐functionalized resin (FFR) was synthesized through the ring‐opening reaction of a conventional epoxy resin [diglycidyl ether bisphenol A (DGEBA)] with furfuryl alcohol as a bio‐based compound. Subsequently, semi‐IPNs with different compositions were obtained through the blending of DGEBA, FFR, 4,4′‐diaminodiphenylmethane, and 1,1′‐(methylenedi‐1,4‐phenylene) bismaleimide in the molten state by following a predetermined time–temperature program. Fourier transform infrared and nuclear magnetic resonance analyses confirmed the successful synthesis of the materials. Thermoreversibility via retro‐DA (rDA) reaction was evidenced by differential scanning calorimetry (DSC) and sol–gel transition tests. Repeated DSC cycle was successfully performed thrice on the DA polyadduct which corroborated repeatability of the DA/rDA association/dissociation. Self‐healing and mechanical properties were preliminarily evaluated by scanning electronic microscopy and flexural testing analyses, respectively. The self‐healing efficiencies were around 80 and 95% for semi‐IPN and DA polyadduct, respectively, based on flexural strength. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48015.