Eugenol-Derived Molecular Glass: A Promising Biobased Material in the Design of Self-Healing Polymeric Materials

One kind of molecular glass material was prepared via the epoxidation of eugenol and a subsequent thermochemical conversion process. This biobased molecular glass (ET-eugenol) shows high potential in the design of self-healing materials while being incorporated into a polymeric matrix to form a multiphase system. Here, an ET-eugenol/polymerized soybean oil (p-ESO) system with a mass ratio of 1:2 was investigated. Results show that the scratch damage can be healed effectively at a temperature of 90 °C within 15 min or by ultraviolet radiation within seconds. Good dimension stability even at high temperatures can be kept in the whole healing process. A mechanical tensile test shows that compared to the neat p-ESO matrix the incorporation of ET-eugenol (weight percent of 33%) led to a 2.7-fold increase in ultimate stress and a healing efficiency up to 88%. Gel permeation chromatography, nuclear magnetic resonance, and gas chromatography–mass spectrometer were carefully conducted to reveal the complex thermochemical reaction during the preparation process of ET-eugenol. Self-healing behaviors were characterized via atomic force microscope and optical images, and the corresponding healing mechanism was discussed from a multiphase structural viewpoint. The work reported here demonstrates the possibility of molecular glass as a promising candidate in the design of self-healing materials.