Chapter 8 - Self-healing Diels–Alder engineered thermosets

Abstract

Self-healing polymer materials in the past two decades have attracted great attention of the researchers due to their potential to overcome conventional polymers limitation, for example, recyclability, removability, and self-healing ability inspired by nature. The self-healing materials are able to restore their properties through different mechanisms. This chapter seeks to review the smart polymer networks based on the Diels–Alder (DA) cycloaddition reaction. First, a brief overview is provided on the different self-healing approaches. Subsequently a comprehensive description of DA-based thermohealable polymers, including their thermodynamics is briefly presented. As one of the main economic and environmental impacts of polymer thermosets are their disability to be repaired and/or reused, furan–maleimide DA reaction can be utilized to engineer healable, weldable, and reusable thermosets. Thus the diene and/or dienophile moieties can be a part of the polymer chains or their cross-linkers. The DA-based self-healable thermosets can be the matrices of polymer composites or the main part of the rubber compounds, surface coatings, polymer adhesives, hydrogels and actuators, and robots. The obtained products have potential to recover their initial structure and properties intrinsically. Therefore the application of DA chemistry for thermosetting polymers, leads to an expansion of their lifetime which is economically and environmentally beneficial, particularly when they are made from biosustainable starting materials.