Recyclable and Mechanically Robust Palm Oil-Derived Epoxy Resins with Reconfigurable Shape-Memory Properties

The development of sustainable epoxy resins from renewable biomass is gaining more and more attention. In most cases, chemically cross-linked biomass-derived epoxy resins are nonrecyclable. Here, mechanically strong and recyclable epoxy resins from palm oil that possess reconfigurable shape memory properties are developed. By converting palm oil-based methyl methacrylate monomers into epoxy monomers, high molecular weight palm oil-based epoxy polymers (EP) are prepared with high conversion. After being cured with citric acid (CA) without using any catalyst, palm oil-based epoxy resins (EP-CA) cross-linked with beta-hydroxyl ester groups are obtained. The EP-CA can rearrange the chemical network topology through transesterification reactions, which endows the materials with the ability to be recycled and reshaped. The EP-CA prepared via the epoxy polymer approach contains a well-defined network structure, resulting in remarkable mechanical properties. Moreover, the dynamic network structure allows the EP-CA samples to possess reconfigurable shape memory properties.