Triple-shape memory epoxy based on Diels–Alder adduct molecular switch

Abstract

In this work, we report a novel tripe-shape memory (TSM) strategy using glass transition and thermally reversible Diels–Alder (DA) reaction as two distinct switch units in a network. Based on this principle, a series of TSM epoxy materials were facilely prepared through the reaction of a conventional epoxy oligomer, an aliphatic diamine and a diamine DA adduct cross-linker via a one-pot approach. The thermal and thermal dynamic properties of the reversible–irreversible dual cross-linking epoxy network were studied by differential scanning calorimetry (DSC) analysis and dynamic mechanical thermal analysis (DMTA), respectively. The thermal reversibility of DA adduct was revealed by Fourier transform infrared spectroscopy (FTIR). The TSM effect of the epoxy materials was demonstrated and quantitatively studied by DMTA. The development of thermal-responsive DA adduct as a molecular switch provides a new insight into the design and functionalization of multi-shape memory polymers.