The Polytannic Acid-Fe3+ Functionalized Graphene Oxide in Poly (Propylene Carbonate) Nanocomposite Enables Enhanced Shape Memory, Uv-Resistance and Self-Healing Performance

Abstract

The substrate materials used for human wearable devices need to have shape memory and self-healing properties that can be triggered at human body temperature. Poly (propylene carbonate) (PPC) featuring proper triggering temperature, excellent ductility, as well as biocompatibility, seems as a promising candidate. However, its poor heat resistance and susceptibility of molecular chains to thermal viscous flow usually result into poor shape recovery and difficulty in thermally induced self-healing constrain. To resolve this issue, it is effective to construct physical or chemical cross-links within polymer. Therefore, we introduced tighter network of hydrogen bonds inside the polymer to inhibit the viscous flow of the molecular chains. We prepared an encapsulated structure of poly (tannic acid) (PTA)@graphene oxide (GO) with the help of iron ions to improve the shape memory and interfacial self-healing. Compared with pure PPC, the obtained 5wt% FPTA@GO/PPC composite films exhibited superior shape fixation ratio (99%), human body temperature triggering shape recovery ratio (94%), while maintaining a specific shape at room temperature and returning to its original state in ~10s with heat treatment. Moreover, the prepared materials possessed a self-healing efficiency (81%), enhanced service temperature and increased tensile strength (17.2 Mpa). In addition, the UV absorption capacity of the material was increased by 180% (far and mid-UV regions) and 480% (near-UV region). These advantages show great potentials in developing shape memory, self-healing and UV-resistant substrate materials for human wearable devices.

Keywords: shape memory, self-healing, polypropylene carbonate, graphene oxide, wearable device