A Self-Folding Dynamic Covalent Shape Memory Epoxy and Its Continuous Glass Fiber Composite

Abstract

Continuous fiber reinforced thermoset composites are highly important in a variety of industrial applications because of their ultrahigh specific strength. However, conventional shaping techniques for such materials can hardly achieve very sophisticated shapes. In this paper, we present an unconventional method to enable complex shapes for continuous fiber reinforced thermoset epoxy composites that provided a capability of topology change due to the dynamic ester bonds. Thus, the corresponding composites providing largely enhanced mechanical strength can be endowed with complex permanent shapes via folding. At lower temperatures, the exchange reaction was frozen and the epoxy networks provided ideal shape memory behavior. Accordingly, the composites with complex permanent shapes enabled a self-folding shape recovery process. In addition, a laser half-cutting technique was applied to build controllable defects within the composites. As a result, more complex folding geometries which were extremely challeng...