High-Strength and Shape-Memory Epoxy Cellular Material with Wood-Like Architecture

Abstract

Epoxy cellular plastics have been widely used in lightweight transportation vehicles and energy-efficient constructions due to their low density, excellent mechanical properties, and corrosion resistance. However, it remains a great challenge to develop a well-defined porous structure in conventional epoxy foam and thereby enhance their mechanical and thermal properties due to the competition between heating and thermosetting of epoxy resins during foaming processes. Herein, inspired by the structure of wood, we report a type of woodmimetic epoxy cellular plastic with well-aligned channels fabricated by a recently developed emulsion ice-templating technique. Despite a relatively low density (around 0.75 g/cm 3 ), the resulting epoxy cellular plastic achieves a high compressive strength (36.7 ± 3.4 MPa), which is 80% higher than that of the epoxy foam with similar density but prepared by conventional foaming processes. We further found that the as-prepared epoxy cellular plastic has a superior shape-recovery ratio (99.7%), which plays a key role in its adaptivity and reusability. In addition, ambient thawing was successfully utilized to replace the tedious freeze-drying process, making our fabrication method more favorable in both time and energy consumption. In addition, our research provides a feasible approach to prepare cellular materials with various biomimetic architectures and functions using a broad range of polymers.