A Triple-function EUG/EVA foam with integrated shape memory, hydrophobic/oleophilic, and thermal management

The development of advanced materials that combine multiple stimulus-responsiveness with sustainable credentials stands as a key frontier in modern polymer science. In this study, we report a novel multifunctional shape-memory foam prepared from renewable Eucommia ulmoides gum (EUG) and ethylene-vinyl acetate (EVA) using a facile one-step chemical foaming method. Moving beyond conventional single-function materials, this work achieves a synergistic structural design that simultaneously delivers outstanding thermal responsiveness, tailored surface activity, and efficient thermal insulation. At the optimal EUG/EVA ratio (70/30), the foam exhibits remarkable temperature-responsive shape-memory performance, with shape-fixity and shape-recovery ratios exceeding 98% and 91%, respectively. The surface is designed to be strongly hydrophobic, reaching a water contact angle of 147.1°, which enables highly selective and efficient absorption of oils and organic solvents, with uptake capacities surpassing 15 g/g. Moreover, the well-defined closed-cell morphology imparts excellent thermal insulation, yielding a low thermal conductivity of 0.049 W m −1  K −1 . This pioneering integration of intelligent shape memory, superior hydrophobic/oleophilic selectivity, and effective thermal insulation into a single eco-friendly platform paves the way for next-generation smart materials toward applications in environmental remediation, adaptive packaging, and thermal management.