Transparent wood-based phase change finishing materials for outdoor furniture surface thermal management inspired by the greenhouse effect

Outdoor furniture is prone to surface undercooling or overheating due to climate variations, severely compromising user comfort. In this study, polyethylene glycol (PEG) was melt blended with epoxy resin (EP) and impregnated into delignified wood (DW) to create a transparent wood-based phase change energy storage finishing material (TW-PEG). The porous structure of DW and the cross linked network of EP jointly formed a dual encapsulation system, effectively preventing PEG leakage. Benefiting from the excellent heat storage and temperature control properties of PEG, the TW-PEG exhibited a melting enthalpy of 102.15 J/g, demonstrating remarkable thermal energy storage capacity. Moreover, under heating conditions, TW-PEG delayed the time to reach 40 °C by 670 s compared with natural wood (NW), while during cooling, it prolonged the time to decline to 25 °C by 2212 s, indicating superior temperature regulation performance. When TW-PEG was used as a finishing material combined with NW (TW-NW) to simulate outdoor furniture, after 4500 s of xenon lamp irradiation, the temperatures on the irradiated and shaded sides were 36.2 °C and 36.9 °C, respectively. Compared to the NW-NW and TW-TW combinations, these values were reduced by 6.8 °C and 3.6 °C, and increased by 3 °C and 4.3 °C, respectively, indicating that the TW-NW combination effectively mitigates overheating and excessive cooling. This performance originates from the synergistic effect of the greenhouse-effect-inspired design and the temperature regulation capability of PEG. In addition, TW-PEG also exhibited good durability. Therefore, TW-PEG shows promising application potential in the field of outdoor furniture. • Composite materials offer temperature regulation capability. • The dual encapsulation system enhances leakage resistance. • A bioinspired greenhouse effect enables solar energy utilization. • The composite exhibited thermal energy storage capability.