Phase change composites based on double-skeleton with melamine formaldehyde foam and boric acid/melamine aerogel for green buildings

The advancement of green buildings addresses the dual objectives of achieving comfortable living environments and reducing energy consumption . This study integrates the advantages of boric acid/melamine aerogel (BMA) and melamine-formaldehyde foam (MFF) to develop a MFF/BMA double-skeleton architecture. The BMA exhibits outstanding flame retardancy and thermal insulation properties , yet suffers from inadequate mechanical strength . MFF possesses considerable mechanical robustness, effectively enhancing the mechanical properties of BMA. Experimental results demonstrate excellent mechanical stability , with the composite maintaining structural integrity after 100 compression-recovery cycles at 50 % strain. MFF/BMA demonstrates exceptional thermal insulation , flame retardancy, and high solar reflectance (92.7 %), making it practically applicable for roof cooling and infrared stealth applications. Tetradecanol (TDC) was successfully stabilized and encapsulated into the MFF/BMA skeleton via melt impregnation, yielding the MFF/BMA@TDC phase change composite with an impressive energy storage capacity of 218.4 J/g. Notably, the bilayer structure combining MFF/BMA and MFF/BMA@TDC achieved sustained cooling performance. The bilayer architecture reduced surface cooling temperature from 65 °C to approximately 40 °C, demonstrating significant potential for green building envelope applications. • MFF/BMA unchanged for 100 compression-rebound cycles at 50% strain. • A bilayer structure was constructed by combining the heat transfer modes of aerogels and PCMs. • The bilayer structure reduces the roof surface temperature from 65 °C to 40 °C.