Benzaldehyde decorated octadecylamine for tailor-made molecular firefighting and efficient thermal energy management

Abstract

• Benzaldehyde decorated octadecylamine for tailor-made thermal management. • Self-crosslinking of aromatic Schiff base for molecular firefighting. • Extensively reversible thermal transformation in a wide range of 30–100 °C. • Open a window for designing multifunctional phase change materials. More than 40% of the energy generated globally is consumed by residential and commercial buildings, so energy efficient materials for buildings are urgently needed at present. On-demand thermal energy storage/release using phase change materials (PCMs) can improve thermal energy utilization efficiency, however, they are facing low adaptability to temperature and easy flammability in the case of fulfilling high thermal management capacity. Herein, we report octadecylamine-based PCMs with tailor-made molecular firefighting and thermal energy management capability. These synthesized octadecylamine-based Schiff base-containing PCMs (SB-PCMs) may self-extinguish while encountering short-time fire and possess variable phase transition temperatures of 33, 42, 92, and 101 °C. Meanwhile, these SB-PCMs own high phase transition enthalpies of 161.4–183.4 J g −1 and excellent cyclic stability. When SB-PCMs as thermal energy management materials in wood plastic-based building materials, they show high adaptability to ambient temperature and excellent thermal management capability, achieving temperature regulation of 9.0 °C. Meanwhile, fire safety of the composite wood plastic materials is significantly improved. Detailed analysis confirms that the incorporated benzaldehyde with various positional substituted hydroxyl may induce noncovalent interactions (mainly hydrogen bond and π-π stacking) of SB-PCMs and further control their self-assembling processes, thus achieving multiple thermal responses of SB-PCMs; self-crosslinking charring of benzaldehyde-based Schiff base structure may retard fire spreading, therefore presenting molecular firefighting. Additional multistage thermochromic behaviors of SB-PCMs may extend their application in temperature-sensitive paint, intelligent fabric, etc. This work firstly represents a method for manipulating the multistage thermal and fire responses of PCM in the case of fulfilling high thermal energy management capacity and confirms its molecular-firefighting and energy efficient application in building materials.