ScholarWorks@중앙대학교

초록

Phase-change materials (PCMs) offer high latent heat and reversible solid–liquid transitions, making them promising candidates for thermal energy storage and management. However, their practical use is hindered by low thermal conductivity, leakage during melting, and poor flame retardancy. In this study, we develop a multifunctional PCM composite comprising a xylitol-grafted epoxy matrix (XYBPA) and a three-dimensional (3D) thermally conductive scaffold formed from hydroxylated boron nitride (BN) plates and SiO2 nanofibers. The 3D filler network was constructed via thermal gelation and freeze-drying using curdlan and alkyl polyglucoside, and subsequently infiltrated with the XYBPA matrix. The covalent bonding between xylitol and the epoxy backbone suppressed leakage and enabled stable phase transitions. The optimized composite with a BN:SiO2 ratio of 3:1 and 60 wt% filler content achieved a through-plane thermal conductivity of 3.81 W/m·K (1632 % improvement over the neat matrix), while retaining a latent heat of about 60 J/g. The composite exhibited negligible leakage up to 390 K, passed UL-94 V-0 flammability standards with a limiting oxygen index of 31.1 %, and showed enhanced mechanical strength (13.7 MPa) and high electrical resistivity (>109 Ω·cm). These results demonstrate that the synergistic integration of chemically functionalized fillers and covalently bonded PCM matrices offers an effective strategy for simultaneously addressing thermal, mechanical, electrical, and fire safety requirements in PCM-based systems.

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