Fabrication of flame-retardant phase-change materials for photo-to-heat conversion and flame-retardant mechanism

Phosphorus-modified hexadecanol is regarded as a promising heat storage medium for form-stable phase-change materials (FSPCMs) because of its high energy storage density and good thermal stability. In this study, a novel FSPCM was fabricated using phosphorus-modified hexadecanol, 1-oxo-4-hydroxymethyl-2,6,7-trioxa-l-phosphabicyclo [2.2.2] octane (PEPA), and pentaerythritol (PER). Among all the samples, FSPCM (P3), containing 9 % PEPA and 3 % PER, exhibited the optimal thermal storage performance and flame-retardant properties. Its latent heat was 122.5 J/g, and its photo-to-heat conversion efficiency was 61.8 %. The limiting oxygen index of P3 approached 29.5 %, and the UL-94 V-0 rating was attained. The decomposition and fire-retardant mechanism were inferred based on the analysis of char residues and the gaseous phase to determine the interaction between the PCMs and flame retardants.