Development of thermoregulating microcapsules with cyclotriphosphazene as a flame retardant agent

• Published in: IOP conference series. Materials Science and Engineering 2017-10, Vol.251 (1), p.12120
• Main Authors: Szczotok, A M, Carmona, M, Serrano, A, Kjøniksen, A L, Rodriguez, J F
• Format: Article
• Language: English
• Subjects: Differential scanning calorimetry; Divinylbenzene; Energy storage; Flame retardants; Flammability; Monomers; Morphology; Phase change materials; Thermal energy; Thermal stability; Thermogravimetric analysis
• ISSN: 1757-8981; 1757-899X
• DOI: 10.1088/1757-899X/251/1/012120

Thermoregulating microcapsules containing phase change material (Rubitherm®RT27) was produced by using the suspension-like polymerization technique with styrene (St), divinylbenzene (DVB) and hexa(methacryloylethylenedioxy) cyclotriphosphazene (PNC-HEMA) as co-monomers. The effect of PNC-HEMA for improving the flame retardant properties of the microcapsules were analyzed by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). It was found that the thermal energy storage (TES) capacity of the microcapsules increased in the presence of PNC-HEMA. However, the morphology of the microcapsules became irregular when the content of monomer with flame retardant properties was increased. Thermogravimetric analysis performed under atmospheric air confirmed that the PNC-HEMA raised the amount of residue after the burning process, proving the formation of thermally stable char. Thus, these materials could be considered as an important alternative to commonly used microcapsules containing phase change materials (PCMs), where a lower flammability is required for their application.