(633b) Microencapsulation of Flame Retardants Using Bio-Based Materials

The development of non-toxic and durable flame retardant fabrics using surface treatment methods is of interest for numerous applications. However, most approaches currently reported for surface treatments render the fabric stiff and non-breathable. Microencapsulation is a strategy that can be used to incorporate additives onto textiles. We present an approach to encapsulate flame retardants using safe bio-based materials and coat them onto a Nylon-Cotton (NyCo) fabric surface. A phosphorous-based flame retardant, melamine polyphosphate, is encapsulated using bio-based materials like gelatin and tannic acid, a plant-based polyphenol. The process parameters such as concentration of ingredients, reaction time, and stirring rate are varied to optimize encapsulation efficiency and flame retardant properties. The microcapsules are characterized using Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDX), Particle Size Analyzer, and FTIR-ATR. The thermal stability and heat release characteristics of these capsules are studied using Thermogravimetric Analysis (TGA) and Pyrolysis Combustion Flow Calorimetry (PCFC), respectively. The flammability of microcapsule-coated fabric swatches is studied using a Vertical Flame Tester (VFT). Flammability data shows that the microcapsule coating imparts flame retardant characteristics to the fabric. Use of safe flame retardants and encapsulating materials opens new possibilities for safer and durable flame retardant solutions for fabrics using a microencapsulation approach.