Environmental-friendly recycled Polyester/Mg(OH)2 nanocomposite: Fire-retardancy and thermal stability

Abstract

Fire retardant composites have had a global concern; these composites are mainly composed of halogens/synthetic fibers fire retardant fillers with synthetic polymers. This work aims to utilize green recycled polyester (Rec PE) matrix, obtained from recycled polyethylene terephthalate and natural oleic acid, with high surface area eco-friendly and non-toxic halogen-free Mg(OH)2 nanoparticles to obtain novel environmental friendly Rec PE-Mg(OH)2 fire retardant nanocomposite with superior properties, for the first time. Mg(OH)2 nanoparticles ~75 nm were synthesized and characterized by XRD, DLS and SEM. Then Rec PE matrix was filled by 5, 10, 15 and 20 wt% nanofiller and finally cured via “in-situ polymerization” to have Rec PE-Mg(OH)2 nanocomposites. The improved ratio is 15% that achieved the most effective fire retardancy due to increase time to ignition and decrease peak heat release rate, specific extinction area, total smoke parameter and mass loss rate, as investigated by come calorimeter. Burning suppressing was confirmed by increasing limiting oxygen index till 34.1%. The prepared nanocomposites have advanced thermal stability regarding increasing thermal decomposition temperatures to higher values through all ignition zones, as detected by TGA. The 15% nanocomposite has improved hardness value by 10.6%; SEM confirmed obtaining of this advanced percentage as well-dispersed nanocomposite. Here, it is demonstrated that protection of our green polymeric matrix from fire diffusion, combustion heat, atmospheric oxygen, emitted gases, weight loss and thermal degradation is the key issue that makes Rec PE-Mg(OH)2 nanocomposite acts as an effective green fire retardant.