Gallic acid-iron complex modified magnesium hydroxide and its effect on flame retardancy of EVA

Abstract

In this paper, a green method of modifying high flame retardant and high mechanical properties MH was proposed, gallic acid (GA)-Fe³⁺ complex was employed to modify the surface of magnesium hydroxide (MH), aiming to achieve novel functionalized MH-based flame retardant for ethylene-vinyl acetate copolymer (EVA). The structural and morphological characterization of the newly designed flame retardant were studied by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, Scanning electron microscope and X-ray Diffraction. The flame retardancy of EVA, EVA/MH, EVA/MH@Fe-GA was investigated via Limiting oxygen index, UL-94 vertical combustion tests, and cone calorimeter test. The LOI and UL94 results showed that EVA/MH@Fe-GA (01) achieved an LOI of 38.5% and UL-94 passed the V-0 grade. The CCT results showed that compared with neat EVA, the peak heat release rate (pHRR) of EVA/MH@Fe-GA decreased by 90.83%, and TSP decreased by 86%, as compared to neat EVA. The mechanical properties of EVA/MH, EVA/MH@Fe-GA were investigated via tensile and impact tests. Compared with EVA/MH, MH@GA-Fe shows good tensile property and impact resistance, the impact strength of EVA/MH@Fe-GA increased by more than 28%, and the elongation at break increased by 145%.