Flammability and thermal degradation behavior of ethylene-vinyl acetate/layered double hydroxides/zinc borate composites

Mg-Al-Fe ternary-layered double hydroxides (LDHs) were synthesized by a calcination-rehydration method using Bayer red mud. The products were characterized using X-ray diffraction and thermogravimetric analysis. The flammability and thermal degradation of ethylene-vinyl acetate/layered double hydroxides/zinc borate (EVA/LDHs/ZB) composites were studied with limiting oxygen index, UL 94, cone calorimeter test, smoke density test, and thermogravimetry-Fourier transform infrared spectrometry. Although limiting oxygen index value of the composites decreased with increasing ZB amount, a suitable addition of ZB can apparently improve the UL 94 rating of the material. The heat release rate of the 5% ZB containing ternary composites decreased compared with the EVA/LDHs composites. It is obtained from smoke density test that ZB could help smoke suppression. The ternary composites possessed a higher thermal stability than the EVA/LDHs composites. Copyright © 2016 John Wiley & Sons, Ltd.