Effect of nickel on the properties of composites composed of layered double hydroxides and ethylene vinyl acetate copolymer

A series of stearate modified layered double hydroxides (LDHs) with different Ni contents were prepared by a coprecipitation method coupled with the microwave hydrothermal treatment. The FT-IR result indicated that the interaction of interlayer anions for S–Ni1.5Mg1.5Al and S–Ni3.0Al was different from S–Mg3.0Al, S–Ni0.05Mg2.95Al and S–Ni0.1Mg2.9Al. The thermal analysis showed that both the maximum mass loss rate temperature and the total mass loss including water, hydroxyls, carbonates and stearate were gradually reduced with the increase of nickel content in LDHs. Furthermore, the cone calorimeter data provided the evidence that S–Ni3.0Al/EVA presented the best functions including both the flame retardance and smoke/toxic gas suppression among all the above composites. The elongation at break and the tensile strength data indicated that although a lot of LDHs reduced the elongation at break and the tensile strength of the composites, the addition of nickel ions evidently enhanced the ductility and strength of the composites in comparison with S–Mg3.0Al/EVA.