Layered double hydroxides used as flame retardant for engineering plastic acrylonitrile–butadiene–styrene (ABS)

Abstract

Acrylonitrile–butadiene–styrene (ABS) resin is widely used as an important engineering thermoplastic polymer in various industrial applications, but suffers from easily burning and generating a large amount of smoke and toxic gases. Here we report a utilization of hydrotalcite-like MgA1- and ZnMgA1-layered double hydroxides (MgA1- and ZnMgA1-LDHs) as an inorganic flame retardant to ABS resin. The LDHs were prepared by a scalable method involving separate nucleation and aging steps (SNAS). The performances of the LDHs/ABS composites were evaluated by measuring limiting oxygen index (LOI), smoke density (Dm), heat release rate (HRR), and average mass loss rate (av-MLR). The results obtained show that both LDH/ABS composites exhibit higher LOI and lower Dm values, lower values of pk-HRR and av-MLR, and a prolonged combustion time, in comparison with the pristine ABS. Comparison between MgAl- and ZnMgAl-LDH-containing composites shows that the introduction of Zn2+ is able to facilitate flame retardance, smoke suppression efficiency, and tensile strength elongation rate of the ZnMgAl-LDH/ABS composite. Our results show that LDHs may be used as a type of promising inorganic flame retardant to enhance smoke suppression and flame retardant for ABS resin.