In‐situ growth of layered double hydroxide on montmorillonite nanosheets to improve the flame retardant performance of ABS resin

Abstract

AbstractLayered double hydroxide (LDH) is a widely used flame retardant in polymer materials; however, the poor dispersion due to its high hydrophilic nature results in disappointing thermal stability and fire safety. In this work, LDH was in‐situ grown on the disordered montmorillonite (MMT) nanosheets to obtain the hybrid of LDH and MMT nanosheets (LDH@MMT, simplified as LM). Various techniques, including X‐ray diffraction, Fourier‐transform infrared spectroscopy, field emission scanning electron microscopy, and transmission electron microscope were used to characterize the microstructure of LM. In addition, the acrylonitrile‐butadiene‐styrene (ABS) composite containing LM and intumescent flame retardant (IFR) was prepared, and its mechanical and flame‐retardant properties were also measured. The characterization results demonstrate that the LM exhibits a periodically alternating layered structure. The Limiting Oxygen Index (LOI) of the ABS composite reaches 27.2% with a V‐0 rating in the UL‐94 vertical burning test, while its flexural strength and tensile strength decrease by only 17.82% and 13.45%, respectively. Furthermore, the heat release rate, total heat release, smoke production rate, and carbon monoxide production rate of the ABS composite present a significant decline in cone calorimeter tests compared with those of pure ABS. The results further indicate that the hybridization could effectively improve the flame‐retardant performance of ABS composites and perform lesser impacts on their mechanical properties.