Preparation and flame retardancy of polystyrene nanocomposites based on layered double hydroxides

Various layered double hydroxides (LDHs), including MgAl, CoAl, NiAl, and ZnAl-LDHs, were synthesized and modified using sodium dodecyl benzene sulfonate. Nonhalogen flame-retardant PS/LDHs nanocomposites were prepared via melt mixing method. The structure of PS/LDHs nanocomposites was investigated by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) pattern technique, and scanning electronic microscope. Results from XRD indicated that intercalated/exfoliated structure was achieved in the polystyrene matrix. Dynamic mechanical thermal analysis suggested that the storage modulus and T-g for the PS/LDHs nanocomposites was efficiently improved. Thermal and flammability properties of PS nanocomposites were investigated using thermogravimetry and cone calorimetry. Thermal analysis was evaluated and the prepared nanocomposites showed slightly lower thermal stability probably due to the presence of LDH, which starts to decompose at a lower temperature. Compared with neat PS, the peak heat release rate of PS/MgAl and PS/ZnAl-LDHs nanocomposites filled with 5 wt% LDHs is reduced by 7% and 12%, respectively. Among all LDHs, MgAl, and ZnAl-LDHs had a better smoke suppression effect with a reduction of peak smoke production rate and CO release rate of 37% and 44%, respectively. POLYM. COMPOS., 38:1680-1688, 2017. (c) 2015 Society of Plastics Engineers