Transparent and flame retardant PMMA/clay nanocomposites prepared with dual modified organoclay

In this study, the dual modified organoclay (DMC), was successfully prepared by the successive cationic exchange reactions of the sodium montomorillonite clay (MMT) with two intercalating reagents, hexadecyl‐triphenyl‐phosphonium bromide and 2‐methacryloxy‐ethyl‐hexadecyl‐dimethyl‐ammonium bromide. A series of the PMMA/DMC nanocomposite membranes (PDCM) were then prepared with the PMMA matrix and various amounts of DMC via the solution cast method. The results of XRD, TEM, SEM, and UV–VIS measurements of the PDCMs prepared showed that the DMC particles were well dispersed in the PMMA matrix with a highly exfoliated structure. The TGA thermograms indicated that the thermal stabilities of the PDCM membranes are higher than that of the PMMA. Furthermore, the tensile mechanical property and glass transition temperature of the nanocomposites were dramatically increased with increasing the DMC content. The limiting oxygen index of PDCM membranes also indicated that the flame retardancy was significantly enhanced due to the presence of DMC. Moreover, more than 90% of the PMMA's transparency was remained in the nanocomposites. Copyright © 2011 John Wiley & Sons, Ltd.