The synthesis of poly(ethylene terephthalate) (PET)/layered double hydroxide (LDH) nanocomposites through microwave methods has been investigated. To enhance the compatibility between the PET polymer and the LDH, dodecyl sulfate was intercalated in the lamellar structure. The organo-LDH structure was confirmed by powder X-ray diffraction (PXRD) and Fourier transform infrared spectroscopy (FTIR). PET nanocomposites were prepared with 0-10 wt % of LDH content by in situ microwave-assisted polymerization. PXRD was used to detect the formation of the exfoliated PET/LDH nanocomposites. Transmission electron microscopy was used to observe the dispersed layers and to confirm the exfoliation process. FTIR spectroscopy confirmed that the polymerization process had occurred. TG and DTA are used to study changes in thermal stability of the nanocomposites, which resulted enhanced by well dispersed LDHs layers. (C) 2008 Wiley Periodicals, Inc.