A new nanocomposite - disorderly exfoliated layered double hydroxides/poly(methyl methacrylate) (LDHs/PMMA) - was prepared by a two-stage process with an in situ bulk polymerization of methyl methacrylate (MMA) in the presence of 10-undecenoate intercalated LDH (LDH-U). The LDH-U was prepared using the co-precipitation method. The structural and compositional details of the LDH-U were determined by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), Al-27 and C-13 magic-angle spinning nuclear magnetic resonance (Al-27 and C-13 MAS NMR), elemental analysis (EA), inductively coupled plasma-mass (ICP) and transmission electron microscopy (TEM). During the preparation of LDHs/PMMA nanocomposite, XRD and TEM were also employed to monitor the formation of the exfoliated LDHs/PMMA nanocomposite and the dispersion behavior of the LDH layers, respectively. The pre-polymerization process exfoliates LDH layers within pre-polymer, according to the XRD and TEM results. Additionally, the LDHs/PMMA nanocornposite contained 5 wt% LDH-U, indicating that the LDH layers were well exfoliated and dispersed in the PMMA matrix in a disordered fashion. (c) 2005 Elsevier Ltd. All rights reserved.