A novel approach to prepare the exfoliated polymer/layered double hydroxide (LDH) nanocomposites was proposed by synthesizing a pre-exfoliated organic LDH (LDH-SH) firstly, then blended into an acrylic resin, and irradiated by a medium pressure mercury lamp. The LDH-SH was prepared by intercalating LDH with sodium dodecyl sulfate, and then gamma-(2,3-epoxypropoxy) propyl trimethoxysilane, followed by grafting with trimethylolpropane thioglycolic acetate. From the X-ray diffraction (XRD) analysis, high resolution scanning electron microscope (HR-SEM) and high resolution transmission electron microscope (HR-TEM) observation, the LDH-SH lost its ordered stacking-structure and was totally pre-exfoliated. After UV irradiation, the formed polymer/LDH nanocomposite possessed the exfoliated microstructure from the transmission electron microscope (TEM) and HR-TEM observations. The dynamic mechanical thermal analyzer (DMTA) results showed that the storage modulus of nanocomposite with 5% LDH-SH loading increased to 44.2 MPa from 34.6 MPa of the pure polymer, while the tensile strength and persoz hardness were enhanced to 9.3 MPa and 107s compared with 8.5 MPa and 87 s of the pure polymer, respectively. (C) 2011 Elsevier B.V. All rights reserved.