In-situ synthesis of exfoliated nanocomposites by photopolymerization using a novel montmorillonite-anchored initiator

A novel quaternized ammonium photoinitiator (BDMBAC) was synthesized by facile neutralization of BDMB and hydrochloric acid, then ion-exchanged with montmorillonite (MMT). An ordered swollen structure of the intercalated montmorillonite was evidenced by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermo gravimetric analysis (TGA). The BDMBAC molecules were anchored in the interlayer space of montmorillonite. These BMDBAC-modified montmorillonite were then dispersed in urethane acrylate oligomers and in-situ photo polymerized yielding exfoliated PUA-montmorillonite nanocomposites. The photopolymerization kinetics was monitored by real-time infrared spectroscopy. X-ray diffraction and transmission electron microscopy (TEM) revealed that the modified montmorillonite layers were uniformly dispersed in the PUA matrix. Thermal properties of the resultant nanocomposites were studied by TGA. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.