Preparation of highly exfoliated epoxy-clay nanocomposites by sol-gel modification

The objective of this work is to intercalate epoxy groups into the layered silicates through sol-gel reaction of cationic triethoxysilanepro-pylamineformylethyl trimethyl ammonium iodide (APS) and 3-glycidoxypropyl trimethoxysilane (GPS). When the ratio of APS to GPS was 1/4 or more, the organoclay was easier to be dispersed in acetone and formed stable slurry. The slurry was then mixed extensively with epoxy resin to form epoxy-nanoclay composites by photopolymerization. The resulting epoxy-nanoclay composites exhibited a high degree of clay exfoliation from ordered exfoliation to highly disordered exfoliation and a better thermal stability property. (c) 2007 Elsevier Ltd. All rights reserved.