Layered silicate-induced enhancement of fracture toughness of epoxy molding compounds over a wide temperature range

Abstract

The fracture toughness of EMC was dramatically increased over a wide temperature range by the addition of a very low volume fraction of layered silicates to EMC filled with micro-silica particles. Layered silicate-EMC nanocomposites containing intercalated and the exfoliated silicates were fabricated by using o-cresol and biphenyl type epoxy resins, respectively. It was found that exfoliated silicates were more effective than intercalated silicates at toughening EMC at temperatures above T. of the epoxy resin. Enhanced fracture toughness of EMC over a wide temperature range, from ambient to 230 degrees C has been attributed to the presence of layered silicates, which induces macroscopic crack deflection and severe plastic deformation in front of the crack tip.