Effect of Moisture Absorption on the Fracture Toughness and Morphology of Halloysite Nanoclay-Epoxy Nanocomposites

Abstract

Epoxy resins are being used in a wide variety of experiments due to the versatility of the material and the various modifications using nano-scale fillers in the epoxy. These resins have a highly cross-linked molecular structure that lead to them having characteristics such as high strength, high creep resistance, low shrinkage, and good resistance to chemicals. The hydrophilic nature of epoxy resins tends to cause them to absorb moisture. Several studies have shown that moisture absorption in epoxy polymers can lead to both reversible and irreversible changes and resulted in degradation of the mechanical properties. However, in the open literature, there are still critical issues related to the effect of moisture absorption on mechanical and chemical composition of nanomodified epoxy. In this work, the effect of moisture absorption from hygrothermal aging on the fracture toughness and morphology of halloysite nanoclay modified epoxy was experimentally investigated. In order to investigate the physical-chemical evolutions and their influences on the fracture toughness and morphology properties, a comparative study was carried out for both unaged and aged specimens. The specimens were weighed prior to and after undergoing hygrothermal aging. SEM was also used to investigate the effect of moisture absorption on the morphology of the specimens. Preliminary results showed that aging time and temperature have a significant influence on the mechanical and morphology of the nanocomposite materials.