  Epoxy polymers are an important class of material for use in various
applications. Due to their hydrophilic nature, epoxy resins tend to absorb
moisture. Absorption of moisture degrades the functional, structural and
mechanical properties. For polymers, it is known that moisture absorption can
lead to both reversible and irreversible changes. In this study, the combined
effect of moisture and elevated temperature on the mechanical properties of
Epon 862 and its nanocomposites were investigated. The extent of permanent
damage on fracture toughness and flexural properties of epoxy, due to the
aggressive degradation provided by hygrothermal ageing, was determined by
drying the epoxy and their clay/epoxy nanocomposites after moisture absorption.
From the investigation it was found that, hygrothermal ageing has detrimental
effect on mechanical properties of both neat polymer and clay/polymer
nanocomposite. Significant permanent damage was observed for fracture toughness
and modulus, while the extent of permanent damage was less significant for
flexural strength.
