AbstractThe effect of montmorillonite clay on the compressive properties of Epikote 828 epoxy was studied. A series of epoxy-based nanocomposites with 1-5wt.% nanoclay content was prepared. The degree of dispersion and exfoliation was investigated using transmission electron microscopy. Static uniaxial compression tests were conducted in order to study the effect of nanoclay on the compressive stress-strain behaviour and compressive properties of the Epikote 828 polymer. It was found that the compressive properties depend on the degree of exfoliation of the clay nanoplatelets in the epoxy. Reduction in compressive strength for 1 and 3 wt% nanoclay was recorded. This is because the intercalated structure of nanoclay in the polymer creates high localised stresses in the matrix during compression that leads to premature failure.