ESO resin was first premixedwith theOMMT clay at amixing ratio as
shown in Table 1, followed by sonication at room temperature for 1 h.
Next, the ESO/OMMT and MHHPA/EMI mixtures were mixed and
stirred mechanically at 300 rpm for 5 min. The ESO mixture was then
poured into the mould and subjected to the thermal curing process
in an oven at 140 °C for 3 h. The cure temperature and time have been
optimized based on our previous study (Tan et al., 2013).