2.6. Morphological studies
The raw OPA and LENR-coated OPA particles were
mounted on aluminium stubs and sputter-coated with a
thin layer of gold in order to avoid electrostatic charge and
poor resolution during examination. This was followed by
scanning with an electron microscope (FESEM: model Zeiss
Supra 35 VP). Tensile fractured surfaces of raw OPA and
LENR-coated OPA filled NR composites were scanned in the
same manner as the OPA particles. The tensile fractured
surfaces observed were used to study the mode of fracture
and support the changes in tensile properties.
2.7. Assessment of swelling percentages
The swelling test was carried out according to ISO 1817.
The cured specimens, with dimensions of
30 mm 5 mm 2 mm, were weighed using an electric
balance, followed by immersion in a toluene for 72 hours at
room temperature (25 C) in a dark environment. After the