There have been previous attempts using
blending as a technique to obtain a combination
of properties inherent in the individual
polymers in fabricating foam rubber. Nakason
et. al8 prepared latex foam rubber from a graft
copolymer of deproteinised natural rubber
and methyl methacrylate then blended them
with high ammonia concentrated latex to
give a product with improved indentation
hardness but inferior compression set. A
study by Angove et. al9 concluded that
foam rubber made from acrylonitrile
isoprene rubber latex had good ageing and
oil resistance, high tensile strength and
elongation properties but lower resilience.
However, blending with NRL, the foam failed
to retain the values of both tensile strength
and elongation in direct proportion to the
values for the foams made from each material
independently.