The development of thermoplastic materials
having more or less elastic properties started in the
early 1930s with the invention of plasticization of
PVC at the B.F. Goodrich Company [1]. This
invention led to further interest in flexible plastics
and eventually to the development of blends of PVC
and NBR (butadiene-acrylonitrile rubber) [2, 3].
The PVC/NBR blends, when properly formulated,
have a rubber-like look and feel and bridge the gap
between liquid plasticized PVC and conventional
cured elastomers. Thus, they can be considered as
the precursors of thermoplastics elastomers, as we
know them today.