Thermoplastic Vulcanizates (TPE-V or TPV) are blends of PP with crosslinked rubber, oil and filler produced under a process developed
in the late seventies called dynamic vulcanization as opposite to thermoset rubber where the crosslinking reaction is
done in a static way after the rubber compound has been processed. The production of such compounds requires a high
shear process where a thermoplastic polymer and a suitable rubber are first intimately mixed before adding the curatives
for the crosslinking reaction. The morphology of the resulting blend is a continuous phase of thermoplastic with crosslinked
particles of rubber finely dispersed; the smaller the particle size, the better the properties.
TPE-V based on PP and EPDM are well known and have been successfully commercialized to replace crosslinked
EPDM, polychloroprene (CR) or chlorosulphonated polyethylene (CSM) rubbers.
PP based TPV containing nitrile, butyl or natural rubbers have also been developed and recently TPE-V
based on high temperature thermoplastic and oil resistant rubbers have been introduced as alternative to expensive acrylate
or hydrogenated nitrile rubbers.
TPE-V (PP) Major Properties
High temperature compression set
Resistance to oil and grease
Long term stress relaxation
Easy to color
Table 1: TPE-V (PP) Major Properties
As a rule, the compatibility between the thermoplastic and the rubber has to be good enough to allow acceptable
interfacial adhesion and mechanical properties. In case the two polymers are incompatible, the addition of a compatibilizer is
TPE-V are probably the TPE that have the closest properties to thermoset rubber. They have been
successfully introduced as rubber replacement in window profile extrusion, automotive weatherseals and suspension bellows.
They are used instead of TPE-S as soft touch materials when oil resistance is needed in power tools applications for