Thermoplastic vulcanizates (TPV) are dynamically vulcanized alloys consisting mostly of fully cured EPDM rubber particles encapsulated in a polypropylene (PP) matrix. They are part of the thermoplastic elastomer (TPE) family of polymers but are closest in elastomeric properties to EPDM thermoset rubber, combining the characteristics of vulcanized rubber with the processing properties of thermoplastics. TPV is a dynamically vulcanized alloy consisting mostly of fully cured EPDM rubber particles encapsulated in a polypropylene (PP) matrix. There are almost 100 grades in the S portfolio that are used globally in the automotive, household appliance, electrical, construction, and healthcare markets. The name Santoprene was trademarked in 1977 by Monsanto, and the trademark is now owned by Celanese. Similar material is available from Elastron and others. Overview TPV was created after several years of research and development aimed at finding new materials for injection-molded tires. Although the search for a new tire material was unsuccessful, it resulted in the development of TPV, which combines the characteristics of vulcanized rubber with the processing properties of thermoplastics. The first sales of developmental products began in 1977, the same year it was registered by Monsanto, and it was fully commercialized in 1981. Part of the TPE family of polymers, TPV is the closest in elastomeric properties to EPDM thermoset rubber. TPVs have a combination of elastomeric properties, like compression and tension sets, coupled with aging performance and chemical resistance. Early successes Santoprene TPV had early application successes in the automotive sector, including rack and pinion boots, due to its flex life, fluid resistance, and sealability. In the appliance sector, a dishwasher sump boot made with Santoprene TPV provided good sealing and resistance to heat and fluids. Due to its sealing properties, Santoprene TPV was also successful in the domestic and high-rise construction sectors in applications such as window seals, caster wheels, tubing, and small hose parts, electrical connectors, and coatings for wire and cables. It was also used in the medical industry as a gasket on syringe plungers. Chemistry Santoprene TPV is a dynamically vulcanized alloy consisting mostly of fully cured EPDM rubber particles encapsulated in a polypropylene (PP) matrix. Photographs made using an atomic force microscope and a scanning electron microscope show a multitude of very small particles, typically no bigger than a couple of microns in diameter. These particles are fully vulcanized rubber (typically EPDM rubber for most Santoprene TPV grades) in a thermoplastic phase