General Properties
Short Name:
Name:
TPV
Thermoplastic Elastomer on a Polyolefin Basis
In accordance with ISO 18064*, TPVs are thermoplastic rubber vulcanizates that consist of a thermoplastic polymer such as PP and a rubber, e.g., EPDM, the curing of which occurs during blending and mixing. The rubber content is usually at approx. 60 to 80 weight%.
*DIN EN ISO 18064, Thermoplastic elastomers – Nomenclature and abbreviated items.
Due to the diversity of existing structures of this thermoplastic elastomer no specific chemical structure is given.
Structural Formula
Properties
| Glass Transition Temperature | -60 to -50°C |
|---|---|
| Melting Temperature | -20 to 40 (EPDM), 150 to 160 (PP)°C |
| Melting Enthalpy | 10 (EPDM), 20 (PP) J/g |
| Decomposition Temperature | 350/460 to 480°C |
| Young's Modulus | 90 to 1400 MPa |
| Coefficient of Linear Thermal Expansion | 15 to 130 *10-6/K |
| Specific Heat Capacity | - |
| Thermal Conductivity | - |
| Density | 0.87 to 1.20 g/cm³ |
| Morphology | Blend of semi-crystalline polyolefin and amorphous rubber |
| General properties | Depending on the mixing ratio and the polyolefin employed |
| Processing | Injection molding, extrusion, blow molding |
| Applications | Automobile industry (bumper covers, cover panels). Shoes |
NETZSCH Measurement
| Instrument | DSC 204 F1 Phoenix® |
| Sample Mass | 12.08 mg |
| Isothermal Phase | 8 min / 3 min / 8 min |
| Heating/Colling Rates | 10 K/min |
| Crucible | Al, pierced lid |
| Atmosphere | N2 (40 ml/min) |
Evaluation
Due to their composition, TPVs exhibit both a glass transition, from their elastomer component, and a melting transition, from their thermoplastic component. In this example, the 2nd heating (red) shows a glass transition at -59°C (midpoint) that is immediately followed by an endothermal eff ect with a peak temperature of -15°C and an enthalpy of less than 10 J/g. Both can be related to the soft and hard segments of a rubber, probably EPDM. A larger endothermal effect with a peak temperature of 154 °C (heat of fusion 16 J/g) is due to the melting of the olefin component and is characteristic of polypropylene. The DSC curves from the two heatings are nearly identical.