TPV: Thermoplastic Elastomer on a Polyolefin Basis

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 (Crosslinking Reactions)Literally translated, the term “crosslinking“ means “cross networking”. In the chemical context, it is used for reactions in which molecules are linked together by introducing covalent bonds and forming three-dimensional networks.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 TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.Glass Transition Temperature	-60 to -50°C
Melting Temperatures and EnthalpiesThe enthalpy of fusion of a substance, also known as latent heat, is a measure of the energy input, typically heat, which is necessary to convert a substance from solid to liquid state. The melting point of a substance is the temperature at which it changes state from solid (crystalline) to liquid (isotropic melt).Melting Temperature	-20 to 40 (EPDM), 150 to 160 (PP)°C
Melting Temperatures and EnthalpiesThe enthalpy of fusion of a substance, also known as latent heat, is a measure of the energy input, typically heat, which is necessary to convert a substance from solid to liquid state. The melting point of a substance is the temperature at which it changes state from solid (crystalline) to liquid (isotropic melt).Melting Enthalpy	10 (EPDM), 20 (PP) J/g
Decomposition reactionA decomposition reaction is a thermally induced reaction of a chemical compound forming solid and/or gaseous products. Decomposition Temperature	350/460 to 480°C
Young's Modulus	90 to 1400 MPa
Coefficient of Linear Thermal Expansion (CLTE/CTE)The coefficient of linear thermal expansion (CLTE) describes the length change of a material as a function of the temperature.Coefficient of Linear Thermal Expansion	15 to 130 *10^-6/K
Specific Heat Capacity	-
Thermal ConductivityThermal conductivity (λ with the unit W/(m•K)) describes the transport of energy – in the form of heat – through a body of mass as the result of a temperature gradient (see fig. 1). According to the second law of thermodynamics, heat always flows in the direction of the lower temperature.Thermal Conductivity	-
DensityThe mass density is defined as the ratio between mass and volume. 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
IsothermalTests at controlled and constant temperature are called isothermal.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 TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.glass transition, from their elastomer component, and a melting transition, from their thermoplastic component. In this example, the 2^nd heating (red) shows a Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.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.