TPA: Thermoplastic Polyamide Elastomer

General Properties

Short Name:

Name:

TPA

Thermoplastic Polyamide Elastomer

Thermoplastic elastomers on a polyamide basis (TPAs) belong to the copolymers with alternating succession of hard and soft segments. The block of the hard segments show amide bonds, the soft segments ether or ester bonds.

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	-70 to 45°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	145 to 200°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	20 to 65 J/g
Decomposition reactionA decomposition reaction is a thermally induced reaction of a chemical compound forming solid and/or gaseous products. Decomposition Temperature	400 to 420°C
Young's Modulus	20 to 500 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	120 to 240 *10^-6/K
Specific Heat Capacity	2.4 to 2.8 J/(g*K)
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	0.2 W/(m*K)
DensityThe mass density is defined as the ratio between mass and volume. Density	0.99 to 1.10 g/cm³
Morphology	Thermoplastic elastomer, copolymer with hard and soft segments
General properties	Good resistance to fuels and lubricating greases
Processing	Injection molding, extrusion, blow molding
Applications	Automotive industry (seals, hoses)

NETZSCH Measurement

Instrument	DSC 204 `F1` `Phoenix^®`
Sample Mass	11.70 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

In the 1^st heating (blue), this example of TPA 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 -60°C (midpoint) with a step height Δc_p of 0.40 J/(g.K). After a broad, but flat ExothermicA sample transition or a reaction is exothermic if heat is generated.exothermal effect with a peak temperature of 32°C (probably a small cold-CrystallizationCrystallization is the physical process of hardening during the formation and growth of crystals. During this process, heat of crystallization is released.crystallization) melting of the hard segments occurred in the temperature range between approx. 80°C and 170°C (with a main peak at 153°C and a preceded shoulder at 121°C). In the 2^nd heating (red), an ExothermicA sample transition or a reaction is exothermic if heat is generated.exothermal effect can no longer be seen. Both the 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 and the endothermal melting range remained. The 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 (midpoint) occurred at -61°C; the melting range with main peak at 150°C is not that strongly structured like in the 1^st heating. The heat of fusion has almost decreased by half compared to the 1^st heating (just under 20 J/g compared to 36 J/g).