TPA: Thermoplastic Polyamide Elastomer

General Properties

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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 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 Temperature145 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 Enthalpy20 to 65 J/g
Decomposition Temperature400 to 420°C
Young's Modulus20 to 500 MPa
Coefficient of Linear Thermal Expansion120 to 240 *10-6/K
Specific Heat Capacity2.4 to 2.8 J/(g*K)
Thermal Conductivity0.2 W/(m*K)
Density0.99 to 1.10 g/cm³
MorphologyThermoplastic elastomer, copolymer with hard and soft segments
General propertiesGood resistance to fuels and lubricating greases
ProcessingInjection molding, extrusion, blow molding
ApplicationsAutomotive industry (seals, hoses)

NETZSCH Measurement

InstrumentDSC 204 F1 Phoenix®
Sample Mass11.70 mg
Isothermal Phase8 min / 3 min / 8 min
Heating/Colling Rates10 K/min
CrucibleAl, pierced lid
AtmosphereN2 (40 ml/min)

Evaluation

In the 1st heating (blue), this example of TPA shows a Temperatura di transizione vetrosaLa transizione vetrosa è una delle più importanti proprietà chimico-fisiche dei materiali amorfi e semi-cristallini, come, ad esempio, vetri, metalli (amorfi), polimeri, ingredienti farmaceutici e alimentari e definisce l’intervallo di temperatura in cui le proprietà meccaniche die materiali variano da duro e fragile a più morbido, malleabile o gommoso.glass transition at -60°C (midpoint) with a step height Δcp of 0.40 J/(g.K). After a broad, but flat EsotermicoUna transizione o reazione è esotermica se il materiale genera calore exothermal effect with a peak temperature of 32°C (probably a small cold-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 2nd heating (red), an exothermal effect can no longer be seen. Both the glass transition and the endothermal melting range remained. The 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 1st heating. The heat of fusion has almost decreased by half compared to the 1st heating (just under 20 J/g compared to 36 J/g).