PUR: Polyurethane

General Properties

Short Name:

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PUR

Polyurethane


Polyurethane (PUR) is a polymer produced from the polyaddition reaction of diols/polyols with di-isocyanates and poly-iso- cyanates to generate a urethane group -NH-CO-O-. Since cross-linking is a polyaddition, it is possible to employ aluminum crucibles with pierced lids.

Structural Formula


Properties

Glass Transition Temperature10 to 180°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-
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-
Decomposition Temperature240 to 350°C
Young's Modulus-
Coefficient of Linear Thermal Expansion130 to 200 *10-6/K
Specific Heat Capacity1.70 to 2.10 J/(g*K)
Thermal Conductivity< 0.19 W/(m*K)
Density1.10 to 1.70 g/cm³
MorphologyThermoset
General propertiesDepending on the composition – the stiffness range expands from soft rubbers to technical plastics. Good abrasion resistance
ProcessingInjection molding, foaming, coating
ApplicationsAutomotive industry. Furniture industry. Building industry. Sports and leisure. Shoe industry (soles). Polyurethane paints and coatings. Casting compounds. Matrix for composites

NETZSCH Measurement

InstrumentDSC 204 F1 Phoenix®
Sample Mass18.95 mg
Isothermal Phase5 min
Heating/Colling Rates10 K/min
CrucibleAl, pierced lid
AtmosphereN2 (40 ml/min)

Evaluation

In the 1st heating, the 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 107°C (midpoint) was followed by a broad, shallow, EsotermicoUna transizione o reazione è esotermica se il materiale genera calore exothermal post-curing effect between approx. 120°C and 200°C (peak temperature 167°C). Due to the post-curing, the glass transition in the 2nd heating (after controlled cooling) was approx. 4 K (midpoint temperature 111°C) higher. The position of the glass transition temperature is directly related to the degree of curing. The more extensive the post-curing, the more the glass transition shifts to higher temperatures.