SB: Styrene/Polybutadiene copolymer

General Properties

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SB

Styrene/Polybutadiene copolymer


SB is a copolymer from styrene and butadiene (and sometimes additional components), in which the individual monomers are lined up either in block form (block copolymer) or one monomer is grafted on the main chain of the second monomer (graft copolymer).

Structural Formula


Properties

Glass Transition Temperature-90 to -50 / 80 to 110°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 Temperature440 to 455°C
Young's Modulus1800 to 2500 MPa
Coefficient of Linear Thermal Expansion70 *10-6/K
Specific Heat Capacity1.2 to 1.3 J/(g*K)
Thermal Conductivity0.17 to 0.18 W/(m*K)
Density1.05 g/cm³
MorphologyAmorphous thermoplastic
General propertiesHigh transparency, high toughness and stiffness
ProcessingInjection molding, extrusion, deep drawing
ApplicationsPackaging, toys

NETZSCH Measurement

InstrumentDSC 204 F1 Phoenix®
Sample Mass12.17 mg
Isothermal Phases5 min
Heating/Colling Rates10 K/min
CrucibleAl, pierced lid
AtmosphereN2 (40 ml/min)

Evaluation

Both for block and graft copolymers, the characteristic properties of the monomers are largely retained so that SB has two glass transitions. 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 in the low-temperature range (here in both heatings at -84°C, midpoint) is due to the butadiene component. The glass transition at 98°C (2nd heating, red, midpoint) is due to the styrene component. The irreversible effect in the 1st heating (peak temperature 76°C) indicates the release of strong tensions in the material that are caused by the thermomechanical history of the polymer.