SAN: Styrene-Acrylonitrile Copolymer

General Properties

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SAN

Styrene-Acrylonitrile Copolymer


Styrene acrylonitrile (SAN) belongs to the family of styrene copolymers. A typical composition is approx. 70% styrene and 30% acrylonitrile. However, other compositions are also possible and have an impact on the material properties such as 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, stiff ness and toughness. It is worth mentioning that the elasticity modulus of SAN, at almost 4.000 MPa, is very high for an unfi lled, amorphous polymer.

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 Temperature95 to 110/(125)°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 Temperature415 to 425°C
Young's Modulus3500 to 3700 MPa
Coefficient of Linear Thermal Expansion60 to 80 *10-6/K
Specific Heat Capacity1.18 to 1.20 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 Conductivity0.15 to 0.17 W/(m*K)
Density1.08 g/cm³
MorphologyAmorphous thermoplastic
General propertiesHigh transparency, chemical resistance, high strength, high surface hardness, high scratch resistance
ProcessingExtrusion, injection moulding, thermoforming
ApplicationsTransparent household goods, cosmetics packaging, medical components

NETZSCH Measurement

InstrumentDSC 204 F1 Phoenix®
Sample Mass11.79 mg
IsothermalTests at controlled and constant temperature are called isothermal.Isothermal Phases5 min
Heating/Colling Rates10 K/min
CrucibleAl, pierced lid
AtmosphereN2 (50 ml/min)

Evaluation

As an entirely amorphous thermoplastic, SAN has 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 in this case at 109°C (both heatings, midpoint each) with a step height (Δcp) of 0.40 J/(g.K) and 0.41 J/(g.K), respectively. In the 2nd heating (red), 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 step shows a RelaxationWhen a constant strain is applied to a rubber compound, the force necessary to maintain that strain is not constant but decreases with time; this behavior is known as stress relaxation. The process responsible for stress relaxation can be physical or chemical, and under normal conditions, both will occur at the same time. relaxation peak, indicating that short-range orders have formed in the polymer during the controlled cooling at 10 K/min. The thermomechanical history of the sample can be noticed in the DSC curve of the 1st heating (blue) by means of some slight waves.

Literature

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