Short Name

PS

Name

Polystyrene

Group

CTP - Commodity Thermoplastics

General Properties

Chemical Formula

(C₈H₈)_n

Structural Formula

Glass Transition Temperature

80 to 105 °C

Melting Temperature

- °C

Melting Enthalpy

- J/g

Decomposition Temperature

415 to 425 °C

Young's Modulus

3100 to 3300 MPa

Coefficient of Linear Thermal Expansion

50 to 70 *10¯6/K

Specific Heat Capacity

1.3 J/(g*K)

Thermal Conductivity

0.14 to 0.18 W/(m*K)

Density

1.05 g/cm³

Morphology

Amorphous or semi-cristalline thermoplastic

Identification

transparant

General properties

Crystal clear and hard, Well resistant to aqueous bases and mineral acids

Processing

Injection and blow molding, Extrusion

Applications

Electrical engineering, Building industry (e.g. expanded polystyrene), Food industry (e.g., packaging), Consumer products for everyday use (e.g., CD covers, cloth hangers)

Modifications

Co-Po with PE, colored, Polymerfoam (EPS),

Manufacturer

Styrolution, Styron, Sabic, Nova Chemicals

Internet Links

Wikipedia: http://en.wikipedia.org/wiki/Polystyrene

This example shows amorphous PS. Glass transition temperatures at 84°C (1st heating, blue, midpoint) and 88°C (2nd heating, green, also midpoint) were observed, each overlapped by relaxation peaks. The relaxation peaks are more distinctive in the
1st heating than in the 2nd heating. The 1st heating shows another small wave after the relaxation peak, indicating the elimination of additional stress.
The step heights (Δcp) were at 0.32 J/(g·K) (1st heating) and 0.29 J/(g·K) (2nd heating).