2. Product Information and Characteristics

2.2. Physical Properties

Table 1: Typical Physical Properties.

Property	Common Usage Value & Unit	International System Value & Unit
Physical Form	Colourless, oily liquid
Colour (acc. ASTM D 1209 / DIN 6271)	10 max. / Pt-Co scale
Odour	Unpleasant, aromatic
Odour threshold	0.1 ppm	0.43 mg/m³
Relative molecular mass	104.14
Density at 20°C (acc. ASTM D 4052	0.906 kg/l	906 kg/m³
Boiling point	V	145°C
Melting point/Freezing point	V	-31°C
Kinematic viscosity at 0°C	1.1 cSt	1.1 mm²/s
Kinematic viscosity at 20°C	0.8 cSt	0.8 mm²/s
Kinematic viscosity at 40°C	0.6 cSt	0.6 mm²/s
Kinematic viscosity at 100°C	0.4 cSt	0.4 mm²/s
Vapour density (air =1)	3.6
Vapour pressure at 20°C	6 mbar	0.6 kPa
Vapour pressure at 50°C	32 mbar	3.2 kPa
Vapour pressure at 80°C	121.2 mbar	12.12 kPa
Conductivity, thermal at 20°C	1.6x10^-3 J/(s.cm.K)	0.16 W/m°C
Flash point (ABEL; acc. IP 170)	VV	31-32°C
Autoignition temperature	VV	490°C
Saturation concentration in air at 20°C	5923 ppm (v/v)	25.6 g/cm³
Explosion limits in air	0.9 - 6.8% vol.
Miscibility in water	immiscible
Solubility in water at 20°C	0.029% wt./vol.	0.29 kg/m³
Solubility of water in substance at 20°C	0.054% wt./vol.	0.54 kg/m³
Coefficient of Expansion at 20°C	V	0.979x10^-3/°C
Specific heat at 20°C	V	1.73 kJ/kg.°C
Heat of combustion, Hc at 25°C	-1018.83 kcal/mole	-4265.64 kJ/mole
Heat of formation, Hf, gas at 25°C	35.22 kcal/mole	147.46 kJ/mole
Heat of formation, Hf, liquid at 25°C	24.72 kcal/mole	103.50 kJ/mole
Heat of polymerisation, Hp at 25°C	-16.88 kcal/mole	-70.67 kJ/mole
Refractive index	1.546 (nD at 20°C)	V
Rel. evaporation rate (di-ethylether = 1 min.)	12.4
Source: CEFIC Styrene Distribution Group

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