PS-HI-FR (High Impact Polystyrene, Flame retarded) Material Data Sheet

PS-HI-FR Designation

HIPS, High Impact Polystyrene, Flame retarded

PS-HI-FR Tradenames

Avantra, Cheng, Edistir, Estastir, Faralloy, Idemitsu, Kumho, Lgstrene, Ramshine, Sicostirolo, Stirofor, Stirolan, Veroplas

PS-HI-FR Typical uses

Toys, light diffusers, beakers, cutlery, general household appliances, video/audio cassette cases, electronic housings, refrigerator liners.

PS-HI-FR Compositional summary

Typically 85-95% styrene and 5-15% cis-butadiene rubber (BR) with graft copolymerization. Some grades use other rubbers: styrene butadiene (SBR), ethylene propylene diene (EPDM), or styrene butadiene styrene (SBS). Flame retardant additives: typically brominated organic or more recently halogen-free.

Material family Plastic (thermoplastic, amorphous)

Base material PS-HI (Polystyrene, high impact)

Additive Flame retardant, Impact modifier

Polymer code PS-HI-FR

PS-HI-FR Composition detail (polymers and natural materials)

Polymer	90	–	95	%
Flame retardant	5	–	10	%

PS-HI-FR Physical properties

Density

1.15

–

1.17

g/cm³

PS-HI-FR Mechanical properties

Young’s modulus	1.65	–	2.07	GPa
Specific stiffness	1.42	–	1.79	MN.m/kg
Yield strength (elastic limit)	21.4	–	28.3	MPa
Tensile strength	18.3	–	28.3	MPa
Specific strength	18.4	–	24.4	kN.m/kg
Elongation	30	–	50	% strain
Compressive modulus	1.65	–	2.07	GPa
Compressive strength	25.7	–	36.4	MPa
Flexural modulus	1.93	–	2.27	GPa
Flexural strength (modulus of rupture)	31	–	51.7	MPa
Shear modulus	0.587	–	0.736	GPa
Bulk modulus	3.18	–	3.34	GPa
Poisson’s ratio	0.397	–	0.413
Shape factor	6.8
Hardness – Vickers	6	–	9	HV
Hardness – Rockwell M	31	–	35
Hardness – Rockwell R	38	–	65
Elastic stored energy (springs)	124	–	217	kJ/m³
Fatigue strength at 10^7 cycles	7.32	–	11.3	MPa

PS-HI-FR Impact & fracture properties

Fracture toughness	0.761	–	2.28	MPa.m^0.5
Toughness (G)	0.38	–	2.32	kJ/m²
Impact strength, notched 23 °C	4.78	–	10.7	kJ/m²
Impact strength, notched -30 °C	2.21	–	4.09	kJ/m²
Impact strength, unnotched 23 °C	44.1	–	110	kJ/m²
Impact strength, unnotched -30 °C	32.8	–	88.9	kJ/m²

PS-HI-FR Thermal properties

Glass temperature	85	–	100	°C
Heat deflection temperature 0.45MPa	80	–	95	°C
Heat deflection temperature 1.8MPa	73	–	83	°C
Vicat softening point	83	–	98	°C
Maximum service temperature	65	–	80	°C
Minimum service temperature	-53	–	-33	°C
Thermal conductivity	0.15	–	0.19	W/m.°C
Specific heat capacity	1.57e3	–	1.63e3	J/kg.°C
Thermal expansion coefficient	79.4	–	82.6	µstrain/°C
Thermal shock resistance	138	–	196	°C
Thermal distortion resistance	0.00185	–	0.00235	MW/m

PS-HI-FR Electrical properties

Electrical resistivity	5.98e21	–	5.38e22	µohm.cm
Electrical conductivity	3.2e-21	–	2.88e-20	%IACS
Dielectric constant (relative permittivity)	3	–	3.2
Dissipation factor (dielectric loss tangent)	0.001	–	0.006
Dielectric strength (dielectric breakdown)	20.8	–	22.5	MV/m
Comparative tracking index	275	–	575	V

PS-HI-FR Magnetic properties

Magnetic type

Non-magnetic

PS-HI-FR Optical, aesthetic and acoustic properties

Transparency	Opaque
Acoustic velocity	1.19e3	–	1.34e3	m/s
Mechanical loss coefficient (tan delta)	0.0193	–	0.0242

PS-HI-FR Absorption & permeability

Water absorption @ 24 hrs	0.005	–	0.01	%
Water vapor transmission	0.713	–	1.44	g.mm/m².day
Permeability (O2)	156	–	163	cm³.mm/m².day.atm

PS-HI-FR Processing properties

Polymer injection molding	Excellent
Polymer extrusion	Excellent
Polymer thermoforming	Excellent
Linear mold shrinkage	0.3	–	0.6	%
Melt temperature	191	–	232	°C
Mold temperature	35	–	55	°C
Molding pressure range	41.3	–	103	MPa

PS-HI-FR Durability

Water (fresh)	Excellent
Water (salt)	Excellent
Weak acids	Acceptable
Strong acids	Limited use
Weak alkalis	Excellent
Strong alkalis	Limited use
Organic solvents	Unacceptable
Oxidation at 500C	Unacceptable
UV radiation (sunlight)	Fair
Flammability	Self-extinguishing