PS-HI (Polystyrene High Impact, HIPS) Material Data Sheet

PS-HI / HIPS Designation

HIPS, High Impact Polystyrene

PS-HI / HIPS Tradenames

Aarolene, Alphalac, Americas Styrenics, Axpoly, Bapolan, Carbo-Rite, Certene, Cheng, Claradex, Dart, Delta, Diamond, Doki, Edistir, Electrafil, Eporex, Hyrene, Innova, Kumho, Lgstrene, Marpol, Neftekhim, Nexus, Osterlene, Polyrex, Ponacom, Primaflex, Solarene, Spartech, Starex, Stirol, Styron, Styron A-Tech, Supreme, Synthos, Tairirex

PS-HI / HIPS Typical uses

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

PS-HI / HIPS 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).
Material family	Plastic (thermoplastic, amorphous)
Base material	PS-HI (Polystyrene, high impact)
Additive	Impact modifier
Polymer code	PS-HI

PS-HI / HIPS Composition detail

Polymer

100

PS-HI / HIPS Physical properties

Density

1.03

–

1.06

g/cm³

PS-HI / HIPS Mechanical properties

Young’s modulus	1.16	–	2.55	GPa
Specific stiffness	1.11	–	2.44	MN.m/kg
Yield strength (elastic limit)	19	–	41.4	MPa
Tensile strength	20	–	42.7	MPa
Specific strength	18.2	–	39.6	kN.m/kg
Elongation	40	–	65	% strain
Compressive modulus	1.1	–	2.55	GPa
Compressive strength	22.8	–	49.7	MPa
Flexural modulus	1.1	–	2.68	GPa
Flexural strength (modulus of rupture)	31.4	–	69	MPa
Shear modulus	0.391	–	0.907	GPa
Bulk modulus	2.9	–	3.04	GPa
Poisson’s ratio	0.397	–	0.418
Shape factor	6
Hardness – Vickers	6	–	12	HV
Hardness – Rockwell M	38	–	42
Hardness – Rockwell R	50	–	82
Elastic stored energy (springs)	111	–	473	kJ/m³
Fatigue strength at 10^7 cycles	8	–	17.1	MPa

PS-HI / HIPS Impact & fracture properties

Fracture toughness	0.999	–	2.96	MPa.m^0.5
Toughness (G)	0.683	–	4.34	kJ/m²
Impact strength, notched 23 °C	7.34	–	11.6	kJ/m²
Impact strength, notched -30 °C	4.03	–	6.75	kJ/m²
Impact strength, unnotched 23 °C	92.2	–	111	kJ/m²
Impact strength, unnotched -30 °C	45.8	–	55	kJ/m²

PS-HI / HIPS Thermal properties

Glass temperature	85	–	99	°C
Heat deflection temperature 0.45MPa	80	–	94	°C
Heat deflection temperature 1.8MPa	74	–	90	°C
Vicat softening point	84	–	98	°C
Maximum service temperature	70	–	90	°C
Minimum service temperature	-53	–	-33	°C
Thermal conductivity	0.13	–	0.19	W/m.°C
Specific heat capacity	1.35e3	–	1.45e3	J/kg.°C
Thermal expansion coefficient	77.9	–	81.2	µstrain/°C
Thermal shock resistance	122	–	344	°C
Thermal distortion resistance	0.00163	–	0.00239	MW/m

PS-HI / HIPS 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)	16.9	–	20.3	MV/m
Comparative tracking index	275	–	575	V

PS-HI / HIPS Magnetic properties

Magnetic type

Non-magnetic

PS-HI / HIPS Optical, aesthetic and acoustic properties

Transparency	Opaque
Acoustic velocity	1.03e3	–	1.59e3	m/s
Mechanical loss coefficient (tan delta)	0.0157	–	0.0364

PS-HI / HIPS Absorption & permeability

Water absorption @ 24 hrs	0.05	–	0.07	%
Water vapor transmission	0.713	–	1.44	g.mm/m².day
Permeability (O2)	156	–	163	cm³.mm/m².day.atm

PS-HI / HIPS Processing properties

Polymer injection molding	Excellent
Polymer extrusion	Excellent
Polymer thermoforming	Excellent
Linear mold shrinkage	0.4	–	0.7	%
Melt temperature	177	–	274	°C
Mold temperature	35	–	55	°C
Molding pressure range	68.8	–	138	MPa

PS-HI / HIPS 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	Highly flammable