HIPS
High-Impact Polystyrene
Glass Transition (Tg)
100 °C
Melting Point (Tm)
— (amorphous)
Density
1.03–1.06 g/cm³
CAS Number
9003-55-8
Recycling Code
♺ 6
Category
Commodity
Repeat Unit
–[CH₂–CH(C₆H₅)]ₙ– + phase –[CH₂–CH=CH–CH₂]ₘ–
The repeating unit is the smallest structural fragment whose repetition builds the whole chain. Subscripts show the relative share of each unit in copolymers.
Key Properties
Rubber-toughened PS; opaque; impact strength roughly 5–10× GPPS through crazing mechanism around rubber particles.
Applications
Refrigerator liners, TV housings, disposable cups, toys.