Question

Describe the important characteristics of high density polythene.

Answer 1

1. High density: linear chains pack closely, giving high crystallinity and density (≈0.94-0.97 g cm⁻³).
2. Strong and stiff: good tensile strength and rigidity.
3. Chemically resistant: resists many acids, bases, and solvents; low water uptake.
4. Thermoplastic: melts ~120-130°C and is easily moulded/welded.
5. Recyclable and used for pipes, bottles, and containers.
6. Good impact and low-temperature toughness.