Question

why does low density polythene hae a large of temp. and pressure while high density polythene have a short (really short) range of temp. and pressure?

Answer 1

The difference in high-density polyethylene and low-density polyethylene is the degree of branching.Branching is more in low density polythene than high density polythene.At high temperature range and high pressure; the branches are created due to intermolecular and intramolecular chain transfer during polymerization. Thus, low density polythene is prepared at high temperature and pressure whereas high density polythene is prepared at low temperature and pressure.