Low density polythene is manufactured by compressing ethane under very high pressure (1500-2000 atmospheres) at about 475 K in the presence of a small amount of oxygen as catalyst.
High density polythene is obtained by passing ethene under pressure of 6 atmospheres at about 340 K into heptane, an inert solvent containing Zielgler-Natta catalyst (triethyl) aluminium and titanium tetrachloride)
