LDPE is low-density polyethylene. It is obtained by the polymerization of ethene under high pressure of 1000 – 2000 atm at 350 – 570 K in the presence of an initiator. HDPE is called high-density polyethylene. It is obtained by the polymerization of ethene in the presence of Ziegler – Natta catalyst at 333 – 343 K under 6-7 atm.
