b) Preparation High density polymer (HDPE) :

b) Preparation High density polymer (HDPE) : 

It is linear addition polymer. The catalyst used is Zeiglar-Natta (TiCl4 + (C2H5)3Al). The polymerisation takes place at 373 K, 6-7 atm pressure. Ethylene first forms titanium complex with TiCl4, hence it is also called co-ordination polymer.

HDPE has high density and high mp. used to make bottle, jar, buckets, drums, pipes etc.