Chemistry Reference
In-Depth Information
POLYETHYLENE
H
H
-(CH
2
-CH
2
-)
n
n
= 2500-5000
n
CC
H
H
Low-density polyethylene (LDPE): film for food packaging, etc.
High-density polyethylene (HDPE): blow molded into bottles and con-
tainers
Linear low-density polyethylene (LLDPE): powder coatings
Polyethylene, a thermoplastic, is the largest selling plastic material. LDPE
is a branched polyethylene whose branches prevent close packing and gives
low density. HDPE is polyethylene that has essentially no branching, so the
molecules pack very well, which leads to high density and high crystallinity.
LLDPE is actually a copolymer prepared at low temperature and low pressure
from a mixture of ethylene and about 10% of a C
4
-C
8
olefin.
